Lebowski wrote:Since I can now do sensorless I modified a small RC motor I have
lying around. It's seen some abuse (notice the wiggle in the rotor)
It's a Scorpion 4025 with the factory windings removed.
(4025 = 40 mm diameter, 25 mm magnet length). It was much harder
to start sensorless (needs messing with the parameters) and took several
attempts but I got it going. My bicycle motor starts very very easy but
after watching the video I think you'll agree this RC motor is a bit
too extreme I did this test just to indicate the capabilities of my
The video shows the motor running, first fast, then very slow. After that
it shows the (low inductance) stator windings and the output stage.
33 V supply, 97 kHz PWM, 40kHz loop frequency, current controlled.
What inductance? 97khz? how warm do your fets and fet drivers get? You should put a load on it. Maybe put some heat sinks on the fets first.