On Thu, 02 Mar 2006 13:35:48 -0500, (Fred McKenzie)
wrote:

snip

Not being familiar with that power supply, it isn't clear what your
problem is. Exactly what is it that is "offset by ~2.5V"? Does the
built-in meter read something different from your Fluke? If the panel
meter agrees with your Fluke, then it would appear to be working properly.

Power dissipated by the transistors is computed by voltage DROP, not
output voltage. Measure the voltage between collector and emitter while
the supply is delivering rated current, multiply by rated current and
divide by the number of transistors.

It is possible that the maximum current rating only applies at maximum
output voltage. I assume you have checked the manufacturer's web site for
data.

Without a cross reference to the Power/Mate proprietary part numbers, the
best you can do is guess. The 2N3055 is as good a guess as any.

Fred

Sorry, didn't mean to be unclear. The panel meter (analog meter) is
correct, agrees w/ the fluke. THe voltage at a minimum is about 2.5v,
and max is around 12.5V. That's what I meant by the offset, the
supply I believe should be adjustable from 0 to 10, not 2.5 to 12.5
(the panel meter is 1-10V). I was trying to be clear that the meter
was not the problem, and ended up being more confusing than anything.

Yes, I now realize my errors in the calculation. Funny, that's why I
wrote that note about the calculations being brutal, because I knew I
was doing something wrong but was too tired to figure it out.

I wasn't able to find specs on the supply anywhere. The only
Power/Mate website I could find is www.pduke.com, which doesn't seem
to be the right company, or they switched.

Anyway, thanks for the reply, hope I cleared things up.

I guess I just need to start checking parts on the board, there really
aren't that many, and I can just check them all (really efficient...).
Should solve the problem.
I hope
Steve