Does 2 caps = increased voltage rating?

[petemoore]

Can caps be paralleled or seriesed to meet a higher voltage rating need?

[Mark Hammer]

As I understand it, yes.  Gerald Weber, in his Vintage Guitar column, often discusses use of two higher value caps in series to achieve a higher voltage rating for safety purposes.  So, the original amp may call for a 22uf/600v cap.  The power section may want 485v on the plates.  The local outlet may stock nothing higher than 450v.  What to do?  A pair of 47uf/450 caps, end to end, will give you a capacitance value of 23.5uf at a 900v rating.

Please, dear lord, somebody correct me if I spent too little time digesting Gerald's column.  That's a whole lotta volts to "misunderstand". :shock:  :shock:

[MartyMart]

I just had a quick "look up" read ( not that article I add ) and thats not how it seems to me.
capacitance adding/dividing YES
voltage rating stays the same ie: 2x 25volt caps doesn't = 1x 50v cap !!
I bow to your greater knowledge and appologise if i'm wrong !  :oops:

Marty.

[petemoore]

I know  a way to find out, but it'd probably be stinky and cost a cap or two...connect a 10v rated cap to 18v volts, the try series/parallel combos [~= to same uf value] and see what happens...I think I'll wait to see if someone elses calculations or field test results get posted !!!...the tube output section board says .1uf   400V, I want to feel like I understand before I start in on that.

[seanm]

This article says that Mark is right: http://www.oz.net/~coilgun/theory/capacitors2.htm

Warning: If one of the caps goes bad, all of them can blow since they now see too much voltage! You might want to triple up for safety. i.e. if you need 400v, 3 x 250v might be safer.

[aron]

That's a great link. We use the resistor network in amps for the power supply all the time. It bleeds the circuit too!

Thanks for the link!

[petemoore]

Very good then.
 If only I could read the math, the bottom half would make sense, filling in the numbers is above my calculating capacity.
 Thanks to Cornell Dublier, responders to this thread, etc., very informative...I hope to try again soon to find an 'exploded' definition of electronic equational terms [like what R = 1/2 + C means].
 I understand capacitors and resistors basically and now, how parallel/series capacitors voltage ratings work, if I spent a while with a printed page of terms used on the link provided, perhaps I'd be able to try filling in the numbers on the balancing schematic. Probably that's more math terms than one page could cover...please don't spend time typing it for me here...
 I know the courses of action I have for the present project, the right size caps are first choice.