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Exploding wires - duelling machines

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LAN_403

Hazmatt_(The Underdog)

Sun May 21 2006, 10:29PM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

It has little to do with holding an insulator. You could have an accidental brush by with the wire which there is only 600V rated!!!!!

I see X1 and X2 no 0, which means no gnd.

Its just dangerous all around.

Electroholic

Mon May 22 2006, 12:07AM

Registered Member #191 Joined: Fri Feb 17 2006, 02:01AM
Location: Esbjerg Denmark
Posts: 720

actually x1, x2, x3 and x4 are all L.V. windings.
then there is H1, H2 and 1-4 on the HV side.
but yea, theres no ground.

Tesladownunder

Mon May 22 2006, 12:48AM

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

Hey guys, give me a break. I was holding an insulated rod. The 3kv is floating with this amazing epoxy secondary. I was staying well away from any thing grounded. There would have been minimal coupling to earth anyway. Ballasting has nothing to do with safety. I was aware of all these things at the time. It's voltage is little different from a ballasted MOT with the difference that a MOT is grounded making it much more dangerous to touch one wire. Compared to adjusting a Nitrogen laser this pic is very safe.

Please remain on topic.

Steve Conner wrote ...

Transformers store hardly any magnetic energy, because the core doesn't have an airgap. I doubt it stores anywhere near 200J. If it did, it would draw 10kVA worth of magnetizing current when connected to the supply but unloaded.

That's not how I understand it. When you turn on a perfect inductor you initially draw power to build the magnetic field. This effect is the thump that sometimes happens when you switch on a variac and is greatest at zero crossing (rather than switching on at peak voltage). After that net power is zero. In my transformer setup the current is far less than 10kVA when it is running at no load but energy had to be expended initially to build the field at turn on and this takes a few cycles until the voltage/current phase relationship settles. 10KVA (200J per 50Hz cycle) of power is what can be extracted from that field at close to maximum capacity. I would guess that it is a bit more as the 10KVA is the thermal limit as efficiency drops after that with increasing iron saturation losses.

The pic below shows the much brighter and very much louder exploding wire at the same energy without the inductor in the circuit.

Peter

1148258919 10 FT9887 Pulsecapexplodingwire35g2kjnoinductor

ragnar

Mon May 22 2006, 03:51AM

Registered Member #63 Joined: Thu Feb 09 2006, 06:18AM
Location:
Posts: 1425

I'm fascinated by your first picture, TDU... I'm trying to work out why the colour of the flash around your inductor isn't the same as the wire vaporisation flash.

What kind of shrapnel is left behind (if any) after a shot such as this?

Tesladownunder

Mon May 22 2006, 10:25AM

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

I am not sure about the different colour. As the plasma seems to extend around the transformer apparently in close proximity, it may mobilise some dust or sweat off the surface

I haven't seen any fragments, but 35G is very fine wire and 2.5kJ can let out a lot of smoke. My previous efforts with fine wire resulted in fragmentation and string of pearls appearance.

Pics of this and other wire thicknesses here

Peter

Richy

Mon May 22 2006, 01:51PM

Registered Member #121 Joined: Fri Feb 10 2006, 12:39PM
Location: Bromley, UK
Posts: 10

Would it be possible to take a picture through a welding mask (or equivilent) to show more detail of the plasma? Or could this be done by reducing the exposure? It would be interesting to see what was going on around the inductor/transformer

Great pics nonetheless

Richy.

Tesladownunder

Mon May 22 2006, 04:24PM

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

I have taken photos of sparks through welding goggle filter(s) before in the pic below.
I could try this again. My camera has a lot of settings and is still using smarts like auto ISO which allows me to take 3 second exposures before the sun has set without overexposing. It will take some experimentation and fiddling with manual settings, I guess.
A heavily neutral filtered shot would be interesting to look at wire disintegration more closely.

Peter

Tesladownunder

Sun Jun 04 2006, 09:30PM

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

Finally found my iron wire. Here is how it goes on my cap bank. The return path is an aluminum tube. Shot was at 3kJ.

If anyone wants the hi res pic for wallpaper it is here.

Peter

1149456620 10 FT9887 Pulsecapexplodingironwire3kj1000

Marko

Sun Jun 04 2006, 09:48PM

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

Wow, pretty scary!
Try not to set a fire wit this thing!

I wonder how long could you actually make a copper wire and still blow it up fully?

evilgecko

Mon Jun 05 2006, 12:21AM

Registered Member #288 Joined: Mon Mar 06 2006, 07:52AM
Location: Palmerston North
Posts: 32

Woah that is crazy you should get a video of the tesla. How do you switch it?

I just fired 182J of energy into a piece of solder and thought that was cool with all these little glowing balls of solder propelling themselves along the table. They hit small piles of black powder that happened to be spilt and made a woosh woosh sound.

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