Stable performance and isolation The 1channel relay board uses optocoupler isolation for clean signal transfer and strong drive. Trigger current is 5 mA, with a jumper to choose active or activelow triggering. Uses a normally open relay for reliable operation. Faulttolerant design 12 V version includes faulttolerant wiring so a broken control line cannot actuate the relay. Indicators: green power LED and red relaystate LED. Flexible voltage and trigger options Available in 5 V, 12 V, or 24 V coil versions. Each channel can be triggered by a or low level via a jumper setting. Easy wiring and mounting Direct terminal wiring for quick connections. Four mounting holes for secure installation. Standard interface compatible with microcontrollers such as Arduino, 8051, AVR, PIC, DSP, ARM, MSP430 and TTL logic. Applications Suitable for home automation (lighting, outlets) and small automation or robotics projects that require isolated switching and reliable control. Note Check coil voltage and current requirements before integration.