Kevin LaHaie <[EMAIL PROTECTED]> made an utterance to the drakelist gang
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Hello Drakelist
I had reported earlier that 'all was well' with my PS7 regulation problem.
Well, it might have been well all along, but I have this unusual (to me,
anyway) finding on why I had such a problem.
The problem still exists, but ONLY WHEN I BRING THE SUPPLY UP WITH A VARIAC!
I finally measured the voltage at the SCR gate which grounds out the
base of the transistor through which power is supplied to the LM723. (In
case the 723 senses trouble.) As the voltage was increased with the
variac, the voltage on the gate of the SCR rose until at about 3 volts
output, the gate voltage hit .8 volts. Result: Conduction, grounding
the base, 723 powerless, end of output.
BUT, when the voltage hit about 12 volts output (I had removed the SCR
from the base) VOLTAGE AT SCR RETURNS TO ZERO. 723 again indicating ALL
IS WELL, and output (and regulation) functioning perfectly.
So, when I power the supply normally (turn on radio with 117v ready at
input to the PS7) all performs as advertised! Can anybody tell me why
this happens?
Bottom line: it works, and I now will venture into the operation of the TR7.
Thanks again everybody!
73 de Kevin K7ZS
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