10.6 Step 6. Demo Tuning

If the motor has a hard time at start-up, consider tuning the following values:

Start-up Voltage – Changes the modulated voltage achieved at the end of the ramp-up time

Ramp-up Time – The amount of time it takes to achieve from the offset voltage to the start-up voltage

Switch-over Speed – The electrical RPM speed reached at the end of the ramp up procedure

Rule of thumb for calculating the commutation values:

  • VBEMF: Back EMF(V/kRPM) – from the Motor data sheet

  • SRPM: X% of Rated Speed – from the Motor data sheet

  • Ramp-up Time – The time it takes to achieve from the offset voltage to the start-up voltage

  • Switch-over Speed – X% of Rated Speed

This formula is a good starting point. After that, tuning might be necessary to obtain the desired results.

In Open Loop, we ensure drive synchronization with the motor’s feedback, and the voltage amplitude (duty cycle) is regulated by the potentiometer.