Build It: 3-Way Switch Circuit
Wire a light that can be turned on or off from either of two switches — the classic hallway/stairs circuit. Connect the source, both switches, and the fixture so the light responds correctly no matter which switch is used.
Tap a terminal, then tap a second terminal to run a wire between them. Tap either terminal of an existing wire (or the wire itself) to remove it.
Switch 1 (Downstairs):
Switch 2 (Upstairs):
| Switch 1 (Downstairs) | Switch 2 (Upstairs) | Light |
|---|---|---|
| up | up | off |
| up | down | off |
| down | up | off |
| down | down | off |
The light never turns on, for any combination of switch positions.