Jacob's Ladder (5D40.10)

Description:

A classic electrical display often seen in the background of mad scientist B movies. Two long vertical electrodes are close together at the bottom, but separate gradually towards the top. 15,000 Volts from a transformer starts an arc at the bottom. Since the voltage is AC the arc breaks as the voltage decreases; the ionized air that was heated during the arc rises while the arc is off. When the AC voltage again becomes high enough to strike an arc, it goes through the ionized air that has risen above the point of the previous arc. The process continues until the arc reaches the top of the electrodes, where it breaks off and reforms at the bottom to begin the cycle again.

Procedure or Operation Notes:

If the spark does not form, turn the switch off and readjust the spacing at the bottom.

If the spark gets stuck and does not rise, use a piece of paper or cardboard to gently give it some airflow.