Re: solid state flyback driver

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

Once you tamper with the frequencies, pulse widths and the feedback used to
alter the pulse width (the regulation in a switching power supply), you no
longer have a 5 and 12 volt power supply. It still sounds like a good cheap
way to run things though as computer power supplies are cheap and plentiful.

KEN
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, August 10, 2002 7:50 AM
Subject: solid state flyback driver


> Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
>
> Hello all,
>
> I've come up with an idea for a flyback driver. Let me know what you
> think.
>
> I was having a look in a regular desktop computer 230W SMPS. This is
> actually a pretty nifty little device :) It uses a PWM chip I thought I
> had never heard of, but after a quick search I found out it was
> actually a relabled TL494. So basically, I figured I could replace the
> resistor that sets the frequency of the TL494 for a POT, and bypass the
> diodes that rectify the HF transformer output. This would give a dandy
> little 200W, variable frequency, 5v/12v power supply. Advantages are:
> runs directly from a power socket, excellent inbuilt circuit
> protection, cheap as peanuts from a dumpster.
>
> The only reason I can see that this may not work, is that the
> transformer is meant to operate at either 50 or 100kHz, and may not
> have sufficient windings on the primary to operate at the lower
> frequencies for powering a TV flyback (15kHz or so). Ideas?
>
>
> Cheers,
> Greg Peters
> Department of Earth Sciences,
> University of Queensland, Australia
> Phone: 0402 841 677
> http://www.geocities-dot-com/gregjpeters
>
>
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