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Hi Team, We need to measure the Back EMF of the 8 pole, 3-phase BLDC Motor. We have the DRV8308EVM board and would like to measure the Back EMF of the Motor. Kindly let me know what are the best means/circuit to find it. I have attached the phase output waveform of 120 degree standard Trapezoidal and 180 degree Sinusoidal commutation of the Motor.
Motor Supply voltage: 24V
120 degree standard Trapezoidal commutation of the Motor, phase waveform:
180 degree Sinusoidal commutation of the Motor, phase waveform:
Denny,
What is the reason for the need to measure the back EMF? This will help define what is needed.
Regards,
-Adam
Hi,
We need to measure the back EMF, as we are interested in determining the motor's speed because we have a application in which both very low torque and very high torque is being applied to the motor.
Hence we need to analyse the Motor behavior at different speed at various torque.
Thanks,
Denny
Denny,
I don't have experience sensing this but you can use the FGOUT signal on the DRV8308 to sense the speed of the motor. You can also use the hall sensor output.
Regards,
-Adam
Hi Adam,
Could you please connect me to the person who could help in measuring the Back EMF of the motor. Since, we are very much interested and keen to measure the Back EMF at different speed of the Motor for our application.
Thanks,
Denny
Denny,
We measure the back EMF for our High speed DRV832x TI design, please check here: http://www.ti.com/tool/TIDA-010031
Regards,
-Adam