"Novelty" Igntion Source - 2 kV Neon Sign Transfor

[mark.f]

I finally got it shipped in from All Electronics. It's simply a 2 kV AC neon sign transformer. So far, I've been powering it off of a 12 volt gel-cell battery, but, if I ever put it onto a cannon, I will probably make some sort of portable battery pack from 9 volts.

Basically, it's as simple as this: you apply 12 volts of electricity across the ingoing black and red leads, and out comes 2,000 volts "unknown frequency", (although I'd say it's pretty high because of the spark gap noise when it get's too wide), AC. This is enough to jump a "small" gap, (think in the spark plug range), but the gap can be drawn out after firing it up initially, because the air between electrodes has become ionized. I think some sort of mechanism like in a camera flash, to ionize the air between spark gaps before firing up, can provide a good method to get longer sparks as well.

These things are cheap. You might even be able to find them at a hardware store somewhere, (their used for setting up neon-tube sign displays).

And finally, here's some pictures.

<div align="center">The transformer... note simplicity... </div>
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<div align="center">The spark gap. This is in a "drawn out" state, and emitting a high-frequency noise...</div>
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[VH_man]

haha. this is the same thing you get out of those glow-ball things that have all the purple thiniges go to your hand when you touch the globe..

notice that spark is PURPLE. that means its HOTTER than the blue sparks from a stungun.

[Carlman]

yay thank you thank you lol

im in oz and cant get a stungun easyly... but now i just go to the electronics store and grab myself one of them!

oooooooo so simple,i love simple!

ive been mucking around with camera flash ignitions but this is way more easier.

[paaiyan]

I like it, but I also like complicated. That's why if I ever make another combustion, I'm going to make an inductor coil for it. I know I can get a good 4 inch spark out of one of those. But this is good.

[mark.f]

This sort of thing is good for people like me, though, who manage to fry an ignition coil circuit.

Carlman, call around before you go anywhere. Some places might have one, and others most probably won't.

[paaiyan]

This sort of thing is good for people like me, though, who manage to fry an ignition coil circuit.

Oh I understand. This is definitely cool. I just like really big, really complicated things.

[jimmy101]

Markfh11q: That's a good find. According to the spec sheet it is is 3KV at 30KHz open circuit, so it should behave as a 3KV source not 2KV. Should be enough for a single gap gun.

I wonder if you put the output through a home-rolled 1:10 transformer...

Here is the link at All Electronics;
http://www.allelectronics.com/cgi-bin/i ... PPLY_.html
$9.50

notice that spark is PURPLE. that means its HOTTER than the blue sparks from a stungun.

I don't think you can judge how hot the spark is from the color in the photo, it is very likely that the camera doesn't reproduce the colors correctly. If it is a digital camera then it is also very sensitve to IR which the human eye can't see. Besides, the temperature of a plasma is so hot that it really doesn't matter.

[cwazy1]

why not just make a tesla coil inside your chamber?!!?!

[paaiyan]

why not just make a tesla coil inside your chamber?!!?!

I thought about it, but I decided it would not be as safe as an indictor coil.

[mark.f]

I wonder if you put the output through a home-rolled 1:10 transformer...

I was thinking about taking apart one of these wall transformers I had lying around and removing things like the rectifier and such to get down to the power transformer, and wiring that in reverse. For now I just hooked it up to one of my hybrids for ignition, because the small piezo sparker got ripped off. It'll probably be there until after New Year's is over.

[jimmy101]

I was thinking about taking apart one of these wall transformers I had lying around and removing things like the rectifier and such to get down to the power transformer, and wiring that in reverse. For now I just hooked it up to one of my hybrids for ignition, because the small piezo sparker got ripped off. It'll probably be there until after New Year's is over.

That sounds like a good test. A 12V transformer is roughly 10:1 so theoretically the voltage would be up around 30 KV. But the inductance and frequency won't be matched properly so I would think the voltage would be quite a bit less. Still, a good chance of getting up near 10KV which would be pretty good.

You can also just get a 12V transformer from RadioShack for a couple bucks. Or like I said, wind you own.

Just a thought, but the setup might work better if there is a small spark gap between the neon sign transformer and the 12V transformer. This would be similar to how most stunguns are wired. The spark gap lets the neon transformer build up to near it's maximum voltage before dumping the voltage into the 12V transformer.

[mark.f]

How wide do you think a feasible spark gap before the transformer would be? Around .01"? I get sparks without "warm up" up to around .035", (tested with two carbon steel ball electrodes and some calipers).

Probably won't be any time soon, like I said. I also might have to settle for a 9v transformer, (a little bigger ratio). I don't have any uncoated wire at the moment, and I only have a little bit of black/red 12 gauge wire to fool with, so I probably won't be winding my own any time soon.

[jimmy101]

Mark

I would think you want the gap up near the limit that it'll spark at, perhaps 0.03".

The 9V transformer should be fine so give it a try.

One challenge in any high voltage circuit is getting it to spark where you want it to. If the connections on the transformer are only sperated by 1/10" then you'll get sparking there instead of at your spark gap if the spark gap is bigger than 1/10". You might need to insulate the connectors on the transformer with some silicone caulk or some other high dielectric material. (High voltage transformers like flybacks and ignition coils are usually potted in either a high dielecric plastic or oil.)