I am using a RPi to switch a relay on and off at certain times of the day. I have an electric motor connected to the relay and would like to use an external 12V DC power supply (wall wart) that I have lying around to drive a 12V DC motor. I have measured various 12V DC power supplies and all of them show >12V: The nearest was 15V and one was 21V. Is that normal? More to the point is it an issue for the motor? LMK if I need to provide more info.