1µF 50V and 1µF 16V - Are they interchangable

[Fei]

I am building my very first circuit. This is the circuit:

http://www.kpsec.freeuk.com/projects/flashl.htm

it says it requires a 1µF 16V radial capacitor...problem is the only one I have on hand is the 1µF 50V one. And radio shack doesn't sell the 16V either...are they interchangable?

 

[David Bridgen]

Yes, a capacitor with a higher voltage rating may be used.
(But not, generally, the other way round.)

 

[monkeytree]

yes but not usually the other way round

 

[theinfamousbob]

Bah! Radio Shack? The past few years they've gone down hill. Although they are selling Parallax Boe-Bot kits in my area now...

 

[Dean Huster]

Having a voltage that's a LOT higher than the required voltage can sometimes result in a change in the capacitance value (lowering) because the electrolytic action doesn't set up quite the same way as it would nearer the rated voltage. Newer caps probably aren't as prone to this as were the electrolytics of the 1960s and 1970s.

Dean

 

[Nigel Goodwin]

Having a voltage that's a LOT higher than the required voltage can sometimes result in a change in the capacitance value (lowering) because the electrolytic action doesn't set up quite the same way as it would nearer the rated voltage. Newer caps probably aren't as prone to this as were the electrolytics of the 1960s and 1970s.

But one important bi-product of using a higher voltage electrolytic is the ESR value, higher voltage capacitors have lower ESR for the same value!.

 

[Screech]

whats esr?

 

[Nigel Goodwin]

whats esr?

Effective Series Resistance - the main failure mode of electrolytics (with the crap modern ones!) is going high ESR.