Simple question, filter caps larger than spec


2008-01-25 4:37 pm
Simple question,

If you were building a PS from a schematic and the caps you had were a bit different (larger) than the spec, would it make that much of a difference?

Say, it was specced for 100uF and then 200uF, if you used 150uf and 250uF because that's what you had, would it hurt at all?

My intuition tells me that it would only filter better as long the values weren't so ridiculously large that some other electric effect (leakage, induction, etc.) might have some weird side effect. Of course intuition can be wrong.
Electrolytic caps usually have a +/- 20% tolerance, so the actual value will be a bit different from what's printed on them. A 50uF difference shouldn't be anything to worry about. (Well, maybe only in some certain situations, but in PSUs this shouldn't be an issue.)

Just make sure the voltage rating of your available caps matches or exceeds the needs of the circuit :)