18 May
2009
18 May
'09
1:32 a.m.
Hi,
You might contact:
http://www.antekinc.com/
for transformers.
As Chuck mentioned, a full-wave bridge feeding a cap will give 1.4x the
secondary output voltage.
You can parallel similar output windings in series or parallel as long
as you watch phase.
Consider that back in the 70s linear regs like LM309 and 7805 needed
fair overhead on the rail.
Newer LDOs by def need less.
If you want to scrounge, you might look in an older high current battery
charger with a "6V" tap.
At the risk of incurring purist wrath you might consider jumpering out
the regs on some boards and using one of the many almost free linear or
switching supplies to be found.
Some boards had multiple regs at same rail IIRC; might be a decoupling prob.
Haven't looked at S-100 since 1979, but believe you might have enough
pins and copper.
GL,
Steve
Andrew Lynch wrote:
Hi! Does anyone know of an available transformer
suitable for making an
S-100 power supply? I need 120VAC input and 10VAC output and +/- 18VAC
outputs.
The best I solution I can find is two separate 80VA transformers; one
parallel 10VAC output and another 36VCT output which can be configured for
+/-18VAC outputs.
I would prefer a single transformer rather than dual transformers because
they are the most expensive part of a linear power supply.
I know Northstar and Vector Graphic used similar dual output transformers
but I cannot find anything like them after searching the usual vendors like
Digikey, Mouser, Jameco, etc. Even transformer manufacturers don't seem to
carry a stock product of this configuration although you can order custom
units.
Thanks in advance for any help. Your ideas greatly appreciated.
Thanks and have a nice day!
Andrew Lynch