Hobby Corner

Two Switches on One Light -- How does it Work?

Every one of us has seen a staircase or hallway with two light switches, but only one lamp. Have you ever wondered how it works? Well, see for yourself.

Just look at the interactive drawing below. At the top are two wall light switches and a ceiling light. On the bottom is a schematic diagram of the light circuit. We start with the two switches down and the light is on. Now, click on either switch button... See the switch position change on the wall switch and the schematic. Try to trace the path from the "plug" to the light bulb. When the light is on, the path is highlighted in red.

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