Hi all,
Just a quick one. But first, I'd just like to reiterate that I'm
noting your comments on the ripple thread and will deal with them in
due course when i have a couple of hours to spare next Sunday.
Yesterday I had 2 minutes to waste so I blew up another electrolytic capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop* but
no bang and it turned out the T3.15 Amp fuse in the variac had blown spectacularly - but the cap had survived unscathed! Tested fine for capacitance and ESR! I never would have believed it. Just wondering
how the hell it didn't get destroyed...
Yesterday I had 2 minutes to waste so I blew up another electrolytic capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop*
but no bang and it turned out the T3.15 Amp fuse in the variac had
blown spectacularly - but the cap had survived unscathed! Tested
fine for capacitance and ESR! I never would have believed it. Just wondering how the hell it didn't get destroyed...
Cursitor Doom <cd@notformail.com> wrote:
Hi all,
Just a quick one. But first, I'd just like to reiterate that I'm
noting your comments on the ripple thread and will deal with them in
due course when i have a couple of hours to spare next Sunday.
Yesterday I had 2 minutes to waste so I blew up another electrolytic
capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop* but
no bang and it turned out the T3.15 Amp fuse in the variac had blown
spectacularly - but the cap had survived unscathed! Tested fine for
capacitance and ESR! I never would have believed it. Just wondering
how the hell it didn't get destroyed...
It's only doing it to annoy you. Make sure it is run well within its
ratings and put it on a board that has to be buried several layers deep
in some complicated equipment and is rivetted in place. It will fail
in no time at all and probably take several other valuable components
with it.
The fuse also did it's job, which is to protect downstream components
from overcurrent situations by blowing before the downstream items
themselves blow up.
On 2024/03/20 2:45 a.m., Liz Tuddenham wrote:
Cursitor Doom <cd@notformail.com> wrote:
Hi all,
Just a quick one. But first, I'd just like to reiterate that I'm
noting your comments on the ripple thread and will deal with them in
due course when i have a couple of hours to spare next Sunday.
Yesterday I had 2 minutes to waste so I blew up another electrolytic
capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop* but
no bang and it turned out the T3.15 Amp fuse in the variac had blown
spectacularly - but the cap had survived unscathed! Tested fine for
capacitance and ESR! I never would have believed it. Just wondering
how the hell it didn't get destroyed...
It's only doing it to annoy you. Make sure it is run well within its
ratings and put it on a board that has to be buried several layers deep
in some complicated equipment and is rivetted in place. It will fail
in no time at all and probably take several other valuable components
with it.
Lots of parts can be forced way past their rated maximums and suffer
internal damage that won't then show for a period of time in normal use.
That's why we have fuses, TSVs, MOVs, etc to help protect against spikes
and their aftereffects.
The only way to find what happened to the cap is to take the capacitor
apart and study the elements under a microscope for punctures and do a >chemical analysis on the electrolyte.
This is just A-Waste-Of-Time experiment and I can't believe I am
commenting on it...
Cursitor Doom <cd@notformail.com> wrote:
Hi all,
Just a quick one. But first, I'd just like to reiterate that I'm
noting your comments on the ripple thread and will deal with them in
due course when i have a couple of hours to spare next Sunday.
Yesterday I had 2 minutes to waste so I blew up another electrolytic
capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop* but
no bang and it turned out the T3.15 Amp fuse in the variac had blown
spectacularly - but the cap had survived unscathed! Tested fine for
capacitance and ESR! I never would have believed it. Just wondering
how the hell it didn't get destroyed...
It's only doing it to annoy you. Make sure it is run well within its
ratings and put it on a board that has to be buried several layers deep
in some complicated equipment and is rivetted in place. It will fail
in no time at all and probably take several other valuable components
with it.
On 20/03/2024 15:22, Bertrand Sindri wrote:
Cursitor Doom <cd@notformail.com> wrote:
Yesterday I had 2 minutes to waste so I blew up another electrolytic
capacitor - or rather I *tried* to. A 10uF 10V cap across the output
of a variac with Vo set to 240VAC. There was a considerable *pop*
but no bang and it turned out the T3.15 Amp fuse in the variac had
blown spectacularly - but the cap had survived unscathed! Tested
fine for capacitance and ESR! I never would have believed it. Just
wondering how the hell it didn't get destroyed...
Obviously it was able to survive the overcurrent situation for long
enough to blow the fuse in the variac. Since, as usual, you've left
off all useful information (i.e., make and model of cap) we can't
comment any further.
The fuse also did it's job, which is to protect downstream components
from overcurrent situations by blowing before the downstream items themselves blow up.
More importantly the fuse protected the variac. They are
very intolerant of even quite modest overloads.
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