Re[2]: Wintron transformers

-----Original Message-----
From: Zonn <zonn@zonn.com>
To: vectorlist@synthcom.com
Date: Thu, 12 Jul 2001 17:53:02 -0700
Subject: Re: VECTOR: Wintron transformers

>
> On Thu, 12 Jul 2001 18:47:02 -0500, Joe Bachmann <joe.bachmann@newmail.net>
> wrote:
>
> >Thank you for the info... With that in mind, I found a site that looks like it may sell just the thing we're after:
> >
> >http://www.emcohighvoltage.com/emcoindex.htm
> >
> >Link to section I am referring to: http://www.emcohighvoltage.com/crt.PDF
> >
> >I am looking at the CRT-200 or 6000 series.. This may be easier than designing something, however I don't know the cost..
> >
> >JB
>
> Those are cool! If they are cheap enough, forget Wintron.
>
> Designing a supply using an off the shelf flyback is not easy.
>
>
> This is my take at doing so. This is more Rodger Boot's field, but here goes...
>
> Everyone seems to forget the flyback circuitry needs a yoke (or the equivalent
> inductor -- this is a tuned circuit and must remain so to work properly) in
> order to produce the HV needed. The second thing shrugged off seems to be HV
> regulation -- needed to keep the picture from growing and shrinking as the
> vector count on the screen goes up and down.
>
> The schematics I've looked at all run the flyback's primary on rectified 120vac.
> This requires that a isolation transformer be used (to avoid electrocution -- a
> bad thing). HV regulation on the raster CRTs I've looked at is done in a
> specialty chip that also controls the horizontal (and sometimes vertical) sync.
> It supplies the free running oscillator that is locked onto the HV sync pulse
> when detected. Way over kill for what we need. But if we design the oscillator
> ourselves, we need to design the regulation circuitry also.
>
> You will also need the current transformer that is used to drive the horizontal
> deflection transistor.
>
> All and all, to use a flyback, you need to design a large part of a horizontal
> sweep circuit that needs to be run with a isolation transformer. It gets
> cumbersome and expensive -- even with a $17 flyback.
>
> Things get much simpler when you start with a properly wound HV transformer (not
> a flyback). Just look at how simple the HV sections of X/Y monitor are compared
> with raster monitors. Raster monitors use flyback simply because the Horizontal
> section is already there, and is real easy to tap into to get the HV needed.
> That and flybacks are a very efficient way off generating HV.
>
> The opposite is not true, it's a pain to start with a flyback and build the
> horizontal circuitry to support it.
>
> These are the reasons that seemed to have stopped every attempt at building an
> HV replacement since I been reading vectorlist. Not the threat of lawsuits.
>
> On the other hand it looks like "low cost" 350 series would run all the B&W
> vectors, and the CRT 200 would probably run the colors -- even the filament in
> an amplifone! Very cool!
>
> -Zonn

just because a flyback 'ran' from the reflected energy from the horizontal yoke
dont mean it has to, ever seen a digital LOPT tester?

all it uses is a micro-controller.

i was thinking of using a pic to generate a 15Khz sweep type pulse, followed by a pulse transformer to increase current.

the transformers used in vector games are no different to the ones in raster monitors & tv's.
you may even find that one of the vector company's used the same transformer as in there raster monitors, i dont know - but it is possible.

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Received on Fri Jul 13 05:16:27 2001