Relay 1 Channel

Lets a microcontroller switch 1 real electrical load — lights, pumps, fans, heaters — at voltages the board could never handle directly. Each channel is optically isolated, so switching noise and back-EMF from the load stay away from your Arduino, which is what prevents the random resets that plague non-isolated boards. Screw terminals give normally open and normally closed contacts on every channel. If you are switching mains voltage, treat this as electrical work: enclose the board, keep mains wiring physically separated from the low-voltage side, and if you are not confident, ask us or use a qualified electrician. Optical isolation protects the microcontroller from switching noise; 1 independent channel with NO and NC contacts; Onboard LED show relay state at a glance; Screw terminals accept solid load wiring