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Old 12th Jan 2012, 3:34 pm   #34
GMB
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Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
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Default Re: capacitors in series - pitfalls?

Quote:
We have all been taught and accepted the wisdom that voltage ratings on components are sacrosanct,
I suggest that they are to a large extent, because you don't know what headroom they have.

The voltage on them is the stress they must endure. The leakage that flows is just an indication of their condition and not a "stress" as such, although it is true that the leakage current leads to potential degradation of the dielectric so is undesirable, but when we talk of new components these currents are seriously small.

I agree with the comments from Kalee20 in that you can get serious and permanent damage to non-electrolytic capacitors when they are taken to their breakdown voltage. Also, that the external leakage must not be ignored (at these tiny levels).

Electrolytics are a bit different in that the effect of low-current leakage is to continuously increase their working voltage (that's rather how it got there in the first place) but at the expense of their capacity of course.
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