Want to detect motor is roatating or not?

Discussion in 'Embedded Systems and Microcontrollers' started by sandeep sangle, Jun 13, 2016.

  1. sandeep sangle

    Thread Starter New Member

    Jun 13, 2016
    I am using c8051f340 controller and i am controling fan from web but i am not receving any feedback that my motor is geting or or not?Can you suggest me any technique for that and same for led lamp?

    Thank You
  2. DickCappels


    Aug 21, 2008
    A current sense resistor in series would indicate whether they are drawing current. In the case of the motor, if voltage is applied but the rotor is locked or blocked then the current would be higher than normal.

    Alternatively you can use a photodetector to look at the at the LED, and another one to look at another LED through the fan blades -this one would have pulses on is as the fan spins and that pulse train can be detected.

    There must be many more ways to tell, just a couple of thoughts.
    boltspinner likes this.
  3. ISB123

    Well-Known Member

    May 21, 2014
    Hall effect sensor can detect changes in magnetic field which should get stronger while motor is running and dependently on how much current it draws.
    Last edited: Jun 13, 2016
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    Get a fan with a tach output wire and read that...
  5. atferrari

    AAC Fanatic!

    Jan 6, 2004
    Maybe this serves to you: PC fans nowadays, when fitted with 4 terminal connectors, one of the pins is the tacho output.