(question at bottom)

Been gathering parts for a few days. As mentioned originally I
want to consolidate a whole pile of transformers into one case
as a general-purpose PSU. So far I've made up some rectifier
boards with raw DC out. +/- 30V 2A, 70V 1A, 26V 15A
and 38V 10A

The low-current outputs aren't a particular problem, based on
LM317/LM350/LM78xx

As a bonus, I found two things whilst looking for something else.
The first was a bag of a few dozen 50V 6800uF caps that I was
given a long time ago and completely forgot about . The second
was a PSU of uncertain origin in a great case, 0-25V 5A it says
on the front, but the transformer says 10A, with 2 x 10-turn 10k
pots for V and I control. The LED display is not there unfortunately
but can be replaced easily enough. The active control is an SFC2723C
in 10-pin can. Research suggests this is an old old precision voltage
controller or reference. All semis have 1980 date codes, and overall
it's in good condition. The non-assuming front panel says VOEDING
25V 5A, with the pots marked I and U. A black and a red binding
post, and that's it

This circuit caught my eye for the higher outputs

http://www.electronics-lab.com/projects/power/003/

It has independently settable voltage and current. One reason it
appeals is that both pots, P1/P2, have an earthy end and the voltage
on the wiper is the control, so it should be fairly simple to interface
these to a PIC for display purposes. They are also both 10k, so a
common digital pot could be used

One question I have is about the bypass transistor Q4, a 2N3055

I'd like to parallel 3 x 2N3055, as in this circuit

http://www.freewebs.com/acselectronics/buildregs.html

How would I best parallel 2N3055 in the electronics-lab link ?

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist