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How to Make a Lethal Traveling Arc of Electricity with a MOT-Powered Jacob's Ladder

Close-up of glowing green fiber optic cables.

With the microwave oven transformer (M.O.T.) salvaged in a previous project, a simple electrical circuit can be rigged to get high voltage arcs to fly outward and upward along a "V" shaped spark gap.

You can look, but don't touch! These arcs of plasma are lethal enough to kill on contact!

The M.O.T. looks like a large metal cube, and is very heavy.

Transformer inside a disassembled appliance.
Electrical transformer with exposed wiring.
Electrical transformer with wires and clips.
Transformer inside a disassembled appliance.
Electrical transformer with exposed wiring.
Electrical transformer with wires and clips.

There are 2 sets of copper coils. A primary coil (the bottom one here), which connects to your house power, and the secondary coil, which generates the high voltage to run your microwave. By tapping one end of the secondary to the transformer body, the circuit is completed, and a large amount of electric current jumps the gap.

How to Make a Lethal Traveling Arc of Electricity with a MOT-Powered Jacob's Ladder

REAL DANGER! When playing with high voltage (HV), it's important to keep your distance. When the power was on, I used an insulated stick, gloves, and also kept one hand behind my back at all times.

Electrical experiment with wires and a transformer connected to a wooden base.
Clamps connected to a wooden surface for electrical testing.
Transformer being connected with wires.
Electrical experiment with wires and a transformer connected to a wooden base.
Clamps connected to a wooden surface for electrical testing.
Transformer being connected with wires.

A diverging spark gap can easily be made with a metal coat hanger, or a couple pieces of un-insulated copper wire. WITH THE POWER OFF, the secondary coil is connected to the spark-gap, then with power back on, the spark is introduced. As the spark heats the air, the air rises, taking the arc with it.

Glowing electrical arc between two wires.
LED light being powered on by connected wires.
Welding process with sparks and electrical connections visible.
Glowing electrical arc between two wires.
LED light being powered on by connected wires.
Welding process with sparks and electrical connections visible.

The hum of the 60Hz arc dissipates as it breaks off the top. A smaller spark gap can capture a glowing orb of plasma, and when a HV capacitor is placed in parallel, the sparks are sharp, powerful, and loud. They even change in color from yellowish green, to a crisp bright blue.

It can't be stated enough that this amount of power needs to be treated with extreme caution and respect. One wrong move could be your last one.

Haven't see the video yet? You can still see it here!

If you like this project perhaps you'll like some of my others. Check them out at www.thekingofrandom.com

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