Controlling Electric Motor Using MOSFET

 The main purpose in the experimient was to achieve a stable speed control of an electric motor using a MOSFET.

Procedure:

 Part 1:
 Building the MOSFET voltage control circuit shown below.

note: the "FET N" is the MOSFET, and there is a diode between the positive ad the ground wire connecting to the electric motor. The external resistor is used to limit the current in the circuit.

A completed MOSFET voltage control circuit on breadboard.

By adjusting the resistance in the potentiometer, we can adjust the voltage through the motor, and therefore, control its speed.

Part 2:

This time, the potentiometer is replaced with a Function Generator.
The Function Generator would produce Square Waves, and its duality was set to be on, as well as its duty cycle.

The completed view of the modifited circuit.

Eventhough the potentiometer was left on the breadboard, it was no longer connected to the circuit.

The voltage on the motor is correspondance with the Oscilloscope.

Displaying the speed control by increasing and decreasing duality.

 Answer to questions for discussion:
The motor rotates faster with a larger duty cycle.
The graph is the on/off times of the square function.
The time required to decelerate is 0.7s.
The voltage is 0.16 V at 30%

The voltage of motor at 30% of its maximum.

 The converter allows a smooth speed control.
T = 1/110 = 9.1ms

Conclusion:
 We had successfully controlled the voltage across the motor with both the potentiometer and FG, but the FG allowed for better speed control than the potentiometer.