ELECTRIC ARC

By far the simplist way (in a car) is with a spark plug and the existing car's electrical sytem.

http://en.wikipedia.org/wiki/Spark_plug

http://en.wikipedia.org/wiki/Ignition_system

What is the application? (it's not hho generation again is it).

Guest,

If, however you are talking about generating an electrical arc from household (AC) electricity, you can do this even more simply than in a car, using a household zip cord, a couple of alligator clips, two carbon rods extracted from dry cell batteries, or in a pinch, you can even use two thick (graphite) pencils.

HOWEVER, AS ALWAYS, PROCEED WITH CAUTION OR DON'T PROCEED AT ALL!

(Please read additional notes & cautions at end of post.)

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All you need to do is connect a carbon rod (or the graphite core of a pencil) to each exposed end of the zip cord (while the cord is unplugged!), and then position the carbon (or graphite) electrodes so that they just touch, tip to tip. Then turn on the power. You will have just created a blindingly bright carbon arc lamp.

I forgot to warn you, you'll also probably want to have some really dark sunglasses handy (or welder's goggles).

Once the "arc is struck", you can then increase the distance between the electrodes, out to around 8 mm or a little further.

The carbon gets consumed as the arc burns, with the rate of consumption depending upon the voltage and current flow. If you can adjust the flow of these parameters you can control the intensity of the arc, even down to 50 volts,at 4 to 5 amps of current.

You will need to devise a (fireproof) method of holding each of the electrodes firmly in position, with a means of easily adjusting the spacing of the tips, ALL WITHOUT ELECTROCUTING YOURSELF!

The first time I did this, I was around 11, and used two thick carbon rods I had extracted from a couple of old 1.5 volt ("ignition") dry cell batteries. You know, the round batteries with screw terminals on top, about the size of a tall-boy, the kind you used in science fair experiments.

After I figured out how to actually get all of the electrolytic "gunk", off of them w/o damaging them, these batteries provided great carbon rods...

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NOTE:

I hereby absolve myself of any liability should anyone proceed carelessly and experience either:

1. Electrocution ( you will be intentionally short-circuiting live wires); or
2. Conflagration (i.e., start a fire), either:

• Via the exposed arc itself, (which is well over 3,000 degrees C); or
• due to the arc itself drawing too much current through inadequate house wiring, causing a feeder to overheat inside a wall in your house.

As a current draw limiting precaution, it may be advisable to hook this arc "circuit" in series with a high wattage appliance, like a space heater before energizing it.

I have done this using a car battery, jumper cables and recovered carbon rods from old dry cell batteries.

Things got HOT FAST!

Eye and flash burn protection as well as instructions to not do this at home are certainly in order for this project!

A welding machine worked better as a power supply.

That is about as simple as I can make it. It would be a huge benefit if you would just tell us what you intend to do with this thing. That could greatly benefit the quality of the responses you get.

There are many ways to generate an electric arc. Do you want heat, light or do you want to just make pretty sparks?

Turbotroll3,

You stated it more succinctly than I believe I am capable of:

(GA from me)

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"It would be a huge benefit if you would just tell us what you intend to do with this thing. That could greatly benefit the quality of the responses you get.

There are many ways to generate an electric arc. Do you want heat, light or do you want to just make pretty sparks?"

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I myself have never tried the carbon arc thing with a car battery, perhaps from some innate fear (perhaps founded, perhaps not), of Hydrogen gas driven explosions and flying H2SO4...

I am also looking to make big electric arcs with household AC current. The reason is for the plot of a novel, I have no intention of doing this myself. The purpose of the arcs would be radio interference (novel set in the '30s), so I would need arcs that are long-lasting, but hopefully not lethal. Couldn't the hero just cut the cord of an iron or radio, strip the insulation off, plug the business end into an outlet and hold the exposed wires some distance from a doorknob or some other conductive surface? I suppose the power cable would have to be held with some kind of insulated wrench or something. Would this create arcs, or would the protagonist just end up fried?

Guest,

It would be better if you were to register and start your own thread.

To give you a quick answer, which may also apply to the other OP, a high voltage transformer intended for use with a neon lamp should be period correct and be capable of generating a sufficient voltage and current to establish an arc capable of disrupting radio reception in the immediate area.

Link: http://inventors.about.com/od/qstartinventions/a/neon.htm