Driving Motors and Other Output Devices

     The video above shows a circuit consisting of a MPSA13 Darlington transistor which is switching a "signal lamp" on and off. The transistor essentially has a Darlington arrangement built into it so that one did not have to be constructed. The light is just as bright as it had been with the actual Darlington arrangement.

     This video shows almost the same circuit as the above video. The difference here is the transistor that is being used. Instead of the MPSA13, a TIP120 power transistor was inserted into the circuit.

 

     This video shows the previously constructed circuit controlling one of the motors of the toy I dissected. It uses the same TIP120 transistor but with a 2.2K ohm resistor used instead of a 3.3K. Also a 1N4001 diode was placed in parallel with the wires that control the motor.

     This circuit was supposed to control the direction of a DC motor. Its two main components are the TIP120 power transistor and a DPDT relay. One pin of the arduino was an output that was to turn the motor on and off, and another pin was to be an output that would control the direction of the motor. However, for some reason the motor did not want to change its direction.