From: Chris Carlen
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Subject: My flyback experiment is on the web
Date: Sun, 13 Oct 2002 23:40:41 GMT
NNTP-Posting-Date: Sun, 13 Oct 2002 16:40:41 PDT
Here is the URL to my web page showing the results of my most recent
experiments with a flyback converter. I still haven't gotten a PWM chip
hooked up yet, as my first goal was to buy some inductors that look like
they are designed for switching supplies, and see if they'd work better
than the hand wound transformer I made from a PC power supply core.
Actually, the inductor seems a bit worse :-(
All the details are on the web page.
My main question is why does the inductor get so warm? I figured I
wasn't really pushing it too hard, so it shouldn't loose much power.
but it seems most of my losses are occurring in the inductor. I was
hoping to avoid complex topologies such as a two transistor flyback,
which requires a transformer, but lends itself to easily shunting the
remaining core energy back to the input rail. Can that be done with the
simple flyback that I am working with? I figured I could get 75% or
better, so I'm not really far off. But I don't like heating the
inductor, and I want to push up the power another 25% from what I'm
testing at before I finish.
I have a smaller inductor, and a larger one too, but all of the toroidal
type, designed for 150kHz switchers.
Comments appreciated on what steps I might take to make this simple
circuit move in the direction of something worth committing to FR-4.
I will put more on the web page when I get to testing out the PWM chips,
Christopher R. Carlen
Suse 7.3 Linux 2.4.10