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[moved] 24,000j Capacitor Bank (Now Complete)

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LAN_403

Tesladownunder

Thu Jul 10 2008, 05:48AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Yes and no.
Evenly distributed the energy would probably only raise your body temperature by a few degrees at a guess. It is only one 2kW electric kettle for 12 seconds after all.
I have tried to explode a sausage with 4kJ with almost no effect at all.
On the other hand if you arrange a high temperature spark inside the sausage like exploding a wire, then the explosive effect will be very destructive without much heating. This is how to blow up a watermelon or similar.

TDU

Marko

Thu Jul 10 2008, 12:51PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Yeah, exploding body parts is pretty much a myth unless you are really going to thrust a wire through yourself. :P

Remember that it takes 4kJ to raise the temperature of 1kg of water for only 1K! Then there is the very high enthalpy of vaporisation: 2.2kJ/g

So if you touch the output of that bank, really the only serious danger would be electric shock, and some rather small burns (compare to TDU's hotdog.)

Marko

Dr. SSTC

Thu Jul 10 2008, 10:49PM

Registered Member #1407 Joined: Fri Mar 21 2008, 07:09AM
Location:
Posts: 222

well thank for explaining that guys i was just thinking thet because i saw water melons being exploded by much smaller banks

Andyman

Fri Jul 11 2008, 02:43AM

Registered Member #1083 Joined: Mon Oct 29 2007, 06:16PM
Location: Upland, California
Posts: 256

I'm wondering if it would be at all possible to recycle the energy from the magnetic field at all? If you had several small coils arranged around the big coil to be induced with the large magnetic field of the discharge and somehow store the induced current for the next shot. I know it wouldn't be a LOT of energy recycled but would it be at all possible?

FastMHz

Fri Jul 11 2008, 09:55PM

Registered Member #179 Joined: Thu Feb 16 2006, 02:08AM
Location: Hagerstown, Maryland - Close to Prime Outlets
Posts: 287

Guys - this bank *would* blow parts of you or various objects apart...check my latest video out to see what happens to a potato and pickles, and other things:

http://www.youtube.com/watch?v=UAgfGGjsoQM

I did not put a wire through that potato (the one that detonates in a shower of sparks and flame)

aonomus

Sat Jul 12 2008, 03:52AM

Registered Member #1497 Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801

Jeez. Girly laughs all around. Did you seriously blow up 10 or so neon tubes??

And on all the other discharges, those are gunshots practically, I hope the neighbors didn't mind.... maybe try making a ETG?

GeordieBoy

Sat Jul 12 2008, 11:48AM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

Looking at that picture...

Capsbarredyp2

it doesnt look like you have any insulation between the cans of the capacitors. If all metal cans are touching then the "internals-to-can" voltage on the left-most and right-most banks of capacitors is going to be very high. You mentioned charging the bank to over 4000 volts. I doubt that the metal can insulation is specified up to this kind of voltage for standard 450 volt electrolytics. Some supplementary insulation is probably advisable since any end-to-end breakdown is going to dump the stored energy of the entire bank into the weakest point... Most likely with vapourised electrolyte and quite spectacular results.

I'd also second the comments made early about electrolytics and reverse voltage, and the importance of balancing resistors. Electrolytics being subject to this abuse will not last long, and when they start to fail the leakage currents for individual components may start to vary a lot.

-Richie,

FastMHz

Sat Jul 12 2008, 05:29PM

Registered Member #179 Joined: Thu Feb 16 2006, 02:08AM
Location: Hagerstown, Maryland - Close to Prime Outlets
Posts: 287

haha yeah I laugh quiet energetically....huge amounts of electricity make me really happy!

Anyway the cans of each cap are not touching, there's a 1/8" airgap between every one. I do plan to add some insulation between each string though, as it wouldn't be hard and is extra insurance.

I was building ETCs for use with my 3.5kj system with success, but even at only 3.5kj the guns were exploding. I'd need some seriously well machined barrels to make one that'd withstand 24kj. I'm most eager to get my 1foot+ diameter pancake coil done.

Arcstarter

Sat Jul 12 2008, 09:43PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

This is one bad @&$ project! Wow, 24 freaking kilojoules is funner that i thought! I cannot wait to see your pancake coil launching 50 pound sandbags through the atmosphere :P. Maybe that was just a tiny bit over exaggerated. But it would be cool to see you put such a force on a disk it basically explodes when it hits something :).

FastMHz

Sun Jul 13 2008, 08:56PM

Registered Member #179 Joined: Thu Feb 16 2006, 02:08AM
Location: Hagerstown, Maryland - Close to Prime Outlets
Posts: 287

Funny is an understatement...I rarely laugh that hard at something, except maybe a standup routine on HBO....but this was more of a test of the system than what I built it for, which is to launch things, big things, really fast and high, using induction coils.

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