Sensorless Brushless Startup Procedure

[endrophie]

Hello,

if you have a look to a modern brushless controller for radio
controlled flying models you can see

- that the motor has a very short startup time until the right moving
(about 100-200ms)

- that no initial alignment for a known position is done

- that a backward rotation only about 30 - 60 ms after starting is
recogniced and the motor is running in the right direction

- that because of the used 8 bit Microcontrollers there is no extrem
complex algorithm possible

- that the controller works probably in voltage controll

Does anywhere have information about the used startprocedure or a
webside/usegroup where mor information is available?

Best regards

Endrophie

 

[CWatters]

Does anywhere have information about the used startprocedure or a
webside/usegroup where mor information is available?

http://www.eng.nus.edu.sg/EResnews/9805/p13.html

 

[Jim Thompson]

http://www.eng.nus.edu.sg/EResnews/9805/p13.html

I've used a ring oscillator to start EC motors, where the sensing was
just the back-EMF of each winding... once turning switch to
EC-control.

...Jim Thompson