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 Obsolete 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 !
All posts are presented here for informative, historical and educative purposes as applicable within Fair Use.


Wednesday, February 28, 2024

WHITE WESTINGHOUSE (FORMENTI) W342 16" CHASSIS V.C.182 INTERNAL VIEW

A very compact CHASSIS THE  CHASSIS  V.C.182  IN MULTI BOARD FASHION for that era and was used even for models of 20 Inches (51Cm) sets. The present invention have recognized, among other things, that a problem to be solved can include organizing, powering, and routing signals to or from various sections of  a tv color receiver. The present subject matter can help provide a solution to this problem, such as by providing a modular equipment chassis. Organizing, powering, and routing signals to and from the electronictv parts  can be challenging when there is limited space within a television set if it's of  a portable type.

Another challenge can include a lack of mounting locations to affix an electronic part  to the compex chassis. Yet another challenge is that each electronic part can have its own unique power requirements and/or a dedicated power supply that can further limit space available within the tv chassis. 

Another challenge can be dissipating or otherwise absorbing heat generated by multiple electronic part (and their respective power supplies) when such part  are mounted within a tv chassis and in close proximity to one another. Elevated temperatures can, in some instances, damage or compromise proper function of an electronic part. The aforementioned challenges and problems can be resolved by a modular equipment chassis like the here present the CHASSIS  V.C.182. 

70 14 654 01 (SYNC  + DEFLECTIONS + EHT PANEL)

70 14 653 02 (SUPPLY  PANEL)

70 14 655 01 (IF + VIDEO + HF PANEL)

 

 WHITE WESTINGHOUSE (FORMENTI)  W342 16"  CHASSIS  V.C.182  POWER SUPPLY.

What is a Flyback Transformer? The low cost, simplicity of design and intrinsic efficiency of flyback transformers have made them a popular solution for power supply designs of below 100W to 150W. Other advantages of the flyback transformer over circuits with similar topology include isolation between primary and secondary and the ability to provide multiple outputs and a choice of positive or negative voltage for the output.
Flyback transformer, or, line output transformers are a part of the power supplies in cathode ray tubes. The flyback transformer generates a high voltage, as needed by the CRT display or similar devices (e.g. plasma lamps). A flyback transformer generates a voltage between a few kilovolts to 50 kilovolts and uses high frequency switched currents between 17 kHz and 50 kHz.
The chief difference between a flyback transformer and main/audio transformer is that flybacks transfer as well as store energy, for a just a fraction of an entire switching period. The secret behind that is the coil winding on a ferrite core that has an air gap; it increases the magnetic circuit reluctance for storing the energy.
The reason it is called a flyback transformer is because the primary winding uses a relatively low-voltage saw-tooth wave. The wave gets strengthened first and then gets switched off abruptly; this causes the beam to fly back from right to left on the display.
Applications Cathode ray tube. Televisions. Plasma Lamps.
Any display requiring high voltage to operate and much more.

Highly and friendly serviceability we can see here, and it's not highly complex.

THE SIEMENS TDA 4600 Semiconductor circuit description  for supplying power to electrical equipment, comprising a transformer having a primary winding connected, via a parallel connection of a collector-emitter path of a transistor with a first capacitor, to both outputs of a rectifier circuit supplied, in turn, by a line a-c voltage; said transistor having a base controlled via a second capacitor by an output of a control circuit acted upon, in turn by the rectified a-c line voltage as actual value and by a reference voltage; said transformer having a first secondary winding to which the electrical equipment to be supplied is connected; said transformer having a second secondary winding with one terminal thereof connected to the emitter of said transistor and the other terminal thereof connected to an anode of a first diode leading to said control circuit; said transformer having a third secondary winding with one terminal thereof connected, on the one hand, via a series connection of a third capacitor with a first resistance, to the other terminal of said third secondary winding and connected, on the other hand, to the emitter of said transistor, the collector of which is connected to said primary winding; a point between said third capacitor and said first resistance being connected to the cathode of a second diode; said control circuit having nine terminals including a first terminal delivering a reference voltage and connected, via a voltage divider formed of a t

hird and fourth series-connected resistances, to the anode of said second diode; a second terminal of said control circuit serving for zero-crossing identification being connected via a fifth resistance to said cathode of said second diode; a third terminal of said control-circuit serving as actual value input being directly connected to a divider point of said voltage divider forming said connection of said first terminal of said control circuit to said anode of said second diode; a fourth terminal of said control circuit delivering a sawtooth voltage being connected via a sixth resistance to a terminal of said primary winding of said transformer facing away from said transistor; a fifth terminal of said control circuit serving as a protective input being connected, via a seventh resistance to the cathode of said first diode and, through the intermediary of said seventh resistance and an eighth resistance, to the cathode of a third diode having an anode connected to an input of said rectifier circuit; a sixth terminal of said control circuit carrying said reference potential and being connected via a fourth capacitor to said fourth terminal of said control circuit and via a fifth capacitor to the anode of said second diode; a seventh terminal of said control circuit establishing a potential for pulses controlling said transistor being connected directly and an eighth terminal of said control circuit effecting pulse control of the base of said transistor being connected through the intermediary of a ninth resistance to said first capacitor leading to the base of said transistor; and a ninth terminal of said control circuit serving as a power supply input of said control circuit being connected both to the cathode of said first diode as well as via the intermediary of a sixth capacitor to a terminal of said second secondary winding as well as to a terminal of said third secondary winding.


Description:
The invention relates to a blocking oscillator type switching power supply for supplying power to electrical equipment, wherein the primary winding of a transformer, in series with the emitter-collector path of a first bipolar transistor, is connected to a d-c voltage obtained by rectification of a line a-c voltage fed-in via two external supply terminals, and a secondary winding of the transformer is provided for supplying power to the electrical equipment, wherein, furthermore, the first bipolar transistor has a base controlled by the output of a control circuit which is acted upon in turn by the rectified a-c line voltage as actual value and by a set-point transmitter, and wherein a starting circuit for further control of the base of the first bipolar transistor is provided.
Such a blocking oscillator switching power supply is described in the German periodical, "Funkschau" (1975) No. 5, pages 40 to 44. It is well known that the purpose of such a circuit is to supply electronic equipment, for example, a television set, with stabilized and controlled supply voltages. Essential for such switching power supply is a power switching transistor i.e. a bipolar transistor with high switching speed and high reverse voltage. This transistor therefore constitutes an important component of the control element of the control circuit. Furthermore, a high operating frequency and a transformer intended for a high operating frequency are provided, because generally, a thorough separation of the equipment to be supplied from the supply naturally is desired. Such switching power supplies may be constructed either for synchronized or externally controlled operation or for non-synchronized or free-running operation. A blocking converter is understood to be a switching power supply in which power is delivered to the equipment to be supplied only if the switching transistor establishing the connection between the primary coil of the transformer and the rectified a-c voltage is cut off. The power delivered by the line rectifier to the primary coil of the transformer while the switching transistor is open, is interim-stored in the transformer and then delivered to the consumer on the secondary side of the transformer with the switching transistor cut off.
In the blocking converter described in the aforementioned reference in the literature, "Funkschau" (1975), No. 5, Pages 40 to 44, the power switching transistor is connected in the manner defined in the introduction to this application. In addition, a so-called starting circuit is provided. Because several diodes are generally provided in the overall circuit of a blocking oscillator according to the definition provided in the introduction hereto, it is necessary, in order not to damage these diodes, that due to the collector peak current in the case of a short circuit, no excessive stress of these diodes and possibly existing further sensitive circuit parts can occur.
Considering the operation of a blocking oscillator, this means that, in the event of a short circuit, the number of collector current pulses per unit time must be reduced. For this purpose, a control and regulating circuit is provided. Simultaneously, a starting circuit must bring the blocking converter back to normal operation when the equipment is switched on, and after disturbances, for example, in the event of a short circuit. The starting circuit shown in the literature reference "Funkschau" on Page 42 thereof, differs to some extent already from the conventional d-c starting circuits. It is commonly known for all heretofore known blocking oscillator circuits, however, that a thyristor or an equivalent circuit replacing the thyristor is essential for the operation of the control circuit.
It is accordingly an object of the invention to provide another starting circuit. It is a further object of the invention to provide a possible circuit for the control circuit which is particularly well suited for this purpose. It is yet another object of the invention to provide such a power supply which is assured of operation over the entire range of line voltages from 90 to 270 V a-c, while the secondary voltages and secondary load variations between no-load and short circuit are largely constant.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a blocking oscillator-type switching power supply for supplying power to electrical equipment wherein a primary winding of a transformer, in series with an emitter-collector path of a first bipolar transistor, is connected to a d-c voltage obtained by rectification of a line a-c voltage fed-in via two external supply terminals, a secondary winding of the transformer being connectible to the electrical equipment for supplying power thereto, the first bipolar transistor having a base controlled by the output of a control circuit acted upon, in turn, by the rectified a-c line voltage as actual value and by a set-point transmitter, and including a starting circuit for further control of the base of the first bipolar transistor, including a first diode in the starting circuit having an anode directly connected to one of the supply terminals supplied by the a-c line voltage and a cathode connected via a resistor to an input serving to supply power to the control circuit, the input being directly connected to a cathode of a second diode, the second diode having an anode connected to one terminal of another secondary winding of the transformer, the other secondary winding having another terminal connected to the emitter of the first bipolar transmitter.
In accordance with another feature of the invention, there is provided a second bipolar transistor having the same conduction type as that of the first bipolar transistor and connected in the starting circuit with the base thereof connected to a cathode of a semiconductor diode, the semiconductor diode having an anode connected to the emitter of the first bipolar transistor, the second bipolar transistor having a collector connected via a resistor to a cathode of the first diode in the starting circuit, and having an emitter connected to the input serving to supply power to the control circuit and also connected to the cathode of the second diode which is connected to the other secondary winding of the transformer.
In accordance with a further feature of the invention, the base of the second bipolar transistor is connected to a resistor and via the latter to one pole of a first capacitor, the anode of the first diode being connected to the other pole of the first capacitor.
In accordance with an added feature of the invention, the input serving to supply power to the control circuit is connected via a second capacitor to an output of a line rectifier, the output of the line rectifier being directly connected to the emitter of the first bipolar transistor.
In accordance with an additional feature of the invention, the other secondary winding is connected at one end to the emitter of the first bipolar transistor and to a pole of a third capacitor, the third capacitor having another pole connected, on the one hand, via a resistor, to the other end of the other secondary winding and, on the other hand, to a cathode of a third diode, the third diode having an anode connected via a potentiometer to an actual value input of the control circuit and, via a fourth capacitor, to the emitter of the first bipolar transistor.
In accordance with yet another feature of the invention, the control circuit has a control output connected via a fifth capacitor to the base of the first bipolar transistor for conducting to the latter control pulses generated in the control circuit.
In accordance with a concomitant feature of the invention, there is provided a sixth capacitor shunting the emitter-collector path of the first transistor.
Other features which are considered as characteristic for the invention are set forth in the appended claim.
Although the invention is illustrated and described herein as embodied in a blocking oscillator type switching power supply, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIGS. 1 and 2 are circuit diagrams of the blocking oscillator type switching power supply according to the invention; and

FIG. 3 is a circuit diagram of the control unit RS of FIGS. 1 and 2.

