I am doing a sinewave ups. the output is full bridge.
I have configured the 2 pwm s in the dsPIC so as to generate sinewave.
But before connectiing and driving a real MOSFET final I would like to see the sinewave with some small filter or transistor circuits.
The PWMs coming through 4 pins to a small circuit to see in a scope. If it is something which can be loaded, I may be able to do the closed loop performance basics also.
Is it possible? any small circuits for this purpose?
Thanks

 

This one usually works well with the PWM being the Vin.


Choose an Rc time constant of 4x or more of the PWM period, and you should be able to see your signal on a scope if the sine wave frequency is substantially less than 1/4x the PWM period.

 

There are 4 pwm pins from the MCU to drive the bridge.
How this single Vin can handle that situation?

 

Use two low pass filters and two channels on the scope, one channel is inverted and the other is not. Switch the scope's vertical mode to "A+B" or "Ch1+Ch2" and after adjusting the vertical centering controls observe the waveform.