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Blowing up electrolytic capacitors
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Cursitor Doom
Dec 31, 2023, 1:24:16 PM12/31/23
to
I had some time on my hands today as the parts I was waiting for still
haven't turned up. I hooked up my HT PSU which is continuously
variable between zero and 400VDC and decided it would pass some time
to blow up some old caps. I took a 1uF 10V electro and applied just
over 100V across it. Just for good measure, I wired it up with the
polarity reversed. ***BANG!!!*** Jeezus they don't half go! My ears
are still ringing. I did put on safety glasses but that was all. I
think if I'd been hit by any little bit of that thing it would
probably have drawn blood. At this point I decided it would not be
wise to move on to blowing up any larger caps. I'm still curious to
know how big a bang one would get from hooking up say a 10,000uF cap
to the mains, though. Anyone tried this?
haven't turned up. I hooked up my HT PSU which is continuously
variable between zero and 400VDC and decided it would pass some time
to blow up some old caps. I took a 1uF 10V electro and applied just
over 100V across it. Just for good measure, I wired it up with the
polarity reversed. ***BANG!!!*** Jeezus they don't half go! My ears
are still ringing. I did put on safety glasses but that was all. I
think if I'd been hit by any little bit of that thing it would
probably have drawn blood. At this point I decided it would not be
wise to move on to blowing up any larger caps. I'm still curious to
know how big a bang one would get from hooking up say a 10,000uF cap
to the mains, though. Anyone tried this?
Jeff Liebermann
Dec 31, 2023, 2:01:51 PM12/31/23
to
On Sun, 31 Dec 2023 18:24:08 +0000, Cursitor Doom <c...@notformail.com>
wrote:
You'll get a bigger bang if with more voltage and less capacitance.
U = 0.5 * C * V^2
Double the voltage gives you 4 times the stored energy.
Yes, I've had some experience making big bangs with high voltage
capacitors. No, I don't want to discuss it. Well, maybe a few hints.
What you experienced with the electrolytic capacitor was a steam
explosion where the heat generated by pushing current through the
internal resistance of the capacitor produced enough heat to boil the
electrolyte. The sealed casing or can provided the necessary
confinement. As you get into physically larger capacitors with oil
dielectrics, it will be the oil that is headed and explodes.
Please remember that you have only one life to give for your hobby.
--
Jeff Liebermann je...@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
U = 0.5 * C * V^2
Double the voltage gives you 4 times the stored energy.
Yes, I've had some experience making big bangs with high voltage
capacitors. No, I don't want to discuss it. Well, maybe a few hints.
What you experienced with the electrolytic capacitor was a steam
explosion where the heat generated by pushing current through the
internal resistance of the capacitor produced enough heat to boil the
electrolyte. The sealed casing or can provided the necessary
confinement. As you get into physically larger capacitors with oil
dielectrics, it will be the oil that is headed and explodes.
Please remember that you have only one life to give for your hobby.
--
Jeff Liebermann je...@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
Sam Plusnet
Dec 31, 2023, 2:06:01 PM12/31/23
to
dreadful smell.
It must be more than 30 years since I had one go 'bang', but the memory
lingers.
--
Sam Plusnet
Carlos E.R.
Dec 31, 2023, 2:35:53 PM12/31/23
to
the methacrylate boards. All other components were on top, but this one
was beneath the board.
When we asked, they pointed to a stain on the ceiling.
And when some of us volunteered to work as aides the next year, they
stressed on us to be very vigilant about when the newbies connected the
caps.
Another point to watch were a pot, when connecting to get a variable ac
voltage to calibrate a meter.
110v ---\
/
\
/<--------
\
/
0C-----\----------
Well, some one connected the 110 (which here is half the mains, as a
precaution) on the right hand. And he had a baffled face when it went up
in smoke as he turned the spindle :-DD
--
Cheers, Carlos.