Referring now to the drawing and, first, particularly to FIG. 1 thereof, there is shown a rectifier circuit G in the form of a bridge current, which is acted upon by a line input represented by two supply terminals 1' and 2'. Rectifier outputs 3' and 4' are shunted by an emitter-collector path of an NPN power transistor T1 i.e. the series connection of the so-called first bipolar transistor referred to hereinbefore with a primary winding I of a transformer Tr. Together with the inductance of the transformer Tr, the capacitance C1 determines the frequency and limits the opening voltages of the switch embodied by the first transistor T1. A capacitance C2, provided between the base of the first transistor T1 and the control output 7,8 of a control circuit RS, separates the d-c potentials of the control or regulating circuit RS and the switching transistor T1 and serves for addressing this switching transistor T1 with pulses. A resistor R1 provided at the control output 7,8 of the control circuit RS is the negative-feedback resistor of both output stages of the control circuit RS. It determines the maximally possible output pulse current of the control circuit RS. A secondary winding II of the transformer Tr takes over the power supply of the control circuit, in steady state operation, via the diode D1. To this end, the cathode of this diode D1 is directly connected to a power supply input 9 of the control circuit RS, while the anode thereof is connected to one terminal of the secondary winding II. The other terminal of the secondary winding II is connected to the emitter of the power switching transistor T1.

The cathode of the diode D1 and, therewith, the power supply terminal 9 of the control circuits RS are furthermore connected to one pole of a capacitor C3, the other pole of which is connected to the output 3' of the rectifier G. The capacitance of this capacitor C3 thereby smoothes the positive half-wave pulses and serves simultaneously as an energy storage device during the starting period. Another secondary winding III of the transformer Tr is connected by one of the leads thereof likewise to the emitter of the first transistor T1, and by the other lead thereof via a resistor R2, to one of the poles of a further capacitor C4, the other pole of which is connected to the first-mentioned lead of the other secondary winding III. This second pole of the capacitor C4 is simultaneously connected to the output 3' of the rectifier circuit G and, thereby, via the capacitor C3, to the cathode of the diode D1 driven by the secondary winding II of the transformer Tr as well as to the power supply input 9 of the control circuit RS and, via a resistor R9, to the cathode of a second diode D4. The second pole of the capacitor C4 is simultaneously connected directly to the terminal 6 of the control circuit RS and, via a further capacitor C 6, to the terminal 4 of the control circuit RS as well as, additionally, via the resistor R6, to the other output 4' of the rectifier circuit G. The other of the poles of the capacitor C4 acted upon by the secondary winding II is connected via a further capacitor C5 to a node, which is connected on one side thereof, via a variable resistor R4, to the terminals 1 and 3 of the control circuit RS, with the intermediary of a fixed resistor R5 in the case of the terminal 1. On the other side of the node, the latter and, therefore, the capacitor C5 are connected to the anode of a third diode D2, the cathode of which is connected on the one hand, to the resistor R2 mentioned hereinbefore and leads to the secondary winding III of the transformer Tr and, on the other hand, via a resistor R3 to the terminal 2 of the control circuit RS.

The nine terminals of the control circuit RS have the following purposes or functions:

Terminal 1 supplies the internally generated reference voltage to ground i.e. the nominal or reference value required for the control or regulating process;

Terminal 2 serves as input for the oscillations provided by the secondary winding III, at the zero point of which, the pulse start of the driving pulse takes place;

Terminal 3 is the control input, at which the existing actual value is communicated to the control circuit RS, that actual value being generated by the rectified oscillations at the secondary winding III;

Terminal 4 is responsive to the occurrence of a maximum excursion i.e. when the largest current flows through the first transistor T1 ;

Terminal 5 is a protective input which responds if the rectified line voltage drops too sharply; Terminal 6 serves for the power supply of the control process and, indeed, as ground terminal;

Terminal 7 supplies the d-c component required for charging the coupling capacitor C2 leading to the base of the first transistor T1 ;

Terminal 8 supplies the control pulse required for the base of the first transistor T1 ; and

Terminal 9 serves as the first terminal of the power supply of the control circuit RS.

Further details of the control circuit RS are described hereinbelow.

The capacity C3 smoothes the positive half-wave pulses which are provided by the secondary winding II, and simultaneously serves as an energy storage device during the starting time. The secondary winding III generates the control voltage and is simultaneously used as feedback. The time delay stage R2 /C4 keeps harmonics and fast interference spikes away from the control circuit RS. The resistor R3 is provided as a voltage divider for the second terminal of the control circuit RS. The diode D2 rectifies the control pulses delivered by the secondary winding III. The capacity C5 smoothes the control voltage. A reference voltage Uref, which is referred to ground i.e. the potential of terminal 6 is present at the terminal 1 of the control circuit RS. The resistors R4 and R5 form a voltage divider of the input-difference control amplifier at the terminal 3. The desired secondary voltage can be set manually via the variable resistor R4. A time-delay stage R6 /C6 forms a sawtooth rise which corresponds to the collector current rise of the first bipolar transistor T1 via the primary winding I of the transformer Tr. The sawtooth present at the terminal 4 of the control circuit RS is limited there between the reference voltage 2 V and 4 V. The voltage divider R7 /R8 (FIG. 2), brings to the terminal 5 of the control circuit RS the enabling voltage for the drive pulse at the output 8 of the control circuit RS.

The diode D4, together with the resistor R9 in cooperation with the diode D1 and the secondary winding II, forms the starting circuit provided, in accordance with the invention. The operation thereof is as follows:

After the switching power supply is switched on, d-c voltages build up at the collector of the switching transistor T1 and at the input 4 of the control circuit RS, as a function in time of the predetermined time constants. The positive sinusoidal half-waves charge the capacitor C3 via the starting diode D4 and the starting resistor R9 in dependence upon the time constant R9.C3. Via the protective input terminal 5 and the resistor R11 not previously mentioned and forming the connection between the resistor R9 and the diode D1, on the one hand, and the terminal 5 of the control circuit RS, on the other hand, the control circuit RS is biased ready for switching-on, and the capacitor C2 is charged via the output 7. When a predetermined voltage value at the capacitor C3 or the power supply input 9 of the control circuit RS, respectively, is reached, the reference voltage i.e. the nominal value for the operation of the control voltage RS, is abruptly formed, which supplies all stages of the control circuit and appears at the output 1 thereof. Simultaneously, the switching transistor T1 is switched into conduction via the output 8. The switching of the transistor T1 at the primary winding T of the transformer Tr is transformed to the second secondary winding II, the capacity C3 being thereby charged up again via the diode D1. If sufficient energy is stored in the capacitor C3 and if the re-charge via the diode D1 is sufficient so that the voltage at a supply input 9 does not fall below the given minimum operating voltage, the switching power supply then remains connected, so that the starting process is completed. Otherwise, the starting process described is repeated several times.

In FIG. 2, there is shown a further embodiment of the circuit for a blocking oscillator type switching power supply, according to the invention, as shown in FIG. 1. Essential for this circuit of FIG. 2 is the presence of a second bipolar transistor T2 of the type of the first bipolar transistor T1 (i.e. in the embodiments of the invention, an npn-transistor), which forms a further component of the starting circuit and is connected with the collector-emitter path thereof between the resistor R9 of the starting circuit and the current supply input 9 of the control circuit RS. The base of this second transistor T2 is connected to a node which leads, on the one hand, via a resistor R10 to one electrode of a capacitor C7, the other electrode of which is connected to the anode of the diode D4 of the starting circuit and, accordingly, to the terminal 1' of the supply input of the switching power supply G. On the other hand, the last-mentioned node and, therefore, the base of the second transistor T2 are connected to the cathode of a Zener diode D3, the anode of which is connected to the output 3' of the rectifier G and, whereby, to one pole of the capacitor C3, the second pole of which is connected to the power supply input 9 of the control circuit RS as well as to the cathode of the diode D1 and to the emitter of the second transistor T2. In other respects, the circuit according to FIG. 2 corresponds to the circuit according to FIG. 1 except for the resistor R11 which is not necessary in the embodiment of FIG. 2, and the missing connection between the resistor R9 and the cathode of the diode D1, respectively, and the protective input 5 of the control circuit RS.

Regarding the operation of the starting circuit according to FIG. 2, it can be stated that the positive sinusoidal half-wave of the line voltage, delayed by the time delay stage C7, R10 drives the base of the transistor T2 in the starting circuit. The amplitude is limited by the diode D3 which is provided for overvoltage protection of the control circuit RS and which is preferably incorporated as a Zener diode. The second transistor T2 is switched into conduction. The capacity C3 is charged, via the serially connected diode D4 and the resistor R9 and the collector-emitter path of the transistor T2, as soon as the voltage between the terminal 9 and the terminal 6 of the control circuit RS i.e. the voltage U9, meets the condition U9 <[UDs -UBE (T2)].

Because of the time constant R9.C3, several positive half-waves are necessary in order to increase the voltage U9 at the supply terminal 9 of the control circuit RS to such an extent that the control circuit RS is energized. During the negative sine half-wave, a partial energy chargeback takes place from the capacitor C3 via the emitter-base path of the transistor T2 of the starting circuit and via the resistor R10 and the capacitor C7, respectively, into the supply network. At approximately 2/3 of the voltage U9, which is limited by the diode D3, the control circuit RS is switched on. At the terminal 1 thereof, the reference voltage Uref then appears. In addition, the voltage divider R5 /R4 becomes effective. At the terminal 3, the control amplifier receives the voltage forming the actual value, while the first bipolar transistor T1 of the blocking-oscillator type switching power supply is addressed pulsewise via the terminal 8.

Because the capacitor C6 is charged via the resistor R6, a higher voltage than Uref is present at the terminal 4 if the control circuit RS is activated. The control voltage then discharges the capacitor C6 via the terminal 4 to half the value of the reference voltage Uref, and immediately cuts off the addressing input 8 of the control circuit RS. The first driving pulse of the switching transistor T1 is thereby limited to a minimum of time. The power for switching-on the control circuit RS and for driving the transistor T1 is supplied by the capacitor C3. The voltage U9 at the capacitor C3 then drops. If the voltage U9 drops below the switching-off voltage value of the control circuit RS, the latter is then inactivated. The next positive sine half-wave would initiate the starting process again.

