I am using a relay module to drive a solenoid based on the output from my micro-controller which provides 5v signal. Following is what the circuit looks like:
My objective is to hook up both relay module and solenoid to separate power supply so that they do not create noise in my micro-controller circuit.
However, since relay module requires micro-controller output, Can I say that it has to share the same ground (i.e same power source as the micro-controller)? Meaning I can only provide separate power supply for blue color part and yellow color has to source the same power supply as micro-controller?
What is the common approach to isolate power for solenoid and relays?