Erik Christiansen wrote:
> But with a little dead-time between one being turned off and the other
> on. So H-bridge drivers with hardware dead-time would be needed where
> only three signals are provided. (AIUI)
>   
You can't drive a 3-phase motor with only high and low drive in six step 
mode.
It needs one bridge to be open-circuit.  If you are driving it with a 
PWM sinewave
scheme, then you could drive with only 3 wires.  This requires the PWM 
amplitude
relationships to change gradually as the motor rotates, so the bldc 
component needs to
know absolute rotor position.  This is the tricky part, until the 
encoder passes the index mark,
or you use the Hall signals, you don't really know the absolute rotor 
position.

Jon

------------------------------------------------------------------------------
Protect Your Site and Customers from Malware Attacks
Learn about various malware tactics and how to avoid them. Understand 
malware threats, the impact they can have on your business, and how you 
can protect your company and customers by using code signing.
http://p.sf.net/sfu/oracle-sfdevnl
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to