By switching the transistor T1, a voltage is transformed in the secondary winding II of the transformer Tr. The positive component is rectified by the diode D1, recharing of the capacitor C3 being thereby provided. The voltage U9 at the output 9 does not, therefore, drop below the minimum value required for the operation of the control circuit RS, so that the control circuit RS remains activated. The power supply continues to operate in the rhythm of the existing conditions. In operation, the voltage U9 at the supply terminal 9 of the control circuit RS has a value which meets the condition U9 >[UDs -UBE (T2)], so that the transistor T2 of the starting circuit remains cut off.

For the internal layout of the control circuit RS, the construction shown, in particular, from FIG. 3 is advisable. This construction is realized, for example, in the commercially available type TDA 4600 (Siemens AG).

The block diagram of the control circuit according to FIG. 3 shows the power supply thereof via the terminal 9, the output stage being supplied directly whereas all other stages are supplied via Uref. In the starting circuit, the individual subassemblies are supplied with power sequentially. The d-c output voltage potential of the base current gain i.e. the voltage for the terminal 8 of the control circuit RS, and the charging of the capacitor C2 via the terminal 7 are formed even before the reference voltage Uref appears. Variations of the supply voltage U9 at terminal 9 and the power fluctuations at the terminal 8/terminal 7 and at the terminal 1 of the control circuit RS are leveled or smoothed out by the voltage control. The temperature sensitivity of the control circuit RS and, in particular, the uneven heating of the output and input stages and input stages on the semiconductor chip containing the control circuit in monolithically integrated form are intercepted by the temperature compensation provided. The output values are constant in a specific temperature range. The message for blocking the output stage, if the supply voltage at the terminal 9 is too low, is given also by this subassembly to a provided control logic.

The outer voltage divider of the terminal 1 via the resistors R5 and R4 to the control tap U forms, via terminal 3, the variable side of the bridge for the control amplifier formed as a differential amplifier. The fixed bridge side is formed by the reference voltage Uref via an internal voltage divider. Similarly formed are circuit portions serving for the detection of an overload short circuit and circuit portions serving for the "standby" no-load detection, which can be operated likewise via terminal 3.

Within a provided trigger circuit, the driving pulse length is determined as a function of the sawtooth rise at the terminal 4, and is transmitted to the control logic. In the control logic, the commands of the trigger circuit are processed. Through the zero-crossing identification at input 2 in the control circuit RS, the control logic is enabled to start the control input only at the zero point of the frequency oscillation. If the voltages at the terminal 5 and at the terminal 9 are too low, the control logic blocks the output amplifier at the terminal 8. The output amplifier at the terminal 7 which is responsible for the base charge in the capacitor C2, is not touched thereby.

The base current gain for the transistor T1 i.e. for the first transistor in accordance with the definition of the invention, is formed by two amplifiers which mutually operate on the capacitor C2. The roof inclination of the base driving current for the transistor T1 is impressed by the collector current simulation at the terminal 4 to the amplifier at the terminal 8. The control pulse for the transistor T1 at the terminal 8 is always built up to the potential present at the terminal 7. The amplifier working into the terminal 7 ensures that each new switching pulse at the terminal 8 finds the required base level at terminal 7.

Supplementing the comments regarding FIG. 1, it should also be mentioned that the cathode of the diode D1 connected by the anode thereof to the one end of the secondary winding II of the transformer Tr is connected via a resistor R11 to the protective input 5 of the control circuit RS whereas, in the circuit according to FIG. 2, the protective input 5 of the control circuit RS is supplied via a voltage divider R8, R7 directly from the output 3', 4' of the rectifier G delivering the rectified line a-c voltage, and which obtains the voltage required for executing its function. It is evident that the first possible manner of driving the protective input 5 can be used also in the circuit according to FIG. 2, and the second possibility also in a circuit in accordance with FIG. 1.

The control circuit RS which is shown in FIG. 3 and is realized in detail by the building block TDA 4600 and which is particularly well suited in conjunction with the blocking oscillator type switching power supply according to the invention has 9 terminals 1-9, which have the following characteristics, as has been explained in essence hereinabove:

Terminal 1 delivers a reference voltage Uref which serves as the constant-current source of a voltage divider R5.R4 which supplies the required d-c voltages for the differential amplifiers provided for the functions control, overload detection, short-circuit detection and "standby"-no load detection. The dividing point of the voltage divider R5 -R4 is connected to the terminal 3 of the control circuit RS. The terminal 3 provided as the control input of RS is controlled in the manner described hereinabove as input for the actual value of the voltage to be controlled or regulated by the secondary winding III of the transformer Tr. With this input, the lengths of the control pulses for the switching transistor T1 are determined.

Via the input provided by the terminal 2 of the control circuit RS, the zero-point identification in the control circuit is addressed for detecting the zero-point of the oscillations respectively applied to the terminal 2. If this oscillation changes over to the positive part, then the addressing pulse controlling the switching transistor T1 via the terminal 8 is released in the control logic provided in the control circuit.

A sawtooth-shaped voltage, the rise of which corresponds to the collector current of the switching transistor T1, is present at the terminal 4 and is minimally and maximally limited by two reference voltages. The sawtooth voltage serves, on the one hand as a comparator for the pulse length while, on the other hand, the slope or rise thereof is used to obtain in the base current amplification for the switching transistor T1, via 

the terminal 8, a base drive of this switching transistor T1 which is proportional to the collector current.

The terminal 7 of the control circuit RS as explained hereinbefore, determines the voltage potential for the addressing pulses of the transistor T2. The base of the switching transistor T1 is pulse-controlled via the terminal 8, as described hereinbefore. Terminal 9 is connected as the power supply input of the control circuit RS. If a voltage level falls below a given value, the terminal 8 is blocked. If a given positive value of the voltage level is exceeded, the control circuit is activated. The terminal 5 releases the terminal 8 only if a given voltage potential is present.


Foreign References:
DE2417628A1 1975-10-23 363/37
DE2638225A1 1978-03-02 363/49
Other References:
Grundig Tech. Info. (Germany), vol. 28, No. 4, (1981).
IBM Technical Disclosure Bulletin, vol. 19, No. 3, pp. 978, 979, Aug. 1976.
German Periodical, "Funkschau", (1975), No. 5, pp. 40 to 44.
Inventors:

Peruth, Gunther (Munich, DE) Siemens Aktiengesellschaft (Berlin and Munich, DE)


 

 

 

A switching mode power supply (SMPS) may be used as an apparatus for supplying power to electronic products. The SMPS converts input alternating current (AC) voltages and outputs static voltages to operate electronic products.The present invention relates to a switched-mode power supply. Such a switched-mode power supply operates on the flyback converter principle, in which a switching transistor is switched through during a switched-on phase and magnetization is in consequence built up in a transformer, and the switching transistor is switched off during a switched-off phase and the magnetization is dissipated again via coupled windings of the transformer.
In a typical switch mode power supply (SMPS) of a television receiver, for example, the AC mains supply voltage is coupled directly to a bridge rectifier for producing an unregulated direct current (DC) input supply voltage that is, for example, referenced to a common conductor, referred to as "hot" ground, and that is conductively isolated from the cold ground conductor. A pulse width modulator controls the duty cycle of a chopper transistor switch that applies the unregulated supply voltage across a primary winding of an isolating flyback transformer. In principle a switched-mode power supply comprises at least the following components: a switch, an inductor, a rectifier, capacitor and a load. The load may be considered as a resistance which is in parallel with the capacitor. During the part of the period in which the switch conducts a current originating from the input voltage source passes through the inductor so that energy which is derived from this source is stored in the inductor. During the other part of the period, in which the switch is not conducting, the energy stored in the inductor produces a current through the rectifier which current recharges the capacitor and, consequently, replenishes the energy losses caused by the load. By the adjustment or control of the conducting period of the switch relative to the cycle, the output D.C. voltage across the load can be independent of variations of the input D.C. voltage, for example, it can be kept constant. Such variations are caused by, for example, fluctuations in the electric AC supply where the input voltage is derived therefrom by rectification. A flyback voltage at a frequency that is determined by the modulator is developed at a secondary winding of the transformer and is rectified to produce a DC output supply voltage such as a voltage B+ that energizes a horizontal deflection circuit of the television receiver. The primary winding of the flyback transformer is, for example, conductively coupled to the hot ground conductor. The secondary winding of the flyback transformer and voltage B+ may be conductively isolated from the hot ground conductor by the hot-cold barrier formed by the transformer. Such a switched mode power supply is generally called SMPS. A SMPS as it is commonly used, for example, in consumer devices like television receivers, video recorders, audio equipments etc. generally includes a main switching transistor connected in series with the primary winding of a transformer, a base drive circuit for periodically switching said switching transistor between ON and OFF, and a control circuit for controlling the base drive current for said main switching transistor in such a way that output voltages derived from several secondary windings of said transformer are stabilized.On the other hand such a SMPS generally includes a protection circuit for case of overloading or a short circuit or any other failures within the operating voltages. Said protection circuit is needed since without protection means the collector-emitter current of the main switching transistor can reach excessively high values in case of a failure which might damage said switching transistor or cause any other damages of circuit components.


For some uses a D.C. isolation between the input voltage source and the output voltage is absolutely required. This is the case, for example, with power supplies of television receivers especially where it is desirable to connect additional apparatus to the receiver, such as, for example, video storage devices or television game circuits. A switched-mode power supply is eminently suitable for this purpose as the transformer which must effect that isolation passes signals which usually have a much higher frequency, for example 15 to 20 kHz, than those of the electric AC supply source so that said transformer may be relatively small in size.
With a switched-mode power supply of the flyback converter type the inductor of the converter can be implemented in a simple manner as a transformer. A primary winding thereof is connected in series with the switch between the terminals of the input voltage source whereas a secondary winding is in series with the rectifier. The publication "Philips Application Information" 472: "properties of d.c.-to d.c. converters for switched-mode power supplies" of Mar. 18, 1975 describes such a circuit. Of the three types the flyback converter has the best control properties which is evidenced by the formula which expresses the output voltage as a function of the input voltage and of the ratio of the time of conduction of the switch to the entire cycle. However, it should be noted that the entire energy which is supplied to the load by a flyback converter must be passed on by the transformer which imposes higher requirements both on the transformer and, particularly, on the storage capacity thereof as well as on the switch.

SIEMENS TDA 4600-2 TDA 4600-2D
ControlIer for Switched-Mode Power Supplies / BipolarlC
In addition to their use with TV receivers and video recorders, the ICs TDA 4600-2 and TDA 4600-2 D can be applied in power supplied of hi-fi sets and active speakers due to their wide operational ranges and superior voltage stability during high load changes.

