Greetings:
For my PWM amp design that has been beaten about in thread "PWM Amp Design" I am now interested in implementing a common mode output filter, per the valuable suggestion of Nico Coesel.
Trouble is, I need to know what load impedance is presented to the output of a filter in order to get the right LC values.
What to figure for the common mode load Z for the output of a PWM amp? The load is isolated from ground, of course, since the H-bridge output is differential and doesn't mean much with respect to ground.
Should the common mode filter be just a common mode choke or a common mode choke followed by a capacitor on each output leg to ground?
How does one typically chose a common mode output filter?
Thanks for input.
Good day!