MOSFET Control of an Electric Motor

The objective of the experiment is to use a MOSFET to obtain a stable speed control.

Procedure:
Part 1:
We built the circuit below.

Using the pot, we were able to control the speed of the motor by adjusting amount of voltage through the motor.

Part 2:
We replace the pot with a Function Generator.
The FG produces Square Waves, and duty cycle was on.

We see how the voltage on the motor acts with the Oscilloscope.

Displaying the speed control by increasing and decreasing duty cycles.

Questions:
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 the maximum.

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

Conclusion:
The lab was a success. Both ways controlled voltage, but part 2's method allowed for better speed control than part 1 with the pot.