[sdiy] Noisy Power Supply

[Needham, Alan]

Scott,
I have never heard of Power-One, despite their website claim of :-
"Power-One is one of the largest manufacturers of power
 conversion and management solutions in the world."
Maybe they just haven't reached the cave I live in.

Is this a linear or switched-mode supply ?
You say it is a 15-3, does that mean it is 15v, 3A ?

On the oscilloscope can you read the frequency of this waveform?
if this is 50-60 or 100-120Hz then it could be mains hum ?
What is the amplitude of this "saw" - a few 100s of millivolts
could be filtered with a capacitor (but shouldn't be there).

A linear supply should be repairable, a SMPSU will take skill,
knowlege and CARE - high DC voltages are present !

	HTH, Alan


#  -----Original Message-----
#  From: synth-diy-bounces at dropmix.xs4all.nl
#  [mailto:synth-diy-bounces at dropmix.xs4all.nl]On Behalf Of Scott
#  Sent: 21 June 2007 5:57 AM
#  To: synth-diy at dropmix.xs4all.nl
#  Subject: [sdiy] Noisy Power Supply
#
#
#  I did a little more testing on my power supply.  I hooked my scope up,
#  and I can see an inverted saw wave on the negative side.
#  ----|/----|/----   Sort of like that.  The positive side was flat.  I've
#  learned a lot about how to troubleshoot a synth module, but don't know
#  where to begin on a power supply.  Is there a common component that
#  could possibly cause this problem, or is it not worth trying to figure
#  out?  It was a fairly inexpensive ebay purchase.  
#  I'll just hate to have to wait to find another power supply.  Once I've
#  got it, I can plug in all of my modules   and call 3 years worth of work
#  done.  (although I have more modules 1/2 completed, and not enough room
#  in this cabinet I just made for it.. work will never be done)
# 
#  Thanks

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