If you've ever seen an old science fiction or horror movie then chances are good that you've seen a Jacob's Ladder in operation. A Jacob's Ladder is a device that makes continuous sparks of electricity flow between two metal rods or wires. These sparks rise from the bottom of the wires to the top, where they wink out, then begin at the bottom again. The device works by creating a high voltage between the two wires. The voltage is high enough to ionize the air between them. When the air is ionized it conducts electricity, and a spark jumps from one wire to the other. Because the spark is hot and hot air rises the spark travels to the tops of the wires.
Drill two holes in the bottom of the wooden box. Set them ¼ inch apart. Use a drill bit that is the same size as, or slightly wider than, the coat hanger wire. Cut a small notch (approximately ½ inch wide and deep) in the top of one of the walls of the box, using the hacksaw.
Straighten out the coat hangers. Use pliers to bend out all the kinks by grabbing the wire with one pair just below the kink and the other just above it. Depending on the style of transformer output terminals you have it may be helpful to bend one end of each wire into a hook.
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Attach the coat hanger wires to the output terminals of the neon sign transformer. Push the wires through the holes in the bottom of the box so that the box settles onto the floor covering the transformer with the wires poking out through the holes. Bend the wires so that they are approximately 3 inches apart at their tops.
Make sure that the power cord for the neon sign transformer is poking out of the box through the notch. Lay the assembly on its side. Screw the lid of the box onto the box itself. Plug the power cord in to operate.
It is possible to use the transformer from an oil burner ignition. It has similar properties to the neon sign transformer.
Do not use transformers from microwave ovens. They do not have the appropriate characteristics for the job, and are dangerous to use in a device like a Jacob's Ladder.
Never adjust any electrical equipment while it is plugged in.
Read the safety instructions for the neon sign transformer and follow them.
Do not touch the sparks produced by this device.
Children should use this device only with adult supervision.