13 Jan
2002
13 Jan
'02
8:03 a.m.
From: Pete Turnbull <pete(a)dunnington.u-net.com>
On Jan 12, 20:14, jpero(a)sympatico.ca wrote:
noise
Sounds like PSU is reacting to overloading or
medium shorts
downstream of that PSU outputs. Also can happen with dried
up capacitors (too high ESR).
I don't think it's any of those. The regulators all make a similar when I put them on a dummy load drawing 5A, on the
bench. And I'm sure
it's not bad caps, as two of them are ones I repaired recently.
This is normal for them as well as the older H780. They are very loud
and
the pitch varies with load as well. That is a side effect of older low
voltage,
low frequency switch mode PS designs of some 20+ years ago.
Allison