PWM, H-Bridge and NCO - PIC16F18446

[richard]

Do not know if or how NCO can be steered PWM/CWG module.


Richard, also nice idea about CLC module. I suppose the low freq signal is external of the PIC. Or may be the NCO signal too.

you need to have a good look at the data sheet
valid cwg input's :-
the nco
a clc output
any of the ccp /pwm modules
the dsm output

valid clc input's:-
the nco
any of the ccp /pwm modules
the dsm output

there are many possible methods of modulating a LF osc source with a HF pwm signal with the clc or dsm modules
any of which can be turned into a full bridge signal source with the cwg module , try a few

[Ioannis]

Hope this draw clarifies a bit the problem.

Ioannis

[richard]

so where does the 1khz fit in ?


i expected more like this

[Ioannis]

You are right, I just didn't want to clutter the draw.

Ioannis

[amgen]

looking at your diagrams, seems like you could ..... set up the PWM module for 1KHZ as normal, for the 20HZ part, set up a timer interrupt for the low freq maybe with a couple of roll overs for lower freq.... then on tmr int, only need to switch the Q's and add a little dead time on each switchover.

[Ioannis]

Alain:
The PWM is controlled by a Pot. I could also make a variable power supply and control directly the voltage on a SMPS circuit instead of PWM. More complicated.

Amgen:
It is easier on the unipolar mode. But gets difficult on bipolar drive having software to control both PWM, low freq signal and the control of the 4 MosFets transitors. Including deadtime.
Better, most if not all of this be done on hardware using NCO, CWG, CLC etc.

I believe that it is possible to do this as Richard is confident too. I just need more reading to understand how all these modules will work together.

Ioannis

[amgen]

did you get someone for your h-bridge circuit ?? have a couple thoughts if not