Brushless motor or BLDC in servo

Thread Starter


Joined Nov 26, 2016
My task is make bldc motor work in servo. I use Maxon 400161 24V 30W motor with hall sensors, H bridge of n-channel mosfet and DSP tms320f28035.
I have tried to use bi-polar complementary PWM. It works, but some strange.
Firstly, I spinned motor outside servo without load. Commutating phases according to hall sensors and using constant PWM duty cycle, I got speed about nominal, but current was 2.2A! Datasheet says about 200mA no-load current.
What I was doing wrong? Or what I could do wrong?
With decreasing PWM duty cycle, speed became lower linearly.
So, how can I reach nominal speed without such huge current consumption?