Features
• Direct driving of switching transistor
• Low start-up current
• Reversing linear overload characteristic
• Collector current - proportional to base-current input



 

 



TDA 4600-2 Circuit description
During start-up, normal and overload operations the TDA 4600-2; or -2D regulates, controls and protects the switching transistor installed in the flyback converter power supplies. 



I) Start-up operation 

The start-up operation is divided into three consecutive phases: 1. An internal reference voltage is built up which supplies the voltage regulator and effects the charging of the coupling electrolytic capaCitor and the switching transistor. During these procedures an 19 current less than 3.2 mA will be maintained, if the supply voltage Vg does not exceed", 12 V. 2. At Vg '" 12 V an internal reference voltage V1 = 4 V is suddenly released to provide all IC components with the exception of the control logic with a thermally stable and overload-resistant current. 3. In concurrence with the release of the reference voltage the control logic is activated by an additional stabilization circuit, and the IC is now ready for operation. Above sequential start-up phases ensure the charging of the switching transistor by the coupling electrolytic capacitor and subsequent precision switching.

II) Normal operation
Zero passages of the feedback coil are registered at pin 2 and forwarded to the control logic. At pin 3 (input control, overload, and standby recognition) the rectified amplitude variations of the feedback coil are applied. The regulating (control) amplifier operates with an input voltage of about 2 V and a current of about 1.4 mA. According to the internal reference voltage, ttie operating region of the regulating amplifier will be defined by the collector current simulation pin 4 and the overload recognition. The simulation of the collector current is generated by an external RC network at pin 4 and an internally set voltage level. By increasing the capacitance (10 nFl, the collector current of the switching transistor is increased as well and establishes the desired control range. The control range extends between a 2 V clamped dc voltage and an ac voltage rising as a sawtooth wave, which may vary up to a maximum amplitude of 4 V (reference voltage). By reducing the secondary load to 20 W, the switching frequency increases to about 50 kHz at an almost constant pulse duty factor (on-time to period approx. 1/3). During additional secondary load reduction to about 1 W, the switching frequency will change to approx. 70 kHz, while the pulse duty factor falls to approx. 1/11. At the same time, the collector peak current falls below 1 A. The output level of the regulating (control) amplifier, the overload recognition, and the collector current simulation are compared in the trigger and the control logic is instructed accordingly. Pin 5 will provide additional blocking alternatives, i.e. the output at pin 8 is blocked at a voltage of equal to or less than 2.2 Vat pin 5. Based on the start-up circuit, the zero crossing identification, and the trigger-activated release, the control logic flipflops are set which control both the base current amplification and shut-down. The base current amplifier forwards the sawtooth voltage V 4 to pin 8. Also, a current feedback with an external resistance of R "" 0.68 Q is inserted between pin 8 and pin 7. The resistance value determines the maximum amplitude of the base current for the switch ing transistor. III) Safety features The base current shut-down, released by the control logic, clamps the output of pin 7 at 1.6 V and thus blocks the driving of the switching transistor. This preventive method will go into effect, if the voltage at pin 9 falls below typo 7.4 V or if voltages of less than typo 22 V are present at pin 5. In case of short-circuited secondary windings in the SMPS, the fault condition will be continuously monitored by the IC. With the load completely removed from the secondary winding in the SMPS, the IC is set at a small pulse duty factor. The total power consumption of the SMPS is kept below n = 6 to 10 W during both operating conditions. After the output has been blocked at a supply voltage Vg of less than or equal to typo 7.4 V, an additional voltage reduction of .1V g = 0.6 V will switch off the reference voltage (4 V).




Thermal resistance (only applicable to TDA 4600-2 D)
Standardized, ambience-related thermal resistance Rth JA 1 versus lateral length 1of a square
copper-clad cooling area (35 IJ.m copper lamination).
Rth JA
 (I = 0) = 60 K/W
Tamb:S;; 70°C
Pv= 1 W
PCB in Ifertical position circuit in vertical position static air.


Measurement circuit 2 and application circuit

Measurement diagram for overload operations


Pin configuration
(TDA 4600-2: Plastic Power Package - 9 pin SIP package)
(TDA 4600-2D: Plastic 18 pin DIP package)
Pin No,
 Function
1 Vre! output

2 Zero passage identification

3 Input regulating amplifier, overload amplifier

4 Collector current simulation

5 Possible connection for additional protective circuit

6 Ground

7 DC voltage output for charging the coupling capacitor

8 Pulse output - driving the switching transistor

9 Current supply input

only applicable to TDA 4600-2 D
10
11
12
13
14
 interconnected (ground)
15
16
17
18

 GENERAL BASIC TRANSISTOR LINE OUTPUT STAGE OPERATION:

The basic essentials of a transistor line output stage are shown in Fig. 1(a). They comprise: a line output transformer which provides the d.c. feed to the line output transistor and serves mainly to generate the high -voltage pulse from which the e.h.t. is derived, and also in practice other supplies for various sections of the receiver; the line output transistor and its parallel efficiency diode which form a bidirectional switch; a tuning capacitor which resonates with the line output transformer primary winding and the scan coils to determine the flyback time; and the scan coils, with a series capacitor which provides a d.c. block and also serves to provide slight integration of the deflection current to compensate for the scan distortion that would otherwise be present due to the use of flat screen, wide deflection angle c.r.t.s. This basic circuit is widely used in small -screen portable receivers with little elaboration - some use a pnp output transistor however, with its collector connected to chassis.

Circuit Variations:
Variations to the basic circuit commonly found include: transposition of the scan coils and the correction capacitor; connection of the line output transformer primary winding and its e.h.t. overwinding in series; connection of the deflection components to a tap on the transformer to obtain correct matching of the components and conditions in the stage; use of a boost diode which operates in identical manner to the arrangement used in valve line output stages, thereby increasing the effective supply to the stage; omission of the efficiency diode where the stage is operated from an h.t. line, the collector -base junction of the line output transistor then providing the efficiency diode action without, in doing so, producing scan distortion; addition of inductors to provide linearity and width adjustment; use of a pair of series -connected line output transistors in some large -screen colour chassis; and in colour sets the addition of line convergence circuitry which is normally connected in series between the line scan coils and chassis. These variations on the basic circuit do not alter the basic mode of operation however.

Resonance
The most important fact to appreciate about the circuit is that when the transistor and diode are cut off during the flyback period - when the beam is being rapidly returned from the right-hand side of the screen to the left-hand side the tuning capacitor together with the scan coils and the primary winding of the line output transformer form a parallel resonant circuit: the equivalent circuit is shown in Fig. 1(b). The line output transformer primary winding and the tuning capacitor as drawn in Fig. 1(a) may look like a series tuned circuit, but from the signal point of view the end of the transformer primary winding connected to the power supply is earthy, giving the equivalent arrangement shown in Fig. 1(b).

The Flyback Period:
Since the operation of the circuit depends mainly upon what happens during the line flyback period, the simplest point at which to break into the scanning cycle is at the end of the forward scan, i.e. with the beam deflected to the right-hand side of the screen, see Fig. 2. At this point the line output transistor is suddenly switched off by the squarewave drive applied to its base. Prior to this action a linearly increasing current has been flowing in the line output transformer primary winding and the scan coils, and as a result magnetic fields have been built up around these components. When the transistor is switched off these fields collapse, maintaining a flow of current which rapidly decays to zero and returns the beam to the centre of the screen. This flow of current charges the tuning capacitor, and the voltage at A rises to a high positive value - of the order of 1- 2k V in large -screen sets, 200V in the case of mains/battery portable sets. The energy in the circuit is now stored in the tuning capacitor which next discharges, reversing the flow of current in the circuit with the result that the beam is rapidly deflected to the left-hand side of the screen - see Fig. 3. When the tuning capacitor has discharged, the voltage at A has fallen to zero and the circuit energy is once more stored in the form of magnetic fields around the inductive components. One half -cycle of oscillation has occurred, and the flyback is complete.

Energy Recovery:
First Part of Forward Scan The circuit then tries to continue the cycle of oscillation, i.e. the magnetic fields again collapse, maintaining a current flow which this time would charge the tuning capacitor negatively (upper plate). When the voltage at A reaches about -0.6V however the efficiency diode becomes forward biased and switches on. This damps the circuit, preventing further oscillation, but the magnetic fields continue to collapse and in doing so produce a linearly decaying current flow which provides the first part of the forward scan, the beam returning towards the centre of the screen - see Fig. 4. The diode shorts out the tuning capacitor but the scan correction capacitor charges during this period, its right-hand plate becoming positive with respect to its left-hand plate, i.e. point A. Completion of Forward Scan When the current falls to zero, the diode will switch off. Shortly before this state of affairs is reached however the transistor is switched on. In practice this is usually about a third of the way through the scan. The squarewave applied to its base drives it rapidly to saturation, clamping the voltage at point A at a small positive value - the collector emitter saturation voltage of the transistor. Current now flows via the transistor and the primary winding of the line output transformer, the scan correction capacitor discharges, and the resultant flow of current in the line scan coils drives the beam to the right-hand side of the screen see Fig. 5.

Efficiency:
The transistor is then cut off again, to give the flyback, and the cycle of events recurs. The efficiency of the circuit is high since there is negligible resistance present. Energy is fed into the circuit in the form of the magnetic fields that build up when the output transistor is switched on. This action connects the line output transformer primary winding across the supply, and as a result a linearly increasing current flows through it. Since the width is
dependent on the supply voltage, this must be stabilised.

Harmonic Tuning:
There is another oscillatory action in the circuit during the flyback period. The considerable leakage inductance between the primary and the e.h.t. windings of the line output transformer, and the appreciable self -capacitance present, form a tuned circuit which is shocked into oscillation by the flyback pulse. Unless this oscillation is controlled, it will continue into and modulate the scan. The technique used to overcome this effect is to tune the leakage inductance and the associated capacitance to an odd harmonic of the line flyback oscillation frequency. By doing this the oscillatory actions present at the beginning of the scan cancel. Either third or fifth harmonic tuning is used. Third harmonic tuning also has the effect of increasing the amplitude of the e.h.t. pulse, and is generally used where a half -wave e.h.t. rectifier is employed. Fifth harmonic tuning results in a flat-topped e.h.t. pulse, giving improved e.h.t. regulation, and is generally used where an e.h.t. tripler is employed to produce the e.h.t. The tuning is mainly built into the line output transformer, though an external variable inductance is commonly found in colour chassis so that the tuning can be adjusted. With a following post I will go into the subject of modern TV line timebases in greater detail with other models and technology shown here at  Obsolete Technology Tellye !

