Quote Originally Posted by old kodger View Post
Whilst your comments are valid for the operation of the device, unless tread mill motors are different in America (quite possible) in Australia they are DC motors, so after you've rectified the output from either of those systems the results are the same so it doesn't matter how you arrived at the most appropriate voltage/speed, so long as it doesn't exceed the max for the motor
The results are not the same. The output in each case is not steady DC, it is pulsing. The pwm pulses will be of higher frequency and easier to smooth. Motors run smoother and last longer when fed with PWM supply. The comment about rectifying the output of these controllers is irrelevant because their output is DC.

In any case, as I pointed out, the post was not about triacs or scr vs pwm, it was about misleading adverts.