Capacitor voltage question

[josephdaniel]

I'm currently doing some work on my Predicta Holiday to see if I can get it working and there is a silver mica capacitor on the PCB that I think I should replace, but when I look at the Sams folder there is no voltage listed for it? Does anyone know what the voltage and tolorence rating on it should be?

Another thing, I am also going to rebuild the K4 network as I hear that these are the most failure prone ones in these TV sets. One of the capacitors is 2200 MMF and the other is 1500 MMF. I'm guessing that the voltage on these should be somewhere around 1K volts judging from the surrounding components?

Sorry if the answer for this question is painfully obvious...

[old_tv_nut]

If you could figure out what voltage is normally across it, you could answer this question. If you just need a safe number without knowing how it's placed in the circuit, it should be greater than the B+ supply voltage to that section.

[bob91343]

Nearly all mica capacitors are rated for high enough voltages. The only exceptions I know of are those multilayer types and they are ceramic anyway. Typically the lowest ratings of mica are about 300 V. You can play it safe by using higher rating.

[bandersen]

I used a 1,000 volt mica, but a 500 is probably more than enough.

[josephdaniel]

Originally Posted by bandersen

I used a 1,000 volt mica, but a 500 is probably more than enough.

Thanks, I will use those to just to be on the safe side.
Should the caps in the K4 network be the same voltage?

[M3-SRT8]

Careful. If they don't quote voltages on the parts list on mica caps, assume 500 volts ratings, just to be safe. If they do quote voltage is on micas, it's usually 800, 1000, 1500, or more.