Cursitor Doom
Dec 31, 2023, 2:37:04 PM12/31/23
to
On Sun, 31 Dec 2023 11:01:34 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:
Thanks for that, Jeff. Yes, one was enough for today! It just struck
me that there might be some scope to use this 'phenomenon' as a
propellant to blast some cylindrical projectile out of a barrel and
measure the energy released (comparative measurement, anyway) by the
depth said projectile was able to penetrate a block of wood. There
ought to be some formula to convert those factors (projectile weight,
cross sectional area, depth of penetration etc) into a credible figure
in joules. That way you could more readily compare the energy released
by igniting different caps with different voltages and seeing what -
literally - gives you the most bang for your buck! Sadly I don't think
I'll ever have the time, though as there are too many other pressing
tasks I need to get to grips with. So no time for any more fun, sadly.
:(
wrote:
me that there might be some scope to use this 'phenomenon' as a
propellant to blast some cylindrical projectile out of a barrel and
measure the energy released (comparative measurement, anyway) by the
depth said projectile was able to penetrate a block of wood. There
ought to be some formula to convert those factors (projectile weight,
cross sectional area, depth of penetration etc) into a credible figure
in joules. That way you could more readily compare the energy released
by igniting different caps with different voltages and seeing what -
literally - gives you the most bang for your buck! Sadly I don't think
I'll ever have the time, though as there are too many other pressing
tasks I need to get to grips with. So no time for any more fun, sadly.
:(
John Larkin
Dec 31, 2023, 2:55:37 PM12/31/23
to
On Sun, 31 Dec 2023 19:36:56 +0000, Cursitor Doom <c...@notformail.com>
The energy stored in the capacitance is trivial. Short a fully charged
cap and you'll get a modest pop. The explosions you are seeing are
from steam pressure, built up over time by the power source. Or with a
really big power supply, vaporization of the wires and foil inside.
cap and you'll get a modest pop. The explosions you are seeing are
from steam pressure, built up over time by the power source. Or with a
really big power supply, vaporization of the wires and foil inside.
Clive Arthur
Dec 31, 2023, 3:03:23 PM12/31/23
to
On 31/12/2023 18:24, Cursitor Doom wrote:
> I had some time on my hands today as the parts I was waiting for still
> haven't turned up. I hooked up my HT PSU which is continuously
> variable between zero and 400VDC and decided it would pass some time
> to blow up some old caps. I took a 1uF 10V electro and applied just
> over 100V across it. Just for good measure, I wired it up with the
> polarity reversed. ***BANG!!!*** Jeezus they don't half go! My ears
> are still ringing.
<snip>
> I had some time on my hands today as the parts I was waiting for still
> haven't turned up. I hooked up my HT PSU which is continuously
> variable between zero and 400VDC and decided it would pass some time
> to blow up some old caps. I took a 1uF 10V electro and applied just
> over 100V across it. Just for good measure, I wired it up with the
> polarity reversed. ***BANG!!!*** Jeezus they don't half go! My ears
> are still ringing.
Years ago, small electrolytics were used to simulate machine gun fire in
films. Typically, a line of such would be wired to a selector switch,
and buried in the plasterwork of a wall. The switch would be manually
rotated to blow them up in sequence.
Cheaper than pyrotechnics and presumably less paperwork. Film and TV
technicians are an ingenious lot.
--
Cheers
Clive
alan_m
Dec 31, 2023, 3:09:59 PM12/31/23
to
On 31/12/2023 18:24, Cursitor Doom wrote:
amplifiers. After manufacture they were put on a soak test. One had a
(very) large electrolytic connected the wrong way around. When that went
up the can hit the warehouse roof.
In another job a tantalum bead capacitor was fitted the wrong way
around. There was a cherry red glow and some magic smoke. A short time
later when examining the PCB the capacitor decided to come apart with a
loud pop sending small shards of its ceramic casing across the room.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
Joe
Dec 31, 2023, 3:32:24 PM12/31/23
to
cylindrical surface-mount types, contain an electrolyte which will
dissolve copper, and quite likely other things. You don't want that
sprayed around.
