How to change the direction of Brushless DC motor
How to change the direction of Brushless DC motor
(OP)
Hi guys,
When I simulate the speed control of the Brushless DC, it is difficult for me to control the direction of motor dynamically. If I don't change the direction of the motor, the simulator works fine. but if I change the direction when the voltage is still high, the motor will oscillate and the speed is out of control. I can change the direction of the motor only a little after the voltage goes down to zero.
I want to know how to change the direction of brushless DC motor in the reality, Do the user need to change the voltage supply to zero before he want to change the direction of brushless DC motor?
Thanks a lot for your help
Min
When I simulate the speed control of the Brushless DC, it is difficult for me to control the direction of motor dynamically. If I don't change the direction of the motor, the simulator works fine. but if I change the direction when the voltage is still high, the motor will oscillate and the speed is out of control. I can change the direction of the motor only a little after the voltage goes down to zero.
I want to know how to change the direction of brushless DC motor in the reality, Do the user need to change the voltage supply to zero before he want to change the direction of brushless DC motor?
Thanks a lot for your help
Min





RE: How to change the direction of Brushless DC motor
<nbucska@pcperipherals.com>
RE: How to change the direction of Brushless DC motor
Thanks a lot for your quick response.
So based on you reply, it is difficult to use the brushless dc motor in the applicition of position control and also the application of closed-loop speed control in which the direction will change frequently.
Is my understanding right?
Thanks
MIn
RE: How to change the direction of Brushless DC motor
http://www.sig-positec.co.uk/
http://www.doc.ic.ac.uk/~ih/doc/stepper/index.html#other
http://www.lasermotion.com/StepMotor.html
http://www.motioncontrol.com/products/level1.cfm
etc. for more info.
Please notice that frequent changes of the motor rotation direction is very demanding for every motor.
RE: How to change the direction of Brushless DC motor
If you have no absolute position feedback, you start it
with a low freq. oscillator, which -- sooner or later --
the rotor follows. It means you can't determine the position
from the input.
<nbucska@pcperipherals.com>