Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and information about some of the electronic, electrical and electrotechnical technology relics that the Frank Sharp Private museum has accumulated over the years .

Premise: There are lots of vintage electrical and electronic items that have not survived well or even completely disappeared and forgotten.

Or are not being collected nowadays in proportion to their significance or prevalence in their heyday, this is bad and the main part of the death land. The heavy, ugly sarcophagus; models with few endearing qualities, devices that have some over-riding disadvantage to ownership such as heavy weight,toxicity or inflated value when dismantled, tend to be under-represented by all but the most comprehensive collections and museums. They get relegated to the bottom of the wants list, derided as 'more trouble than they are worth', or just forgotten entirely. As a result, I started to notice gaps in the current representation of the history of electronic and electrical technology to the interested member of the public.


Following this idea around a bit, convinced me that a collection of the peculiar alone could not hope to survive on its own merits, but a museum that gave equal display space to the popular and the unpopular, would bring things to the attention of the average person that he has previously passed by or been shielded from. It's a matter of culture. From this, the Obsolete Technology Tellye Web Museum concept developed and all my other things too. It's an open platform for all electrical Electronic TV technology to have its few, but NOT last, moments of fame in a working, hand-on environment. We'll never own Colossus or Faraday's first transformer, but I can show things that you can't see at the Science Museum, and let you play with things that the Smithsonian can't allow people to touch, because my remit is different.

There was a society once that was the polar opposite of our disposable, junk society. A whole nation was built on the idea of placing quality before quantity in all things. The goal was not “more and newer,” but “better and higher" .This attitude was reflected not only in the manufacturing of material goods, but also in the realms of art and architecture, as well as in the social fabric of everyday life. The goal was for each new cohort of children to stand on a higher level than the preceding cohort: they were to be healthier, stronger, more intelligent, and more vibrant in every way.

The society that prioritized human, social and material quality is a Winner. Truly, it is the high point of all Western civilization. Consequently, its defeat meant the defeat of civilization itself.

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

OLD, but ORIGINAL, Well made, Funny, Not remotely controlled............. and not Made in CHINA.

How to use the site:

- If you landed here via any Search Engine, you will get what you searched for and you can search more using the search this blog feature provided by Google. You can visit more posts scrolling the left blog archive of all posts of the month/year,
or you can click on the main photo-page to start from the main page. Doing so it starts from the most recent post to the older post simple clicking on the Older Post button on the bottom of each page after reading , post after post.

You can even visit all posts, time to time, when reaching the bottom end of each page and click on the Older Post button.

- If you arrived here at the main page via bookmark you can visit all the site scrolling the left blog archive of all posts of the month/year pointing were you want , or more simple You can even visit all blog posts, from newer to older, clicking at the end of each bottom page on the Older Post button.
So you can see all the blog/site content surfing all pages in it.

- The search this blog feature provided by Google is a real search engine. If you're pointing particular things it will search IT for you; or you can place a brand name in the search query at your choice and visit all results page by page. It's useful since the content of the site is very large.

Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

Every CRT Television saved let revive knowledge, thoughts, moments of the past life which will never return again.........

Many contemporary "televisions" (more correctly named as displays) would not have this level of staying power, many would ware out or require major services within just five years or less and of course, there is that perennial bug bear of planned obsolescence where components are deliberately designed to fail and, or manufactured with limited edition specificities..... and without considering........picture......sound........quality........

..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

Have big FUN ! !
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©2010, 2011, 2012, 2013, 2014 Frank Sharp - You do not have permission to copy photos and words from this blog, and any content may be never used it for auctions or commercial purposes, however feel free to post anything you see here with a courtesy link back, btw a link to the original post here , is mandatory.
All sets and apparates appearing here are property of
Engineer Frank Sharp. NOTHING HERE IS FOR SALE !

Monday, January 31, 2011

GRUNDIG SUPER COLOR 1610 YEAR 1975.








































The GRUNDIG SUPER COLOR 1610 is A portable 16 Inches color television from GRUNDIG.


This is the first portable color television from GRUNDIG with 16 Inches screen format and it's the brother of the SUPER COLOR 1510 which is the very first color portable in 1973.

It's sporting an in-line type triple electron gun CRT assembly which comprises three electron gun members arranged in the same plane with the axis of the side gun members inclined at a predetermined angle to that of the central gun member; and support members fitted to the gun members for their integral assembly, said support member comprising two longitudinal elements each disposed between two adjacent gun members and at least one bridge element connecting said two longitudinal elements.


It has 8 Program preselection with touch sensor program change system and no remote.
It's a Circuit arrangement for establishing a reference potential of a chassis of an electrical device such as a radio and/or TV receiver, such device being provided with at least one contactless touching switch operating under the AC voltage principle. The device is switched by touching a unipole touching field in a contactless manner so as to establish connection to a grounded network pole. The circuit arrangement includes in combination an electronic blocking switch and a unidirectional rectifier which separates such switch from the network during the blocking phase.In electronic devices, for example TV and radio receivers, there are used in ever increasing numbers electronic touching switches for switching and adjusting the functions of the device. In one known embodiment of this type of touching switch, which operates on a DC voltage principle, the function of the electronic device, is contactlessly switched by touching a unipole touching field, the switching being carried out by means of an alternating current voltage.


The set is build with a Modular chassis design because as modern television receivers become more complex the problem of repairing the receiver becomes more difficult. As the number of components used in the television receiver increases the susceptibility to breakdown increases and it becomes more difficult to replace defective components as they are more closely spaced. The problem has become even more complicated with the increasing number of color television receivers in use. A color television receiver has a larger number of circuits of a higher degree of complexity than the black and white receiver and further a more highly trained serviceman is required to properly service the color television receiver.
Fortunately for the service problem to date, most failures occur in the vacuum tubes used in the television receivers. A faulty or inoperative vacuum tube is relatively easy to find and replace. However, where the television receiver malfunction is caused by the failure of other components, such as resistors, capacitors or inductors, it is harder to isolate the defective component and a higher degree of skill on the part of the serviceman is required.
Even with the great majority of the color television receiver malfunctions being of the "easy to find and repair" type proper servicing of color sets has been difficult to obtain due to the shortage of trained serviceman.
At the present time advances in the state of the semiconductor art have led to the increasing use of transistors in color television receivers. The receiver described in this application has only two tubes, the picture tube and the high voltage rectifier tube, all the other active components in the receiver being semiconductors.
One important characteristic of a semiconductor device is its extreme reliability in comparison with the vacuum tube. The number of transistor and integrated circuit failures in the television receiver will be very low in comparison with the failures of other components, the reverse of what is true in present day color television receivers. Thus most failures in future television receivers will be of the hard to service type and will require more highly qualified servicemen.
The primary symptoms of a television receiver malfunction are shown on the picture tube of the television receiver while the components causing the malfunction are located within the cabinet. Also many adjustments to the receiver require the serviceman to observe the screen. Thus the serviceman must use unsatisfactory mirror arrangements to remove the electronic chassis from the cabinet, usually a very difficult task. Further many components are "buried" in a maze of circuitry and other components so that they are difficult to remove and replace without damage to other components in the receiver.
Repairing a modern color television receiver often requires that the receiver be removed from the home and carried to a repair shop where it may remain for many weeks. This is an expensive undertaking since most receivers are bulky and heavy enough to require at least two persons to carry them. Further, two trips must be made to the home, one to pick up the receiver and one to deliver it. For these reasons, the cost of maintaining the color television receiver in operating condition often exceeds the initial cost of the receiver and is an important factor in determining whether a receiver will be purchased.
Therefore, the object of this invention is to provide a transistorized color television receiver in which the main electronic chassis is easily accessible for maintenance and adjustment. Another object of this invention is to provide a transistorized color television receiver in which the electronic circuits are divided into a plurality of modules with the modules easily removable for service and maintenance. The main electronic chassis is slidably mounted within the cabinet so that it may be withdrawn, in the same manner as a drawer, to expose the electronic circuitry therein for maintenance and adjustment from the rear closure panel after easy removal. Another aspect is the capability to be serviced at eventually the home of the owner.


- Horizontal Beam Deflection  and high voltage generating circuits realized with Thyristors circuits.
       Numerous circuit designs for completely transistorized television receivers either have been incorporated in commercially available receivers or have been described in detail in various technical publications. One of the most troublesome areas in such transistor receivers, from the point of View of reliability and economy, lies in the horizontal deflection circuits.
       As an attempt to avoid the voltage and current limitations of transistor deflection circuits, a number of circuits have been proposed utilizing the silicon controlled rectifier (SCR), a semiconductor device capable of handling substantially higher currents and voltages than transistors.
       The circuit utilizes two bi-directionally conductive switching means which serve respectively as trace and commutating switches. Particularly, each of the switching means comprises the parallel combination of a silicon controlled rectifier (SCR) and a diode. The commutating switch is triggered on shortly before the desired beginning of retrace and, in conjunction with a resonant commutating circuit having an inductor and two capacitors, serves to turn off the trace switch to initiate retrace. The commutating circuit is also arranged to turn oft the commutating SCR before the end of retrace. 


All other standard commands are even manual.

These tellyes were offering excellent superb picture and they were running warm.

(It's a Heavy Weight Portable)

Grundig AG is (WAS) a German manufacturer of consumer electronics for home entertainment which transferred to Turkish control in the period 2004-2007. Established in 1945 in Nuremberg, Germany by Max Grundig the company changed hands several times before becoming part of the Turkish Koç Holding group. In 2007, after buying control of the Grundig brand, Koc renamed its Beko Elektronik white goods and consumer electronics division Grundig Elektronik A.Ş., which has decided to merge with Arçelik A.Ş. as declared on February 27, 2009


Max Grundig (7 May 1908 – 8 December 1989) was the founder of electronics company Grundig AG.Max Grundig is one of the leading business personalities of West German post-war society, one of the men responsible for the German “Wirtschaftswunder” (post-war economic boom).


GRUNDIG Early years

Max Grundig was born in Nuremberg on May 7, 1908. His father died early, so Max and his three sisters grew up in a home without a father. At 16, Max Grundig began to be fascinated by radio technology, which at the time was gaining in popularity. He built his first detector in the family’s apartment, which he had turned into his own laboratory. In 1930, he turned his hobby into his profession and opened a shop for radio sets in Fürth with an associate. The business prospered and soon Grundig was able to employ his sisters and buy out his associate. By 1938, he was already manufacturing 30,000 small transformers.



GRUNDIG Success after World War II

Max Grundig’s real success story began after World War II. On May 15, 1945, Grundig opened a production facility for universal transformers at Jakobinerstraße 24 in Fürth. Using machines and supplies from the war era, he established the basis for what would turn into a global company at this address. In addition to transformers, Grundig soon manufactured tube-testing devices. As manufacturing radios was subject to a licence, Grundig had the brilliant idea of developing a kit that would allow anyone to quickly build a radio on their own. This kit was sold as a “toy” called “Heinzelmann”.


Following the monetary reform, Max Grundig quickly expanded his production under the new company name “Grundig Radio-Werke GmbH” and served the expanding mass market. From 1952, his company was the biggest European manufacturer of radios and the worldwide leader in the production of audio tape recorders.



Grundig became a real pioneer in consumer electronics. From 1951, the company’s portfolio also included the production and distribution of television sets, and dictaphones were added in 1954. The company was turned into a shareholding company, the Grundig AG, in 1971. In the 1970s, the company was one of the leading companies in Germany, employing more than 38,000 people in 1979. Max Grundig had built a strong company from the ruins of the war.


GRUNDIG and the rules are changing

In the second half of the 1970s, another innovation entered the market for consumer electronics, the VCR. And with the VCR, competitors from Japan and later other countries of the Far East entered the world market. Even though the European competitors Philips and Grundig had developed the superior technology for recording video, the Japanese VHS succeeded on the market. The rules of the game changed dramatically in the field of consumer electronics. The competition for establishing the video standard proved that companies could only succeed in consumer electronics with the financial power of global corporations. In 1979, Max Grundig decided to sell some shares to his Dutch competitor Philips, and in 1984 he began the process of restructuring the ownership of the Grundig companies, which would be completed two decades later.



Max Grundig died on December 8, 1989 in Baden-Baden. The Grundig name continues to be known to this day and is now a globally recognised brand for innovative consumer electronics. Max Grundig is remembered in Germany as a dynamic entrepreneur from the post-war era.


Max GRUNDIG: Born on 7 May 1908 in the Denis Street 3 in Nuremberg
 workers district Gostenhof Parents of "Magaziners" or warehouse worker Max Emil and his wife Marie. The enlargement of the family through the birth of three sisters require in the aftermath several moves within Nuremberg.
In 1920, his father died unexpectedly at the consequences of an appendectomy. The already poor family is financially worse rapidly. This is followed by further moves into ever smaller and cheaper housing. Max Grundig starts in April 1922 commercial apprenticeship at the installation company Jean Hilpert in Nuremberg. His interest lies in the crafting of radios, a hobby, the early 1920s was indulged by tech-savvy youngsters often. But Max Grundig tinkering not only simple radios, but also more complex technical equipment such as image receiver.(Photos refering to
Father and Mother of Max GRUNDIG.)

After the end of his teaching is Max Grundig 1927 Head of a new branch of the company in Fürth Hilpert and supervised by commercial side of the installation work of the under construction Municipal Hospital Fürth. In May 1928 and in October 1930 Grundig also occurs on a radio dealer and take part in an event organized by Workers' Radio Association Germany on the occasion of Fürth Kirchweih 1930 radios exhibition. A first marriage in 1929 held only briefly. From her daughter Inge comes.
Following the closure of Fürth Branch company Hilpert for the finished installation works at the hospital, Max Grundig together with Karl Wurzer, who was funders primarily, on 15 November 1930 as a radio dealer in Sternstraße 4 in Fürth independently. Today this street Ludwig-Erhard-Straße is, since there - was directly opposite the first by Max Grundig Radio Load - - the business of the parents of the future economy minister and Chancellor Ludwig Erhard (1977 1897).
His radio action called Max Grundig "Radio Sales Fürth" short RVF. On June 21, 1934, a procession of RVF in the Schwabacher Straße carried 1. The partnership Karl Wurzer is paid, Max Grundig is now the sole owner. In addition to selling and repairing radios Grundig starts construction of transformers. In 1938, he is Sales millionaire. In the same year he married the singer and manufacturer's daughter Annelie Jorgensen. The marriage remains childless.

