1 Channel 5V Relay Module with Optocoupler – 1CH Opto-Isolated Relay Board for Arduino, ESP32, Raspberry Pi & Microcontroller Projects

The 1 Channel 5V Relay Module with Optocoupler is a compact switching module designed to control higher-voltage or higher-current electrical loads using low-voltage signals from Arduino, ESP32, Raspberry Pi, microcontrollers, development boards, and other electronic control circuits.

This module uses a 5V electromagnetic relay together with an optocoupler isolation circuit, helping provide electrical separation between the control-side circuitry and the relay switching section. This makes it suitable for automation, robotics, IoT projects, home-control systems, DIY electronics, educational projects, and prototype development.

The relay provides Normally Open (NO), Normally Closed (NC), and Common (COM) terminals, allowing users to configure the load according to the required switching condition. Screw terminals provide convenient and secure wiring for the load connection.

The module can be controlled using a digital output from a compatible microcontroller or controller board. When the relay is triggered, the internal electromagnetic mechanism changes the connection between the COM, NO, and NC terminals, allowing external appliances, lamps, motors, solenoids, pumps, and other suitable electrical loads to be switched.

The onboard optocoupler helps reduce direct electrical interaction between the control signal and relay-driving circuitry. Depending on the exact board version, the module may include status indicator LEDs and transistor-based relay driving circuitry for stable operation.

This single-channel relay board is particularly useful when only one electrical device or circuit needs to be switched, making it smaller and more economical than multi-channel relay boards.

It can be used for experiments involving automatic lighting, motor switching, water-level controllers, smart-home systems, security alarms, IoT appliances, temperature-controlled equipment, timers, sensor-based switching, and numerous other electronics applications.

Important: When switching mains AC voltage, proper insulation, enclosure, wiring, clearances, fuses, and electrical safety precautions must be followed. High-voltage wiring should only be handled by a suitably qualified person.

Specifications

*Actual safe switching capacity depends on the exact relay model, load type, PCB design, operating conditions, and electrical safety requirements. For inductive or high-inrush loads, suitable derating and protection should be used.