> On Jan 29, 2024, at 8:47 PM, Jonathan Chapman via cctalk
> <cctalk@classiccmp.org> wrote:
>
>> This apparently is true of some capacitors as well, I'm not sure which types.
>
> It is true of all capacitors (CRTs are intentional capacitors, after all)
> designed for and subjected to sufficiently high voltage. It's referred to as
> dielectric absorption, and is why HV caps ship from the factory with the
> leads shorted.
>
> I have a 4.7 uF tens-of-kV capacitor in the shop for reasons. The shorting
> jumper got knocked off once while moving stuff past it, and I noticed it the
> next day. By that point, it had accumulated enough charge to register over
> 200V on a Simpson 260 VOM (not a high impedance meter). I don't know if that
> was accumulated static charge or from dielectric absorption.
>
> Thanks,
> Jonathan
Thanks for the confirmation. And also a good reminder that static electricity
is one way to charge capacitors, at least ones with good dielectrics. After
all, the famous Leyden jar is nothing more than a capacitor charged by static
electricity, and it can certainly hand out substantial shocks.
paul
