28 Feb
2009
28 Feb
'09
7:37 a.m.
Rich is right.
No commodity LDO regulators to be had then.
Suplies to rail were usually big transformer and bridge rectifier in
front of large caps.
American iron was inexpensive then.
Steve
Richard A. Cini wrote:
On 2/28/09 10:03 AM, "Andrew Lynch"
<lynchaj at yahoo.com> wrote:
Hi! What are acceptable voltage supply ranges
for an S-100 power supply? I
am assuming 115VAC input. My intended application is a small home brew
S-100 backplane.
I have seen the S-100 voltage rails vary but I believe +15VDC, -15VDC, and
+9VDC would be sufficient. Herb's S-100 page lists the voltages as +18VDC,
-16VDC, and +8VDC but I have seen other voltages used.
Most of the S-100 cards used on-board linear regulators so I'm sure that the
filtered DC voltages on those rails were set to provide adequate input
headroom for the 7805's and 7812's that were typically used.
Of course there may be exceptions.
Rich
--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.altair32.com
http://www.classiccmp.org/cini