adrian_sm said:I did a few runs on the dyno at low speeds, and found the higher PWM rate definitely kept the controller cooler. I just assumed that the low inductance, low resistance, and lower BEMF all colluded to create big current spikes. But what your saying is that the timing is possibly off at these low speeds. Very interesting, and makes sense since the RC styles ESCs are really not expected to run at high load and low speed, so they probably don't care at all if they have the right timing then.
So given these cheaper trapezoidal controllers I am playing with have no phase current measurement, then the last thing for me to optimise appears to be the timing or advance. Guess I'll add that to the todo list.
Oh, here is an example of how the predicted equilibrium temperature fr the ESC under load was affected by the motor speed, and the PWM frequency, under the same load conditions.
Sorry if this is all too for off topic. But this may help explain a few things I was not quite sure off. Cheers.
That is a seriously huge difference!
Interesting! So that graph is a prediction, not an actual dyno test?
I very like it.
