Re: heating a cap

On 04/10/2024 18:00, Cursitor Doom wrote:

On Thu, 03 Oct 2024 16:36:24 -0700, john larkin <jl@glen--canyon.com>
wrote:
 

I got a small (under 1" long) aluminum electro cap, 220 uF 63v, and
cranked up the voltage. It started drawing a bunch of current at 105
volts, got hot, and folded back to 80 mA at 87v.
>
It got too hot to touch in a couple of minutes, after roughly 500
joules. Freeze spray let it go back up to 100 volts or so.
>
None of that seemed to damage it, so an electrolytic cap sort of has a
built-in MOV.

 That's a hell of sweeping conclusion to come to based on a test of
just one random electrolytic!

I once tried heating a large electrolytic salvaged from a valve TV.
With a blowtorch.  The side started to bulge, then it split.
A large flame maybe 1m long emerged, coloured a brilliant green.
I was wearing safety glasses.
John