Relay Shield

Lets an Arduino switch real electrical loads: lights, pumps, fans and motors that run on voltages the board could never handle directly. Optical isolation separates the relay side from the Arduino side, so switching noise and back-EMF do not reach the microcontroller. If you are switching mains voltage, treat this as electrical work: enclose the board, keep mains wiring away from the low-voltage side, and if you are not confident, ask us or use a qualified electrician. Optically isolated to protect the Arduino from switching noise; Screw terminals accept solid load wiring; Onboard LEDs show relay state at a glance; Handles mains and DC loads alike