During the Second World War Grundig continues its production of small transformers continued on a larger scale in the Fürth suburb Vach, where he rents rooms in three inns. He himself is in 1941 drafted into the army, some time must remain as a corporal in Paris, but shortly before his entire company is reassigned to the East - also because of its possibilities, to provide supervisors with radios - "indispensable" (uk) provided and forwards Fuerth his company to continue the war.

On 18 May 1945, the US Army occupied the suburb Vach. Grundig's stock will not be plundered, neither of German or foreign looters nor by the US military because the workforce that consists partly of Ukrainian slave laborers, has a sign "Off limits" - "no trespassing" - at the door, protects the company. In June 1945, Grundig rented a factory building in the Jakobinenstraße 24 in Fürth. are manufactured now transformers and measuring instruments: The tube tester "Tubatest" and the fault locator "Nova Test". The commercial license is replaced by the Radio-sales Fürth on 7 November 1945. In December 1945, Grundig has 42 employees.

On April 10, 1946 Max Grundig starts own production of radios. His first instrument is the "Heinzelmann" This radio can also complete as a kit or under the hand, but are always acquired without tubes. But the tubes are widely available on the black markets of the early postwar years. Since a wireless without tubes per se is not operational, allowing the American military government Max Grundig, "no quota", ie without limitation in quantity, produce radio and distribute. With the mass sale of "Heinzelmann" Max Grundig creates the basis for further economic success of the company as a manufacturing company after the Second World War.
As of August 1, 1946 is the company "RVF - Electrotechnical Factory". Beginning in March 1947, work began in the Kurgartenstraße 37 in Fuerth, the later main plant of the company Grundig. On 7 July 1948 re-naming of the company is carried out in "Grundig radio-Werk GmbH". As of spring 1948, the superhit radio "Weltklang" comes on the market. In February 1949, the 100,000th Wireless is already prepared. In the same year built a Grundig FM radio stations trying to prepare for the introduction of the ultra-short wave on 15 March 1950. In December 1949 the company Grundig counts 1,600 employees.

In May 1951 Max Grundig acquires Lumophon radio stations in Nuremberg and Georgensgmünd and integrates them into its "Grundig radio-Werke GmbH". In September and October 1951, he is with a purpose-built television station Directorate building his company in Fürth the first public television broadcasts in Southern Germany. he produced 94 televisions this year. The production of tape recorders starts 1951st
1954 lets Max Grundig his first dictation machine, the "Stenorette" build. In 1957 he buys the office machine manufacturer Triumph-Adler in Nuremberg and Adler in Frankfurt that remain until 1968 in his possession. In 1958 he founds the Grundig Bank in Fürth. In the same year, with the introduction of the transistor instead of the Radio tube, penetrate the first Japanese companies like Sony in the European and German market, initially still in the lowest price segment. 1960 Grundig has 16,495 employees.

The 1960s are marked by the further expansion of the company: Grundig is the biggest radio manufacturer in Europe. In 1961 he acquired a large area in Nuremberg-Langwasser, on the 1963 first tape recorders are produced. In other parts of Germany companies to buy or newly built shortly afterwards in Italy and Austria.
1964 leads the Dutch company Philips in tape recorders, the compact cassette CC and thus the cassette recorder, and it initially in the lower price range. The leader Grundig countered in 1965 with the cassette system DC International, but can not prevail.
After 1967, the beginning of color television initially causes a strong boom in the production of related hardware. This results not only in their own country overcapacity, but the Japanese competition suppressed due to lower wages and production costs at the same time always noticeable with affordable devices on the European and German market.
1969 bring the company Philips and Grundig together the first video recorder for home appliances on the market. It is still a tape machine. But soon the world led the struggle for the enforcement of various video cassette systems begins.

In 1970, Grundig has approximately 25,000 employees. This year, Max Grundig builds to his company. He built on 22 February 1970, the "Max Grundig Foundation", added on 12 March 1970, the "Grundig-family club". The Max Grundig Foundation is now the sole owner. In addition, on 1 April 1972, the "Grundig-Werke GmbH" in a corporation, the "Grundig AG" converted. The foundation holds about 94% of the capital.
From 1970, the television production is relocated to Nuremberg-Langwasser. The expectations regarding equipment sales for the 1972 Olympic Games in Munich true. With the Super-Color TVs a new product range is presented in a modular design. In Nuremberg-Langwasser, daily production reached 1,200 color TV.
1977 founds the Grundig "Hotel Management Max Grundig Foundation". The Hotel Forsthaus Fuerth and Hotel Fuschl near Salzburg to buy. A year later Grundig donates 30 million DM for the "Grundig Academy of Economics and Technology", which serves the training of professionals and executives. 1978 produced in Langwasser also a new VCR plant.
Increasingly Max Grundig is weakened by illness, repeated he needs surgery. The European consumer electronics industry is committed to strategies against existing overcapacity and the growing economic influence of companies from the Far East. In Europe, these are mainly the French state company Thomson-Brandt, the Dutch company Philips and Grundig.
The cooperation with the Dutch company Philips thickens in the VCR production. In 1979 share swaps. Philips makes 24.5% of the shares of Grundig AG, Grundig 6% of Philips and is thereby the largest single shareholder.


1979 achieved the Grundig AG with 38,460 employees worldwide their personal peak. The company has 31 plants, nine branches with 20 branches and three Werksvertretungen, eight sales companies and 200 worldwide export missions. Also, sales continue to rise. But the profit is shrinking. In 1981, the Grundig AG writes first losses. After divorcing his second wife Annelie Max Grundig marries 1980, the French woman Chantal Girard. In the same year the daughter Marie was born.
1982 at the presentation of "Eduard Rhein honor ring" and before the European Commission, presents Max Grundig be EURO concept, the united front of the European consumer electronics market to Japanese companies: "Acting together, jointly produce, market share". But he can not prevail. Too much stalking and distrusts you also mutually in the European broadcasting industry. And Japan is not the only competitor. An agreement between the companies Grundig and Thomson-Brandt, which is scheduled also built in 1982, can - among other things due to the resistance of the Bundeskartellamt and because the company Philips is involved in Grundig - not be implemented.
On 26 March 1984 Philips increased its share of Grundig AG by 7.1% to 31.6%. In April 1984, the Federal Cartel Office approved the merger of Grundig and Philips under the condition that Grundig sells its voice recorders range. New CEO of Grundig AG is the Dutchman Hermanus Koning on April 1 (1924 - 1998). From 1984 to 1998, the Dutch have entrepreneurial saying. Max Grundig receives for his departure from the company, among other things a guaranteed 20-year-income annual return of 50 million marks.
Not quite voluntarily leaving Max Grundig the company he has built up and which bears his name. But there can be only one boss. 1985 must Grundig also his top job at the Grundig-Bank ad, which is sold to a Swiss institute.
Grundig expands its hotel ownership, 1986, he acquired the luxury hotel "Bühlerhöhe", which he renovated at great expense. On 8 December 1989 Max Grundig dies. Under great public participation he will be buried in Baden-Baden.

After a brief economic boom as a result of German reunification takes place until 1991 a rapid decline of the company Grundig. Between 1992 and 1996 the Grundig Group makes almost two billion marks loss. The number of employees decreased from 16,250 to 8,580 employees.
1998, the Philips Group withdraws. According to its own description Philips has been paying 1.5 billion marks. A consortium of banks and insurance companies under the leadership of the antenna manufacturer Kathrein, the personally liable partners of Kathrein Werke KG, takes on 18 December 1998 the Grundig AG.

In 2000 and 2001, the company headquarters and the remaining departments of Fürth be routed to Nuremberg. But Grundig continues to make losses. On 1 April 2003, Grundig AG announces insolvency.
2004 Turkey company Beko electronics in Istanbul, belonging to the Turkish Koc Holding, together with the British company Alba Radio Ltd. accepts the division consumer electronics. This company is now called "Grundig Intermedia". Both companies each own fifty percent of "Grundig Multimedia B.V.", which is a holding full ownership of Grundig Intermedia GmbH. In addition, proceeds from the office equipment division as buy-out the company "Grundig Business Systems" produced. The car radio range is taken from the Delphi Corporation, the activities of the former Grundig range satellites for "Grundig SAT Systems GmbH".
In October 2006 and January 2007, two production lines for TV at Grundig Elektronik in Istanbul are put into operation. On 18 December 2007, Koç Group acquires through its subsidiary Arçelik A.S. the shares of Alba plc. And that is the sole owner of Grundig Multimedia B.V. or the Grundig Intermedia GmbH. The development area in Nuremberg closes the end of 2008 as part of an ending in 2009 the restructuring process. When Grundig headquarters in Nuremberg with around 140 employees Sales, marketing, communications, design, quality assurance, customer service and the office staff remain. The Turkish Grundig Intermedia GmbH is now divided into six product areas: TV, Audio, HiFi, "Personal Care", "Floor Care" and kitchen appliances.

The Radio Museum in Fürth, located in the former Directorate of Max Grundig, shows in addition to the history of the development of broadcasting in Germany and the corporate and entrepreneurial story of Max Grundig, the man who the radio and television development in Germany after the Second World War three has for decades dominated the market leader.

He was married lastly to Chantal Grundig.



Early history

The history of the company began in 1930 with the establishment of a store named Fuerth, Grundig & Wurzer (RVF), which sold radios. After World War II Max Grundig recognized the need for radios in Germany, and in 1947 produced a kit, while a factory and administration centre were under construction at Fürth. In 1951 the first televisions were manufactured at the new facility with the company and the surrounding area growing rapidly. At the time Grundig was the largest radio manufacturer in Europe. Divisions in Nuremberg, Frankfurt and Karlsruhe were set up.

Grundig in Belfast

A plant was opened in 1960 to manufacture tape recorders in Belfast, Northern Ireland, the first production by Grundig outside Germany. The managing director of the plant Thomas Niedermayer, was kidnapped and later killed by the Provisional IRA in December 1973. The factory was closed with the loss of around 1000 jobs in 1980.

Philips takeover

In 1972, Grundig GmbH became Grundig AG. After this Philips began to gradually accumulate shares in the company over the course of many years, and assumed complete control in 1993. Philips resold Grundig to a Bavarian consortium in 1998 due to unsatisfactory performance.

Later history

At the end of June 2000 the company relocated its headquarters in Fürth and Nuremberg. Grundig lost €1.281 million the following year. In autumn 2002, Grundig's banks did not extend the company's lines of credit, leaving the company with an April 2003 deadline to announce insolvency. Grundig AG declared bankruptcy in 2003, selling its satellite equipment division to Thomson. In 2004 Britain's Alba plc and the Turkish Koc's Beko jointly took over Grundig Home InterMedia System, Grundig's consumer electronics division. In 2007 Alba sold its half of the business to Beko for US$50.3 million, although it retained the licence to use the Grundig brand in the UK until 2010, and in Australasia until 2012.




















...........................................The Federal Republic of Germany: Holding the Ring?

For more than thirty years after the Second World War, consumer
electronics in West Germany, as elsewhere, was a growth industry.
Output growth in the industry was sustained by buoyant consumer
demand for successive generations of new or modified products,
such as radios (which had already begun to be manufactured, of
course, before the Second World War), black-and-white and then
colour television sets, hi-fi equipment.” Among the largest West
European states, West Germany had by far the strongest industry.
Even as recently as 1982, West Germany accounted for 60 per cent
of the consumer electronics production in the four biggest EEC
states. The West German industry developed a strong export
orientation--in the early 1980s as much as 60 per cent of West
German production was exported, and West Germany held a larger
share of the world marltet than any other national industry apart
from the]apanese.ltwas also technologicallyextremelyinnovative-
the first tape recorders, the PAL colour television technology, and
the technology which later permitted the development of the video
cassette recorder all originated in West Germany.

The standard-bearers of the West German consumer electronics
industry were the owner-managed firm, Grundig, and Telefunken,
which belonged to the electrical engineering conglomerate, AEG-
Telefunlten. The technological innovations for which the West
German industry became famous all stemmed from the laboratories
of Telefunlten, which, in the 19605, still constituted one of AEG’s
most profitable divisions. Telefunlcen and Grundig together prob-
ably accounted for around one-third of employment in the German
Industry in the mid-1970s. Both had extensive foreign production
facilities. At the same time, compared with the other EEC states,
there was still a relatively large number of small and medium-sized
consumer electronics firms in Germany. Besides Grundig and
Telefunken, the biggest were Blaupunkt, a subsidiary of Bosch, the
automobile components manufacturer, Siemens, and the sub-
sidiaries of the ITT-owned firm, SEL. Up until the late 1970s, there
was relatively little foreign-owned manufacturing capacity in the
West German consumer electronics industry.

GOVERNMENTS, MARKETS, AND REGULATION
During the 1970s, this picture of a strong West German
consumer electronics industry began slowly to change and, by the
end of the 19705, colour television manufacture no longer offered a
guarantee for the continued prosperity or even survival of the
German industry. The market for colour television sets was
increasingly saturated——by 1978 56 per cent of all households in
West Germany had a colour television set and 93 per cent of all
households possessed a television set of some kind.2° From 1978
onwards, the West German market for colour television sets began
to contract. Moreover, the PAL patents began to expire around
1980 and the West German firms then became exposed to more
intense competition on the (declining) domestic market.

