On Sun, 04 Jan 2004 16:10:10 GMT, Larry wrote:

On Sun, 04 Jan 2004 03:18:07 GMT, Larry W4CSC wrote:

...snip

Junk it. I did mine. If that damned series pass transistor ever
shorts, you can kiss all your equipment hooked to it good bye when the
20-some volts hits them.

You probably know this, but you can (actually, must) prevent that happening
by putting a "crowbar" circuit across the output, after the fuse. This is
just a large scr with a resistor from the bus to the gate with a 14 or 15
volt zener to ground. It doesn't conduct until the voltage exceeds the
zener limit and then the scr shorts to ground, blowing the fuse and
protecting the equipment.

Nifty - I think I'll do that. Thanks.

Later,

Tom
S. Woodstock, CT
----------
"We may say of angling as Dr. Boteler said of strawberries:
Doubtless God could have made a better berry, but doubtless
God never did and so, if I might be judge, God never did make
a more calm, quiet, innocent recreation than angling."

Izaak Walton "The Compleat Angler"(1653)