Using these things above their rated temperature caused the electrolyte
to ooze out, which could cause any fault you can imagine, as well as
often making the PCB non-repairable (at least, without jumper wires).
--
Joe
Jeff Liebermann
Dec 31, 2023, 4:07:55 PM12/31/23
to
On Sun, 31 Dec 2023 19:36:56 +0000, Cursitor Doom <c...@notformail.com>
wrote:
>It just struck me
Hopefully, it did not strike you very hard.
>that there might be some scope to use this 'phenomenon' as a
>propellant to blast some cylindrical projectile out of a barrel and
>measure the energy released (comparative measurement, anyway) by the
>depth said projectile was able to penetrate a block of wood.
Sure. Just put the capacitor in a suitable gun like device. Stuff a
projectile down the barrel and a capacitor in the chamber. Apply
power and the steam or oil explosion will do the rest. Unfortunately,
capacitors are not designed for efficient combustion so the useful
power might be rather limited. I think the big problem will be the
slow recharge time. Charging energy storage caps to kilovolt levels
can take something close to forever.
Perhaps if you start with a coil gun. (That's a coil gun, not a rail
gun).
<https://www.electroboom.com/?p=101>
<https://www.youtube.com/watch?v=mdZo_keUoEs>
You'll probably like ElectroBoom. He make videos of things that
explode, electrocute, burn etc and posts them to his YouTube channel.
<https://www.youtube.com/@ElectroBOOM/videos>
>There
>ought to be some formula to convert those factors (projectile weight,
>cross sectional area, depth of penetration etc) into a credible figure
>in joules.
That's been done for firearms. The result is muzzle energy in ft-lbs.
1 joule = 0.737562 ft-lbs
1 ft-lb = 1.35582 joules
Everything beyond the muzzle is called ballistics. There are tables
for the energy required to penetrate various materials but I'll
pretend not to know anything about those.
>That way you could more readily compare the energy released
>by igniting different caps with different voltages and seeing what -
>literally - gives you the most bang for your buck!
All you need it the weight of the projectile and its velocity. There
are ballistics tables and calculators that will provide the remaining
velocity at a given range.
>Sadly I don't think
>I'll ever have the time, though as there are too many other pressing
>tasks I need to get to grips with. So no time for any more fun, sadly.
>:(
Good. For a moment, I thought you were serious. Please find
something to do which is safer and less destructive.
wrote:
>It just struck me
Hopefully, it did not strike you very hard.
>that there might be some scope to use this 'phenomenon' as a
>propellant to blast some cylindrical projectile out of a barrel and
>measure the energy released (comparative measurement, anyway) by the
>depth said projectile was able to penetrate a block of wood.
projectile down the barrel and a capacitor in the chamber. Apply
power and the steam or oil explosion will do the rest. Unfortunately,
capacitors are not designed for efficient combustion so the useful
power might be rather limited. I think the big problem will be the
slow recharge time. Charging energy storage caps to kilovolt levels
can take something close to forever.
Perhaps if you start with a coil gun. (That's a coil gun, not a rail
gun).
<https://www.electroboom.com/?p=101>
<https://www.youtube.com/watch?v=mdZo_keUoEs>
You'll probably like ElectroBoom. He make videos of things that
explode, electrocute, burn etc and posts them to his YouTube channel.
<https://www.youtube.com/@ElectroBOOM/videos>
>There
>ought to be some formula to convert those factors (projectile weight,
>cross sectional area, depth of penetration etc) into a credible figure
>in joules.
1 joule = 0.737562 ft-lbs
1 ft-lb = 1.35582 joules
Everything beyond the muzzle is called ballistics. There are tables
for the energy required to penetrate various materials but I'll
pretend not to know anything about those.
>That way you could more readily compare the energy released
>by igniting different caps with different voltages and seeing what -
>literally - gives you the most bang for your buck!
are ballistics tables and calculators that will provide the remaining
velocity at a given range.