The West German firms’ best chances for maintaining or
expanding output and profitability lay in their transition to the
manufacture of a new generation of consumer electronics products,
that of the video cassette recorder (VCR). Between 1978 and 1983,
the West German market for VCRs expanded more than tenfold, so
that, by the latter year, VCRs accounted for over a fifth of the
overall consumer electronics market.“ However, in this product
segment, Grundig was the only West German firm which, in
conjunction with Philips, managed to establish a foothold, while
the other firms opted to assemble and/or sell VCRs manufactured
according to one or the other of the two Japanese video
technologies. By 1981, the West German VCR market was more
tightly in the grip of Japanese firms than any other segment of the
market. More than any other, this development accounted for the
growing crisis of the West German consumer electronics industry in
the early 1980s. The West German market stagnated, production
declined as foreign firms conquered a growing share of the
domestic market and this trend was not offset by an expansion of
exports, production processes were rationalized to try to cut costs
as prices fell, employment contracted,” and more and more plants
were either shut down or—more frequently——taken over.

The relationship between the state and the consumer electronics
industry in the long post-war economic ‘boom’ was of the ‘arm’s
length’ kind which corresponded to the West German philosophy
of the ‘social market economy’. The state's role was confined
largely to ‘holding the ring’ for the firms and trying to ensure by
means of competition policy that mergers and take-overs did not
enable any single firm or group of firms to achieve a position of
market domination and suspend the ‘free play of market forces’.

The implementation of competition policy was the responsibility of
the Federal Cartel Office (FCO), which must be informed of any
planned mergers or take-overs if the two firms each have a turnover
exceeding 1 DM billion or one of them has a turnover of more than
2 DM billion. The FCC must reject any proposed merger which, in
its view, would lead to the emergence of a, or strengthen any
existing, position of market domination.“

Decisions of the FCO may be contested in the Courts, and firms
whose merger or take-over plans have been rejected by the Cartel
Office may appeal for permission to proceed with their plans to the
Federal Economics Minister. He is empowered by law to grant such
permission when it is justified by an ‘overriding public interest’ or
‘macroeconomic benefits’, which may relate to competitiveness on
export markets, employment, and defence or energy policy.”
However, the state had no positive strategy for the consumer
electronics industry and industry, for its part, appeared to have no
demands on the state, other than that, through its macroeconomic
policies, it should provide a favourable business environment. This
situation changed only when, as from the late 1970s onwards, the
Japanese export offensive in consumer electronics plunged the West
German industry into an even deeper crisis.

The Politics of European Restructuring
The burgeoning crisis of not only the West German, but also the
other national consumer electronics industries in the EC in the
early 1980s prompted pleas from the firms (and also organized
labour) for protective intervention by the state——by the European
Community as well as by its respective national Member States.
The partial ‘Europeanization’ of consumer electronics politics
reflected the strategies chosen and pursued by the major European
firms to try to counter, or avoid, the Japanese challenge. These
strategies contained two major elements:  measures of at least
temporary protection against Japanese imports to give the firms
breathing space to build up or modernize their production
capacities and improve their competitiveness uis-ci-uis the Japanese
and partly also to put pressure on the Japanese to establish
production facilities in Europe and produce under the same
conditions as the European firms and (b), through mergers, take-
overs, and co-operation agreements, to regroup forces with the aim
of achieving similar economies of scale to those enjoyed by the most
powerful Japanese firms. The first element of these strategies
implicated the European Community in so far as it is responsible
for the trade policies of its Member States. The second element did
not necessarily involve the European Community, but had a Euro-
pean dimension to the extent that most of the take-overs and mergers
envisaged in the restructuring of the industry involved firms from
two or more of the EEC Member States, including the French state-
owned Thomson (see above). As this ‘regrouping of the forces’ of
the European consumer electronics industry was to unfold at first
largely on the West German market, the firms could only
implement their strategies once they had obtained the all-clear of
the FCO or, failing that, of the Federal Economics Ministry.

The Politics of Video Recorder Trade between japan and the EEC:

The Dutch-based multinational conglomerate, Philips, 
was the first
firm in the world to bring a VCR on to the market. Between 1972
and 1975, it had no competitors at all in VCR manufacture and, as
late as 1977, it split up the European market with Grundig, with
which Philips developed the V2000 VCR which came on to the
market in 1980. By this time, the Japanese consumer electronics
firms had already built up massive VCR production capacities and
had cornered first their own market and then, unchallenged by the
European firms, the American as well. With the advantage of much
greater economies of scale, they were able to manufacture and offer
VCRs more cheaply than Philips and Grundig when the VCR
market did eventually ‘take off‘ in Western Europe. German
imports of VCRs, for example, increased almost eightfold between
1978 and 1981.2

The immediate background to the calls for protection against
imported Japanese VCRs by European VCR manufacturing firms
was formed by massive cuts in prices for Japanese VCRs, as a
consequence of which, in 1982, the market share held by the V2000
VCR manufactured by Philips and Grundig declined sharply.”
Losses incurred in VCR manufacture led to a dramatic worsening
of Grundig’s financial position. In November 1982 Philips and
Grundig announced that they were considering taking a dumping
case against the Japanese to the European Commission. The case,
which was later withdrawn, can be seen as the first move in a
political campaign designed to secure controls or restraints on
Japanese VCR exports to the EEC states. This campaign was
pursued at the national and European levels, both through the
national and European trade associations for consumer electronics
firms and particularly through direct intervention by the firms at
the national governments and the European Commission. However,
the European firms, many of whom had licensing agreements with
the Japanese, were far from being united behind it.

Philips, seconded by its VCR partner, Grundig, was the ‘real
protagonist’ of protectionist measures against Japanese VCRs. In
pressing their case on EEC member states and the European
Commission, they emphasized the unfair trading practices of the
Japanese in building up production capacities which could meet the
entire world demand for VCRs (‘laser-beaming’), and the threats
which the Japanese export offensive posed to jobs in Western
Europe and to the maintenance of the firms’ R. 8: D. capacity and
technological know-how. Above all, however, was the threat which
the crisis in VCR trade and the consumer electronics industry
generally posed to the survival of a European microelectronic
components industry, over half of whose output, according to
Grundig, was absorbed in consumer electronics products.”

These arguments found by all accounts a very receptive audience
at the European Commission, where, by common consent of
German participants in the policy-formation process, Philips wields
great political influence. By all accounts, Philips‘s pressure was also
responsible for the conversion to the protectionist camp of the
Dutch Government, which hitherto had been a bastion of free trade
philosophy within the EEC. By imposing unilateral import controls
through the channelling of imported VCRs through the customs
depot at Poitiers (see above), the French Government had already
staked out its position on VCR trade with Japan. It presumably
required no convincing by Philips and Grundig on the issue,
although it is interesting to speculate over the extent to which its
stance also reflected the preferences of Thomson which in the past
had been the ‘chief of the protectionists’ in the European
industry.”

With the Dutch Government having been shifted into the
protectionist camp by Philips, the greatest resistance to the

mposition of some form of import controls on Japanese VCRs

could have been expected to come from the West German
Government. Along with the Danish and (hitherto) the Dutch
Governments, the West German Government had generally been
the stoutest defender of free trade among the EEC Member States.
The Federal Economics Ministry’s antipathy towards import
controls may in fact have had some impact on the form of
protection ultimately agreed by the EEC Council of Ministers,
which was a ‘voluntary self-restraint agreement’ with japan.
However, even such self-restraint agreements had in the past been
vetoed by West Germany in the Council. The West German
Government’s abstention in the vote on the agreement in the
Council of Ministers signified if not a radical, then none the less a
significant, modification of its past trade policy.

Within the Bonn Economics Ministry, the section for the
electrical engineering industry-—characteristically—had the most
receptive attitude to the V2000 firms’ case. Elsewhere in the
Ministry, in the trade and European policy and policy principles
divisions and at the summit, the Ministry’s traditional policy in
favour of free trade was given up much more reluctantly. The
Ministry did not oppose the voluntary restraint agreement after it
had been negotiated, but it may be questioned whether the
Ministry’s acquiescence in the agreement was motivated solely by its
feeling of impotence vis-£1-vis the united will of the other Member
States. Abstaining on the vote in the Council of Ministers enabled
the V2000 protectionist lobby to reap its benefits without the West
German Government being held responsible for its implementation.
The Govemment’s abstention may equally have been the result of
the pressure exerted on the Economics Ministry by the V2000
firms, particularly Philips and Grundig, both of which engaged in
bilateral talks with the Ministry, and from the consumer electronics
sub-association of the electrical engineering trade association of the
ZVEI (Zentralverband der Elektrotechnischen lndustrie), in which
a majority of the member firms had sided with Philips and Grundig.
The Ministry, by its own admission, did not listen as closely to the
firms which were simply marketing Japanese VCRs as to those
which actually manufactured VCRs in Europe: ‘we were interested
in increasing the local content (of VCRs) to preserve jobs.’

The success of the V2000 firms in obtaining any agreement at all
from the Japanese to restrain their exports of VCRs to the EEC
does not mean that they were happy with all aspects of the
agreement, least of all with its contents concerning VCR prices and
concrete quotas which were agreed with the Japanese. As the
market subsequently expanded less rapidly than the European
Commission had anticipated, the quota allocated to Japanese
imports (including the ‘kits’ assembled by European licensees of
Japanese firms) amounted to a larger share of the market than
expected and the European VCR manufacturers did not sell as
many VCRs as the agreement provided. Ironically, within a year of
the adoption of the agreement, both Philips and Grundig announced
that they were beginning to manufacture VCRs according to the
Japanese VHS technology and by the time the agreement had
expired (to be superceded by increased tariffs for VCRs) in 1985,
the two firms had stopped manufacturing V2000 VCRs altogether.

The Politics of Transnational European Mergers and Take-overs
The wave of merger and take-over activity in the European
consumer electronics industry which peaked around 1982 and
1983 had begun in West Gemany in the late 1970s, when Thomson
swallowed up several of the smaller West German firms- Normende,
Dual, and Saba ...and Philips, apparently reacting to the threat it
perceived Thomson as posing to its West German interests, bought
a 24.5 per cent shareholding in Grundig.3° The frenzied series of
successful and unsuccessful merger and take-over bids which
unfolded in 1982 and 1983 is inseparable from the growing crisis of
the European industry and the major European firms’ perceptions
as to how they could restructure in order to survive in the face of
Japanese competition.

The first candidate which emerged for take-over on the West
German market was Telefunken, for which AEG, itself in desperate
financial straits, had been seeking a buyer since the late 1970s.
Telefunken’s heavy indebtedness, which was largely a consequence
of losses it had incurred in its foreign operations, posed a
formidable obstacle to its disposal, however, and first Thomson,
which had bought AEG’s tube factory, and then Grundig, baulked
at taking it on as long as AEG had not paid off its debts. While talks
on Telefunken’s possible sale to Grundig were still going on in
1982, Grundig’s own financial position was quickly worsening as a
result primarily of its mounting losses in VCR manufacture.

Grundig confessed publicly that if the firm carried on five more
years as it was doing, it would ‘go under like AEG’, which, in
summer 1982, had become insolvent. Grundig intensified his search
for stronger partners, which he had apparently begun by talking
with Siemens in 1981. In late 1982, at the same time as Grundig
and Philips were pressing for curbs on Japanese VCR imports,
Grundig floated the idea of creating, based around Grundig, a
European consumer electronics ‘superfirm’ involving Philips,
Thomson, Bosch, Siemens, SEL, and Telefunken. Most of the
prospective participants in such a venture were unenthusiastic
about Grundig’s plans, however, and the outcome of Grundig’s
search for a partner or partners to secure its survival was that
Thomson offered to buy a 75.5 per cent shareholding in the firm.

Political opinion in West Germany was overwhelmingly, if not
indeed uniformly, hostile to Thomson’s plan to take over Grundig.
The political difficulties which Thomson and Grundig faced in
securing special ministerial permission for their deal were exacer-
bated by the probability of job losses given a rapidly deteriorating
labour market situation, and by the fact that, as late as 1982 and
early 1983, an election campaign was in progress. Moreover, the
Federal Economics Ministry was apparently concerned that, if
Thomson took over Grundig, the West German Government would
have been exposed to the danger of trade policy blackmail from the
French Government, which could then have demanded increased
protection for the European consumer electronics industry as the
price for Thomson not running down employment at Grundig (and
in other West German subsidiaries).

The decisive obstacle to Thomson's taking over Grundig,
however, lay not with the position of the Federal Economics
Ministry (or that of the Government or the FCO or the Deutsche
Bank), but rather in that of Grundig’s minority shareholder,

Philips. Against expectations, the FCO announced that it would
approve the take-over, but only provided that Philips gave up its
shareholding in Grundig and that Grundig also abandoned its plans
to assume control of Telefunken. As talks on Grundig’s plan to take
over Telefunken had already been suspended, the latter condition
posed no problem to Thomson’s taking over Grundig.

Once it had been put on the spot by the FCO's decision, Philips
was forced to leave its cover and declare that it would not withdraw
from Grundig. Apart from its general concern at being confronted
with an equally strong competitor on the European consumer
electronics market, Philips’s motives in thwarting Thomson's take-
over of Grundig were probably twofold. First, Thomson evidently
did not want to commit itself to continue manufacturing VCRs
according to the Philips—-Grundig V2000 technology, but wanted
rather to keep the Japanese (VHS) option open and, according to its
public declarations, to work with Grundig on the development of a
new generation of VCRs. Secondly, Philips was, ahead of Siemens,
Grundig’s biggest components supplier, with annual sales to
Grundig worth several hundred million Deutschmarks. lf Thomson
had taken over Grundig, this trade would have been lost.

A sequel to the failure of Thomson's bid for Grundig was that in
1984, with bank assistance, Philips assumed managerial control of
Grundig. Thus, at the end of this phase of the restructuring
programme of the European consumer electronics industry, two
main groups have emerged, one centred around Philips, the other
around Thomson, and Blaupunkt is the only significant firm in
West Germany left under West German control. But a common
European response (i.e. one involving Philips and Thomson) to the
Japanese challenge of the kind which Max Grundig
had envisaged
in 1982 had not come about, and may be less likely given
Thomson’s acquisitions in Britain and the US which make it a much
more powerful competitor to Philips. But the acceleration in
Japanese and also Korean inward investment in Europe in 1986-7,
especially in VCR production where there are now a total of twenty
Far Eastern-owned plants, suggests that the process of restructuring
within Europe is far from complete.

