[R-390] CAPACITOR FIGHT

[John]

What RF voltage is across the filter?  Anyone ever
consider protective zener diodes?

John
KK6IL

On 8/4/2014 2:13 PM, David Wise wrote:
> I tried to calculate the reliability of film/foil vs. ceramic for C553 and got unclear results; it depended on the method I used.  Both types had a definite voltage derating effect; if you pick something rated at 1kV or more, it's overwhelmingly likely that your cap will outlast many generations, which realistically speaking is so far in the future it's meaningless.
>
> Do burn in your part before installing it, by floating it at its rated voltage and temperature for a few days.  If it gets past that, you're not likely to see an infant-mortality event.
>
> I also simulated a metalized-film self-heal event in SPICE, and got an 80mA current peak that lasted 10us.  I don't think this will heat the wire enough to fuse it, but who wants to test it when film/foils are still readily available?
>
> Dave Wise
>