>Sadly I don't think
>I'll ever have the time, though as there are too many other pressing
>tasks I need to get to grips with. So no time for any more fun, sadly.
>:(
something to do which is safer and less destructive.
Brian Gregory
Dec 31, 2023, 5:32:52 PM12/31/23
to
On 31/12/2023 19:01, Jeff Liebermann wrote:
> Please remember that you have only one life to give for your hobby.
And that capacitors may contain unpleasant, and possibly even mildly
> Please remember that you have only one life to give for your hobby.
poisonous chemicals. You can end up with a mess that it takes more than
just a dustpan and brush to clean up.
--
Brian Gregory (in England).
Cursitor Doom
Dec 31, 2023, 5:34:31 PM12/31/23
to
On Sun, 31 Dec 2023 13:07:39 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:
>On Sun, 31 Dec 2023 19:36:56 +0000, Cursitor Doom <c...@notformail.com>
>wrote:
>
>>It just struck me
>
>Hopefully, it did not strike you very hard.
>
>>that there might be some scope to use this 'phenomenon' as a
>>propellant to blast some cylindrical projectile out of a barrel and
>>measure the energy released (comparative measurement, anyway) by the
>>depth said projectile was able to penetrate a block of wood.
>
>Sure. Just put the capacitor in a suitable gun like device. Stuff a
>projectile down the barrel and a capacitor in the chamber. Apply
>power and the steam or oil explosion will do the rest. Unfortunately,
>capacitors are not designed for efficient combustion so the useful
>power might be rather limited. I think the big problem will be the
>slow recharge time. Charging energy storage caps to kilovolt levels
>can take something close to forever.
>
>Perhaps if you start with a coil gun. (That's a coil gun, not a rail
>gun).
><https://www.electroboom.com/?p=101>
><https://www.youtube.com/watch?v=mdZo_keUoEs>
I'm not sure if one could build a credible hand-held weapon of the
coil gun kind. You'd never get anywhere close to the velocities
achieved by convenional firearms. Nevertheless, I guess this is coming
down the pike in the near future as supercaps become cheaper or if
battery technology makes a quantum leap. That could become a major
headache for law enforment agencies in x number of years from now. I'm
surprised we haven't had some serious terrorist attacks using drones
and lasers before now, in fact.
>You'll probably like ElectroBoom. He make videos of things that
>explode, electrocute, burn etc and posts them to his YouTube channel.
><https://www.youtube.com/@ElectroBOOM/videos>
Yes, I've seen this chap before a while back. It's amazing he still
seems to have both eyes and all his fingers - and is still breathing
for that matter!
>
>>There
>>ought to be some formula to convert those factors (projectile weight,
>>cross sectional area, depth of penetration etc) into a credible figure
>>in joules.
>
>That's been done for firearms. The result is muzzle energy in ft-lbs.
>1 joule = 0.737562 ft-lbs
>1 ft-lb = 1.35582 joules
>Everything beyond the muzzle is called ballistics. There are tables
>for the energy required to penetrate various materials but I'll
>pretend not to know anything about those.
>
>>That way you could more readily compare the energy released
>>by igniting different caps with different voltages and seeing what -
>>literally - gives you the most bang for your buck!
>
>All you need it the weight of the projectile and its velocity. There
>are ballistics tables and calculators that will provide the remaining
>velocity at a given range.
>
>>Sadly I don't think
>>I'll ever have the time, though as there are too many other pressing
>>tasks I need to get to grips with. So no time for any more fun, sadly.
>>:(
>
>Good. For a moment, I thought you were serious. Please find
>something to do which is safer and less destructive.
Gladly. As I say, fortunately I don't have the time for indulging in
such nonsense!
wrote:
>On Sun, 31 Dec 2023 19:36:56 +0000, Cursitor Doom <c...@notformail.com>
>wrote:
>
>>It just struck me
>
>Hopefully, it did not strike you very hard.
