ELEGOO 4 Channel DC 5V Relay Module with Optocoupler for Arduino Projects — Open-Box, 19% Off

Four Independent 5 V Relay Channels: Control four separate loads from compatible microcontroller outputs; each channel uses an active-low input and has its own status LED for easier wiring checks and troubleshooting Optocoupler-Equipped Input Stages: Four optocouplers separate the control-input stages from the relay-drive circuitry; use the JD-VCC/VCC configuration required by your project and follow the board documentation for isolated-power setups 10 A Relay Contact Rating: Each relay is marked for up to 10 A at 250 V AC or 30 V DC under the relay manufacturer's specified conditions; choose wiring, protection and load types appropriate to the application Flexible NO/NC Wiring: Each relay channel includes NO, COM and NC screw terminals, allowing the connected circuit to use normally open or normally closed operation Compatible with Common MCU Projects: 5 V control module for compatible Arduino, AVR, PIC, ARM and STM32 projects; package includes one 4-channel relay module, and controller boards, power supplies and load wiring are not included

Add four independently controlled mechanical switches to a microcontroller project with the ELEGOO 4 Channel DC 5V Relay Module. The board uses active-low IN1–IN4 control inputs and provides an individual status LED for each channel, helping you confirm code, wiring and switching behavior while testing.

Each relay provides NO, COM and NC screw terminals, so a load can remain normally off or normally on according to the circuit design. This makes the module useful for low-voltage prototypes, multi-zone lighting controls, fans, pumps, solenoids, irrigation projects, robot accessories, garage-door button simulation and smart-home controller experiments.

EL817 optocouplers and diode protection help reduce interference between the control side and the relay coils. With the JD-VCC jumper installed, the logic side and relay-coil side share the module’s 5V supply. For a separately powered coil side, remove the jumper and follow the official wiring diagram before connecting the external 5V relay supply. The module itself requires a suitable 5V supply; do not assume a 3.3V controller can safely power the relay coils.

The 72 × 51.7 mm PCB provides four relay channels, mounting holes and clearly labeled input and load terminals. Contact ratings are up to 10A at 250VAC or 10A at 30VDC, but these figures are maximum relay-contact ratings rather than a guarantee for every appliance or installation. Actual safe load depends on startup current, inductive load behavior, switching frequency, wire size, terminal condition, fuse or breaker protection, enclosure design and local electrical requirements.

For motors, pumps, solenoids and other inductive loads, apply suitable suppression and derating. Mains-voltage wiring should be completed only by a qualified person with the module enclosed so exposed terminals cannot be touched.