26 Jun
2000
26 Jun
'00
11:02 a.m.
Tony Duell wrote:
Bob: As you have one of these supplies in front of
you, what is it? I
there a big iron-cored transformer? Is there a medium-sized ferrite-cored
transformer? What about capacitors of a few hundred uF with working
voltages around 200V?
-tony
OK, I'll bite, as I have one of these; I am in a bit
of a hurry right now so I won't disassemble the thing
entirely -- it has way too many screws and plates.
The supply is rated 8A max, 110V, 47.5-66Hz in the rear plate.
No large transformers. There is a large EMI filter right at the
mains, then the input circuitry features a large coil, two
1150 uF @ 200V caps, one small transformer which I think
supplies what seems to be a small control board nearby,
then another board with five IOR 4-772 TO-3 transistors;
several diodes and something that looks like a bridge
(sorry; can't get a good look without disassembling)
there is another transistor nearby in the main board,
a 2S02429; all of these components seem to be part of
the main switcher; later on there are more
caps, transistors, SCR's and a multiple-tap xformer
(laminated core!). It looks like a two-stage switcher to me.
carlos.
--
Carlos Murillo-Sanchez email: cem14(a)cornell.edu
428 Phillips Hall, Electrical Engineering Department
Cornell University, Ithaca, NY 14853