>
>>that there might be some scope to use this 'phenomenon' as a
>>propellant to blast some cylindrical projectile out of a barrel and
>>measure the energy released (comparative measurement, anyway) by the
>>depth said projectile was able to penetrate a block of wood.
>
>Sure. Just put the capacitor in a suitable gun like device. Stuff a
>projectile down the barrel and a capacitor in the chamber. Apply
>power and the steam or oil explosion will do the rest. Unfortunately,
>capacitors are not designed for efficient combustion so the useful
>power might be rather limited. I think the big problem will be the
>slow recharge time. Charging energy storage caps to kilovolt levels
>can take something close to forever.
>
>Perhaps if you start with a coil gun. (That's a coil gun, not a rail
>gun).
><https://www.electroboom.com/?p=101>
><https://www.youtube.com/watch?v=mdZo_keUoEs>
coil gun kind. You'd never get anywhere close to the velocities
achieved by convenional firearms. Nevertheless, I guess this is coming
down the pike in the near future as supercaps become cheaper or if
battery technology makes a quantum leap. That could become a major
headache for law enforment agencies in x number of years from now. I'm
surprised we haven't had some serious terrorist attacks using drones
and lasers before now, in fact.
>You'll probably like ElectroBoom. He make videos of things that
>explode, electrocute, burn etc and posts them to his YouTube channel.
><https://www.youtube.com/@ElectroBOOM/videos>
seems to have both eyes and all his fingers - and is still breathing
for that matter!
>
>>There
>>ought to be some formula to convert those factors (projectile weight,
>>cross sectional area, depth of penetration etc) into a credible figure
>>in joules.
>
>That's been done for firearms. The result is muzzle energy in ft-lbs.
>1 joule = 0.737562 ft-lbs
>1 ft-lb = 1.35582 joules
>Everything beyond the muzzle is called ballistics. There are tables
>for the energy required to penetrate various materials but I'll
>pretend not to know anything about those.
>
>>That way you could more readily compare the energy released
>>by igniting different caps with different voltages and seeing what -
>>literally - gives you the most bang for your buck!
>
>All you need it the weight of the projectile and its velocity. There
>are ballistics tables and calculators that will provide the remaining
>velocity at a given range.
>
>>Sadly I don't think
>>I'll ever have the time, though as there are too many other pressing
>>tasks I need to get to grips with. So no time for any more fun, sadly.
>>:(
>
>Good. For a moment, I thought you were serious. Please find
>something to do which is safer and less destructive.
such nonsense!
Pamela
Dec 31, 2023, 6:26:36 PM12/31/23
to
On 22:32 31 Dec 2023, Brian Gregory said:
> On 31/12/2023 19:01, Jeff Liebermann wrote:
>>
>> Please remember that you have only one life to give for your hobby.
>
> And that capacitors may contain unpleasant, and possibly even mildly
> poisonous chemicals. You can end up with a mess that it takes more than
> just a dustpan and brush to clean up.
>
As a child, I got rid of some dead zinc-carbon batteries by throwing them
> On 31/12/2023 19:01, Jeff Liebermann wrote:
>>
>> Please remember that you have only one life to give for your hobby.
>
> And that capacitors may contain unpleasant, and possibly even mildly
> poisonous chemicals. You can end up with a mess that it takes more than
> just a dustpan and brush to clean up.
>
onto the coal fire in the living room. What a noise and what a mess.
Paul
Dec 31, 2023, 9:26:33 PM12/31/23
to
https://i.postimg.cc/rFKXgJ1f/Mister-Potentiometer.gif
And the reason this happens, is the treatment of potentiometers is poor in
Introductory Electronics.
The students end up in the Power Lab, with no practical experience
or education about pots.
Basically, the students are given a three terminal device, without
knowing the canonical (practitioner) usage forms. And they're sent
into Power Lab, to learn about the behavior "at scale" :-) The
best way to learn. Nothing reinforces a mistake better, than
a cloud of smoke. Right ?
