1 Channel SinglePhase 5V Relay Module KY019 is designed for 5V and 12V TTL control signals, providing a simple yet effective solution for MCU development. This blue relay module features a single channel and a single-phase design, making it suitable for basic relay control tasks. With 5V operation, it can be easily integrated into 5V based circuits, delivering reliable switching functionality. The module is ideal for controlling external devices in MCU projects, enabling efficient signal transfer and power management. Its compatibility with 5V and 12V TTL signals ensures seamless connection with different microcontrollers, enhancing development versatility. Use cases: - Prototyping with Arduino, ESP32, or other MCUs to switch loads such as a lamp, fan, or heater via TTL control. - Robotics or automation projects to drive a DC motor or solenoid through the relay. - Home automation prototypes to remotely control appliances from a microcontroller.