"Ian Field" wrote in message
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"Arfa Daily" wrote in message
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"Jim Yanik" wrote in message
4...
"Arfa Daily" wrote in
:



You shouldn't take things quite so literally, Phil. I was talking
about the primary side only when I said that, but yes, it pretty much
has a pair of small TO92 transistors, and a TO220 mosfet. Obviously,
it also has input filtering, a bridge, made of 4 discrete diodes, a
main filter cap, and assorted R and C to make those two little
transistors into an oscillator. About 20 components altogether. The
secondary side is exactly like any other fixed voltage typical design,
and there is, of course, a perfectly normal 6 pin opto for regulation
feedback. Better ?

Arfa



I've been wondering about how the regulating feedback loop works.
How does it modify the multivibrator's output?


--
Jim Yanik

Don't know, Jim. I don't have any schematics for it, as is ever the case,


Can't remember the last time I had a schematic for a PSU I was repairing,
I frequently trace them out by hand.

If its only an astable driving a MOSFET (or thereabouts) and you have a
few to fix, it shouldn't be too much of a hardship for the gain.

The company have now come back to me, and accepted the quotes that I have
given them for quantity repair on this supply, so it will now be worth
spending the time to trace it out.

Arfa