5V/12V/24V 4 Channel Relay Module， Optocoupler Module Board High & Low Trigger for Arduino(24V)

▶【Double Edition Design】: It adopts PCB double board design, 4 channels of independent design, and does not interfere with each other. Adopt single-chip design, stable and performance, strong anti-interference, no false triggering, superior performance. ▶【Isolation work】: Trigger optocoupler isolation, the trigger power supply can be an independent external power supply, truly completely isolated. (If you need external contact power supply: DC12V version of the trigger, a 5.1-6.8K resistor in series; DC24V version of the trigger, a 15-22K resistor in series; otherwise it will damage the chip) ▶【Indicator】: Use 4 tactile switches as product test to directly verify product stability (low level trigger is effective); with power indicator (green LED) and 4 switch indicators (red LED); ▶【Friendly design】: User-friendly interface design, all interfaces can be directly connected through the terminal leads. Four fixing bolt holes are provided. ▶【Application】: This module is widely used in the design and development of home and industrial electronics for most electronic enthusiasts. Suitable for electronic circuit design, automation equipment transformation, PLC industrial control, robot, intelligent products for college students.