Ripple

[Andy Le Blanc]

What happens to the max rms ripple current rating when caps are connect in series?
How is it affected by balancing resistors in the PS?

[Structo]

I may be wrong but I think the main reason we see caps in series with balancing resistors is to increase the voltage rating of that node.
EDIT:
Yes I got that wrong about the formula.

The resistors help keep the voltage even between them and as a side benefit they also act as bleeder resistors draining the caps when powered down.

But you probably knew all that, eh?

Maybe it just makes it gooder.

[Andy Le Blanc]

I was thinking of a parts order. When I noticed a cost correlation with the
ripple rating of the cap and which cap brands I've seen in popular use.

They look like the best max ripple for the buck. Is it halved with the capacitance value
when in series? or is it the other way round?

Can you use two lower rated caps in series and get an equivalent max ripple rating?

CAPS IN SERIES....

the total capacitance is the product of the two capacitances divided by their sum

say 1x1/1+1 = .5

CAPS IN PARALLEL.....

the total capacitance is the sum of the individual capacitances

say 1+1 + 2

Does the ripple rating follow the same basic relationships?

[Structo]

Yeah, I typed without thinking on the series capacitance formula.

I know this and still wrote it wrong.

I just try to remember it is the opposite of resistance.

Parallel capacitance you add the two values.

Like this:

[img:179:136]http://www.tpub.com/neets/book2/0151.GIF[/img]

I would have to read up on the ripple effect but I think you are on the right track, as I think it is part of the specifications of a cap.

Wiki has a write up on ripple

http://en.wikipedia.org/wiki/Ripple_(electrical)

[Merlinb]

If you use two caps identical in parallel then the ripple current rating is effectively doubled, since they should share it equally.

If you use two identical caps in series then their ripple current rating stays the same, since they both handle the same current.

[Andy Le Blanc]

Thank you....... It seemed to be a very basic and practical question, I've never seen it addressed.

I want to try a triode dress, but the donor PT requires a bridge rectifier.
I'm a bit worried about the PS ripple with the triode choice. It will be a P-P circuit,
but ..... cant rely solely on that for quieting PS issue's.