|Re: Classic Series Power Supply Schematic?|
Message #3 Posted by Dan on 23 Mar 2007, 12:03 p.m.,
in response to message #2 by Tony Duell
Thanks. I sent a note to Dave.
Looks like this is a flyback converter with the oscillator circuit to the left, 3 windings on the transformer, and 2.2 uF capacitor/diode circuits to the right providing the voltages.
On the oscillator circuit there appear to be two transistors, both Motorola, labeled 4-094 and 4-550 (NPN and PNP?). I tried looking up these part numbers but didn't find anything. It also has a 60uF cap.
Usually the least reliable components would be the capacitors. But I would agree if the oscillator is dead the transistors may be the problem.
So far I've only hooked it up to a multimeter. This weekend I'll scope it to see what I find.
Also I took the board and scanned both sides on a flatbed scanner at a ridiculously high DPI in case I decide to try to reverse engineer this thing myself.
With all of the gold plating and the gold/ceramic Mostek chips, this board is a real work of art. I'm half tempted to frame the picture.
Any other thoughts or related experiences are welcome.