finding RPM of stepper motor

Discussion in 'The Projects Forum' started by venkatesh.n.s, Jul 17, 2014.

  1. venkatesh.n.s

    Thread Starter New Member

    Jul 17, 2014
    Hi this is venkatesh

    how to calculate the speed of stepper motor when the pulse width is known. for a motor of 1600 pulses/revolution and a step angle of 1.8 deg
    what will be the speed if the pulse width supplied is 170 microsecond.
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    hi ven,

    Assuming 360 deg /revolution and a 1.8deg step thats 200 steps/rev.

    Also assuming a pulse ON period of 170uS and an OFF period of 170uSec.
    Thats 340uS which is a frequency of ~2940 . So 2940/200 = ~15rpm.
    for a two pole stepper.

    Do you have a datasheet for your motor that you could post.?
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    I'm getting a different answer. If we assume 170uS on/ 170us off, then the time for one rev is 1600 x 340uS = 0.544 sec. So rpm = 60/0.544 = 110.3.

    Edit: What we really need to know is the pulse period, rather than pulse width.