Talk:Flyback transformer

message: :"The air gap increases the reluctance of the magnetic circuit and therefore its ability to store energy."
Air gap increases reluctance, so less B-field occurs per applied H-field. And since the stored energy is measured by volume integral of product of H and B-fields, stored energy will tend to decrease as the air gap increases.
An expert of this topic should revise this statement and remove it if necessary.
AhmedHan (talk) 06:03, 2 May 2014 (UTC)
thread_title:  Does air gap increase ability to store energy? 

message: Wtshymanski & Light current have good points. The deflection power supply is typically on the order of 70vdc and it is not correct to claim line voltage (AC) as the input to the LOPT. Additionally the inductance of mains (50/60Hz) transformers must be made high in order to reduce the magnetising current to acceptable levels and also to prevent saturation (applies to audio as well).
On leakage inductance, it would be highly undesirable to have high leakage inductance in a LOPT as leakage inductance represents stored energy that has to be adsorbed by snubber circuits. In the case of mains transformers, if the output is driving a capacitive load (eg the voltage multiplier in a microwave oven) a high leakage inductance would be desirable in order to zero the power factor. I am not an audio expert, but I would imagine that the leakage inductance of an audio transformer would be quite low to insure minimal parasitic inductance in the circuit.
It should also be made clear that the LOPT and associated circuitry is operated as a switched mode power supply and outputs a square voltage waveform given that the circuit switches between positive, constant di/dt and negative, constant di/dt. Additionally the voltage multiplier is not distinct from the "rectifier" as a CW multiplier intrinsically has a DC output.
The author of the claims that the LOPT is responsible for the wine of monitors - this cannot be correct as all monitors operate with horizontal scans in excess of 40kHz - well above the range of human hearing. A much more likely source of audible sound is the mains stepdown transformer which may operate within the range of human hearing.
::Many units with CRT's use a degausing coil, which makes a loud HUM sound when they start up.cmacd 19:30, 16 February 2007 (UTC)
replies: text: That is true - and completely irrelevant in the current context.  And: only cheap crappy ones (such as in many domestic TVs) make a loud hum. 86.163.86.161 (talk) 17:15, 24 February 2011 (UTC)

text: The deflection power supply depends on the design of the circuit and the technology used.  In valve days (vaccuum tube if you don't speak English), the deflection supply could be as high as 600 volts (with the deflection circuit itself producing around 400-500 of them depending on which side of the pond you live).  86.163.86.161 (talk) 17:01, 24 February 2011 (UTC)

text: Especially these days when the primary use is in flyback type switch mode power supplies, given that CRT televisions are obsolete. 86.163.86.161 (talk) 17:01, 24 February 2011 (UTC)

text: Just found the time.  My years spent servicing and repairing television and (more lately) exotic video display systems wasn't wasted after all! 86.183.175.209 (talk) 16:56, 7 April 2011 (UTC)

text: The major error here is that everyone (and the article) is incorrectly assuming that the both the primary and secondary currents are sawtooth to the extent of incorrectly assuming that the deflection coils were energised from the secondary.  The primary current is indeed a sawtooth (or at least it would be but for the presence of other components designed to make it more 'S' shaped).  The secondary current is not a sawtooth in any shape or form.  The EHT rectifier sees to that only allowing the large flyback pulses to pass.  The deflection coils are connected in series with the primary of the transformer.  Indeed: for deflection purposes, the secondary might just as well not be there as indeed it wasn't in early television designs. DieSwartzPunkt (talk) 15:53, 10 November 2012 (UTC)
thread_title: This article need improvement

message: A user placed the floowing in the article, at has been removed "A better description is on flyback converter. This whole article is merely about the application in the TV, the only place where it is synchronized with the flyback of an electron beam, even computer monitors do not do it this way."  Since the Flyback system is specific to television and related techniques, I don't think the comment is valid, but wanted to preserve it just so it is not acted on.  cmacd 19:30, 16 February 2007 (UTC)
thread_title: Not to merge

