17 Jan
2015
17 Jan
'15
4:53 p.m.
In my case of vt100 powersupply test (i hope that i
remember corretly) i need to load 5V with a small load.
With nothing connected, some voltages fail.
From what I remember, the VT100 and VT101 PSUs are very
different. The former is a fairly conventional
SMPSU, albeit one which (as was
typical for DEC at the time) has the control circuitry on the output side of
the isolation barrier and a little linear startup PSU. The VT101 has a large mains
transformer and a regulator
board, I think some of those regulators are switchers, but they run from a lowish input
voltage (not mains) and
the isolation is provided by the big transformer.
I don't know about running them with no load, although I could well believe the VT101
PSU will work
correctly like that.
-tony