Introduction to the Three-Way Switch

Introduction to the Three-Way Switch

A three-way switch is a common household switch. Rather than controlling a light from a single location, a three-way switch allows a person to turn on and off a light from two locations. This is particularly useful for rooms with more than one entrance, hallways, and stairs. Imagine the inconvenience of having to walk across a dark room to reach the light switch on the other side. This is where three-way switches shine!

The three-way switch is fairly simple. The light switch you have used in the last few lessons was a single-pole, single-throw switch. The switch is considered to have one pole because it is only controlling one connection point in the circuit. It is considered a single-throw because there is only one possible output connection that can be made, such as turning on or off a light bulb.

The three-way switch is in a category of “multi-way switches.” This means that there are multiple ways and configurations to control a single fixture. Need a third switch to add in to a circuit? Then you would need a four-way switch! This course will limit the multi-way switches to the three-way switch. This switch, like the regular light switch, only controls a single point in the circuit. However, rather than having one possible output, a three-way switch has two possible outputs. Because of this, a three-way switch is considered a single-pole, double-throw switch!