"Ralph Cameron" wrote in message
...
Looking for a circuit diagram for a Pyramid PS-50, 12-15V dc @50Amps
supply. This is marked as having been made by Tenna and has both
voltsage and current meters.

Any help appreciated to get this thing operational.
Thanks
Ralph VE3BBM
Ralph -

I have never seen Pyramid or Temma release to the public their schematic
diagrams (BUT Astron does -- support & quality)
http://www.repeater-builder.com/astr...ron-index.html

IF this is a linear power supply (large heavy transformer) -- a majority of
these designs are based on the common "723" regulator chip [IC] (originally
designed by Fairchild Semiconductor in the 1970s) with 2N3055, 2N3771 or
2N3772 transistors on external heatsinks serving as the "pass" transistors.
[LM723 is the Signetics number]. Pyramid likes to solder this chip to PC
board-- which I replace with socket for future service.

You will find most of the information you require on the KBT DC Supplies web
site
http://www.kbt-dc-supplies.com/index.php

David Metz's classic 1996 web page on linear power supplies.
http://www.seits.org/features/pwrsup.htm

g. beat
w9gb