Posted on August 15, 2013 at 15:37I am working on a BLDC motor implementation. The motor has 4 Pole Pairs with 3 hall sensors.
I am storing the time between any successive hall sensor interrupt.
The time between hall sensor interrupts is
(TIMER * LSB) where my LSB is microseconds
The total time for one mechanical revolution of the motor is
T = (TIMER * LSB) * 6 * NUMBER_OF_POLE_PAIRS
The rotation rate, in degrees per second, is therefore
(360*1000000)/T which is
60,000,000 / ( (TIMER * LSB) * NUMBER_OF_POLE_PAIRS)
Notice that the last equation is missing the factor of 6 in the denominator.
What I’m finding is that the rotation rate is correct if I still have the 6 in the denominator, which doesn’t make sense to me.
Help!
