Cap voltage values

[Yoda]

In an amp design, it called for 25v caps, but i accidentally put 50v devices in... will this have any harmful effects, or is it just uneccesary?

 

[P.Lacombe]

Aluminium electrolytics capacitors can be used between 1/10 and 10/10 of nominal voltage without inconvenience.

This is not true for tantalum capacitors...

Regards, P.Lacombe.

 

[tschrama]

what's the story with those tantalum capacitors?

thijs

 

[P.Lacombe]

Tantalum capacitors exhibit abnormally high distortion level when DC voltage across them is low. I suppose that DC bias is necessary to maintain the integrity of the oxyde layer at the surface of the anode. User manuals of capacitance bridge meters advise to always charge tantalum capacitors at nominal value before measuring.

Regards, P.Lacombe.

 

[haldor]

Tantalum capacitors exhibit abnormally high distortion level when DC voltage across them is low. I suppose that DC bias is necessary to maintain the integrity of the oxyde layer at the surface of the anode.

Thanks for the info, that was news to me. Given the premium you pay for high voltage tantalum caps I have never tried to use a significantly over voltage rated tant. I do like to jump up a step or two voltage rating for electrolytics though to extend operating life.

Phil