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Magnetic sensor to measure RPM of the motor

Nirmith H
Prodigy 20 points
Other Parts Discussed in Thread: TMAG5110, TMAG5111, TMAG5170, TMAG5273

Hi all 

I'm looking for a magnetic sensor which should be a industrial grade and it should be able to determine the speed and RPM of the motor in the industry.

I'm not able to find a sensor which can detect it can anyone suggest me with a component which can determine the RPM of the motor when it is mounted on it.

And I need technical document of it and the application notes as well.

Regards

Nirmith 

  • 0
    TI__Mastermind 21260 points

    Nirmith,

    Thank you for reaching out with your question.  There are multiple approaches. Please refer to the following literature for recommendations:

    https://www.ti.com/lit/an/sbaa544/sbaa544.pdf

    https://www.ti.com/lit/an/slvaeg3a/slvaeg3a.pdf

    Typically this function is performed using a Latch type device, which will toggle with alternating field polarity.  This helps provide two transitions per revolution which will improve the quality of the speed measurement.  If desired, it is possible to use a 2D latch, such as TMAG5110 or TMAG5111 to gather information about both speed and direction.

    If more resolution is needed, then it is possible to use linear sensors to produce sine/cosine outputs which may be used to calculate absolute position at any time.

    Thanks,

    Scott

  • 0 in reply to Scott Bryson
    Prodigy 20 points

    Hi Scott,

    I need a magnetic sensor which has 3 axis and which should be industrial grade.

    I need it for measuring the RPM and the mounting position on how I can measure it.

    Can you help me out with it 

    Regards 

    Nirmith 

  • 0 in reply to Nirmith H
    TI__Mastermind 21260 points

    Nirmith ,

    We have two linear 3 axis sensors, TMAG5170 and TMAG5273.  Both devices offer integrated angle calculations which may be tracked to determine absolute position at any time.  This would allow the user to calculate speed based on the rate of change of the angle.  Another approach using TMAG5170 would be to to use the programmable input thresholds of the device.  For instance, if the X channel saw a sinusoidal input with a magnitude of +/-20 mT, it might be possible to set the thresholds at +/-15 mT.  The device would send an output on the ALERT pin each time this crossing happened with two events per revolution (+15mT and -15mT).  If you were also able to determine the time between each pulse, the motor speed could be easily calculated.

    Thanks,

    Scott