Re: router speed control

Hi,
OK so to get the speed you measure the BackEMF. I'm guessing you
use an electronic switch, disconnect the motor from the supply at a
zero crossing point, then sense the voltage produced by the motor.
How often would this be done (a couple of times a second?). Do you
measure for a complete cycle or half cycle? More info (or point me
in the right direction) would be great as I have an interest in this.

Thanks,

Jeff


caudlet wrote:
You can get speed (RPM) from back emf of the motor since it is a
generator as well as a motor. If the speed control has any ability
to maintain a constant speed under load they probably use that
method.