N-MOSFET heating up and not giving enough voltage for Motor to rotate

Discussion in 'Homework Help' started by soodvinay, May 11, 2019.

  1. soodvinay

    Thread Starter New Member

    May 11, 2019
    2
    0
    i am working on my daughter's project. which is supposed to run a 12V motor.
    motor is connected via a n-channel mosfet, which supposed to produce enough voltage for motor to run.
    however mosfet is getting heated up and upon checking with multi meter mosfet's drain output is coming up as 6V.

    could you please suggest what can be the issue ?
     
  2. bertus

    Administrator

    Apr 5, 2008
    19,929
    4,148
    Hello,

    Can you post a decent schematic?
    The picture tells me nothing.
    There are no values and partnumbers.

    Bertus
     
  3. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    8,174
    2,030
    What is the MOSFET and what is the gate to source voltage?
     
  4. soodvinay

    Thread Starter New Member

    May 11, 2019
    2
    0
    Thanks for the reply
    Attaching ckt diagram.
    looks like mosfet got damaged now as its is getting heated up as soon as i turn on the connection.. sorry can not measure gate to source voltage until i get the new mosfet.
    Regards
     
  5. bertus

    Administrator

    Apr 5, 2008
    19,929
    4,148
    Hello,

    The main problem is that the mosfet is used in a linear mode.
    The best way to use a mosfet is as switch.
    Using a comparator between the sensor circuit and the mosfet would already be an improvement.

    Bertus
     
  6. crutschow

    Expert

    Mar 14, 2008
    23,130
    6,860
    If you need to vary the speed of the motor by operating the MOSFET in the linear mode, then it will likely need to be on a heatsink.

    What is the current rating of the motor?
     
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