Solid State Relays

Solid state relays are required to allow a temperature controller or other type of controller such as Raspberry Pi and Arduino to turn a heating element or pump on and off. The controller provides a signal to the low voltage (ie 5V) side of the solid state relay, which then controls the high voltage (ie 240V) side of the relay. This ensures that the controller is isolated from the high voltage and current that would cause damage to it.