The recent experience of the European consumer electronics
industry points to the critical role of the framework and instruments
of regulation in trying to account for the different responses of the
various national industries and governments to the challenges
posed by growing Japanese competitive strength and technological
leadership. At one extreme is self-regulation by individual firms,
where governments eschew any attempt to determine the responses
which particular firms make to changing market conditions, whilst
adopting policy regimes such as tax and tariff structures and
openness to inward investment which critically affect the conditions
under which self-regulation takes place." At the other extreme is
regulation by government intervention at the level of firm strategy,
where governments seek specific policy outcomes by offering
specific forms of inducement to selected firms and denying them to
others.”

HISTORY OF GRUNDIG IN GERMAN:

1930 gründet der Kaufmann und Radiobastler Max Grundig (1908-1989) den Radio-Vertrieb Fürth, Grundig & Wurzer (RVF), ein Radio-Fachgeschäft mit Werkstatt. Bald fabriziert der Betrieb auch Transformatoren und Spulen, später zudem Prüfgeräte. 1934 zahlt Grundig den Teilhaber und Freund Karl Wurzer aus. 1938 beträgt der Umsatz mehr als 1 Mio. RM. Während des Krieges fabriziert Grundig im Dorf Vach mit etwa 600 Personen, darunter vielen Ukrainerinnen, Kleintrafos, elektrische Zünder und Steuergeräte für die V-Raketen. Das Grundig-Vermögen schätzt man am Kriegsende auf 17,5 Mio. RM

Ab 18. Mai 1945 kann Grundig wieder in Fürth produzieren. Er lässt Transformatoren wickeln, Reparaturen ausführen und stellt kurz darauf das Röhrenprüfgerät «Tubatest» und das Fehler-Suchgerät «Novatest» her. Ab 15.1.46 lässt Grundig den externen Ing. Hans Eckstein, den früheren Konstrukteur bei Lumophon, einen Einkreiser-Baukasten mit späterem Namen «Heinzelmann» entwickeln. Anfang 1946 beschäftigt Grundig ca. 100 Personen. Ab Oktober 1946 läuft die Produktion des «Heinzelmann» und die Firma stellt bis Ende 1946 391 Baukästen her. Die vierseitige Geschichte dazu findet sich in der Zeitschrift «rft» 1991, ab Seite 421. Grundig hat auch 1947 grossen Erfolg, denn ein Baukasten ist ohne Bezugsschein erhältlich. Das erste Modell (A) ist ein Zwei-Röhren-Allstromempfänger mit Wehrmachtsröhren RV12P2000. Die Produktion findet bald mit 120 Mitarbeitern auf 400 qm statt. Anfang 1947 folgt Modell W [634701]. Der Baukasten erreicht 1948 eine Stückzahl von 39'256 [DRM].

Am 15.3.47 beginnt Grundig mit dem Bau eines modernen Fabrikgebäudes auf 8000 qm Fläche. Mitte 1948 kann die Firma den Superhet «Weltklang» anbieten; er findet ebenfalls guten Absatz. 400 Personen arbeiten auf 3000 qm Fläche. Im Juli 1948 benennt Grundig seine Firma in Grundig-Radiowerke GmbH um. Jetzt arbeiten 650 Personen im Betrieb. 1949 kommt als erstes deutsches Nachkriegs-Koffergerät der «Grundig-Boy» auf den Markt. Die Firma bringt eine Neukonstruktion des «Heinzelmann» auf den Markt. Zudem entsteht der Vier-Kreis-Super «Weltklang 268GW». Im Mai 1949 erreicht der Betrieb in der Bizone (eigentlich Trizone!) 20 % Marktanteil [664905]. Die Bizone ist der Zusammenschluss der amerikan. und brit. Besatzungszone von 1947 bis 8.4.49, die sich ab dann durch den Anschluss der frz. Besatzungszone zur Trizone erweitert.

Am 16. Mai 1951 übernimmt Grundig die Lumophon-Werke (ebenfalls in Fürth) für den Betrag von 1,7 Mio. DM. Im gleichen Jahr entstehen erste Grundig-Tonbandgeräte. 1952 beginnt die Produktion von Fernsehgeräten. Das Unternehmen beschäftigt nun 6000 Personen und feiert am 12. Mai 1952 den millionsten Rundfunkempfänger. Die Baureihe von 1952/53 ist erstmals technisch und formal einheitlich gestaltet, wobei Grundig die prinzipielle Form bis 1956/57 beibehält. Ausser Typ 810 mit Flankengleichrichter enthalten alle Geräte einen integrierten FM-Teil mit Ratiodetektor. 1955 bezeichnet sich Grundig als den grössten Tonbandgeräte-Hersteller der Welt. 1956 kauft er das Telefunken-Rundfunkgerätewerk Dachau [639071]. 1959 besteht Grundig aus sieben Werken, zwei Tochtergesellschaften plus einer Neugründung in den USA. 1964 übernimmt Grundig die Tonfunk-Werke, Karlsruhe. 1969 beteiligt sich Grundig mehrheitlich an der Kaiser-Radio in Kenzingen. Max Grundig ist seit 1970 gesundheitlich angeschlagen.

1978 gehören 31 Werke, 9 Niederlassungen mit 20 Filialen und drei Werksvertretungen, 8 Vertriebs- und 200 Exportvertretungen zur Grundig AG. 1979 beschäftigt das Unternehmen 38'000 Personen; der Umsatz liegt bei 3 Mrd. DM. Ein Hauptstandort ist Nürnberg. Grundig muss sich jedoch einer Umstrukturierung unterziehen und Philips erhält 1979 eine Beteiligung von rund 25 %. 1980/81 muss Grundig einen Verlust von 187 Mio. DM hinnehmen. Zusätzlich scheitert das Gerät «VIDEO 2000» finanziell.

Eine detaillierte Firmengeschichte enthält das 1983 erschienene Buch: «Sieben Tage im Leben des Max Grundig» von Egon Fein.

Allerdings lässt sich aus auch wenig Schmeichelhaftes über das Machtstreben von Max Grundig erfahren.

1984 erhöht Philips die Beteiligung um 7 % und übernimmt die unternehmerische Verantwortung. 1986/87 kann das Unternehmen mit noch 19'500 Mitarbeitern wieder schwarze Zahlen schreiben. 1987/88 beschäftigt Grundig noch 18'700 Personen bei einem Umsatz von

3,2 Mrd. DM, wovon 90 % auf die Unterhaltungselektronik entfallen. In diesem Geschäftsjahr verlassen 2 Mio. Farbfernsehgeräte und 750'000 Videorecorder die Bänder. Max Grundig stirbt im Dezember 1989 [639071] - letztlich hatte er nicht das vierblättrige, sondern das dreiblättrige Kleeblatt als Firmenemblem gewählt.

Philips hat das Unternehmen vollständig übernommen. Mitte 90er Jahre beschäftigt Grundig noch 8000 Personen. Eine detaillierte Firmengeschichte findet sich in «kleeblatt radio» ab 5/93 des Förderverein des Rundfunkmuseums der Stadt Fürth eV.

1998 verkaufte Philips das Unternehmen an ein Konsortium unter Führung von Anton Kathrein von den Kathrein-Werken. Im Jahre 2001 wurde bei einem Umsatz von 1,2 Milliarden Euro ein Verlust von 150 Millionen Euro erwirtschaftet. Daher verlängerten die Banken im Herbst 2002 die Kreditlinien nicht mehr, was zur Insolvenz im April 2003 führte. In der Folgezeit wurden gewinnbringende Sparten (wie z.B. Bürogeräte, Autoradios) aus dem Konzern herausgelöst und einzeln verkauft. Verlustreiche Sparten wurden stillgelegt und die Mitarbeiter entlassen. Heute erhältliche Neuware von Grundig ist kaum noch "made in Germany".



GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) INTERNAL VIEW.




































































































GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) (Grundig GSC100) PCB CIRCUIT Viewing.








































- Right side Line deflection output + EHT + Line supply transductor regulation.


- Left side Frame deflection output oscillator, Syncronization, Luminance Amplifier, Color difference amplifier, Luminace + Chrominance Signal processing, Sound amplifier, VIF Video IF.





















GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) CONTACTLESS TOUCH SENSOR PROGRAM CHANGE KEYBOARD CIRCUIT ARRANGEMENT FOR ESTABLISHING A CONSTANT POTENTIAL OF THE CHASSIS OF AN ELECTRICAL DEVICE WITH RELATION TO GROUND :




Circuit arrangement for establishing a reference potential of a chassis of an electrical device such as a radio and/or TV receiver, such device being provided with at least one contactless touching switch operating under the AC voltage principle. The device is switched by touching a unipole touching field in a contactless manner so as to establish connection to a grounded network pole. The circuit arrangement includes in combination an electronic blocking switch and a unidirectional rectifier which separates such switch from the network during the blocking phase.


1. A circuit arrangement for establishing, at the chassis of an electrical device powered by a grounded AC supply network, a reference potential with relation to ground, said device having at least one contactless touching switch operating on the AC voltage principle, the switch being operated by touching a unipole touching field in a contactless manner, said arrangement comprising an electronic switch for selectively blocking the circuit of the device from the supply network, a half-wave rectifier including a pair of diodes individually connected in series-aiding relation between the terminals of the supply network and the terminals of the device for separating the electronic blocking switch from the supply network during a blocking phase defined by a prescribed half period of the AC cycle, and a pair of condensers individually connected in parallel with the respective diodes. 2. A circuit arrangement according to claim 1, wherein the capacitances of the two condensers are of equal magnitude.
Description:
This invention relates to a circuit arrangement for establishing a constant reference potential on the chassis of an electrical instrument such as a radio and/or a TV receiver. Such instrument includes at least one contactless touching switch operating under the AC voltage principle, whereby by touching a single pole touching field the contactless switch is operated.

In electronic devices, for example TV and radio receivers, there are used in ever increasing numbers electronic touching switches for switching and adjusting the functions of the device. In one known embodiment of this type of touching switch, which operates on a DC voltage principle, the function of the electronic device, is contactlessly switched by touching a unipole touching field, the switching being carried out by means of an alternating current voltage. When using such a unipole touching electrode, one takes advantage of the fact that the AC current circuit is generally unipolarly grounded. In order to close the circuit by touching the touching surface via the body of the operator to ground, it is necessary to provide an AC voltage on the touching field. In one special known embodiment there is employed a known bridge current rectifier for the current supply. This type of arrangement has the drawback that the chassis of the device changes its polarity relative to the grounded network pole with the network frequency. With such construction considerable difficulties appear when connecting measuring instruments to the device, such difficulties possibly eventually leading to the destruction of individual parts of the electronic device.

In order to avoid these drawbacks, the present invention provides a normal combination of a unidirectional rectifier with an electronic blocking switch that separates the chassis of the electronic device from the network during the blocking phase. In accordance with the present invention, the polarity of the chassis of the electronic device does not periodically change, because the electronic device is practically separated from the network during the blocking phase of the unidirectional rectifier by means of the electronic blocking switch.

In a further embodiment of the invention a further rectifier is connected in series with the unidirectional rectifier in the connection between the circuit and the negative pole of the chassis. Such further rectifier is preferably a diode which is switched in the transfer direction of the unidirectional rectifier. According to another feature of the invention there are provided condensers, a respective condenser being connected parallel with each of the rectifiers. Preferably the two condensers have equal capacitances. Because of the use of such condensers, which are required because of high frequency reasons, during the blocking phase there is conducted to the chassis of the electronic device an AC voltage proportional to the order of capacitances of the condensers. Thus there is placed upon the touching field in a desired manner an AC voltage, and there is thereby assured a secure functioning of the adjustment of the device when such touching occurs.

In the embodiment of the invention employing two rectifiers there is the further advantage that over a bridging over of the minus conduit of the rectifier that is connected between the network and the negative pole of the chassis connection, no injuries can be caused by a measuring instrument in the electronic device itself and in the circuit arrangement connected thereto.

In the accompanying drawing:

The sole FIGURE of the drawing is a circuit diagram of a preferred embodiment of the invention.

In the illustrated embodiment the current supply part of the device, shown at the left, is connected via connecting terminals A and B to an AC voltage source, the terminal B being grounded at 8. The current supply part consists of a unidirectional rectifier in the form of a diode 1 with its anode connected to the terminal I, the cathode of diode 1 being connected to one input terminal 9 of an electronic device 2. In the device 2 there is also arranged a sensor circuit 3, shown here mainly as a block, circuit 3 being shown as including a pnp input transistor the emitter of which is connected to an output terminal 11 of the device 2. The collector of such transistor is connected to the other output terminal 12 of the device 2. The base of the transistor is connected by a wire 13 to a unipolar touching field 4 which may be in the form of a simple metal plate instead of the pnp transistor shown, the sensor circuit itself may consist of a standard integrating circuit which controls, among other things, the periodic sequential switching during the touching time of the touching field 4. All of the circuits of the electronic device 2 are isolated in a known manner from the chassis potential. Between the network terminal B and the negative pole 10 of the chassis there is arranged in the direction opposite that of diode 1 a further diode 5, the anode of diode 5 being connected to the terminal 10, and the cathode of diode 5 being connected to the terminal B of the current supply. To provide for HF type bridging of the diodes 1 and 5 there are arranged condensers 6 and 7 respectively, which are connected in parallel with such diodes.

