Starter Switches

The starter switch is parallel to the power supply. It sends a current through the filaments to ionize the gas, while building a magnetic field in a coil. Then once enough heat has been generated, many starters turn off using a bimetallic strip, and in doing so releases extra stored current from its coil. This serves the voltage kick required to get electrons moving through length of the tube from one filament to the other. If for some reason this doesn't start the continuous flow, the process iterates again. If the bulb is worn out, the process will repeat indefinitely, the light will flicker wildly and you will realize that you need to change the bulb.

What's a bimetallic strip?

A bimetallic strip makes use of two metals with differing coefficients of thermal expansion. Two flat strips of these metals are welded together. When subjected to a rise in temperature, the strip will bend in the direction of the metal expanding the least