CHASSIS   Simplified horizontal /  line deflection circuit.
-----------------------------------------------------------------------------------------------

A horizontal deflection circuit makes a sawtooth
current flow through a deflection coil. The current
will have equal amounts of positive and negative
current. The horizontal switch transistor conducts
for the right hand side of the picture. The damper
diode conducts for the left side of the picture.
Current only flows through the fly back capacitor
during retrace time.



For time 1 the transistor is turned on. Current
ramps up in the yoke. The beam is moved from the
center of the picture to the right edge. Energy is
stored on the inductance of the yoke.
E=I2L/2


For time 2 the transistor is turned off. Energy
transfers from the yoke to the flyback capacitor. At
the end of time two all the energy from the yoke is
placed on the flyback capacitor. There is zero
current in the yoke and a large voltage on the
capacitor. The beam is quickly moved from the
right edge back to the middle of the picture.









During time 3 the energy on the capacitor flows
back into the yoke. The voltage on the flyback
capacitor decreases while the current in the yoke
builds until there is no voltage on the capacitor. By
the end of time 3 the yoke current is at it's
maximum amount but in the negative direction.
The beam is quickly deflected form the center to the
left edge.






Time 4 represents the left hand half of the picture.
Yoke current is negative and ramping down. The
beam moves from the left to the center of the
picture.












The current that flows when the horizontal switch is
closed is approximately:
Ipk ≅ Vcc T / Ldy
Ipk = collector current
T = 1/2 trace time
Ldy = total inductance (yoke + lin coil + size coil)
note:The lin coil inductance varies with current.
______
Tr ≅ 3.14 √ L C
The current that flows during retrace is produced by
the C and L oscillation. The retrace time is 1/2 the
oscillation frequency of the L and C.
I2L /2 ≅ V2C /2 or I2L = V2C As stated earlier the energy in the yoke moves to the
flyback capacitor during time 2.
V= the amount of the flyback pulse that is above the
supply voltage.


D.C. annualizes is inductors are considered
shores, capacitors are open and generally
semiconductors are removed. The voltage at the
point “B+” is the supply voltage. The collector
voltage of Q1 is also at the supply voltage. The
voltage across C2 is equal to the supply voltage.
When we A.C. annualize this circuit we will find
that the collector of Q1 has a voltage that ranges
from slightly negative to 1000 volts positive. The
average voltage must remain the same as the D.C.
value.
In the A.C. annualizes of the circuit, the
inductance of the yoke (DY) and the inductance of
the flyback transformer are in parallel. The
inductance of T2 is much larger than that if the
DY. This results is a total system inductance of
about 10% to 20% less than that of the DY it’s
self.
The voltage across the Q1 is a half sinusoid pulse during the flyback or retrace period and close to zero at
all other times. It is not possible or safe to observe this point on an oscilloscope without a proper high
frequency high voltage probe. Normally use a 100:1 probe suitable for 2,000V peak. The probe must have
been high frequency calibrated recently.

VIDEO CHROMA PROCESSING WITH TDA3300 (MOTOROLA)




TDA3300 3301 TV COLOR PROCESSOR

This device will accept a PAL or NTSC composite video signal and output the
three color signals, needing only a simple driver amplifier to interface to the pic-
ture tube. The provision of high bandwidth on-screen display inputs makes it
suitable for text display, TV games, cameras, etc. The TDA3301 B has user con»
trol laws, and also a phase shift control which operates in PAL, as well as NTSC.
0 Automatic Black Level Setup
0 Beam Current Limiting
0 Uses Inexpensive 4.43 MHZ to 3.58 MHz Crystal
0 No Oscillator Adjustment Required
0 Three OSD Inputs Plus Fast Blanking Input
0 Four DC, High Impedance User Controls
0 lnterlaces with TDA33030B SECAM Adaptor
0 Single 12 V Supply
0 Low Dissipation, Typically 600 mW
The brilliance control operates by adding a pedestal to the output
signals. The amplitude of the pedestal is controlled by Pin 30.
During CRT beam current sampling a standard pedestal is
substituted, its value being equivalent tothe value given by V30 Nom
Brightness at black level with V30 Nom is given by the sum of three gun
currents at the sampling level, i.e. 3x20 |.1A with 100 k reference
resistors on Pins 16, 19, and 22.
During picture blanking the brilliance pedestal is zero; therefore, the
output voltage during blanking is always the minimum brilliance black
level (Note: Signal channels are also gain blanked).

Chrominance Decoder
The chrominance decoder section of the TDA3301 B
consists of the following blocks:
Phase-locked reference oscillator;
Phase-locked 90 degree servo loop;
U and V axis decoders
ACC detector and identification detector; .
Identification circuits and PAL bistable; .
Color difference filters and matrixes with fast blanking
Circuits.
The major design considerations apart from optimum
performance were:
o A minimum number of factory adjustments,
o A minimum number of external components,
0 Compatibility with SECAM adapter TDA3030B,
0 Low dissipation,
0 Use of a standard 4.433618 Mhz crystal rather
than a 2.0 fc crystal with a divider.

The crystal VCO is of the phase shift variety in which the
frequency is controlled by varying the phase of the feedback.
A great deal of care was taken to ensure that the oscillator loop
gain and the crystal loading impedance were held constant in
order to ensure that the circuit functions well with low grade
crystal (crystals having high magnitude spurious responses
can cause bad phase jitter). lt is also necessary to ensure that
the gain at third harmonic is low enough to ensure absence of
oscillation at this frequency.

It can be seen that the
necessary 1 45°C phase shift is obtained by variable addition
ol two currents I1 and I2 which are then fed into the load
resistance of the crystal tuned circuit R1. Feedback is taken
from the crystal load capacitance which gives a voltage of VF
lagging the crystal current by 90°.
The RC network in the T1 collector causes I1 to lag the
collector current of T1 by 45°.
For SECAM operation, the currents I1 and I2 are added
together in a fixed ratio giving a frequency close to nominal.
When decoding PAL there are two departures from normal
chroma reference regeneration practice:
a) The loop is locked to the burst entering from the PAL
delay line matrix U channel and hence there is no
alternating component. A small improvement in signal
noise ratio is gained but more important is that the loop
filter is not compromised by the 7.8 kHz component
normally required at this point for PAL identification
b) The H/2 switching of the oscillator phase is carried out
before the phase detector. This implies any error signal
from the phase detector is a signal at 7.8 kHz and not dc.
A commutator at the phase detector output also driven
from the PAL bistable coverts this ac signal to a dc prior
to the loop filter. The purpose ot this is that constant
offsets in the phase detector are converted by the
commutator to a signal at 7.8 kHz which is integrated to
zero and does not give a phase error.
When used for decoding NTSC the bistable is inhibited, and
slightly less accurate phasing is achieved; however, as a hue
control is used on NTSC this cannot be considered to be a
serious disadvantage.


90° Reference Generation
To generate the U axis reference a variable all-pass network
is utilized in a servo loop. The output of the all-pass network
is compared with the oscillator output with a phase detector of
which the output is filtered and corrects the operating point of
the variable all»pass network .
As with the reference loop the oscillator signal is taken after
the H/2 phase switch and a commutator inserted before the
filter so that constant phase detector errors are cancelled.
For SECAM operation the loop filter is grounded causing
near zero phase shift so that the two synchronous detectors
work in phase and not in quadralure.
The use of a 4.4 MHz oscillator and a servo loop to generate
the required 90° reference signal allows the use of a standard,
high volume, low cost crystal and gives an extremely accurate
90° which may be easily switched to 0° for decoding AM
SECAM generated by the TDA3030B adapter.

ACC and Identification Detectors
During burst gate time the output components of the U and
also the V demodulators are steered into PNP emitters. One
collector current of each PNP pair is mirrored and balanced
against its twin giving push-pull current sources for driving the
ACC and the identification filter capacitors.
The identification detector is given an internal offset by
making the NPN current mirror emitter resistors unequal. The
resistors are offset by 5% such that the identification detector
pulls up on its filter capacitor with zero signal.
Identification
See Figure 11 for definitions.
Monochrome I1 > I2
PAL ldent. OK I1 < lg
PAL ldent_ X l1 > I2
NTSC I3 > I2
Only for correctly identified PAL signal is the capacitor
voltage held low since I2 is then greater than I1.
For monochrome and incorrectly identified PAL signals l1>l2
hence voltage VC rises with each burst gate pulse.
When V,ef1 is exceeded by 0.7 V Latch 1 is made to conduct
which increases the rate of voltage rise on C. Maximum
current is limited by R1.
When Vref2 is exceeded by 0.7 V then Latch 2 is made to
conduct until C is completely discharged and the current drops
to a value insufficient to hold on Latch 2.
As Latch 2 turns on Latch 1 must turn off.
Latch 2 turning on gives extra trigger pulse to bistable to
correct identification.
The inhibit line on Latch 2 restricts its conduction to alternate
lines as controlled by the bistable. This function allows the
SECAM switching line to inhibit the bistable operation by firing
Latch 2 in the correct phase for SECAM. For NTSC, Latch 2
is fired by a current injected on Pin 6.
lf the voltage on C is greater than 1.4 V, then the saturation
is held down. Only for SECAM/NTSC with Latch 2 on, or
correctly identified PAL, can the saturation control be
anywhere but minimum.
NTSC Switch
NTSC operation is selected when current (I3) is injected into
Pin 6. On the TDA33O1 B this current must be derived
externally by connecting Pin 6 to +12 V via a 27 k resistor (as
on TDA33OOB). For normal PAL operation Pin 40 should be
connected to +12 V and Pin 6 to the filter capacitor.

4 Color Difference Matrixing, Color Killing,
and Chroma Blanking
During picture time the two demodulators feed simple RC
filters with emitter follower outputs. Color killing and blanking
is performed by lifting these outputs to a voltage above the
maximum value that the color difference signal could supply.
The color difference matrixing is performed by two
differential amplifiers, each with one side split to give the
correct values of the -(B-Y) and -(Ft-Y) signals. These are
added to give the (G-Y) signal.
The three color difference signals are then taken to the
virtual grounds of the video output stages together with
luminance signal.
Sandcastle Selection
The TDA3301B may be used with a two level sandcastle
and a separate frame pulse to Pin 28, or with only a three level
(super) sandcastle. In the latter case, a resistor of 1.0 MQ is
necessary from + 12 V to Pin 28 and a 70 pF capacitor from
Pin 28 to ground.


Timing Counter for Sample Control
In order to control beam current sampling at the beginning
of each frame scan, two edge triggered flip-flops are used.
The output K ofthe first flip-flop A is used to clock the second
tlip-flop B. Clocking of A by the burst gate is inhibited by a count
of A.B.
The count sequence can only be initiated by the trailing
edge of the frame pulse. ln order to provide control signals for:
Luma/Chroma blanking
Beam current sampling
On-screen display blanking
Brilliance control
The appropriate flip-flop outputs ar matrixed with sandcastle
and frame signals by an emitter-follower matrix.

