RPM calculations and understanding

Hi,

i am confused with RPM calculations of the motor that is the rotations per minute of the motor.
Let us say the RPM of a machine is 6000 RPM.
6000 RPM -> 6000/60 Rotations per second -> 100 rps. If it is a n pole pair motor that is n*2 poles. Then it is 100 * n * 2 electrical angles per second.

electrical angles

100 * n * 2 ----> 1 second
then the number of electrical angles for 1 ms is (100*n*2/1000).
for
1degree ---> 1/(100 * n * 2) seconds.
Am i correct in the above calculations? Why i am asking is i want to estimate the rotor position every 1 ms based on the hall sensor. Currently i don't have either encoder or resolver. One big confusion i have where is the processor clock coming into picture? Can you please help me to understand in what part of calculations does the processor clock will come into picture?

Hi,

Not sure what you try to calculate... but i nowhere see that 1 revolution means 360°.

Klaus

Sorry my mistake
360 degrees -> 1/(100 * n * 2) seconds.
1 degree-> 1/(100 * n * 2 * 360) seconds.
I am mainly trying to understand the following equation attached



I don't understand the Timer1 input clock parameter. Can you please help to understand the significance of that clock. Long time trying to understand that term. What happens for different clock frequencies? Please help.

KlausST said:

Hi,

but i nowhere see that 1 revolution means 360°.

Klaus

Click to expand...

I am confused does it mean that 1 revolution is not equal to 360degrees.

hi,

I am confused does it mean that 1 revolution is not equal to 360degrees.

Click to expand...

from post#2:

Not sure what you try to calculate... but i nowhere see that 1 revolution means 360°.

Click to expand...

--> nowhere in your formule of post#1..

Klaus

Your formula has nothing to do with the electrical degree. I looked at the image. It gives you the number of the pulses your timer receive when the rotor complete an electrical revolving (360 electrical). your timer can recieve any number of pulses according to your oscilator, rotating speed, timer prescale, etc. It is not necessarily 360. It can be any number.