[Rickertsen2]

Originally Posted by Manoel

Wouldn't it be three FETs in parallel sourcing current plus three FETs in parallel drawing current, and hence 0.008 Ω? It's an H-Bridge after all, isn't it?



Interesting data, just be aware when comparing your results with Rickertsen2's that you used a resistor and he used a motor (resistor + voltage source + inductor model). Of course, your tests are better, because this resistor setup will not interfere with the Victor's output waveform.
With your data, we can say for sure that the Victor's are linear (something the IFI guys already told us, for the matter), I'm just a little puzzled about the current "crop" at the graphic's extremes, were you using a battery to feed the Victor or maybe a different power supply with a maximum output current?

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His data is not "better". Neither is mine for that matter. Put together they reinforce the inductance theory. My graphs were corect. What was not was my assumption that my curve was caused by a nonlinearity of the victors. Given your data we can see this is not the case.I think at this point we can conclude (to IFIs credit), that the victors are linear. This does not mean that my data was wrong. BOTH sets of results are correct. The tests were different. KVermilion measured current across a RESISTOR ONLY with a constant resistance and varying PWM input to the speed controller. This would be nice if we were powering heaters with the victors but we are powering motors.

A motor's torque output is porportional to the current through it regardless of why that amount of current is going through it. It has been shown that while the victors output a linear voltage, the load is not purely resistive and this does not lead to a linear current. It has an inductive Component. It may still be useful to compensate for the the pwm vs. current curve that we now know is caused by inductance. Even though I mistaked the cause of the curve, it is still there. There is still a possibility that my voltage test was wrong due to my meter not being able to properly read a square wave however the pwm vs. speed curve is still viable. After all, we are trying to control speed here, so that is the ultimate test



Btw. Andy, it happens to me about every other post. I have learned to copy my post before submittting. Sessions either always time our for me or arn't working properly.