Northstar S100 compatability

From: Jack Peacock <peacock_at_simconv.com>
Date: Fri Mar 20 13:06:49 1998

>Well, the mains transformer is wired OK; it happily takes the
240V in and
>spits out something (?) like 8VAC, 16VAC and respectively. The
16VAC then
>goes through what I assume is a bridge rectifier, and out comes
approx.
>+32VDC and -32VDC. The snag *is* that it's meant to be
supplying 16, not
>32v! The 8v rail, fortunately, is fine.


Are you sure you measured from the right ground? I have never
seen a bridge rectifier that would take 16VAC going in, then
provide +/-32VDC coming out the DC side. Connect your ground
lead to pin 50 on the S-100 bus (the rightmost side, pins 50 and
100 are signal/power ground). You should see +8VDC (roughly) on
bus pin 1/51, +16VDC on pin 2 (or 52, I forget which, don't have
a schematic in front of me), and -16Vdc on pin 52 (or pin 2).
If you still show +/-32VDC, look at the transformer, something's
wrong there (you would have a 120V xfrmr instead of a 240V one).
    Jack Peacock
Received on Fri Mar 20 1998 - 13:06:49 GMT