04-11-2022, 04:59 PM
(This post was last modified: 04-11-2022, 05:17 PM by Mike Watterson.)
Assume 300V rating (minimum).
The neon only flashes if there is a non-leaky capacitor across it and a test capacitor is only a bit leaky. A typical paper dielectric cap has so much leakage the neon seems just lit.
A microwave oven rectifier is a bad idea. A single 1N4007 rectifier.
Is this like yours?
Schematic revised by someone here.
I checked the PDF downloaded from here and there is a capacitor across the neon. It will need replaced. Any polyester 150V or more. It's listed as C7 0.47 uF, but 0.1uF or more will work. Claimed to need 500V, but the neon strikes at less than 100V and is about 55V to 60V when lit. I suppose needs to be 500V if the neon broke.
Unplug valves and disconnect metal rectifier. Put 30V limited to 5mA on + of C5 to reform the C5 & C6. If the current doesn't fall to zero they may be leaky. If the 30V disappears too quick when PSU removed, then the caps may be dried out.
C1 and C2 are silver mica so likely OK.
C4 is allegedly 1000V 10nF. A ceramic part should do.
C8 is ceramic so should be OK
C5 & C6 are electrolytic, supposedly 500V
The neon only flashes if there is a non-leaky capacitor across it and a test capacitor is only a bit leaky. A typical paper dielectric cap has so much leakage the neon seems just lit.
A microwave oven rectifier is a bad idea. A single 1N4007 rectifier.
Is this like yours?
Schematic revised by someone here.
I checked the PDF downloaded from here and there is a capacitor across the neon. It will need replaced. Any polyester 150V or more. It's listed as C7 0.47 uF, but 0.1uF or more will work. Claimed to need 500V, but the neon strikes at less than 100V and is about 55V to 60V when lit. I suppose needs to be 500V if the neon broke.
Unplug valves and disconnect metal rectifier. Put 30V limited to 5mA on + of C5 to reform the C5 & C6. If the current doesn't fall to zero they may be leaky. If the 30V disappears too quick when PSU removed, then the caps may be dried out.
C1 and C2 are silver mica so likely OK.
C4 is allegedly 1000V 10nF. A ceramic part should do.
C8 is ceramic so should be OK
C5 & C6 are electrolytic, supposedly 500V
