PWM generation in Simulink - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a PWM signal using a Compare To Constant block.

Simulink

pwm_signal = (input_signal [1] threshold);

Drag options to blanks, or click blank then click option'

A==

B<

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality operator instead of greater than.

Using less than operator which inverts the PWM signal.

The PWM signal is generated by comparing the input signal to a threshold using the greater than operator.

2fill in blank

medium

Complete the code to set the PWM frequency by adjusting the carrier signal period.

Simulink

carrier_period = 1 / [1];

Drag options to blanks, or click blank then click option'

Aduty_cycle

Bphase_shift

Cfrequency

Damplitude

Attempts:

3 left

💡 Hint

Common Mistakes

Using duty cycle instead of frequency.

Using amplitude or phase shift which do not set frequency.

The carrier period is the inverse of the frequency, so setting carrier_period = 1 / frequency sets the PWM frequency.

3fill in blank

hard

Fix the error in the PWM duty cycle calculation code.

Simulink

duty_cycle = [1] / max_signal_value;

Drag options to blanks, or click blank then click option'

Ainput_signal

Bmin_signal_value

Ccarrier_signal

Dthreshold

Attempts:

3 left

💡 Hint

Common Mistakes

Using min_signal_value which does not represent the current input.

Using threshold or carrier_signal which are unrelated to duty cycle calculation.

The duty cycle is calculated by dividing the input signal by the maximum signal value to normalize it between 0 and 1.

4fill in blank

hard

Fill both blanks to create a PWM signal dictionary with duty cycle and frequency keys.

Simulink

pwm_params = {"duty_cycle": [1], "frequency": [2]

Drag options to blanks, or click blank then click option'

Aduty_cycle

Bfrequency

Cpwm_frequency

Dduty

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'frequency' variable instead of 'pwm_frequency'.

Using 'duty' instead of 'duty_cycle'.

The dictionary keys are 'duty_cycle' and 'frequency'. The values should be the variables duty_cycle and pwm_frequency respectively.

5fill in blank

hard

Fill all three blanks to generate a PWM signal array with given duty cycle, frequency, and time vector.

Simulink

pwm_signal = (mod([1] * [2], 1) < [3])

Drag options to blanks, or click blank then click option'

Atime_vector

Bduty_cycle

Cfrequency

Damplitude

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up duty cycle and frequency in the multiplication.

Using amplitude which is unrelated here.

The PWM signal is generated by computing mod(time_vector * frequency, 1) and checking if it is less than duty_cycle.