I just read couple of posts and would like to ask you for advice. Pretty simple situation: Arduino controlling 5V/50mA relay (with protective diode) throught transistor; relay is controlling 12V/250mA solenoid.
1) Can I use just one power source to power Arduino, relay and solenoid? I read post discussing unexpected reseting of Arduino in this configuration and 2 power sources were suggested. I have 12V/1.25A power source which should easily drive this load.
2) If I use one power source, is it neccessary to use protective diode also for solenoid to prevent surge to come back to power suply when turning solenoid off?