The invention functions by reason of the fact that in an AC network separate devices radiate electromagnetic waves which produce freely traveling fields in the body of the person who is operating and/or adjusting the device, thereby producing an alternating current through his body to ground, as indicated by the - line at the right of the circuit diagram. If now the person operating the device touches the switching field 4, then the pnp type input transistor of the sensor circuit 3, which is placed on a definite reference potential (for example 12 Volts) and is connected with the negative halfwave of the AC voltage potential, is made conductive. There is thereby released a control command in the sequential switching, for example, for switching the electronic device to the next receiving channel. It is understood that the most suitable connection is formed between ground and the touching field 4 by means of a wire. By the use of such wires it would be assured that in all cases the base of the transistor in circuit 3 is connected to ground. This would, however, not permit anyone to operate the switch without the use of an auxiliary means such as a wire. It will be assumed that the touching almost always results directly via the almost isolated human body. For this reason the AC current fields are necessary, because otherwise there cannot always be provided a ground contact. Thus this connection is established via the body resistance of the person carrying out the touching of the switch.

The positive half wave of the alternating current travels to the terminal 9 of the electronic device 2 after such current has been rectified and smoothed by the devices 1, 6. Such positive halfwave is also conducted to the sensor circuit 3. The thus formed current circuit is closed by way of the chassis of the electronic device 3, the diode 5, and the terminal B. When there is a negative halfwave of the alternating current delivered by the current supply, both diodes 1 and 5 remain closed so that the chassis of the device 2 remains separated from the network during the blocking phase. Nevertheless, by means of condensers 6 and 7 the chassis is placed in a definite network potential, which depends on the relationship of the order of magnitude of the two condensers 6 and 7. When the capacitances of such condensers are equal, there is placed upon the chassis of the device 2 the constant reference potential, and simultaneously there is present via the sensor circuit 3 the required AC voltage at the touching field 4 for adjusting the function or functions of the device 2 upon the touching of the touching field 4.

The reference character 15 indicates a terminal or point at which the potential of the chassis of the device 2 may be measured. As above explained, the diode 5 causes the potential of the chassis at 15 to be separated from the network ground when a negative AC halfwave arrives. It will be noted that the return conduit of the circuit is held at a fixed chassis potential. The input transistor of the sensor circuit 3 remains, however, locked because it is subjected to a DC current of about 12 volts. If now, by means of touching the touching field 4, the chassis potential is connected to ground, then the transistor switches through and releases a switching function.

If the connecting terminals AB of the current source are exchanged, as by changing the plug, then there is still secured the condition that the chassis of the device is separated from the network ground via the diode, in this case the diode 1. The reference potential of the chassis consequently remains constant and the changing AC fields which are superimposed on the condensers can produce in the touching human body an AC current voltage due to the fields which are radiated by the device.

A suitable sensor which may be employed for the circuit 3 herein may be a sensor known as the "SAS 560 Tastatur IS," manufactured and sold by Siemens AG.

It is to be understood that the present invention is not limited to the illustrated environment. They can also be used in electronic blocking switch including a Thyristor circuit, which in the same manner separates the electronic device during the blocking phase from the network rectifier. With such Thyristor circuit the drawbacks described in the introductory portion of the specification of known circuit arrangements are also avoided.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.


















- Frame oscillator Unit: 29301 - 009.02















































- Synchronization Unit + Line oscillator:29301 - 008.02 (TBA920C)

- Sound Unit:29301- 004.02

- Luminance amplifier:29301 - 005.01

- Color difference amplifier:29301 - 006.01

- Luminance + Chrominance Signal processing:29301 - 024.01 (TDA2510 + TDA2521)

- Tuning control / drive :29301 -056.11

- Line supply stabiliser with magnetic transductor:29301 - 035.01

- Line deflection Thyristors Trace and Return (RCA17057 + RCA17056).






































































































































































































































































GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) Horizontal deflection circuit




























Description:



1. A horizontal deflection circuit for generating the deflection current in the deflection coil of a television picture tube wherein a first switch controls the horizontal sweep, and wherein a second switch in a so-called commutation circuit with a commutating inductor and a commutating capacitor opens the first switch and, in addition, controls the energy transfer from a dc voltage source to an input inductor, characterized in that the input inductor (Le) and the commutating inductor (Lk) are combined in a unit designed as a transformer (U) which is proportioned so that the open-circuit inductance of the transformer is essentially equal to the value of the input inductor (Le), while the short-circuit inductance of the transformer (U) is essentially equal to the value of the commutating inductor (Lk), and that the second switch (S2) is connected in series with the dc voltage source (UB) and a first winding (U1) of the transformer (U). 2. A horizontal deflection circuit according to claim 1, characterized in that the transformer (U) operates as an isolation transformer between the supply (UB) and the subcircuits connected to a second winding. 3. A horizontal deflection circuit according to claim 1, characterized in that the second switch (S2) is connected between ground and that terminal of the first winding (U1) of the transformer (U) not connected to the supply potential (+UB). 4. A horizontal deflection circuit according to claim 1, characterized in that a capacitor (CE) is connected across the series combination of the first winding (U1) of the transformer and the second switch (S2). 5. A horizontal deflection circuit according to claim 1, characterized in that the second winding (U2) of the transformer (U) is connected in series with a first switch (S1), the commutating capacitor (Ck), and a third, bipolar switch (S3) controllable as a function of the value of a controlled variable developed in the deflection circuit. 6. A horizontal deflection circuit according to claim 5, characterized in that the third switch (S3) is connected between ground and the second winding (U2) of the transformer. 7. A horizontal deflection circuit according to claim 2, characterized in that the isolation transformer carries a third winding via which power is supplied to the audio output stage of the television set. 8. A horizontal deflection circuit according to claims 2, characterized in that the voltage serving to control the first switch (S1) is derived from a third winding of the transformer.
Description:
The present invention relates to a horizontal deflection circuit for generating the deflection current in the deflection coil of a television picture tube wherein a first switch controls the horizontal sweep, and wherein a second switch in a so-called commutation circuit with a commutating inductor and a commutating capacitor opens the first switch and, in addition, controls the energy transfer from a dc voltage source to an input inductor.
German Auslegeschrift (DT-AS) No. 1,537,308 discloses a horizontal deflection circuit in which, for generating a periodic sawtooth current within the respective deflection coil of the picture tube, in a first branch circuit, the deflection coil is connected to a sufficiently large capacitor serving as a current source via a first controlled, bilaterally conductive switch which is formed by a controlled rectifier and a diode connected in inverse parallel. The control electrode of the rectifier is connected to a drive pulse source which renders the switch conductive during part of the sawtooth trace period. In that arrangement, the sawtooth retrace, i.e. the current reversal, also referred to as "commutation", is initiated by a second controlled switch.
The first controlled switch also forms part of a second branch circuit where it is connected in series with a second current source and a reactance capable of oscillating. When the first switch is closed, the reactance, consisting essentially of a coil and a capacitor, receives energy from the second current source during a fixed time interval. This energy which is taken from the second current source corresponds to the circuit losses caused during the previous deflection cycle.
As can be seen, such a circuit needs two different, separate inductive elements, it being known that inductive elements are expensive to manufacture and always have a certain volume determined by the electrical properties required.
The object of the invention is to reduce the amount of inductive elements required.
The invention is characterized in that the input inductor and the commutating inductor are combined in a unit designed as a transformer which is proportioned so that the open-circuit inductance of the transformer is essentially equal to the value of the input inductor, while the short-circuit inductance of the transformer is essentially equal to the value of the commutating inductor, and that the second switch is connected in series with the dc voltage source and a first winding of the transformer.
This solution has an added advantage in that, in mass production, both the open-circuit and the short-circuit inductance are reproducible with reliability.
According to another feature of the invention, the electrical isolation between the windings of the transformer is such that the transformer operates as an isolation transformer between the supply and the subcircuits connected to a second winding or to additional windings of the transformer. In this manner, the transformer additionally provides reliable mains isolation.
According to a further feature of the invention, the second switch is connected between ground and that terminal of the first winding of the transformer not connected to the supply potential. This simplifies the control of the switch.
According to a further feature of the invention, to regulate the energy supply, the second winding of the transformer is connected in series with the first switch, the commutating capacitor, and a third, bipolar switch controllable as a function of the value of a controlled variable developed in the deflection circuit.

The advantage gained by this measure lies in the fact that the control takes place on the side separated from the mains, so no separate isolation device is required for the gating of the third switch. Further details and advantages will be apparent from the following description of the accompanying drawings and from the claims. In the drawings,
FIG. 1 is a basic circuit diagram of the arrangement disclosed in German Auslegeschrift (DT-AS) No. 1,537,308;
FIG. 2 shows a first embodiment of the horizontal deflection circuit according to the invention, and
FIG. 3 shows a development of the horizontal deflection circuit according to the invention.
FIG. 1 shows the essential circuit elements of the horizontal deflection circuit known from the German Auslegeschrift (DT-AS) No. 1,537,308 referred to by way of introduction.
Connected in series with a dc voltage source UB is an input inductor Le and a bipolar, controlled switch S2. In the following, this switch will be referred to as the "second switch"; it is usually called the "commutating switch" to indicate its function.
In known circuits, the second switch S2 consists of a controlled rectifier and a diode connected in inverse parallel.
The second switch S2 also forms part of a second circuit which contains, in addition, a commutating inductor Lk, a commutating capacitor Ck, and a first switch S1. The first switch S1, controlling the horizontal sweep, is constructed in the same manner as the above-described second switch S2, consisting of a controlled rectifier and a diode in inverse parallel. Connected in parallel with this first switch is a deflection-coil arrangement AS with a capacitor CA as well as a high voltage generating arrangement (not shown). In FIGS. 1, 2, and 3, this arrangement is only indicated by an arrow and by the reference characters Hsp. The operation of this known horizontal deflection circuit need not be explained here in detail since it is described not only in the German Auslegeschrift referred to by way of introduction, but also in many other publications.
FIGS. 2 and 3 show the horizontal deflection circuit modified in accordance with the present invention. Like circuit elements are designated by the same reference characters as in FIG. 1.
FIG. 2 shows the basic principle of the invention. The two inductors Le and Lk of FIG. 1 have been replaced by a transformer U. To be able to serve as a substitute for the two inductors Le and Lk, the transformer must be proportioned in a special manner. Regardless of the turns ratio, the open-circuit inductance of the transformer is chosen to be essentially equal to the value of the input inductor Le, and the short-circuit inductance of the transformer is essentially equal to the value of the commutating inductor Lk.
To permit the second switch S2 to be utilized for the connection of the dc voltage source UB, it is included in the circuit of that winding U1 of the transformer connected to the dc voltage UB.
In principle, it is of no consequence for the operation of the switch S2 whether it is inserted on that side of the winding U1 connected to the positive operating potential +UB or on the side connected to ground. In practice, however, the solution shown in FIGS. 2 and 3 will be chosen since the gating of the controlled rectifier is less problematic in this case.
In compliance with pertinent safety regulations, the transformer U may be designed as an isolation transformer and can thus provide mains separation, which is necessary for various reasons. It is known from German Offenlegungschrift (DT-OS) No. 2,233,249 to provide dc isolation by designing the commutating inductor as a transformer, but this measure is not suited to attaining the object of the present invention.
If the energy to be taken from the dc voltage source is to be controlled as a function of the energy needed in the horizontal deflection circuit and in following subcircuits, the embodiment of the horizontal deflection circuit of FIG. 3 may be used.
The circuit including the winding U2 of the transformer U contains a third controlled switch S3, which, too, is inserted on the grounded side of the winding U2 for the reasons mentioned above. This third switch S3, just as the second switch S2, is operated at the frequency of a horizontal oscillator HO, but a control circuit RS whose input l is fed with a controlled variable is inserted between the oscillator and the switch S3. Depending on this controlled variable, the controlled rectifier of the third switch S3 can be caused to turn on earlier. A suitable controlled variable containing information on the energy consumption is, for example, the flyback pulse capable of being taken from the high voltage generating circuit (not shown). Details of the operation of this kind of energy control are described in applicant's German Offenlegungsschrift (DT-OS) No. b 2,253,386 and do not form part of the present invention.
With mains isolation, the additional, third switch S3 shown here has the advantage of being on the side isolated from the mains and eliminates the need for an isolation device in the control lead of the controlled rectifier.
As an isolation transformer, the transformer U may also carry additional windings U3 and U4 if power is to be supplied to the audio output stage, for example; in addition, the first switch S1 may be gated via such an additional winding.
The points marked at the windings U1 and U2 indicate the phase relationship between the respective voltages. Connected in parallel with the winding U1 and the second switch S2 is a capacitor CE which completes the circuit for the horizontal-frequency alternating current; this serves in particular to bypass the dc voltage source or the electrolytic capacitors contained therein.
If required, a well-known tuning coil may be inserted, e.g. in series with the second winding U2, without changing the basic operation of the horizontal deflection circuit according to the invention.




TBA920 line oscillator combination

DESCRIPTION
The line oscillator combination TBA920 is a monolithic
integrated circuit intended for the horizontal deflection of the black and white
and colour TV sets
picture tube.

FEATURES:
SYNC-PULSE SEPARATION
OPTIONAL NOISE INVERSION
GENERATION OF A LINE FREQUENCY VOL-
TAGE BY MEANS OF AN OSCILLATOR
PHASE COMPARISON BETWEEN SYNC-
PULSE AND THE OSCILLATOR WAVEFORM
PHASE COMPARISON BETWEEN THE OS-
CILLATOR WAVEFORM AND THE MIDDLE OF
THE LINE FLY-BACK PULSE
AUTOMATIC SWITCHING OF THE VARIABLE
TRANSCONDUCTANCE AND THE VARIABLE
TIME CONSTANT TO ACHIEVE NOISE SUP-
PRESSION AND, BY SWITCHING OFF, POS-
SIBILITY OF TAPE-VIDEO-REGISTERED RE-
PRODUCTION
SHAPING AND AMPLIFICATION OF THE OS-
CILLATOR WAVEFORM TO OBTAIN PULSES
FOR THE CONTROL OF DRIVING STAGES IN
HORIZONTAL, DEFLECTION CIRCUITS
USING EITHER TRANSISTORS OR THYRISTORS.


TDA2521
synchronous demodulator for PAL

GENERAL DESCRIPTION
The TDA2521 is a monolithic integrated circuit designed as a synchronous demodulator for PAL color television receivers. It includes an 8.8 MHz oscillator and divider, to generate two 4.4 MHz reference signals, and provides color difference output.

The TDA2521 is intended to interface directly with the TDA251O with a minimum of external components and is constructed on a single silicon chip using the Fairchild Planar
epitaxial process.

ABSOLUTE MAXIMUM RATINGS
Supply Voltage 14 V
Internal Power Dissipation 600 mW ORDER INFQRMATIQN
Operating Temperature Range —2O°C to +6O°C TYPE PART NO.
Storage Temperature Range —55°C to +125°C 2521 TDA2521
Pin Temperature iSo|dering 10 si 260°C

Planar is a patented Fairchild process















TDA2510
CHROMINANCE COMBINATION

GENERAL DESCRIPTION —

The TDA2510 is a monolithic integrated circuit designed for the function of a color television receiver. It Is designed to Interface directly with the TDA2521, using a minimum number of external components.
TDA251O is constructed on a single silicon chip using the Fairchild Planar‘ epitaxial process.

ABSOLUTE MAXIMUM RATINGS

supply Voltage 15 V
Collector voltage of chroma output transistor (pin 7) 20 V
(PD I 100 mW max)
Collector current of chroma output transistor (pin 7) 20 mA
Collector current of color killer output transistor (pin 11) 10 mA
Power dissipation 500 mW
Operating temperature range —25°C 10 +6O°
Storage temperature range *55°C to +12!-3°C


GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) Electron beam deflection circuit including thyristors Further Discussion and deepening of knowledge, Thyristor horizontal output circuits:
(Thyristor Horizontalsteuerung ZEILEN ABLENKUNG)
1. An electron beam deflection circuit for a cathode ray tube with electromagnetic deflection by means of a sawtooth current waveform having a trace portion and a retrace portion, said circuit comprising: a deflection winding; a first source of electrical energy formed by a first capacitor; first controllable switching means comprising a parallel combination of a first thyristor and a first diode connected together to conduct in opposite directions, for connecting said winding to said first source during said trace portion, while said first switching means is turned on; a second source of electrical energy including a first inductive energy storage means coupled to a voltage supply; reactive circuit means including a combination of inductive and capacitive reactances for storing the energy supplied by said second source; second controllable switching means, substantially similar to said first one, for completing a circuit including said reactive circuit means and said first switching means, when turned on before the end of said trace portion, so as to pass through said first switching means an oscillatory current in opposite direction to that which passes through said first thyristor from said first source and to turn said first thyristor off after these two currents cancel out, the oscillatory current flowing thereafter through said first diode for an interval termed the circuit turn-off time, which has to be greater than the turn-off time of said first thyristor; wherein the improvement comprises: means for drawing, during at least a part of said trace portion, a substantial amount of additional current through said first switching means, in the direction of conduction of said first diode, whereby to perceptibly shift the waveform of the current flowing through said first switching means towards the negative values by an amount equal to that of said substantial additional current and to lengthen, in proportion thereto, said circuit turn-off time, without altering the values of the reactances in the reactive circuit which intervene in the determination of both the circuit turn-off and retrace portion time intervals.

2. A deflection circuit as claimed in claim 1, wherein said amount of additional current is greater than or equal to 5 per cent of the peak-to-peak value of the current flowing through the deflection winding.

3. A deflection circuit as claimed in claim 1, wherein said means for drawing a substantial amount of additional current through said first switching means comprises a resistor connected in parallel to said first capacitor.

4. A deflection circuit as claimed in claim 1, wherein said means for drawing an additional current is formed by connecting said first and second energy sources in series so that the current charging said reactive circuit means forms the said additional current.

5. A deflection circuit as claimed in claim 1, further including a series combination of an autotransformer winding and a second high-value capacitor, said combination being connected in parallel to said first switching means, wherein said autotransformer comprises an intermediate tap located between its terminals respectively connected to said first switching means and to said second capacitor, said tap delivering, during said trace portion, a suitable DC supply voltage lower than the voltage across said second capacitor; and wherein said means for drawing a substantial amount of additional current comprises a load to be fed by said supply voltage and having one terminal connected to ground; and further controllable switching means controlled to conduct during at least part of said trace portion and to remain cut off during said retrace portion, said further switching means being connected between said tap and the other terminal of said load.


Description:
The present invention relates to electron beam deflection circuits including thyristors, such as silicon controlled rectifiers and relates, in particular, to horizontal deflection circuits for television receivers.

The present invention constitutes an improvement in the circuit described in U.S. Pat. No. 3,449,623 filed on Sept. 6, 1966, this circuit being described in greater detail below with reference to FIGS. 1 and 2 of the accompanying drawings. A deflection circuit of this type comprises a first thyristor switch which allows the conenction of the horizontal deflection winding to a constant voltage source during the time interval used for the transmisstion of the picture signal and for applying this signal to the grid of the cathode ray tube (this interval will be termed the "trace portion" of the scan), and a second thyristor switch which provides the forced commutation of the first one by applying to it a reverse current of equal amplitude to that which passes through it from the said voltage source and thus to initiate the retrace during the horizontal blanking interval.

A undirectional reverse blocking triode type thyristor or silicon controlled rectifier (SCR), such as that used in the aformentioned circuit, requires a certain turn-off time between the instant at which the anode current ceases and the instant at which a positive bias may be applied to it without turning it on, due to the fact that there is still a high concentration of free carriers in the vicinity of the middle junction, this concentration being reduced by a process of recombination independently from the reverse polarity applied to the thyristor. This turn-off time of the thyristor is a function of a number of parameters such as the junction temperature, the DC current level, the decay time of the direct current, the peak level of the reverse current applied, the amplitude of the reverse anode to cathode voltage, the external impedance of the gate electrode, and so on, certain of these varying considerably from one thyristor to another.

In horizontal deflection circuits for television receivers, the flyback or retrace time is limited to approximately 20 percent of the horizontal scan period, the retrace time being in the case of the CCIR standard of 625 lines, approximately 12 microseconds and, in the case of the French standard of 819 lines, approximately 9 microseconds. During this relatively short interval, the thyristor has to be rendered non-conducting and the electron beam has to be returned to the origin of the scan. The first thyristor is blocked by means of a series resonant LC circuit which is subject to a certain number of restrictions (limitations as to the component values employed) due to the fact that, inter alia, it simultaneously determines the turn-off time of the circuit which blocks the thyristor and it forms part of the series resonant circuit which is to carry out the retrace. To obtain proper operation of the deflection circuit of the aforementioned Patent, especially when used for the French standard of 819 lines per image, the values of the components used have to subject to very close tolerances (approximately 2%), which results in high costs.

The improved deflection circuit, object of the present invention, allows the lengthening of the turn-off time of the circuit for turning the scan thyristor off, without altering the values of the LC circuit, which are determined by other criteria, and without impairing the operation of the circuit.

According to the invention, there is provided an electron beam deflection circuit for a cathode ray tube with electromagentic deflection by means of a sawtooth current waveform having a trace portion and a retrace portion, said circuit comprising: a deflection winding; a first source of electrical energy formed by a first capacitor; first controllable switching means comprising a parallel combination of a first thyristor and a first diode, connected together to conduct in opposite directions, for connecting said winding to said first source during said trace portion when said first switching means is turned on; a second source of electrical energy including a first inductive energy storage means coupled to a voltage supply; reactive circuit means including a combination of inductive and capacitive reactances for storing the energy supplied by the said second source; a second controllable switching means, substantially identical with the first one, for completing a circuit including said reactive circuit means and said first switching means, when turned on, so as to pass through said first thyristor an oscillatory current in the opposite direction to that which passes through it from said first source and to turn it off after these two currents cancel out, the oscillatory current then flowing through said first diode for an interval termed the circuit turn-off time which has to be greater than the turn-off time of said first thyristor; and means for drawing duing at least a part of said trace portion a substantial amount of additional current from said first switching means in the direction of conduction of said first diode, whereby said circuit turn-off time is lengthened in proportion to the amount of said additional current, without altering the values of the reactances in the reactive circuit by shifting the waveform of the current flowing through said first switching means towards the negative by an amount equal to that of said additional current.

A further object of the invention consists in using the supplementary current in the recovery diode of the first switching means to produce a DC voltage which may be used as a power supply for the vertical deflection circuit of the television receiver, for example.

The invention will be better understood and other features and advantages thereof will become apparent from the following description and the accompanying drawings, given by way of example, and in which:

FIG. 1 is a schematic circuit diagram partially in bloc diagram form of a prior art deflection circuit according to the aforementioned Patent;

FIG. 2 shows waveforms of currents and voltages generated at various points in the circuit of FIG. 1;

FIG. 3 is a schematic diagram of a deflection circuit according to the invention which allows the principle of the improvement to be explained;

FIG. 4 is a diagram of the waveforms of the current through the first switching means 4, 5 of the circuit of FIG. 3;

FIG. 5 is a circuit diagram of another embodiment of the circuit according to the invention;

FIG. 6 is a schematic representation of the preferred embodiment of the circuit according to the invention; and

FIG. 7 shows voltage waveforms at various points of the high voltage autotransformer 21 of FIG. 6.

In all these Figures the same reference numerals refer to the same components.

FIG. 1 shows the horizontal deflection circuit described and claimed in the U.S. Pat. No. 3,449,623 mentioned above, which comprises a first source of electrical energy in the shape of a first capacitor 2 having a high capacitance C 2 for supplying a substantially constant voltage Uc 2 across its terminals. A first terminal of the first capacitor 2 is connected to ground, whilst its second terminal which supplies a positive voltage is connected to one of the terminals of a horizontal deflection winding shown as a first inductance 1. A first switching means 3, consisting of a first reverse blocking triode thyristor 4 (SCR) and a first recovery diode 5 in parallel, the two being interconnected to conduct current in opposite directions, is connected in parallel with the series combination formed by the deflection winding 1 and the first capacitor 2. The assembly of components 1, 2, 4 and 5 forms the final stage of the horizontal deflection circuit in a television receiver using electromagnetic delfection.

The deflection circuit also includes a drive stage for this final stage which here controls the turning off of the first thyristor 4 to produce the retrace or fly-back portion of the scan during the line-blanking intervals i.e. while the picture signal is not transmitted. This driver stage comprises a second voltage source in the shape of a DC power supply 6 which delivers a constant high voltage E. The negative terminal of the power supply 6 is connected to ground and its positive terminal to one of the terminals of a second inductance 7 of relatively high value, which draws a substantially lineraly varying current from the power supply 6 to avoid its overloading. The other terminal of the second inductance 7 is connected, on the one hand, to the junction of the deflection winding 1 and the first switching means 3 by means of a second inductance 8 and a second capacitor 9 in series and, on the other hand, to one of the terminals of a second controllable bi-directionally conducting switching means 10, similar to the first one 3, including a parallel combination of a second thyristor 11 and a second recovery diode 12 also arranged to conduct in opposite directions.

The respective values of the third inductance 8 (L 8 ) and of the second capacitor 9 (C 9 ) are principally selected so that, on the one hand, one half-cycle of oscillation of the first series resonant circuit L 8 - C 9 , (i.e. π √ L 8 . C 9 ) is longer than the turn-off time of the first thyristor 4, but still is as short as possible since this time interval determines the speed of the commutation of the thyristor 4, and, on the other hand, one half-cycle of oscillation of another series resonant circuit formed by L 1 , L 8 and C 9 , i.e. π √ (L 1 + L 8 ) . C 9 , is substantially equal to the required retrace time interval (i.e. shorter than the horizontal blanking interval).

The gate (control electrode) of the second thyristor 11 is coupled to the output of the horizontal oscillator 13 of the television receiver by means of a first pulse transformer 14 and a first pulse shaping circuit 15 so that it is fed short triggering pulses which are to turn it on.

The gate of the first thyristor 4 fed with signals of a substantially rectangular waveform which are negative during the horizontal blanking intervals, is coupled to a winding 16 by means of a second pulse shaping circuit 17, the winding 16 being magnetically coupled to the second inductance 7 to make up the secondary winding of a transformer of which the inductance 7 forms the primary winding. It will be noted here that it is also possible to couple the secondary winding 16 magnetically to a primary winding connected to a suitable output (not shown) of the horizontal oscillator 13.

The operation of a circuit of this type will be explained below with reference to FIG. 2 which shows the waveforms at various points in the circuit of FIG. 1 during approximately one line period.

FIG. 2 is not to scale since one line period (t 7 - t 0 ) is equal to 64 microseconds in the case of 625 lines and 49 microseconds in the case of 819 lines, while the durations of the respective horizontal blanking intervals are approximately 12 and 9.5 microseconds.

Waveform A shows the form of the current i L1 passing through deflection winding 1, this current having a sawtooth waveform substantially linear from t 0 to t 3 and from t 5 to t 7 , and crossing zero at time instants t 0 and t 7 , and reaching values of + I 1m and - I 1m , at time instants t 3 and t 5 respectively, these being its maximum positive and negative amplitudes.

During the second half of the trace portion of the horizontal deflection cycle, that is to say from t 0 to t 3 , the thyristor 4 of the first switching means 3 is conductive and makes the high value capacitor 2 discharge through the deflector winding 1, which has a high inductance, so that current i L1 increases linearly.

A few microseconds (5 to 8 μ s) before the end of the trace portion, i.e. at time instant t 1 , the trigger of the second thyristor 11 receives a short voltage pulse V G11 which causes it to turn on as its anode is at this instant at a positive potential with respect to ground, which is due to the charging of the second capacitor 9 through inductances 7 and 8 by the voltage E from the power supply 6.

When thyristor 11 is made conductive at time t 1 , on the one hand, inductance 7 is connected between ground and the voltage source 6 and a linearly increasing current flows through it and, on the other hand, the reactive circuit 8, 9 forms a loop through the second and first switching means 10 and 3, thus forming a resonant circuit which draws an oscillatory current i 8 ,9 of frequency ##EQU1##

This oscillatory current i 8 ,9 will pass through the first switching means 3, i.e. thyristor 4 and diode 5, in the opposite direction to that of current i L1 . Since the frequency f 1 is high, current i 8 ,9 will increase more rapidly than i L1 and will reach the same level at time t 2 , that is to say i 8 ,9 (t 2 ) = -i L1 (t 2 ) and these currents will cancel out in the thyristor 4 in accordance with the well known principle of forced commutation. After time instant t 2 , current i 8 ,9 continues to increase more rapidly than i L1 , but the difference between them (i 8 ,9 - i L1 ) passes the diode 5 (see wave form B) until it becomes zero at time instant t 3 which is the turn off time instant of the first switching means 3, at which the retrace begins.

The interval between the time instant t 2 and t 3 , i.e. (t 3 -t 2 ), during which diode 5 is conductive and the thyristor is reverse biased will be termed in what follows the circuit turn-off time and it should be greater than the turn-off time of the thyristor 4 itself since the latter will subsequently become foward biased (i.e. from t 3 to t 5 ) by the retrace or flyback pulse (see waveform E) which should not trigger it.

At time instant t 3 , the switching means 3 is opened (i 4 and i 5 are both zero -- see waveforms B and C) and the reactive circuit 8, 9 forms a loop through capacitor 2 and the deflection coil 1 and thus a series resonant circuit including (L 1 + L 8 ) and C 9 , C 2 being of high value and representing a short circuit for the flyback frequency ##EQU2## thus obtained.

The retrace which stated at time t 3 takes place during one half-cycle of the resonant circuit formed by reactances L 1 , L 8 and C 9 , i.e. during the interval between t 3 and t 5 . In the middle of this interval i.e. at time instant t 4 , both i L1 (waveform A) and i 8 ,9 (waveform D) pass through zero and change their sign, whereas the voltage at the terminals of the first switching means 3 (V 3 , waveform E) passes through a maximum. Thus, from t 4 onwards, thyristor 11 will be reverse biased and diode 12 will conduct the current from the resonant circuit 1, 8 and 9 in order to turn the second thyristor 11 off.

At time instant t 5 , when current i L1 has reached - I 1m and when voltage v 3 falls to zero, diode 5 of the first switching means 3 becomes conductive and the trace portion of scan begins.

Current i 8 ,9 nevertheless continues to flow in the resonant circuit 8, 9 through diodes 5 and 12, which causes a break to appear in waveform D at t 5 , and a negative peak to appear in waveform D and a positive one in waveform B in the interval between t 5 and t 6 , these being principally due to the distributed capacities of coil 1 or to an eventual capacitor (not shown) connected in parallel to the first switching means 3.

At time instant t 6 , diode 12 of the second switching means 10 ceases to conduct after having allowed thyristor 11 time to become turned off completely.

The level of current i 8 ,9 at time instant t 5 (i.e. I c ) as well as the negative peak I D12 in i 8 ,9 and the positive peak I D5 in i 5 depend on the values of L 8 and C 9 in the same way as does the turn-off time of the circuit (t 3 - t 2 ). If, for example, L 8 and C 9 , are increased I D5 increases towards zero and this could cause diode 5 to be cut off in an undesirable fashion. I c also increases towards zero, which is liable to cause diode 12 to be blocked and thyristor 11 to trigger prematurely.

From the foregoing it can be clearly seen that the choice of values for L 8 and C 9 is subject to four limitations which prevent the values from being increased to lengthen the turn-off time of the driver circuit of first switching thyristor 4 so as to forestall its spurious triggering.

Waveform F shows the voltage v G4 obtained at the gate of thyristor 4 from the secondary winding 16 coupled to the inductor 7. This voltage is positive from t 0 to t 1 and from t 6 to t 7 and is negative between t 2 and t 6 i.e. while the second switching means 10 is conducting.

The present invention makes the lengthening of the turn-off time of thyristor 4 possible without altering the parameters of the circuit such as inductance 8 and capacitor 9.

In the circuit shown in FIG. 3, which illustrates the principle of the present invention, means are added to the circuit in FIG. 1 which enable the turn-off time to be lengthened by connecting a load to diode 5 so as to increase the current which flows through it during the time that it is conductive. These means are here formed by a resistor 18 connected in parallel with a capacitor 20 (which replaces capacitor 2) which is of a higher capacitance so that, in practice, it holds its charge during at least one half of the line period. FIG. 4, which shows the waveform of the current in the first switching means 3 for a circuit as shown in FIG. 3, makes it possible to explain how this lenthening of the turn-off time is achieved.

In FIG. 4, the broken lines show the waveform of the current in the first switch device 3 in the circuit of FIG. 1, this waveform being produced by adding waveforms B and C of FIG. 2. The current i 4 above the axis flows through thyristor 4 and current i 5 below the axis flows through diode 5. When the capacitance C 20 of the capacitor in series with the deflector coil is increased to some tens of microfarads (C 2 having been of the order of 1 μ F) and when there is connected in parallel with capacitor 20 a resistor 18 the value of which is calculated to draw a strong current I R18 from capacitor 20, that is to say a current at least equal to 0,1 I m (I m being of the order of some tens of amperes), current I R18 is added to that i 5 which flows through diode 5 without in any way altering the linearity of the trace portion nor the oscillatory commutation of thyristor 4 which is brought about by the resonant circuit L 8 , C 9 .

The fact of loading capacitor C 20 by means of a resistor 18 thus has the effect of permanently displacing the waveform of the current in the negative direction by I R18 . Thus, during the trace portion of the scan, the transfer of the current from the diode 5 to the thyristor 4 begins at time t 10 instead of t 0 , that is to say with a delay proportional to I R18 . The effect of the triggering pulse delivered by the horizontal oscillator (13 FIG. 1) to the second thyristor 11 at time instant t 1 , will be to start the commutation process of the first thyristor 4 when the current it draws is less by I R18 than that i 4 (t 1 ) which it would have been drawing had there been no resistor 18. Because of this, the turn-off time of the thyristor 4 proper, which as has been mentioned increases with the maximum current level passing throught it, is slightly reduced. Moreover, because the oscillatory current i 8 ,9 (FIG. 2) from circuit L 8 , C 9 which flows through thyristor 4 in the opposite direction is unchanged, it reaches a value equal to that of the current i L1 (FIG. 1) flowing in the coil 1 in a shorter time, that is to say at time t 12 . Diode 5 will thus take the oscillatory current i 8 ,9 (FIG. 2) over in advance with respect ro time instant t 2 and will conduct it until it reaches zero value at a time instant t 13 later than t 3 , the amounts of advance (t 2 - t 12 ) and delay (t 13 - t 3 ) being practically equal.

It can thus be seen in FIG. 4 that the circuit turn-off time T R of a circuit according to the invention and illustrated by FIG. 3 is distinctly longer than that T r of the circuit in FIG. 1. This increase in the turn-off time (T R - T r ) depends on the current I R18 and increases therewith.

It should be noted at this point that the current I R18 produces a voltage drop at the terminals of the resistor the only effect of which is to heat up the resistor since the level of this voltage (40 to 60 volts) does not necessarily have a suitable value to be used as a voltage supply for other circuits in an existing transistorised television receiver.

In accordance with one embodiment of the invention, illustrated in FIG. 5, an application is proposed for the additional current which is to be drawn through diode 5. In FIG. 5, the positive terminal of capacitor 20 is connected by a conductor 19 to the negative pole of the power supply 6 and the voltage at the terminals of capacitor 20 is thus added to that E from the source 6.

In the preferred embodiment of the present invention, which is shown in FIG. 6, it is possible to cause a supplementary current of a desired value to flow through the first diode 5 while obtaining a voltage which has a suitable value for use in another circuit in the television receiver.

If the voltage at the terminals of capacitor 20 in FIG. 3 is not a usable value, it is possible to connect in parallel with the series circuit comprising the deflector coil 1 and the capacitor 2 in FIG. 1, i.e. in parallel with the terminals of the first switching means 3, a series combination of an autotransformer 21 and a high value capacitor 22 (comparable with capacitor 20 in FIGS. 3 and 5). The autotransformer 21 has a tap 23 is suitably positioned between the terminal connected to capacitor 22 at the tap 24 connected to the first switching means 3. This autotransformer 21 may be formed by the one conventionally used for supplying a very high voltage to the cathode ray tube, as described for example in U.S. Pat. No. 3,452,244; such a transformer comprises a voltage step-up winding between taps 24 and 25, which latter is connected to a high voltage rectifier (not shown).

The waveform of the voltage at the various points in the autotransformer is shown in FIG. 7, in which waveform A shows the voltage at the terminals of capacitor 22, waveform B the voltage at tap 24 and waveform C the voltage at tap 23 of the autotransformer 21.

The voltage V c22 at the terminals of capacitor 22 varies slightly about a mean value V cm . It is increasing while diode 5 is conducting and decreasing during the conduction of the thyristor 4.

The voltage v 24 at tap 24 follows substantially the same curve as waveform E in FIG. 2, that is to say that during the retrace time interval from t 13 to t 5 to a positive pulse called the flyback pulse is produced and, during the time interval while the first switching means 3 is conducting, the voltage is zero. The mean valve of the voltage v 24 at tap 24 of the auto-transformer 21 is equal to the mean value V cm of the voltage at the terminals of capacitors 2 and 22.

Thus, there is obtained at tap 23 a waveform which is made up, during the retrace portion, of a positive pulse whose maximum amplitude is less than that of v 24 at tap 24 and, during the trace portion, of a substantially constant positive voltage, the level V of which is less than the mean value V cm of the voltage v c22 at the terminals of capacitor 22. By moving tap 23 towards terminals 24 the amplitude of the pulse during fly-back increases while voltage V falls and conversely by moving tap 23 towards capacitor 22 voltage V increases and the amplitude of the pulse drops.

In more exact terms, the voltage V at tap 23 is such that the means value of v 23 is equal to V cm . It has thus been shown that by choosing carefully the position of tape 23, a voltage V may be obtained during the trace portion of the scan, which may be of any value between V cm and zero.

This voltage V is thus obtained by periodically controlled rectification during the trace portion of the scan. For this purpose an electronic switch is used to periodically connect the tap 23 of trnasformer winding 21 to a load. This switch is made up of a power transistor 26 whose collector is connected to tap 23 and the emitter to a parallel combination formed by a high value filtering capacitor 27 and the load which it is desired to supply, which is represented by a resistor 28. The base of the transistor 26 receives a control voltage to block it during retrace and to unblock it during the whole or part of the trace period. A control voltage of this type may be obtained from a second winding 29 magnetically coupled to the inductance 7 of the deflection circuit and it may be transmitted to the base of transistor 26 by means of a coupling capacitor 30 and a resistor 31 connected between the base and the emitter of transistor 26.

It may easily be seen that the DC collector/emitter current in transistor 26 flows through the first diode 5 of the first switching means 3 via a resistor 28 and the part of the winding of auto-transformer 21 located between taps 23 and 24.

Experience has shown that a circuit as shown in FIG. 6 can supply 24 volts with a current of 2 amperes to the vertical deflection circuit of the same television set, the voltage at the terminals of capacitor 22 being from 50 to 60 volts.

It should be mentioned that, when the circuit which forms the load of the controlled rectifier 26, 27 does not draw enough current to sufficiently lengthen the circuit turn-off time T R , an additional resistor (not shown) may be connected between the emitter of transistor 26 and ground or in parallel to capacitor 22, which resistor will draw the additional current required.


INTEGRAL THYRISTOR-RECTIFIER DEVICE
A semiconductor switching device comprising a silicon controlled rectifier (SCR) and a diode rectifier integrally connected in parallel with the SCR in a single semiconductor body. The device is of the NPNP or PNPN type, having gate, cathode, and anode electrodes. A portion of each intermediate N and P region makes ohmic contact to the respective anode or cathode electrode of the SCR. In addition, each intermediate region includes a highly conductive edge portion. These portions are spaced from the adjacent external regions by relatively low conductive portions, and limit the conduction of the diode rectifier to the periphery of the device. A profile of gold recombination centers further electrically isolates the central SCR portion from the peripheral diode portion.
That class of thyristors known as controlled rectifiers are semiconductor switches having four semiconducting regions of alternate conductivity and which employ anode, cathode, and gate electrodes. These devices are usually fabricated from silicon. In its normal state, the silicon controlled rectifier (SCR) is non-conductive until an appropriate voltage or current pulse is applied to the gate electrode, at which point current flows from the anode to the cathode and delivers power to a load circuit. If the SCR is reverse biased, it is non-conductive, and cannot be turned on by a gating signal. Once conduction starts, the gate loses control and current flows from the anode to the cathode until it drops below a certain value (called the holding current), at which point the SCR turns off and the gate electrode regains control. The SCR is thus a solid state device capable of performing the circuit function of a thyratron tube in many electronic applications. In some of these applications, such as in automobile ignition systems and horizontal deflection circuits in television receivers, it is necessary to connect a separate rectifier diode in parallel with the SCR. See, for example, W. Dietz, U. S. Pat. Nos. 3,452,244 and 3,449,623. In these applications, the anode of the rectifier diode is connected to the cathode of the SCR, and the cathode of the rectifier is connected to the SCR anode. Thus, the rectifier diode will be forward biased and current will flow through it when the SCR is reverse biased; i.e., when the SCR cathode is positive with respect to its anode. For reasons of economy and ease of handling, it would be preferable if the circuit function of the SCR and the associated diode rectifier could be combined in a single device, so that instead of requiring two devices and five electrical connections, one device and three electrical connections are all that would be necessary. In fact, because of the semiconductor profile employed, many SCR's of the shorted emitter variety inherently function as a diode rectifier when reverse biased. However, the diode rectifier function of such devices is not isolated from the controlled rectifier portion, thus preventing a rapid transition from one function to the other. Therefore, it would be desirable to physically and electrically isolate the diode rectifier portion from that portion of the device which functions as an SCR.



GRUNDIG SUPER COLOR 1610 CHASSIS 29301-374.01 (08) Gating circuit for television SCR deflection system AND REGULATION / stabilization of horizontal deflection NETWORK CIRCUIT with Transductor reactor / Reverse thyristor energy recovery circuit.

In a television deflection system employing a first SCR for coupling a deflection winding across a source of energy during a trace interval of each deflection cycle and a second SCR for replenishing energy to the source of energy during a commutation interval of each deflection cycle, a gating circuit for triggering the first SCR. The gating circuit employs a voltage divider coupled in parallel with the second SCR which develops gating signals proportional to the voltage across the second SCR.


1. In a television deflection system in which a first switching means couples a deflection winding across a source of energy during a trace interval of each deflection cycle and a second switching means replenishes energy to said source of energy during a commutation interval of each deflection cycle, a gating circuit for said first switching means, comprising:
capacitive voltage divider means coupled in parallel with said second switching means for developing gating signals proportional to the voltage across said second switching means; and
means for coupling said voltage divider means to said first switching means to provide for conduction of said first switching means in response to said gating signals.
2. A gating circuit according to claim 1 wherein said voltage divider includes first and second capacitors coupled in series and providing said gating signals at the common terminal of said capacitors. 3. A gating circuit according to claim 2 wherein said first and second capacitors are proportional in value to provide for the desired magnitude of gating signals. 4. A gating circuit according to claim 3 wherein said means for coupling said voltage divider means to said first switching means includes an inductor. 5. A gating circuit according to claim 4 wherein said inductor and said first and second capacitors comprise a resonant circuit having a resonant frequency chosen to shape said gating signal to improve switching of said first switching means.
Description:
BACKGROUND OF THE INVENTION
This invention relates to a gating circuit for controlling a switching device employed in a deflection circuit of a television receiver.






























Various deflection system designs have been utilized in television receivers. One design employing two bidirectional conducting switches and utilizing SCR's (thyristors) as part of the switches is disclosed in U.S. Pat. No. 3,452,244. In this type deflection system, a first SCR is









employed for coupling a deflection winding across a source of energy during a trace interval of each deflection cycle, and a second SCR is employed for replenishing energy during a commutation interval of each deflection cycle. The first SCR is commonly provided with gating voltage by means of a separate winding or tap of an input reactor coupling a source of B+ to the second SCR.





Various regulator system designs have been utilized in conjunction with the afore described deflection system to provide for uniform high voltage production as well as uniform picture width with varying line voltage and kinescope beam current conditions.
One type regulator system design alters the amount of energy stored in a commutating capacitor coupled between the first and second SCR's during the commutating interval. A regulator design of this type may employ a regulating SCR and diode for coupling the input reactor to the source of B+. With this type regulator a notch, the width of which depends upon the regulation requirements, is created in the current supplied through the reactor and which notch shows up in the voltage waveform developed on the separate winding or tap of the input reactor which provides the gating voltage for the first SCR. The presence of the notch, even though de-emphasized by a waveshaping circuit coupling the gating voltage to the first SCR, causes erratic control of the first SCR.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the invention, a gating circuit of a television deflection system employing a first switching means for coupling a deflection winding across a source of energy during a trace interval of each deflection cycle and a second switching means for replenishing energy to said source of energy during a commutation interval of each deflection cycle includes a voltage divider means coupled in parallel with the second switching means for developing gating signals proportional to the voltage across the second switching means. The voltage divider means are coupled to the first switching means to provide for conduction of the first switching means in response to the gating signals.
A more detailed description of a preferred embodiment of the invention is given in the following description and accompanying drawing of which:
FIG. 1 is a schematic diagram, partially in block form, of a prior art SCR deflection system;
FIG. 2 is a schematic diagram, partially in block form, of an SCR deflection system of the type shown in FIG. 1 including a gating circuit embodying the invention;
FIG. 3 is a schematic diagram, partially in block form, of one type of a regulator system which employs an SCR as a control device and which is suitable for use with the SCR deflection system of FIG.2;
FIG. 4 is a schematic diagram, partially in block form, of another type of a regulator system suitable for use with the deflection circuit of FIG. 2; and
FIG. 5 is a schematic diagram, partially in block form, of still another type of a regulator system suitable for use with the SCR deflection system of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic diagram, partially in block form, of a prior art deflection system of the retrace driven type similar to that disclosed in U.S. Pat. No. 3,452,244. This system includes a commutating switch 12, comprising a silicon controlled rectifier (SCR) 14 and an oppositely poled damper diode 16. The commutating switch 12 is coupled between a winding 18a of an input choke 18 and ground. The other terminal of winding 18a is coupled to a source of direct current voltage (B+) by means of a regulator network 20 which controls the energy stored in the deflection circuit 10 when the commutating switch is off, during an interval T3 to T0' as shown in curve 21 which is a plot of the voltage level at the anode of SCR 14 during the deflection cycle. A damping network comprising a series combination of a resistor 22 and a capacitor 23 is coupled in parallel with commutating switch 12 and serves to reduce any ringing effects produced by the switching of commutating switch 12. Commutating switch 12 is coupled through a commutating coil 24, a commutating capacitor 25 and a trace switch 26 to ground. Trace switch 26 comprises an SCR 28 and an oppositely poled damper diode 30. An auxiliary capacitor 32 is coupled between the junction of coil 24 and capacitor 25 and ground. A series combination of a horizontal deflection winding 34 and an S-shaping capacitor 36 are coupled in parallel with trace switch 26. Also, a series combination of a primary winding 38a of a horizontal output transformer 38 and a DC blocking capacitor 40 are coupled in parallel with trace switch 26.
A secondary of high voltage winding 38b of transformer 38 produces relatively large amplitude flyback pulses during the retrace interval of each deflection cycle. This interval exists between T1 and T2 of curve 41 which is a plot of the current through windings 34 and 38a during the deflection cycle. These flyback pulses are applied to a high voltage multiplier (not shown) or other suitable means for producing direct current high voltage for use as the ultor voltage of a kinescope (not shown).
An auxiliary winding 38c of transformer 38 is coupled to a high voltage sensing and control circuit 42 which transforms the level of flyback pulses into a pulse width modulated signal. The control circuit 42 is coupled to the regulator network 20.
A horizontal oscillator 44 is coupled to the gate electrode of commutating SCR 14 and produces a pulse during each deflection cycle slightly before the end of the trace interval at T0 of curve 21 to turn on SCR 14 to initiate the commutating interval. The commutating interval occurs between T0 and T3 of curve 21. A resonant waveshaping network 46 comprising a series combination of a capacitor 48 and an inductor 50 coupled between a winding 18b of input choke 18 and the gate electrode of trace SCR 28 and a damping resistor 52 coupled between the junction of capacitor 48 and inductor 50 and ground shapes the signal developed at winding 18b (i.e. voltage waveform 53) to form a gating signal voltage waveform 55 to enable SCR 28 for conduction during the second half of the trace interval occurring between T2 and T1' of curve 41.
The regulator network 20, when of a type to be described in conjunction with FIG. 3, operates in such a manner that current through winding 18a of input choke 18 during an interval between T4 and T5 (region A) of curves 21, 53 and 55 is interrupted for a period of time the duration of which is determined by the signal produced by the high voltage sensing and control circuit 42. During the interruption of current through winding 18a a zero voltage level is developed by winding 18b as shown in interval T4 to T5 of curve 53. The resonant waveshaping circuit 46 produces the shaped waveform 55 which undesirably retains a slump in region A corresponding to the notch A of waveform 53. The slump in waveform 55 applied to SCR 28 occurs in a region where the anode of SCR 28 becomes positive and where SCR 28 must be switched on to maintain a uniform production of the current waveshape in the horizontal deflection winding 34 as shown in curve 41. The less positive amplitude current occurring at region A of waveform 55 may result in insufficient gating current for SCR 28 and may cause erratic performance resulting in an unsatisfactory raster.
FIG. 2 is a schematic diagram, partially in block form, of a deflection system 60 embodying the invention. Those elements which perform the same function in FIG. 2 as in FIG. 1 are labeled with the same reference numerals. FIG. 2 differs from FIG. 1 essentially in that the signal to enable SCR 28 derived from sampling a portion of the voltage across commutating switch 12 rather than a voltage developed by winding 18b which is a function of the voltage across winding 18a of input choke 18 as in FIG. 1. This change eliminates the slump in the enabling signal during the interval T4 to T5 as shown in curve 64 since the voltage across the commutating switch 12 is not adversely effected by the regulator network 20 operation.
A series combination of resistor 22, capacitor 23 and a capacitor 62 is coupled in parallel with commutating switch 12, one terminal of capacitor 62 being coupled to ground. The junction of capacitors 23 and 62 is coupled to the gate electrode of SCR 28 by means of the inductor 50. The resistor 52 is coupled in parallel with capacitor 62.
Capacitors 23 and 62 form a capacitance voltage divider which provides a suitable portion of the voltage across commutating switch 12 for gating SCR 28 via inductor 50. The magnitude of the voltage at the junction of capacitors 23 and 62 is typically 25 to 35 volts. It can, therefore, be seen that the ratio of values of capacitors 23 and 62 will vary depending on the B+ voltage utilized to energize the deflection system. Capacitors 23 and 62 and inductor 50 form a resonant circuit tuned in a manner which provides for peaking of the curve 64 between T4 and T5. This peaking effect further enhances gating of SCR 28 between T4 and T5.
Since the waveshape of the voltage across commutating switch 12 (curve 21) is relatively independent of the type of regulator system employed in conjunction with the deflection system, the curve 64 also is independent of the type of regulator system.
When commutating switch 12 switches off during the interval T3 to T0' curve 21, the voltage across capacitor 62 increases and the voltage at the gate electrode of SCR 28 increases as shown in curve 64. As will be noted, no slump of curve 64 occurs between T3 and T5 because there is no interruption of the voltage across commutating switch 12.



















FIG. 3 is a schematic diagram, partially in block form, of one type of a regulator system which may be used in conjunction with the invention. B+ is supplied through a regulator network 20 which comprises an SCR 66 and an oppositely poled diode 68. The diode is poled to provide for conduction of current from B+ to the horizontal deflection circuit 60 via winding 18a of input choke 18. Current flows through the diode during the period T3 to T4 of curve 21 FIG. 1 after which current tries to flow through the SCR 66 from the horizontal deflection circuit to B+ since the commutating capacitor 25 is charged to a voltage higher than B+.
The horizontal deflection circuit 60 produces a flyback pulse in winding 38a of the flyback transformer 38 which is coupled to winding 38c. The magnitude of the pulse on winding 38c determines how long the signal required to switch SCR 66 on is delayed after T4 curve 21 FIG. 1. If the flyback pulse is greater than desirable, the SCR 66 turns on sooner than if the flyback pulse is less than desirable and provides a discharge path for current in commutating capacitor 25 back to the B+ supply. In this manner a relatively constant amplitude flyback pulse is maintained.
FIG. 4 is a schematic diagram, partially in block form, of another well-known type of a regulator system which may be used in conjunction with the invention shown in FIG. 2. B+ is coupled through winding 18a of input choke 18 and through a series combination of windings 70a and 70b of a saturable reactor 70 and a parallel combination of a diode 72 and a resistor 74 to the horizontal deflection circuit 60. Diode 72 is poled to conduct current from the horizontal deflection circuit 60 to B+.
Flyback pulse variations are obtained from winding 38c of the horizontal output transformer 38 and applied to a voltage divider comprising resistors 76, 78 and 80 of the high voltage sensing and control circuit 42. A portion of the pulse produced by winding 38c is selected by the position of the wiper terminal on potentiometer 78 and coupled to the base electrode of a transistor 82 by means of a zener diode 84. The emitter electrode of transistor 82 is grounded and a DC stabilization resistor 85 is coupled in parallel with the base-emitter junction of transistor 82. When the pulse magnitude on winding 38c exceeds a level which results in forward biasing the base-emitter junction of transistor 82, current flows from B+ through a resistor 86, a winding 70c of saturable reactor 70 and transistor 82 to ground. Due to the exponential increase of current in winding 70c during the period of conduction of transistor 82, the duration of conduction of transistor 82 determines the magnitude of current flowing in winding 70c and thus the total inductance of windings 70a and 70b. The current in winding 70c is sustained during the remaining deflection period by means of a diode 88 coupled in parallel with winding 70c and poled not to conduct current from B+ to the collector electrode of transistor 82. A capacitor 90 coupled to the cathode of diode 88 provides a bypass for B+. Windings 70a and 70b are in parallel with input reactor 18a and thereby affect the total input inductance of the deflection circuit and thereby controls the transfer of energy to the deflection circuit. The dotted waveforms shown in conjunction with a curve 21' indicate variations from a nominal waveform provided at the input of horizontal deflection circuit 60 by the windings 70a and 70b.













FIG. 5 is a schematic diagram of yet another type of a regulator system which may be used in conjunction with the invention. B+ is coupled through a winding 92a and a winding 92b of a saturable reactor to the horizontal deflection circuit 60. Windings 92a and 92b are used to replace the input choke 18 shown in FIGS. 1 and 2 while also providing for a regulating function corresponding to that provided by regulating network 20.
Flyback pulse variations are obtained from winding 38c and applied to the high voltage sensing and control circuit 42 as in FIG. 4. Current flows from B+ through resistor 86, a winding 92c and transistor 82 to ground. As in FIG. 4 the duration of the conduction of transistor 82 determines the energy stored in winding 92c and thus the total inductance of windings 92a and 92b which control the amount of energy transferred to the deflection circuit during each horizontal deflection cycle. The variations in waveforms of curve 21', shown in conjunction with FIG. 4, are also provided at the input of horizontal deflection circuit 60 by windings 92a and 92b.
For various reasons including cost or performance, a manufacturer may wish to utilize a particular one of the regulators illustrated in FIGS. 3, 4 and 5. Regardless of the choice, the gating circuit according to the invention may be utilized therewith advantageously by providing improved performance and the possibility of cost savings by eliminating taps or extra windings on the wound components which heretofore normally provided a source of SCR gating waveforms.