message: Before the flyback (1940s) - Tv sets sometimes used an RF power supply for the High voltage, which could be lethal.  The flyback system will be loaded so much that it does not normaly kill.cmacd 19:32, 16 February 2007 (UTC)
replies: text: No they didn't. Prior to 1940, the only available circuit was to derive the EHT from the mains transformer (which was lethal). Due to the poor insulating materials available, breakdowns and even fires were not unknown.  After 1940, before the EHT shifted to the output transformer (and virtually all rear projection TVs did this) the EHT was produced by a self contained oscillator driving a ringing choke converter (actually a transformer). These usually operated at about 1kHz (not RF), though the frequency was not critical. Rear projection TVs usually used a tripler circuit to produce the 25,000 volts required but regular TVs just rectified the pulse train from the transformer. 185.69.145.2 (talk) 17:56, 3 March 2021 (UTC)
thread_title: wonder if Historical alternative should be mentioned

message: "Flyback transformers are a frequent source of TV tube failure."
I can't imagine how this could occur. CRTs are pretty robust things, like most thermionic devices, and I cant imagine any real world LOPT failure putting damagingly high V or i onto the tube.
Tabby (talk) 23:26, 25 November 2007 (UTC)
thread_title: Question

message: how do i change a flyback transformer  —Preceding unsigned comment added by Rcaman (talk • contribs) 01:24, 15 March 2010 (UTC)
replies: text: If you are not trained or experienced in performing this type of service, it would be best to submit the job to someone who has the proper qualifications.  There can be dangerous voltages present around a flyback transformer, making it hazardous if you don't know what you are doing.  Wikipedia is not a "how to" guide, so information and guidance on how to perform this type of service would need to be found elsewhere.  At the very least, if you insist on attempting it, it is essential to disconnect the CRT and ensure that all voltages around the flyback are discharged.  Wearing thick rubber gloves while working on high voltage circuitry is an advisable precaution. Wildbear (talk) 02:30, 15 March 2010 (UTC)
replies: text: The canonical answer is "Very very carefully". --Wtshymanski (talk) 17:01, 7 April 2011 (UTC)
thread_title:  How to change a flyback transformer 

message: This article is still very much based on guesswork and supposition.  It is far from accurate as shown by the above discussion.  Areas of concern include (but are not limited to):
* The article is mostly centred around a discussion of television deflection systems.  Although this is an application of a flyback transformer, it is by no means the sole application.  Most other applications are power supply related rather than TV deflection related.
* That the article insists that the TV deflection circuit has to use a transformer.  This is not correct.  The device acts solely as an inductor for deflection purposes.  The transformer part is purely for the secondary function of power supply.  Indeed early TV sets that derived the tube's high voltage directly from the mains transformer did not have a transformer in the deflection circuit, only an inductor.
* The article describes a circuit producing a saw tooth current varying from zero to some maximum value.  Such a circuit would be useless for a television deflection system unless the viewer is content to watch a picture displayed on one quarter of the tube face only.  The article does not describe how a deflection current varying from a minus maxima to a positive maxima is achieved.
* The article describes a system that is designed to produce a linear ramp to the saw tooth current.  This is the last thing that is required as the deflection sensitivity of a CRT increases as the beam departs from the screen centre.  The deflection circuit has to produce an 'S' shaped ramp to the waveform.  The article does not describe how this is achieved.
Most (but not all) of these points not necessarily relevant to a purely flyback type power supply DieSwartzPunkt (talk) 15:41, 10 November 2012 (UTC)
thread_title:  Factual accuracy 

message: Most of the electrical components pages could use a bit of tidying up, but...
Out of all the different articles of this sort, the expected quality of this page is much lower than the actual quality.
It's obviously lower rank than resistors and capacitors and the like, but it's still far from an obscure component. Considering the noteworthiness of the topic of this article, it really ought to get a bit of dedicated attention one of these days (imho)
50.46.228.138 (talk) 23:02, 10 January 2014 (UTC)
thread_title:  Article needs work 

message: This article is empty. I can see there is discussion about this though. There are no schematics or diagrams, no numbers or units, and seemingly no facts. Half the article goes off into television repair, which does not even apply to the main article.  — Preceding unsigned comment added by 99.229.12.128 (talk) 23:31, 17 March 2016 (UTC)
thread_title:  Where is the information?