Connect the Arduino outputs with 5 volt power to the relay coils. Use a separate 9 or 12 volt battery for powering the motor.  Connect the 9 or 12 volt power to the relay contacts and the motor.  Be sure to avoid connecting the 9 or 12 volt power to any of the Arduino input or output pins. Write an Arduino sketch to run the elevator up and down in the center of the “hoistway” for a fixed length of time in e ...