In my Power Lab, one of the student teams, just put the ends of
the rheostat across mains (240V). I calculated later, that this mis-step
dissipated about 5kW. No reason for the breaker to open of course.
And it made a festive Yule Log out of the device,
glowing bright cherry red like an "electric fire". The device got hot
enough, the coils of wire fell of it. Such a beautiful piece of handiwork.
Stu-dentin.
Paul
Jan Panteltje
Jan 1, 2024, 1:06:09 AM1/1/24
to
On a sunny day (Sun, 31 Dec 2023 18:24:08 +0000) it happened Cursitor Doom
<c...@notformail.com> wrote in <pub3pi5hco64nms8o...@4ax.com>:
Here you can just buy firecrackers around this time of year
last night was bangs all over the place.
Keep you elcos in a box, you may need those for fun projects.
Also there was an hospital alarm over all the people with eye damage from the fireworks here.
2 people died so far igniting whatever it was.
<c...@notformail.com> wrote in <pub3pi5hco64nms8o...@4ax.com>:
last night was bangs all over the place.
Keep you elcos in a box, you may need those for fun projects.
Also there was an hospital alarm over all the people with eye damage from the fireworks here.
2 people died so far igniting whatever it was.
The Natural Philosopher
Jan 1, 2024, 7:56:09 AM1/1/24
to
On 31/12/2023 18:24, Cursitor Doom wrote:
I'm still curious to
> know how big a bang one would get from hooking up say a 10,000uF cap
> to the mains, though. Anyone tried this?
Not me personally, but a guy who used to work for Marshall amplification
> know how big a bang one would get from hooking up say a 10,000uF cap
> to the mains, though. Anyone tried this?
said they did...
...once... :-)
--
"I guess a rattlesnake ain't risponsible fer bein' a rattlesnake, but ah
puts mah heel on um jess the same if'n I catches him around mah chillun".
Carlos E.R.
Jan 1, 2024, 8:32:59 AM1/1/24
to
On 2024-01-01 03:26, Paul wrote:
> On 12/31/2023 2:35 PM, Carlos E.R. wrote:
>> On 2023-12-31 19:24, Cursitor Doom wrote:
...
> On 12/31/2023 2:35 PM, Carlos E.R. wrote:
>> On 2023-12-31 19:24, Cursitor Doom wrote:
>> Another point to watch were a pot, when connecting to get a variable ac voltage to calibrate a meter.
>>
>>
>> 110v ---\
>> /
>> \
>> /<--------
>> \
>> /
>> 0C-----\----------
>>
>>
>> Well, some one connected the 110 (which here is half the mains,
>> as a precaution) on the right hand. And he had a baffled face
>> when it went up in smoke as he turned the spindle :-DD
>>
>
> [Picture]
>
> https://i.postimg.cc/rFKXgJ1f/Mister-Potentiometer.gif
>
> And the reason this happens, is the treatment of potentiometers is poor in
> Introductory Electronics.
>
> The students end up in the Power Lab, with no practical experience
> or education about pots.
> Basically, the students are given a three terminal device, without
> knowing the canonical (practitioner) usage forms. And they're sent
> into Power Lab, to learn about the behavior "at scale" :-) The
> best way to learn. Nothing reinforces a mistake better, than
> a cloud of smoke. Right ?
>
> In my Power Lab, one of the student teams, just put the ends of
> the rheostat across mains (240V). I calculated later, that this mis-step
> dissipated about 5kW. No reason for the breaker to open of course.
> And it made a festive Yule Log out of the device,
> glowing bright cherry red like an "electric fire". The device got hot
> enough, the coils of wire fell of it. Such a beautiful piece of handiwork.
> Stu-dentin.
Gosh, 5 KW :-)
--
Cheers, Carlos.
Brian Gregory
Jan 1, 2024, 9:43:24 AM1/1/24
to
John Smiht
Jan 2, 2024, 11:03:40 PM1/2/24
to
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