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From: john larkin <jl@glen--canyon.com>
Newsgroups: sci.electronics.design
Subject: Re: heating a cap
Date: Fri, 04 Oct 2024 14:42:34 -0700
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On Fri, 4 Oct 2024 19:15:14 +0100, John R Walliker
<jrwalliker@gmail.com> wrote:

>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

You could get similar results from a bottle of vodka.