Pic of relay module is attached below, it has only one GND As i want to use a separate power supply of 5V, i connected separate supply's +Ve terminal to JD-Vcc and -Ve terminal to "GND-IN1-IN2-IN3-IN4-Vcc"'s GND of relay module.... and connected Arduino's 5V to "GND-IN1-IN2-IN3-IN4-Vcc"'s Vcc... do…

relay JD-VCC connection

LarryD April 13, 2017, 4:13am 5

From dlloyd

Are relay shields safe?