How to generate PWM with duty cycle varying in sinusoidal fashion?

Question

I have to regulate a sinusoidal current in an inductor.

I have only a DC supply.

There are many ways to do it like using stepper motor driver to regulate step wise sinusoidal in 1/256th step mode.

For a specific application, I want to regulate the current by changing the duty cycle of the input PWM to a half-bridge.

If I can generate PWM pulses with a changing duty cycle in sinusoidal way then I'll be able to regulate the current.

I tried using a BeagleBone and an Arduino to generate PWM with a sinusoidal duty cycle, but wasn't able to do that. Mistakenly I had uploaded wrong drawing, now corrected.

I don't have waveform now to upload. But I can paste the beaglebone code I tried.

import Adafruit_BBIO.PWM as PWM 
import time
import math 

Ain1 = "P9_14"
duty=50 # initial value

sin_frequency=100
pwm_frequency=10000
pwm_period = 1.0/pwm_frequency
print("pwm period : ", pwm_period )

PWM.start(Ain1,0)
PWM.set_frequency(Ain1, pwm_frequency)
PWM.set_duty_cycle(Ain1, 0)

count=0
no_pulses=(0.5*pwm_frequency)/(sin_frequency)
print("number of pulses : ", no_pulses)
a=1

while True:
    duty= abs(10.0*math.sin((3.14*count)/(no_pulses)))
    PWM.set_duty_cycle(pin, duty)
    time.sleep(0.1*pwm_period)
    count=count+1
    print(duty)

    if count>=no_pulses:
        count = 0
        duty=0


PWM.stop(Ain1)
pwm.stop(Ain2)
PWM.cleanup()
print("Closed the pwm")

Answer 1

Your circuit won't work because you have a dead short across your supply: -

If you want to approach it this way you need to use a full H-bridge: -

Note that I haven't shown the flyback diodes on the right-side transistors because the bulk diodes in the two MOSFETs serve that purpose.

Of course, if you already have a sinewave signal you could use a PWM modulator such as the LTC6992: -