2-channel 12 V relay module with optical isolation for Arduino, ESP32 and automation systems

A 2-channel 12 V relay module designed for independent control of two high-power loads, such as lamps, pumps, fans, electromagnetic locks and valves, using signals from a microcontroller. The board carries two FL-3FF-S-Z relays with 12 V DC coils. The control inputs are isolated by optocouplers, which protect the microcontroller from interference from the power section. Each channel has its own 3-pin screw terminal block (NO, COM, NC), a protection diode and an indicator LED. Control is connected through a pin header: GND, IN1, IN2, VCC. A jumper on the board allows the relay coils to be powered from a separate source. The module is convenient wherever the system is already powered by 12 V: automotive electronics, solar installations, greenhouses, aquariums and smart home systems. Specifications: Relay supply voltage: 12 V DC Number of channels: 2 Relay: FL-3FF-S-Z (12 V DC) Switched load per relay rating: 10 A 250 V AC / 30 V DC, 12 A 125 V AC / 28 V DC Input isolation: optocouplers Load contacts: NO, COM, NC on each channel Control connector: GND, IN1, IN2, VCC