Recommended · for beginners
Raspberry Pi - (Relay) Controlling mains electric
Why people recommend it
A Raspberry Pi demonstration of switching a mains lamp through a relay board, recommended as a clear explanation for anyone wanting to drive bigger loads from GPIO.
Watch for: Mains wiring; the method involves cutting an appliance lead
In their words
I've found this useful video which demonstrates the concept on a mains-powered lamp.
daiscog on electronics.stackexchange.com, Dec 2015. CC BY-SA.
See this YouTube video, he gives a good explanation
nagyben on raspberrypi.stackexchange.com, Feb 2014. CC BY-SA.