Armed Polite Society
Main Forums => The Roundtable => Topic started by: 230RN on August 06, 2010, 10:52:29 AM
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Exploding watermelons with a 10kV power company line transformer.
This kinda makes R. Lee Ermy's efforts look pitiful
http://blog.makezine.com/archive/2010/07/splodin_watermelons_with_10000_volt.html
Terry, 230RN
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I showed this to a couple of electrical engineers at my office and their statement is "We have to do this."
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I wonder how he has that sucker wired up? Looks like a residential area.
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I wonder how he has that sucker wired up? Looks like a residential area.
Look carefully, in the video (0:25), you can see a transformer that would normally be sitting on an electric pole. I would have to assume that it is a step up transformer.
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Look carefully, in the video (0:25), you can see a transformer that would normally be sitting on an electric pole. I would have to assume that it is a step up transformer.
Right, but back-feeding something that large would result in so much in-rush, I don't see how it wouldn't pop breakers.
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Right, but back-feeding something that large would result in so much in-rush, I don't see how it wouldn't pop breakers.
Good point. I can ask one of the EEs what he thinks is going on.
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I wondered if somehow he charged up one of those humongous phase-correcting power line capacitors and dumped that into the melon. He'd have to rectify it to DC first, though. I would guess if he had that xfrmr in the yard, he had access to other HV stuff, maybe HV rectifiers, too.
In some spark-photography experiments I did years ago, I used 16 1kV silicon rectifiers (1N4006) in series to charge a couple of caps from a 10kV oil burner ignition xfrmr. (10kV x 1.414 = 14.14 kV peak voltage.) But those were only one-amp units.
The crack from the spark sounded like a .22 rifle, at least in my garage.
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I wondered if somehow he charged up one of those humongous phase-correcting power line capacitors and dumped that into the melon.
Maybe. It's entirely possible, and really not a bad idea.
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Okay, so can anyone make me a Lightning gun like in Quake? =D
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Don't give Nick any ideas, Cromlech. >:D
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The local power co-op does stuff like that at their safety demonstrations.
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Pfft...
All you techno types and no one noticed the Tesla coil. And you call yourselves observant. :laugh:
Brad
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Pfft...
All you techno types and no one noticed the Tesla coil. And you call yourselves observant. :laugh:
Brad
...cause I can't see how the tesla coil isn't relevant to what they are doing. ???
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Meh. A .50 Beowulf blows 'em just just as well: http://www.youtube.com/watch?v=1DDVnrESOk0&NR=1
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Meh. A .50 Beowulf blows 'em just just as well.
But with ergs I don't have to worry about my backstop.
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Edison was right!
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Edison was right!
Edison talked about 'splodin' watermelons?
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Edison talked about 'splodin' watermelons?
Edison may have patented exploding watermelons....he patented everything else....
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Meh. A .50 Beowulf blows 'em just just as well.
I will admit that I was spectacularly underwhelmed when I shot a bunch of pumpkins(just after Thanksgiving) with my 5.45x39 Tantal. Teeny, tiny little holes.
Made me want a shotgun :/
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I will admit that I was spectacularly underwhelmed when I shot a bunch of pumpkins(just after Thanksgiving) with my 5.45x39 Tantal. Teeny, tiny little holes.
I got satisfying results blowing up 1-gallon water jugs with a .44 Magnum carbine firing Federal Hydrashoks.
BANG! *splash*
Ammo did get a bit expensive, though.
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*cue RevDisk, pumpkins and semtex, somewhere in eastern europe.* :lol: [popcorn]
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Edison talked about 'splodin' watermelons?
Edison warned us that AC power was dangerous stuff! ;)
http://en.wikipedia.org/wiki/War_of_Currents#Edison.27s_publicity_campaign
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It's the amps that get you. ;)
jim
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Amps, schmamps. It's the coulombs-per-second what getcha.
The local power co-op does stuff like that at their safety demonstrations.
So, Tallpine, did they just pop them with plain old AC directly from the transformer?
Terry, 230RN
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What happened to your math? ???
I was going to try to convert it to BTU's. =D X 1054.9
It's been a while since I messed with capacitor discharge systems. I do remember how it felt. :O
jim
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Dang it, Jim 147, I'm sorry. I pulled that math part out of the post on the grounds that I was thoroughly confused in jumping back and forth with exponential notation on the Windows scientific calculator*. Forget it. I'm going to bed. Maybe things will be more clear in the AM. Saturday mornings are better for that sort of stuff.
Terry, 230RN
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* A lot of people don't know that Windows has a scientific calculator. Go to Start, Programs, Accessories, Calculator. When the four-banger comes up, click on View, and select Scientific.
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:lol:
jim
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Jim, see your PMs.
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I was spectacularly underwhelmed when I shot a bunch of pumpkins(just after Thanksgiving) with my 5.45x39 Tantal. Teeny, tiny little holes.
You did it wrong, there is supposed to be a small (or large) container of tannerite in the pumpkin before you shoot it.
bob
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Jim, see your PMs.
Is it that time of the month again?... :facepalm:
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So, Tallpine, did they just pop them with plain old AC directly from the transformer?
Actually, they hooked a transformer up backwards so that the current was back up to the line voltage - 15K or some such.
They fried various fruits and vegetables and even set a car tire on fire (and you thought rubber was an insulator? :O )
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Jim, see your PMs.
I have a house full right now. I'm in the garage doing some work. (Working on some cold ones.)
The first CD box we ever used for the race car was rated in Joules ??? I flipped through my books and found a conversion to BTU. That helped a lot. ;/ It did get me once. It left a pretty good mark.
I had a tech get between a transformer and a mag tube once. And he only did it once.
I didn't even think about hooking the transformer up backwards. That would be about the same as someone running a generator without a transfer or pulling the main. :O No wonder the power company doesn't like to see backfeed cables.
jim
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Actually, they hooked a transformer up backwards so that the current was back up to the line voltage - 15K or some such.
They fried various fruits and vegetables and even set a car tire on fire (and you thought rubber was an insulator? :O )
Use enough voltage and anything will conduct =D
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Use enough voltage and anything will conduct =D
And, if you put the right thing in there (electrodes in a vacuum), you can create a ton of hard X-rays!
Think I saw someone get up to 3 rad/hr on the net in a home shop. :O
I'm still surprised that you could backfeed a transformer of that many KVA without the inrush blowing every breaker along the way.
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Think I saw someone get up to 3 rad/hr on the net in a home shop. :O
Aieee! That's a little into insane territory....
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I'm still surprised that you could backfeed a transformer of that many KVA without the inrush blowing every breaker along the way.
They had a high voltage breaker hooked in with the transformer.
They actually had to reset it quite a few times.
Very interesting demonstration. You don't want to be anywhere near a downed power line :O
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"A kilovolt here, a kilovolt there, pretty soon you're talking real electricity."
(Paraquoted from Senator Everett McKinley Dirksen, with respect.)
Terry, 230RN