What (else) can one do with 15 Kilovolts, 30 MA?

[Arkay]

Today I passed by the scrap-recycling place and saw something I couldn't resist... several 15,000 Volt neon sign transformers. I paid a whopping $2.50 apiece for these.

These things run off the local 220V house current, are rated 30 MA (450 VA), and are the old kind with the coils fully potted in a steel housing with a classic hammered green finish, with brown ceramic insulators sticking out on either end for outputs. [I asked the guy there to save for me any more of those kind of ceramic insulators that come along. Not sure if he'll remember or bother, but there is always hope.]

They were originally made right here in Hong Kong by the Luen Tat Transformer Company. I think they are a little old, judging from the style, but they are in excellent shape, without any signs of corrosion or other problems. I haven't plugged them in yet, but the coils have continuity and I'm pretty sure they will work fine.

My brother brought home one of these when I was a little kid, and proceeded to make a Jacob's ladder out of it. I think I ended up playing with it more than he did, making "spark trails" up paper and experimenting with it in various ways, taking it to school for show-and-tell, and generally feeling like a horror-movie "mad scientist", bwaa-haa-haa!

For old time's sake, I'll make a Jacob's ladder again, using one of these. I should be able to do a little better job these days, perhaps with a recycled transparent cylinder around the electrodes (for increased arc height) and better materials and "fit and finish" in general.

But OTHER than that, and perhaps a power source for a Tesla coil or a neon sign (which I don't want), or perhaps minor welding (?), what are these things good for?

Any chance of powering up a huge electrostatic speaker of some kind, with these? Perhaps some kind of plasma tweeter?

Any other fun or funky ideas?

 

[similost]

COuld always wire one up to your front door.. Steel doormat, electrified knob.. great burgler deterant.. just don't ever forget when you have it on..

 

[kretinus]

Heh, when I was a maintenance manager for a motel chain one of the onsite guys and I discussed the door knob thing for some convention guests...

Jacobs ladder would have been the first thing i would have thought of.

Maybe it's time to unleash your hidden artist and learn the art of neon lights.

 

[toxcrusadr]

I think tube circuits are right out. I don't know of a tube that takes that kind of voltage. The TH and TL series of transmitter tubes takes 1 kV or thereabouts. Someone chime if there are higher ones.

I like the homebrew plasma tweeter idea...if you could run one on landfill gas or something, you could call it 'green.'

 

[markthefixer]

15kv 0.030A = 450 watts, and 30ma is way past killing current, it's cooking / burning current.

And 15,000 volts makes sure the full 30mA gets pushed through any incidential body resistance.

 

[markdi]

I have 2 neon sign transformers.

one of them is 30kv at 60 ma

the other is 15kv at 30 ma

they are both made by the acme transformer company.

I always think of road runner cartoons when I play with them.

you could use your transformer to make a big tesla coil.

 

[Fisherdude]

CRT's.

 

[SolderIron]

Bug zapper?

 

[Conchord]

I second (third?) Tesla coil.

 

[Arkay]

Thanks for the comments, guys!

15kv 0.030A = 450 watts, and 30ma is way past killing current, it's cooking / burning current.

And 15,000 volts makes sure the full 30mA gets pushed through any incidential body resistance.

You are sure right about that. I remember holding paper sheets in the path of the arcs of the jabob's ladder, to get burn-hole patterns. Half the time, the paper would burst into flames. Tried cardboard, thin plastic (NOT a good idea!) and other materials ... the current just zapped through almost anything, and ignited it much of the time.

I don't remember what the rating on that transformer was, but I think it was probably similar to the ones I have now. Under good conditions (no drafts, nice desert air, good electrodes) I could get spark-arcs that would climb up to about 4 inches wide before they'd break up and start again below. Quite impressive, complete with ozone smells and zaap-zaap sound effects, fully worthy of any horror movie lab scene. Today I have a few plasma balls and other display pieces to add to what could be a really "cool" looking corner... I'm SO tempted to make a complete "mad scientist's lab" display... but I shudder to think how low-WAF that might be in this household. :sigh:

I have 2 neon sign transformers.

one of them is 30kv at 60 ma

the other is 15kv at 30 ma

they are both made by the acme transformer company.

I always think of road runner cartoons when I play with them.

you could use your transformer to make a big tesla coil.

Beep-beep!

The tesla coil idea is tempting, because they are great fun to play with, too, but winding the coil for the thing can be quite time-consuming. Just too much of a project right now, with all the audio and other potential projects I have "in the pipeline" that are potentially more useful/important to me.

I don't mind sitting one or two of these aside for "one day (maybe in a year or two or five) making a tesla coil, but I don't know if/when I'll ever actually get around to making it. In contrast, a jacob's ladder is relatively simple and not very time-consuming to make, so I don't mind doing that sooner.

I'd rather spend more time doing something audio-related, though. The plasma-tweeter idea was one, or some variation of an electrostatic or other speaker would be more satisfying to me. What kind of magnetic fields can you generate with this kind of current, if you have appropriate coils, and what can you drive with it.. without creating fatal accidents or burning down the home? I realize it is drastic over-kill for most audio purposes, but I can't help but wonder if there isn't potential for something wonderful there. Guess I need to research plasma tweeters a little more; I suspect that may be the only audio application where this kind of thing might actually be useful, and I'm not even sure about that.