This project showcases a 5V single channel relay module designed for safely controlling high-voltage or high-current loads using low-voltage microcontrollers. Built with simplicity and reliability in mind, the module allows boards such as Arduino, ESP32, STM32, and other MCUs to switch AC or DC loads without exposing sensitive logic pins to dangerous voltages.

At the core of the design is a 5V electromagnetic relay, driven through a transistor-based switching stage. This ensures the microcontroller only needs to supply a small control signal while the relay coil is powered and isolated correctly. A flyback diode is included to protect the driver circuitry from voltage spikes generated when the relay is switched off, improving long-term reliability.

The PCB layout is compact and practical, with clear separation between the low-voltage control side and the high-voltage load side. Screw terminals on the relay output make it easy to connect appliances, motors, lamps, or other external loads, while a standard 3-pin header (VCC, GND, SIG) allows quick interfacing with development boards.

Operating from a 5V supply, this relay module is ideal for automation projects, smart switches, home control systems, robotics, and industrial prototypes. It serves both as a ready-to-use module and as a clean reference design for anyone learning how to interface relays safely with microcontrollers.

Overall, this single channel relay module demonstrates how a straightforward hardware design can provide dependable isolation and control, making it a fundamental building block for countless embedded and DIY electronics projects.

Credit & Acknowledgement

Complete Design & Engineering Credit: Ampnics (This project is shared for educational and community reference purposes)