!!! There is a delay until the circuit starts operating !!!
The duty cycle of the PWM can be adjusted by changing the potentiometer position.
This circuit uses a Schmitt-Trigger to continuously cycle an integrator. This creates a triangle wave.
The rightmost OP-Amp works as a comparator and compares the output of the triangle wave generator with the comparison voltage, which is given by the potentiometer.
The potentiometer % roughly corresponds to the duty-cycle %.
With a few adjustments, the values would be more accurate; this is more of a functional overview.
