Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Unit Conversion, kRPM/V

  1. Jul 3, 2011 #1
    For a motor modeling project im trying to find a value that is measured in Volts/kRPM (Voltage constant) , in the motor specs that I am given i have a value in RPM/Kv,

    If the value for RPM/Kv given is 245, how can i find Volts/KRPM, or is that even possible

    Last edited: Jul 3, 2011
  2. jcsd
  3. Jul 3, 2011 #2


    User Avatar
    Homework Helper

    I assume K means 103

    so 245 rpm/kV = 0.245 rpm/V

    So now dividing by 1000, 0.245(10-3)krpm/V.

    Just invert now to get the units of V/krpm.
  4. Jul 3, 2011 #3
    So, it would be 1/0.245(10^-3)?

    That comes to 408, which is a ridiculously high voltage constant, or at least from what ive seen anyway
  5. Jul 3, 2011 #4


    User Avatar

    My guess is that your second value is in kRPM/V, not RPM/kV. Very few motors run on thousands of volts, so RPM/kV wouldn't make sense as a unit.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook