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 !

Thursday, May 19, 2011

NORDMENDE SPECTRA SK2-COLOR TP8732 CHASSIS F5 INTERNAL VIEW.


















































































































The NORDMENDE CHASSIS F5 is the first chassis with completely modular design and it's introducing furthermore the 20AX inline PHILIPS CRT Technology!

The circuitry is higly sophisticated and it's complex even if it's modular.

This model series was introducing in 1976 the SK2 series which was standing for "System Kalt"
named as Cool system referring to low chassis temperature.
Was more related to the RGB OUTPUT amplifiers than the line / horizontal output wich is realized with THYRISTORS and for that it runs warm as any Thyristor line output stage.

(The only THYRISTORS Horizontal Deflection stages running almost really cool was that in GRUNDIG GSC600 AND GRUNDIG GSC700 CHASSIS which you can see Here at Obsolete technology Tellye museum [ search for it here ] ).

It was even introducing the 20AX CRT TUBE (PHILIPS) in models from 26 to 22 Inches but in few it was replaced by the VIDEOCOLOR P.I.L.

It runs warm despite that it was advertised as "System Kalt" which stays for cool system

indeed the line deflection stages and even other stages are at high power running and furthermore it's a 20AX system which requires high deflection currents.

So as any respectable CRT tellye it does his job in Warm style !

NORDMENDE CHASSIS F5 SCHEMATIC CIRCUIT DIAGRAM:












 

 















NORDMENDE CHASSIS F5 Supply circuit for a television receiver:
Isolated mains chassis thyristor technology:

A supply circuit for television receivers in which power source isolation is effected via a backward transformer. For the sake of achieving an insusceptibility to interferences, the operating frequency is equal to the line frequency. According to the invention, the supplied energy is controlled by varying the switch-on time during one period of the line frequency, in that the disconnecting time position is changed with the aid of a thyristor switching stage.





1. A supply circuit for a television receiver having a horizontal output stage including means for controlling line sweep and commutation, the energy required by said horizontal output stage being provided by a power source through a controllable supply circuit that isolates the power source from the horizontal output stage, said controllable supply circuit comprising:
an input transformer having a secondary winding connected to the horizontal output stage for providing the energy required thereby and a primary winding adapted for connection to the power source and being electrically isolated from the secondary winding and the horizontal output stage;
electronic switch means connected in series with the primary winding of the transformer;
first switching control means for switching on the electronic switch means as a function of line frequency; and
second switching control means for switching off the electronic switch means as a function of the energy required by the horizontal output stage, whereby the supply circuit provides the horizontal output stage with the required energy from the power source while also electrically isolating the horizontal output stage from the power source.


2. A supply circuit as described in claim 1, wherein the electronic switch means comprises a thyristor stage.

3. A supply circuit as described in claim 1, wherein the thyristor stage comprises a thyristor and a diode connected in inverse parallel manner, the gate electrode of the thyristor being connected to the first switching control means for turning on the thyristor.

4. A supply circuit as described in claim 3, wherein the first switching control means includes a horizontal deflection oscillator.

5. A supply circuit as described in claim 4, additionally comprising an isolation transformer connected between the thyristor gate and the horizontal deflection oscillator.

6. A supply circuit as described in claim 2, wherein the second switching control means comprises a series resonant circuit having an adjustable resonant frequency, said circuit being connected in parallel with the thyristor stage for causing commutation of the current in the thyristor stage.

7. A supply circuit as described in claim 6, wherein the series resonant circuit includes a transductor having a control winding, and the second switching control means additionally comprises a control circuit adapted to receive a signal from a high voltage transformer of the horizontal output stage and to provide in response thereto an output signal to the control winding of the transductor, said output signal varying in accordance with the signal from the high voltage transformer for varying the inductance of the transductor.

Description:
The present invention relates to a supply circuit for a television receiver in which, for effecting isolation of the power source , an input transformer serving the horizontal or line output stage, is operated as a backward transformer and in which, within the horizontal (line) output stage, there are taken off further voltages required for operating the television receiver.
Owing to the various attachments which are capable of being operated in connection with a television receiver, it has increasingly become necessary, for safety reasons, to provide for isolation of the power source the television receiver.
In conventional types of circuits employing backward transformers for effecting the source isolation, it is customary to control the energy supply by way of inserting a transistorized control stage.
The use of transistors in such a circuit part, however, has proved to be problematic owing to the fact that the transistors are sensitive to any case of exceeding the prescribed operational values.
From the German technical journal "Funkschau" 1975, No. 5, page 40 there has already become known a circuit employing a thyristor switching stage for controlling the energy supply. In this circuit, the operating frequency of the thyristor switching stage is dependent upon the operating frequency of the subsequently following horizontal (line) output stage; accordingly, there is concerned a so-called free-running switching stage.
In order to eliminate as far as possible the danger of noise influences as linked thereto, the actually advantageous thyristor switching stage involves a rather considerable investment.,
It is the object of the invention, therefore, with respect to a circuit of the type mentioned hereinbefore, to avoid the described disadvantages of the conventional arrangments, and to safeguard an operationally reliable control of the supplied energy.
This object is achieved in that the energy as supplied to the horizontal (line) output stage is capable of being controlled by means of a thyristor switching stage arranged in series with the primary winding of the input transformer, with first switching means, in dependence upon the line frequency, switching the thyristor switching stage to the conducting state, and with further switching means serving to block the thyristor switching stage in dependence upon the required energy.
Further details and advantages of the invention may be taken from the patent claims as well as from the following description of the accompanying drawing.
FIG. 1 shows one example of embodiment of the invention.
The horizontal output (final) stage 20 is connected via the input transformer 10 including the primary winding 11 and the secondary winding 12, to the source of supply current B.
As an example relating to the horizontal output (final) stage there is shown in FIG. 1 a thyristor circuit as described in the company publication "Deflection, Power Supply and Correction Circuits for 110° Color Picture Tube A67 - 150x with Toroidal Yoke", No. 59-72-E of Standard Elektrik Lorenz AG, dated Apr. 20, 1972.
By the input transformer 10, the horizontal output stage 20 is galvanically separated from the source of supply current B, i.e. also from the power source. The most important function units of the horizontal output stage will now be mentioned briefly hereinafter.
The reference numeral 21 indicates the schematically shown combined inductive component consisting of deflecting coils and EHT transformer.
The switching stage 22 consisting of a thyristor and of an anti-parallel connected diode, represents the stage controlling the line sweep while the similarly designed switching stage 23 is the so-called commutating switch.
Between these two switching stages there is connected the commutating inductive component 25 and the commutating capacitor consisting of a capacitor combination 26.
The electrical energy as required in the deflection circuit and the remaining circuit parts not shown herein, and connected to the horizontal output stage 20, is fed to this horizontal output (final) stage 20 in the way according to the invention to be explained hereinafter.
The primary circuit of the inductive component 10 designed as an input transformer, is connected to the supply source B, at the "plus" and "minus" terminals of which the rectified power source voltage is available. The input transformer 10 comprises the primary winding 11 and the secondary winding 12. In series with the primary winding 11 there is arranged a thyristor switching stage consisting of a thyristor 13 and of a diode 14, with both the thyristor and the diode being connected antiparallel.
The thyristor 13 is controlled in this case by inserting an isolating transformer 19, by the horizontal oscillator 18, which means to imply that the operating frequency of the supply circuit including the input transformer 10 is identical to that of the horizontal final stage 20.
The switch-on time position, i.e. the one at which the thyristor 13 is switched to the conducting state, is determined by the control pulse from the horizontal oscillator 18.
Disconnection of the thyristor 13 or switching to the non-conducting state, is effected in the usual way by a current reversal during the time interval in which e.g. the commutating switch 23 is blocked. This is effected by the series resonant circuit arranged in parallel with the thyristor switching stage, including the capacitor 16 and the inductive component 15, in cooperation with the diode 14. This disconnecting time position or the time position at which the thyristor 13 is switched to the non-conducting state, is determined by the resonant frequency of the series-resonant circuit. Accordingly, at a constant switch-on time position, it is possible to determine the period of time during which the thyristor 13 is switched to the conducting state, by varying the resonant frequency and, consequently, by shifting the time position at which the thyristor 13 is switched to the non-conducting state. The period of time during which the thyristor 13 is switched to the conducting state, and, consequently, the period of time of the current flow, however, are decisive for the amount of energy capable of being taken off the input transformer 10 or the secondary winding 12 respectively.
The aforementioned variation of the resonant frequency of the series-resonant circuit, may be carried out, on principle, by a capacitance variation of the capacitor 16, as well as by changing the inductance 15, or else by both.
In the shown example of embodiment there has been chosen a variation of the inductance, in which case, as an inductive component, a transductor is inserted in such a way that its operating winding is in series with the capacitor 16. Transductor 15 provides an inductance that varies in accordance with a DC signal applied thereto. If now, in accordance with stipulations, the energy supply is to be controlled in dependence upon the energy requirement, a corresponding control circuit will have to be provided for.
The energy consumed in the horizontal final stage can be measured by the value of the voltage of the kick-back pulse at the EHT transformer. In order to obtain this value, a tap 211 is schematically shown at the inductive component 21 of the horizontal final stage 20. This tap is connected to a control circuit 17.
As already mentioned, a transductor 15 is used as the adjustable inductive component of the series resonant circuit, whose inductance is capable of being varied by varying the current or voltage as applied to the control winding. At the same time, the transductor effects a galvanic separation. The control circuit 17 into the output circuit of which, according to FIG. 1, there is connected the control winding of the transductor 15, thus serves to convert the value of the voltage of the kickback pulse available as the input or control quantity, into a corresponding value for adjusting the inductive component 15.
Control circuits, such as e.g. 17, are on principle generally known to those skilled in the art and, therefore, do not need to be explained in detail herein, especially since the circuit-technical embodiment thereof is not germane to the present invention. An example of a control circuit that may be used for circuit 17 is shown in the publication previously referred to and entitled: "Deflection, Power Supply and Correction Circuits for 110° Color Picture Tube A67 - 150x with Toroidal Yoke".
It should still be mentioned that the input transformer 10 is operated as a backward transformer comprising a correspondingly polarized diode 24 in the secondary circuit, which is of advantage for reasons of dimensioning the input transformer 10.

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