Video Output Sections
Each video output stage consists of a feedback amplifier in A further drive current is used to control the DC operating
which the input signal is a current drive to the virtual earth from point; this is derived from the sample and hold stage which
the luminance, color difference and on-screen display stages. samples the beam current after frame flyback.


 TDA2541 IF AMPLIFIER WITH DEMODULATOR AND AFC

DESCRIPTION
The TDA2540 and 2541 are IF amplifier and A.M.
demodulator circuits for colour and black and white
television receivers using PNP or NPN tuners. They
are intended for reception of negative or positive
modulation CCIR standard.
They incorporate the following functions : .Gain controlled amplifier .Synchronous demodulator .White spot inverter .Video preamplifier with noise protection .Switchable AFC .AGC with noise gating .Tuner AGC output (NPN tuner for 2540)-(PNP
tuner for 2541) .VCR switch for video output inhibition (VCR
play back).
An automatic fine tuning (AFT) circuit is provided which generates an AFT control signal in response to a video intermediate frequency (I.F.) signal. The I.F. signal is supplied to the inputs of two buffer amplifiers, which couple signals of like phase relationship to two inputs of a discriminator network. The discriminator network is tuned to the desired frequency of the video I.F. signal, and is responsive to the buffered I.F. signals for causing respective signal voltages to be developed at its inputs which vary differentially in magnitude in response to the frequency deviation of the I.F. signals from the desired I.F. frequency. The differentially related signals are detected by two peak detector networks for use as AFT control signals. The buffer amplifiers and peak detectors may be conveniently fabricated on a single I.C. chip. The discriminator network is coupled to the buffer amplifiers by two external I.C. terminals. 

WHITE WESTINGHOUSE (FORMENTI)  W342 16"  CHASSIS  V.C.182  Digital phase locked loop tuning system / PLL FREQUENCY SYNTHESIZER:

A phase locked loop circuit for use in an automatic frequency synthesizing system. The system includes a programmer circuit which is responsive to a channel number input signal and generates a first digital control signal which is representative of the selected channel number and a second digital control signal which is representative of a predetermined group of channel numbers. A programmable divider is controlled by the programming circuit and generates a digital output signal which causes the phase locked loop circuit to generate a desired system output frequency corresponding to the selected channel number input signal. The phase locked loop circuit includes automatic fine tuning and manual fine tuning features.


1. A digital phase locked loop tuning system responsive to a local oscillator signal for producing a frequency synthesized digital output signal which is utilized to control the frequency of the local oscillator, the local oscillator having a plurality of frequencies associated therewith corresponding, respectively, to a plurality of selectable channels, each of the channels being allocated to one of at least two channel groups with each channel in a particular channel group being separated from an adjacent channel in the particular channel group by a predetermined frequency spacing of the local oscillator, comprising:
programming means responsive to an input signal representing a selected channel number of a particular channel group for generating a first digital control signal having a value corresponding to the selected channel number and for generating a second digital control signal representative of said particular channel group, said second digital control signal being a constant predetermined value for all of said channel numbers that are within said group; and
programmable divider means coupled to said programming means being responsive to said first, second digital control signals and the local oscillator signal, in a local oscillator mode, for generating the digital output signal which is representative of a desired frequency corresponding to said selected channel number, said programmable divider means including means for dividing the local oscillator signal by first and second factors, said first factor being related to the frequency separation between local oscillator signals by an integral number, the local oscillator signal being divided by said first factor during a first interval for a first number of periods of the output signal and being divided by said second factor for a second number of periods of the output signal, said first number of periods being related to the number of the channel selected, said second number being related to the channel group within which the selected channel lies.


2. Phase locked loop system according to claim 1, wherein said programming means including means coupled to said programming means for receiving an MFT signal and being responsive to said MFT signal for altering said first and second digital control signals, and said programmable divider means being responsive to said altered digital control signals for generating an altered system output frequency.

3. Phase locked loop system according to claim 2, wherein said programming means includes first terminal means coupled to said programming means for receiving an AFT control signal, and first logic means responsive to the input signal and the AFT control signal for generating the first digital control signal.

4. Phase locked loop system according to claim 3, wherein said programming means includes second logic means coupled to said first logic means and responsive to the AFT control signal for generating the second digital control signal.

5. Phase locked loop system according to claim 4, wherein said second logic means includes group decoder means coupled to said first logic means.

6. Phase locked loop circuit means according to claim 5, wherein said second logic means includes memory means coupled to said group decoder means and to said first terminal means.

7. Phase locked loop system according to claim 6, wherein said second logic means includes second terminal means for receiving an MFT signal, and up/down counter latch means coupled to said memory means and to said second terminal means for altering said first and second digital control signals in response to said MFT signal.

8. Phase locked loop system according to claim 7, wherein said second logic means includes adder means coupled to said up/down counter latch means to said memory means.

9. Phase locked loop system according to claim 3, wherein said first logic means includes channel number generator means coupled to said first terminal means and responsive to said input signal.

10. Phase locked loop system according to claim 9, wherein said channel number generator means includes first and second data selector means coupled to said first terminal means, and adder means coupled to said second data selector means and to said up/down counter latch means.

11. Phase locked loop system according to claim 1, wherein said means for dividing the local oscillator signal includes programmable counter means for generating a modulus control output signal, and variable modulus prescaler divider means coupled to and responsive to said programmable counter means, said variable modulus prescaler divider means dividing the local oscillator signal by said first and second factors.

12. Phase locked loop system according to claim 11, wherein said programmable counter means includes third data selector means coupled to receive said first and second digital control signals and said modulus control signal.

13. Phase locked loop system according to claim 12, wherein said programmable counter means includes a programmable counter coupled to said third data selector means and to said variable modulus prescaler divider means.

14. Phase locked loop system according to claim 13, wherein said programmable counter means includes look ahead circuit means coupled to said programmable counter, and divide by two circuit means coupled to said look ahead circuit means for generating said modulus control output signal.

15. Phase locked loop tuning system according to claim 1 including digital automatic fine tuning (AFT) means wherein:
said programmable divider means includes switching means responsive to an AFT control signal to inhibit the local oscillator signal to said programmable divider means and to provide an input signal thereto of a different frequency than the local oscillator signal; and
said programming means including logic means responsive to said AFT control signal for altering said first and second digital control signals to predetermined values to cause the phase locked loop tuning system to be operable in an automatic fine tuning mode.


16. Phase locked loop tuning system of claim 15 wherein said programmable divider means includes:
programmable counter means for generating first and second modulus control signals; and
dual modulus prescaler means responsive to said first modulus control signal for dividing the local oscillator signal in said local oscillator mode and said input signal of a different frequency in said automatic fine tuning mode by said first factor which is equal to the integer six and being responsive to said second modulus control signal for dividing said local oscillator signal and said input signal of a different frequency by said second factor which is equal to the integer five respectively.


17. Phase locked loop tuning system of claim 16 wherein said signal of a different frequency is an intermediate frequency signal provided by the tuning system and supplied to said switching means.

18. In a phase locked loop tuning system for receiving a channel number input signal and a local oscillator signal having groups of selectable frequencies wherein the frequency spacing between each adjacent local oscillator frequency within a single group is uniform, the improvement comprising programmable divider means for generating a digital output signal representative of a desired tuning system output frequency including variable modulus prescaler divider means having a prescaler division ratio being equal to P = S/Y' for dividing the local oscillator frequency by said prescaler division ratio during a first interval for a first number of periods of the digital output signal and for dividing the local oscillator frequency by a second prescaler division ratio during a second interval for a second number of periods, said second ratio being related to said first ratio, where S is the frequency spacing between each adjacent local oscillator frequency within a single group (i), Yi =Di -Xi S, where Di is said desired tuning system output frequency within said selected group; Xi =Di /S rounded off to the nearest integer; Y' is chosen such that Yi /Y' is an integer and S/Y' is an integer and Y' is the smallest value of all values of Yi.

19. In a receiver including a tuning apparatus for providing a plurality of local oscillator signals each corresponding to a respective one of a plurality of selectable channels, each of the channels being allocated to one of at least two channel groups wherein each channel is separated from an adjacent channel in the respective channel group by a predetermined frequency spacing, a phase locked loop tuning system for producing a frequency synthesized output signal for controlling the frequency of the local oscillator, comprising:
variable modulus divider means for selectively dividing the frequency of the local oscillator signal by first and second factors in response to a modulus control signal to provide an output signal, said first factor being related to the frequency separation between local oscillator signals by an integral number; and
programmable means for generating said modulus control signal to cause said variable modulus divider means to divide by said first factor during a first interval for a first number of periods of said output signal and to divide by said second factor during a second interval for a second number of periods of said output signal, said first number of periods being related to the number of the channel selected, said second number of periods being related to the channel group corresponding to the selected channel.


20. The phase locked loop tuning system of claim 19 wherein said programmable means includes:
programming means responsive to a selected channel input signal for producing first and second digital output signals, said first digital output signal being related to the selected channel number plus one of two constant values which are determined in accordance within which channel group the selected channel input signal lies, said second digital signal being a constant value for all selected channels within a channel group; and
programmable divider means responsive to said first and second digital output signals from said programming means for providing said variable modulus control signal and the frequency synthesized output signal.


21. The phase locked loop tuning system of claim 20 wherein said programming means includes automatic fine tuning (AFT) means responsive to a AFT control signal being applied thereto when the receiver is placed in an AFT mode wherein:
said variable modulus divider means is caused to receive a input signal different from the local oscillator signal;
said programming means being responsive to the AFT control signal for altering said first and second digital signals such that the receiver is finely tuned to the frequency of the received signal applied to the receiver.


22. The phase locked loop tuning system of claim 21 wherein said programming means includes means for receiving a manual fine tuning (MFT) signal for altering said first and second digital output signals, and said programmable divider means being responsive to said altered digital control signals for generating an altered output signal.

23. The phase locked loop tuning system of claim 19 wherein the one of said first and second factors is an even number and the other is an odd number.

24. The phase locked loop tuning system of claim 23 wherein said first factor is the integer six and said second factor is the integer five.

