I am trying to safely (i.e. without magic smoke) power up an old power supply with a ferroresonant transformer circuit. It is in a vintage computer I am restoring. There is a schematic at http://96.0.36.155/parasitic.pdf. Since the supply is loaded with old, big electrolytic capacitors and has not been in a climate-controlled environment or powered on in 30+ years, I decided to be very cautious. I hooked the power supply up to a 0-120 vac variac with a 60 watt light bulb in series with the output, figuring that if the light lights there is a short somewhere. When I turned it on and got the variac up to about 25 vac, the lamp started glowing. I disconnected all the rectifiers from the power supply transformer and tried again with the same result. I disconnected the big 3 uf 330 vac capacitor that is across one of the power supply transformer secondaries and got no glow up to about 60 volts, where I stopped. I discharged the power supply 3 uf capacitor and measured across it with a vom. That showed no short in either direction (it looks open).
My questions are:
- Is it safe to power up the supply all the way with the 3 uf capacitor out of the circuit? Will the transformer voltages be abnormal in any way, or will there just not be any regulation or transient suppression?
- Can a low input voltage cause the ferroresonant circuit to draw abnormal current until the supply voltage gets up to normal?
Power supplies are NOT my thing . Any help or advice is greatly appreciated!
My questions are:
- Is it safe to power up the supply all the way with the 3 uf capacitor out of the circuit? Will the transformer voltages be abnormal in any way, or will there just not be any regulation or transient suppression?
- Can a low input voltage cause the ferroresonant circuit to draw abnormal current until the supply voltage gets up to normal?
Power supplies are NOT my thing . Any help or advice is greatly appreciated!