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Jacob's Ladder with 5KV?

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carbonzit

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Inspired by another thread here, I remembered I have a neon sign transformer sitting around doing nothing. Was wondering if I could use it to make a Jacob's Ladder. It produces 5,000 volts: would that be enough? Looking around on the web, all the designs I saw operated at at least twice that.

Hmm; maybe if I get some reeeeally high-voltage diodes and make a voltage doubler?

Any other ideas for kewl sparky-sparky projects that will run on 5KV?
 
Something else you can try is find yourself an old clear incandescent light bulb, larger bulbs are better. Snag one of those every day lamp sockets as used in basement lighting, porcelain is cool but the newer plastic ones work fine. Connect ground to both socket terminals (matters not if the bulb is burned out or not). Using aluminum foil make a little cap or dome for the bulb. Connect the HV lead to the foil cap. Turn on the transformer and watch the show inside the bulb. When I did this years ago I took pictures of the lightening storm inside the glass envelop and it was pretty cool. If you have an everyday lamp dimmer you can try to drive the transformer using it. The trick is you don't want the arcs and sparks getting the thin glass too hot in a single spot or the bulb cracks.

Another method was to use an old 12 Volt auto ignition coil and drive it with the lamp dimmer, yes, it does work.

Happy arcs and sparks..... :)

Note: When I first did this it was with a 10 KV neon sign transformer but 5 KV may work? Not real sure.

Ron
 
Last edited:
Inspired by another thread here, I remembered I have a neon sign transformer sitting around doing nothing. Was wondering if I could use it to make a Jacob's Ladder. It produces 5,000 volts: would that be enough? Looking around on the web, all the designs I saw operated at at least twice that.

Hmm; maybe if I get some reeeeally high-voltage diodes and make a voltage doubler?

Any other ideas for kewl sparky-sparky projects that will run on 5KV?

Yes, you can make a small Jacob's Ladder using only 5000 volts. However, the contacts will have to start very close together (roughly 5mm at the base). Also, the current output from the transformer determines how far you can draw the arc before it breaks and a new one starts.

Another method was to use an old 12 Volt auto ignition coil and drive it with the lamp dimmer, yes, it does work.

That was what I used for my first ignition coil driver. I started with some .5uF caps to limit the current, but they did not allow enough current through to give a spectacular output. Just some thin white and blue arcs. I then took a few caps and put them together, giving a capacitance of about 733uF. Higher capacitance = higher current = nicer arc. That worked until I burnt out the caps. If you ask me, any AC capacitor rated for between 15 and 100uF and over twice your mains voltage will work, though you should be careful not to run the coil too long at one time--it could get dangerously hot. You can generally get 10-40kV out of a standard ignition coil, at several milliamps. Works very well for a Jacob's Ladder.

Oh, I almost forgot to give you the circuit that I think Ron was suggesting:

**broken link removed**

Good luck, have fun, and be careful ;)
Regards,
Der Strom
 
Hmm, very eenteresting ...

So about the automobile ignition-coil way: it's intriguing, but I'm a little hesitant to put 120 VAC through one (even through a capacitor). How about driving one from a transformer, say 30-40-50 volts? What is the turns ratio of an ignition coil, anyhow?

If I could get 8-10KV, I'd be happy.
 
The primary of an ignition coil generally sees several hundred volts anyway due to voltage spikes. They are designed to withstand a rather high voltage, so putting 120 volts into it is not a problem.

I am not sure how running a coil via a dimmer on 30-50VAC would work. You could try it, but running it off 120 volts does not hurt it. And trust me, it will give you a lot more voltage and current out ;)
 
I guess an ignition coil will not last long. Their primary resistance is 0.7Ohm (electronic ignition systems).

Carefully clocked at 100KHz at a low duty cycle they should generate about 20 to 30KV.

Boncuk
 
When I did this I used an old style automotive ignition coil. Like those found in a 57 Chevy, long before high voltage ignition systems when the coil was driven by points. :) When a plug gap was actually set to about .030" or so. The old coils never got very hot as I recall and I drove them direct sans the cap but can see now where the cap would help.

A few things I remember with the bulb trick. The foil cap on the bulb needs to be smooth, the smoother the better. If the arc continues in one place the glass gets hot and cracks, you can't have a hot spot. When I did this my goal was time lapse photography at the time using a Canon A1 and AE1 camera with film (remember 35mm film).

Ron
 
I guess an ignition coil will not last long.

This type of ignition coil is usually quite rugged, and can take quite a beating:

**broken link removed**

I think it will work just fine, as long as you do not go above 100uF, and don't run it for too long at a time. I've never had a problem with this type of driver.
 
Dat be the puppy! :)

Ron
 
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