Description:
BACKGROUND OF THE INVENTION
This invention relates to digital tuning systems, and more particularly, to a simplified digital phase locked loop (PLL) tuning system incorporating unique digital automatic fine tuning and manual fine tuning schemes.
Since the appearance of varactor tuners for television, many tuning address schemes have evolved for controlling them. PLL techniques have maintained a performance advantage but have suffered a cost disadvantage due to complexity, the high frequencies involved, the need for automatic fine tuning and in some localities, the need for a manual fine tuning arrangement. With the advances that have taken place in semiconductor technology in the last several years, the high operating frequencies no longer present a significant problem.
Prior art PLL systems for use in television tuners have not yet been able to incorporate an automatic fine tuning feature, nor have they been able to incorporate a manual fine tuning system which would enable the PLL tuning system to be intentionally offset in predetermined increments. Television sets normally have an automatic fine tuning (AFT) feature, but this is normally incorporated as a separate circuit which is not directly incorporated into the television tuner.

An additional disadvantage of prior art PLL systems which are designed for use in a television tuner environment is that they are highly complex and relatively expensive. In order to convert the channel number input into the proper digital control signals for the PLL, a relatively large ROM having a capacity on the order of 82 words by 12 bits was required. The best prior art PLL tuning systems require two high speed programmable counters which greatly increase the system complexity. This together with the large ROM which the system required, greatly decreased the cost effectiveness of the system so that commercial manufacturers were able to use these prior art PLL systems only in their most expensive commercial television receivers.
Therefore, it is a feature of this invention to provide a digital PLL tuning system which incorporates design techniques that vastly simplify the complexity of the PLL while at the same time allowing the system to meet the latest needs of a television tuning system or any other PLL tuning system which is addressed by a channel number.
It is another feature of this invention to provide a digital PLL tuning system that has the ability to automatically tune nonprecise station frequencies and the ability to be manually fine tuned.
It is yet another feature of the present invention to provide a digital PLL tuning system having only a single high speed programmable counter and requiring a ROM capacity of only 5 words by 9 bits.
It is still another feature of this invention to provide a digital PLL tuning system which performs the automatic fine tuning feature by utilizing the PLL tuning system as a digital discriminator.
It is yet another feature of this invention to provide a digital PLL tuning system incorporating a manual fine tuning (MFT) arrangement which is capable of intentionally offsetting the local oscillator frequency of a TV tuner in one megahertz steps or of offsetting TV IF frequency in steps of 125 kilohertz. 


SUMMARY OF THE INVENTION
The preferred embodiment of the present invention includes a phase locked loop circuit means for an automatic frequency synthesizing system. The phase locked loop circuit means includes programming means which is responsive to an input signal representing a selected channel number for generating a first digital control signal representative of the selected channel number and for generating a second digital control signal representative of a predetermined group of channel numbers. A programmable divider means is coupled to the first and second digital control signals and generates a digital output signal representative of a desired system output frequency corresponding to the selected channel number.
The phase locked loop circuit means further includes an automatic fine tuning feature for fine tuning the phase locked loop output frequency to the exact frequency of the received signal. The system further includes a manual fine tuning provision which allows the phase locked loop operating frequency to be intentionally offset in predetermined increments.

PHILIPS TDA2594 HORIZONTAL COMBINATION

 The PHILIPS TDA2594 is a monolithic integrated circuit intended for use in colour television receivers.
The circuit incorporates the following functions:
0 Horizontal oscillator based on the threshold switching principle.
0 Phase comparison between sync pulse and oscillator voltage (tp1).
0 Internal key pulse for phase detector (-D) fYP~ ‘I V
V3-1elp-pl WP- 1° V

* Permissible range: 1 t








Field Timebase IC :
The TDA1170 field timebase i.c. is shown in block diagram form in Fig. 3. The i.c. is housed in a 12 -pin package with copper frame and heat dissipation tabs. It is capable of supplying up to 1.6A peak -to -peak to drive any type of saddle -wound scanning yoke but for a colour receiver it is suggested that the toroidal deflection coil system developed by RCA is used. In this case the i.c. acts as a driver in conjunction with a complementary pair of output transistors. The yoke current in this case is in the region of 6A. The TDA1170 is designed for operation with a nominal 22V supply. It can be operated at up to 35V however. A voltage doubler within the i.c. is brought into action during the flyback time to raise the supply to 70V. Good frequency stability is claimed and the yoke current stability with changes in ambient temperature is such that the usual thermistor in series with the field coils is not required. For monochrome receiver use the power supplied to the yoke would be 0-83W for a yoke current of lA peak -to -peak with a 1012 coil impedance and 20V supply. As the power dissipation rating of the i.c. is 2.2W no further heatsink is required. For use in a colour receiver with a toroidal coil impedance of 1.6Ohm the scanning current would be 7A peak -to -peak. The power supplied to the yoke may be as much as 6.5W while the dissipation in the i.c. would be up to 2-3W. In this case a simple heatsink can be formed from a thin copper sheet soldered to the heat fins- an area of about 3-4 sq. in. should be adequate. The sync circuit at the input gives good noise immunity while the difference between the actual and ideal interlace is less than 0-3% of the field amplitude. Because of the high output impedance a relatively low value (1/iF or less) output coupling capacitor can be used. This means that mylar types instead of electrolytics can be used, reducing the problems of linearity and amplitude stability with respect to temperature and ageing.











DESCRIPTION
The TDA2006 is a monolithic integrated circuit in Pentawatt package, intended for use as a low frequency class ”AB” amplifier. At ±12V, d = 10 % typically it provides 12W output power on a 4Ω load and 8W on a 8Ω . The TDA2006 provides high output current and has very low harmonic and cross-over distortion. Further the device incorporates an original (and patented)short circuit protection system comprising an arrangement for  automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. A conventional thermal shutdown system is also included. The TDA2006 is pin to pin equivalent to the TDA2030.

 

 

 

 


 











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Filippov AF (1960) Differential equations with discontinuous right hand side. Am Math Soc
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Guffon S (2000) Modelling and variable structure control for active power filters (in French:
“Modelisation  ́
 et commandes `
 a structure variable de filtres actifs de puissance”). Ph.D. thesis,
Grenoble Institute of Technology, France
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active power filter. In: Proceedings of the 29th annual IEEE Power Electronics Specialists
Conference – PESC 1998. Kyushu Island, Japan, pp 1408–1414
Hung JY, Gao W, Hung JC (1993) Variable structure control: a survey. IEEE Trans Ind Electron
40(1):2–22
Itkis U (1976) Control systems of variable structure. Wiley, New York
Levant A (2007) Principles of 2-sliding mode design. Automatica 43(4):576–586
Levant A (2010) Chattering analysis. IEEE Trans Autom Control 55(6):1380–1389
Malesani L, Rossetto L, Spiazzi G, Tenti P (1995) Performance optimization of Cuk  ́
 converters by
sliding-mode control. IEEE Trans Power Electron 10(3):302–309
Malesani L, Rossetto L, Spiazzi G, Zuccato A (1996) An AC power supply with sliding mode
control. IEEE Ind Appl Mag 2(5):32–38
Martinez-Salamero L, Calvente J, Giral R, Poveda A, Fossas E (1998) Analysis of a bidirectional
coupled-inductor Cuk  ́
 converter operating in sliding mode. IEEE Trans Circuit Syst I Fundam
Theor Appl 45(4):355–363
Mattavelli P, Rossetto L, Spiazzi G (1997) Small-signal analysis of DC–DC converters with
sliding mode control. IEEE Trans Power Electron 12(1):96–102
ˇ
Sabanovic A (2011) Variable structure systems with sliding modes in motion control—a survey.
IEEE Trans Ind Inform 7(2):212–223
Sabanovic ˇ
 A, Fridman L, Spurgeon S (2004) Variable structure systems: from principles to
implementation, IEE Control Engineering Series. The Institution of Engineering and Technol-
ogy, London

Sira-Ramırez  ́  H (1987) Sliding motions in bilinear switched networks. IEEE Trans Circuit Syst 34
(8):919–933
Sira-Ramırez  ́
 H (1988) Sliding mode control on slow manifolds of DC to DC power converters. Int
J Control 47(5):1323–1340
Sira-Ramırez  ́
 H (1993) On the dynamical sliding mode control of nonlinear systems. Int J Control
57(5):1039–1061
Sira-Ramırez  ́
 H (2003) On the generalized PI sliding mode control of DC-to-DC power converters:
a tutorial. Int J Control 76(9/10):1018–1033
Sira-Ramırez  ́
 H, Silva-Ortigoza R (2006) Control design techniques in power electronics devices.
Springer, London
Slotine JJE, Sastry SS (1983) Tracking control of non-linear systems using sliding surface, with
application to robot manipulators. Int J Control 38(2):465–492
Spiazzi G, Mattavelli P, Rossetto L, Malesani L (1995) Application of sliding mode control to
switch-mode power supplies. J Circuit Syst Comput 5(3):337–354
Tan S-C, Lai YM, Cheung KHM, Tse C-K (2005) On the practical design of a sliding mode
voltage controlled buck converter. IEEE Trans Power Electron 20(2):425–437
Tan S-C, Lai Y-M, Tse C-K (2011) Sliding mode control of switching power converters:
techniques and implementation. CRC Press, Taylor & Francis Group, Boca Raton
Utkin VA (1972) Equations of sliding mode in discontinuous systems. Autom Remote Control 2
(2):211–219
Utkin VA (1977) Variable structure systems with sliding mode. IEEE Trans Autom Control 22
(2):212–222
Utkin V (1993) Sliding mode control design principles and applications to electric drives. IEEE
Trans Ind Electron 40(1):23–36
Venkataramanan R, Sabanovic ˇ
 A, Cuk  ́
 S (1985) Sliding mode control of DC-to-DC converters. In:
Proceedings of IEEE Industrial Electronics Conference – IECON 1985. San Francisco,
California, USA, pp 251–258
Young KD, Utkin VI, Ozguner U (1999) A control engineer’s guide to sliding mode control. IEEE
Trans Control Syst Technol 7(3):328–342

