KY-019 5V Relay Module

KY-019 Relay Module is used to control AC circuits, the relay acts as a switch that responds to a signal received from the Arduino, it has an integrated LED that indicates if the signal is high or low.

Commonly used in IoT projects to control lights and other electronic appliances, compatible with Arduino, Raspberry Pi, ESP32 and other microcontrollers.

On the DC side of the board there are 3 male header pins for signal, power and ground. On the AC side there are 3 contacts, NC (Normally Closed),  Common and NO (Normally Open).