Controlling high power AC load using relays

Control of high-power devices, such as 120V power outlets, is an objective of home automation. While a Raspberry Pi Zero cannot power devices on its own, it does can control relays that are designed to control power sources.

Note

Working with AC power, such as 120V house power (also known as line voltage), is extremely dangerous and potentially lethal. Do not ever attempt to work with live circuits, and always work with experienced electricians when designing systems that control power. Mishandling high power can be deadly!

Getting ready

For this recipe, you will need a protective relay. The one included in the Elegoo Kit works perfectly for this recipe, but any relay that takes a 5V DC switching input should work. You'll also need the following components, along with the usual breadboard, jumper cables, and Raspberry Pi Zero:

• 1N4001 diode, though any small diode will work here, except for Zener diodes

• 2N2222 transistor

• 2kOhm resistor (2.2KOhms+/-5% resistors...