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Other References
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& Francis Group, Boca Raton, pp 50-1–50-22
Emelyanov SV (1967) Variable structure control systems. Nauka, Moscow (in Russian)
Filippov AF (1960) Differential equations with discontinuous right hand side. Am Math Soc
Transl 62:199–231
Guffon S (2000) Modelling and variable structure control for active power filters (in French:
“Modelisation  ́
 et commandes `
 a structure variable de filtres actifs de puissance”). Ph.D. thesis,
Grenoble Institute of Technology, France
Guffon S, Toledo AS, Bacha S, Bornard G (1998) Indirect sliding mode control of a three-phase
active power filter. In: Proceedings of the 29th annual IEEE Power Electronics Specialists
Conference – PESC 1998. Kyushu Island, Japan, pp 1408–1414
Hung JY, Gao W, Hung JC (1993) Variable structure control: a survey. IEEE Trans Ind Electron
40(1):2–22
Itkis U (1976) Control systems of variable structure. Wiley, New York
Levant A (2007) Principles of 2-sliding mode design. Automatica 43(4):576–586
Levant A (2010) Chattering analysis. IEEE Trans Autom Control 55(6):1380–1389
Malesani L, Rossetto L, Spiazzi G, Tenti P (1995) Performance optimization of Cuk  ́
 converters by
sliding-mode control. IEEE Trans Power Electron 10(3):302–309
Malesani L, Rossetto L, Spiazzi G, Zuccato A (1996) An AC power supply with sliding mode
control. IEEE Ind Appl Mag 2(5):32–38
Martinez-Salamero L, Calvente J, Giral R, Poveda A, Fossas E (1998) Analysis of a bidirectional
coupled-inductor Cuk  ́
 converter operating in sliding mode. IEEE Trans Circuit Syst I Fundam
Theor Appl 45(4):355–363
Mattavelli P, Rossetto L, Spiazzi G (1997) Small-signal analysis of DC–DC converters with
sliding mode control. IEEE Trans Power Electron 12(1):96–102
ˇ
Sabanovic A (2011) Variable structure systems with sliding modes in motion control—a survey.
IEEE Trans Ind Inform 7(2):212–223
Sabanovic ˇ
 A, Fridman L, Spurgeon S (2004) Variable structure systems: from principles to
implementation, IEE Control Engineering Series. The Institution of Engineering and Technol-
ogy, London

References:
 Sira-Ramırez  ́
 H (1987) Sliding motions in bilinear switched networks. IEEE Trans Circuit Syst 34
(8):919–933
Sira-Ramırez  ́
 H (1988) Sliding mode control on slow manifolds of DC to DC power converters. Int
J Control 47(5):1323–1340
Sira-Ramırez  ́
 H (1993) On the dynamical sliding mode control of nonlinear systems. Int J Control
57(5):1039–1061
Sira-Ramırez  ́
 H (2003) On the generalized PI sliding mode control of DC-to-DC power converters:
a tutorial. Int J Control 76(9/10):1018–1033
Sira-Ramırez  ́
 H, Silva-Ortigoza R (2006) Control design techniques in power electronics devices.
Springer, London
Slotine JJE, Sastry SS (1983) Tracking control of non-linear systems using sliding surface, with
application to robot manipulators. Int J Control 38(2):465–492
Spiazzi G, Mattavelli P, Rossetto L, Malesani L (1995) Application of sliding mode control to
switch-mode power supplies. J Circuit Syst Comput 5(3):337–354
Tan S-C, Lai YM, Cheung KHM, Tse C-K (2005) On the practical design of a sliding mode
voltage controlled buck converter. IEEE Trans Power Electron 20(2):425–437
Tan S-C, Lai Y-M, Tse C-K (2011) Sliding mode control of switching power converters:
techniques and implementation. CRC Press, Taylor & Francis Group, Boca Raton
Utkin VA (1972) Equations of sliding mode in discontinuous systems. Autom Remote Control 2
(2):211–219
Utkin VA (1977) Variable structure systems with sliding mode. IEEE Trans Autom Control 22
(2):212–222
Utkin V (1993) Sliding mode control design principles and applications to electric drives. IEEE
Trans Ind Electron 40(1):23–36
Venkataramanan R, Sabanovic ˇ
 A, Cuk  ́
 S (1985) Sliding mode control of DC-to-DC converters. In:
Proceedings of IEEE Industrial Electronics Conference – IECON 1985. San Francisco,
California, USA, pp 251–258
Young KD, Utkin VI, Ozguner U (1999) A control engineer’s guide to sliding mode control. IEEE
Trans Control Syst Technol 7(3):328–342

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92. Texas Instruments/Unitrode Data Sheet UCC3895 SLUS 157B & application notes U136A & U154.
93. Stanley, William D., Operational Amplifiers with Linear Integrated Circuits, 2d Ed., Merrill, Columbus,
Ohio, 1989. ISBN 067520660-X.
94. “LM13700 Dual Operational Transconductance Amplifiers with Linearizing Diodes and Buffers,”
National Semiconductor Corporation, 2004. http://www.national.com/ds/LM/LM13700.pdf.

Further References:
1. G. Aboud, Cathode Ray Tubes, 1997, 2nd ed., San Jose, CA, Stanford Resources, 1997.
2. G. Aboud, Cathode Ray Tubes, 1997, Internet excerpts, available http://www.stanfordresources.com/
sr/crt/crt.html, Stanford Resources, February 1998.
3. G. Shires, Ferdinand Braun and the Cathode Ray Tube, Sci. Am., 230 (3): 92–101, March 1974.
4. N. H. Lehrer, The challenge of the cathode-ray tube, in L. E. Tannas, Jr., Ed., Flat Panel Displays
and CRTs, New York: Van Nostrand Reinhold, 1985.
5. P. Keller, The Cathode-Ray Tube, Technology, History, and Applications, New York: Palisades Press,
1991.
6. D. C. Ketchum, CRT’s: the continuing evolution, Society for Information Display International
Symposium, Conference Seminar M-3, 1996.
7. L. R. Falce, CRT dispenser cathodes using molybdenum rhenium emitter surfaces, Society for
Information Display International Symposium Digest of Technical Papers, 23: 331–333, 1992.
8. J. H. Lee, J. I. Jang, B. D. Ko, G. Y. Jung, W. H. Kim, K. Takechi, and H. Nakanishi, Dispenser
cathodes for HDTV, Society for Information Display International Symposium Digest of Technical
Papers, 27: 445–448, 1996.
9. T. Nakadaira, T. Kodama, Y. Hara, and M. Santoku, Temperature and cutoff stabilization of
impregnated cathodes, Society for Information Display International Symposium Digest of Technical
Papers, 27: 811–814, 1996.
10. W. Kohl, Materials Technology for Electron Tubes, New York, Reinhold Publishing, 1951.
11. S. Sugawara, J. Kimiya, E. Kamohara, and K. Fukuda, A new dynamic-focus electron gun for color
CRTs with tri-quadrupole electron lens, Society for Information Display International Symposium
Digest of Technical Papers, 26: 103–106, 1995.
12. J. Kimiya, S. Sugawara, T. Hasegawa, and H. Mori, A 22.5 mm neck color CRT electron gun with
simplified dynamically activated quadrupole lens, Society for Information Display International
Symposium Digest of Technical Papers, 27: 795–798, 1996.
13. D. Imabayashi, M. Santoku, and J. Karasawa, New pre-focus system structure for the trinitron gun,
Society for Information Display International Symposium Digest of Technical Papers, 27: 807–810,
1996.
14. K. Kato, T. Sase, K. Sasaki, and M. Chiba, A high-resolution CRT monitor using built-in ultrasonic
motors for focus adjustment, Society for Information Display International Symposium Digest of
Technical Papers, 27: 63–66, 1996.
15. S. Sherr, Electronic Displays, 2nd ed., New York: John Wiley, 1993.
16. N. Azzi and O. Masson, Design of an NIS pin/coma-free 108° self-converging yoke for CRTs with
super-flat faceplates, Society for Information Display International Symposium Digest of Technical
Papers, 26: 183–186, 1995.
17. J. F. Fisher and R. G. Clapp, Waveforms and spectra of composite video signals, in K. Benson and
J. Whitaker, Television Engineering Handbook, Featuring HDTV Systems, New York: McGraw-Hill
Reinhold, 1992.
18. D. Pritchard, Standards and recommended practices, in K. Benson and J. Whitaker, Television
Engineering Handbook, Featuring HDTV Systems, New York: McGraw-Hill Reinhold, 1992.
19. A. Vecht, Phosphors for color emissive displays, Society for Information Display International Sym-
posium Conference Seminar Notes F-2, 1995.
20. Optical Characteristics of Cathode Ray Tube Screens, EIA publication TEP116-C, Feb., 1993.
21. G. Wyszecki and W. S. Stiles, Color Science: Concepts and Methods, Quantitative Data and Formulae,
2nd ed., New York: John Wiley & Sons, 1982.
© 1999 by CRC Press LLC
22. A. Robertson and J. Fisher, Color vision, representation, and reproduction, in K. Benson and J.
Whitaker, Television Engineering Handbook, Featuring HDTV Systems, New York: McGraw-Hill
Reinhold, 1992.
23. M. Maeda, Trinitron technology: current status and future trends, Society for Information Display
International Symposium Digest of Technical Papers, 27: 867–870, 1996.
24. C. Sherman, Field sequential color takes another step, Inf. Display, 11 (3): 12–15, March, 1995.
25. L. Ozawa, Helmet mounted 0.5 in. crt for SVGA images, Society for Information Display Interna-
tional Symposium Digest of Technical Papers, 26: 95–98, 1995.
26. C. Infante, CRT display measurements and quality, Society for Information Display International
Symposium Conference Seminar Notes M-3, 1995.
27. J. Whitaker, Electronic Displays, Technology, Design, and Applications, New York: McGraw-Hill, 1994.
28. P. Keller, Electronic Display Measurement, Concepts, Techniques, and Instrumentation, New York:
John Wiley & Sons, 1997.
Further Information
L. Ozawa, Cathodoluminescence: Theory and Applications, New York: Kodansha, 1990.
V. K. Zworykin and G. A. Morton, Television: The Electronics of Image Transmission in Color and Mono-
chrome, New York: John Wiley & Sons, 1954.
B. Wandell, The foundations of color measurement and color perception, Society for Information Display
International Symposium, Conference Seminar M-1, 1993. A nice brief introduction to color science
(31 pages).
Electronic Industries Association (EIA), 2500 Wilson Blvd., Arlington, VA 22201 (Internet: www.eia.org).
The Electronic Industries Association maintains a collection of over 1000 current engineering publi-
cations and standards. The EIA is an excellent source for information on CRT engineering, standards,
phosphors, safety, market information, and electronics in general.
The Society for Information Display (SID), 1526 Brookhollow Dr., Suite 82, Santa Ana, CA 92705-5421
(Internet: www.display.org). The Society for Information Display is a good source of engineering
research and development information on CRTs and information display technology in general.

Internet Resources:
The following is a brief list of places to begin looking on the World Wide Web for information on CRTs
and displays, standards, metrics, and current research. Also many of the manufacturers listed in Table
91.3 maintain Web sites with useful information.
The Society for Information Display
The Society of Motion Picture and Television Engineers
The Institute of Electrical and Electronics Engineers
The Electronic Industries Association
National Information Display Laboratory
The International Society for Optical Engineering
The Optical Society of America
Electronics & Electrical Engineering Laboratory
National Institute of Standards and Technology (NIST)
The Federal Communications Commission

www.display.org
www.smpte.org
www.ieee.org
www.eia.org
www.nta.org
www.spie.org
www.osa.org
www.eeel.nist.gov
www.nist.gov
www.fcc.gov




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