SLVA654B June   2014  – March 2019 DRV8301 , DRV8301-Q1 , DRV8302 , DRV8303 , DRV8307 , DRV8308 , DRV8312 , DRV8323R , DRV8332

 

  1.   Hardware design considerations for an efficient vacuum cleaner using a BLDC motor
    1.     Trademarks
    2. 1  Suction Principle
    3. 2  Brushless DC Motors (BLDC)
      1. 2.1 Construction of BLDC Motors
      2. 2.2 Working of the BLDC Motor
        1. 2.2.1 Types of Control
          1. 2.2.1.1 Sensor Control
          2. 2.2.1.2 Sensorless Control
            1. 2.2.1.2.1 Sensorless Control: Using Zero Crossing of the Back EMF Signal
          3. 2.2.1.3 Calculations
    4. 3  Microcontrollers
    5. 4  Gate Driver and MOSFETs
    6. 5  Isolation
    7. 6  Power Management (6 to 60-V DC Power Supply)
    8. 7  CAP and QEP interfaces
    9. 8  Enhanced Controller Area Network (eCAN)
    10. 9  High-Resolution and Synchronized ADCs
    11. 10 DRV8323R
    12. 11 Feedback Stage
      1. 11.1 Torque or Commutation Loop
      2. 11.2 Speed Loop
      3. 11.3 Position Loops
    13. 12 Conclusion
    14. 13 About the Author
    15. 14 References
  2.   Revision History

11.3 Position Loops

A resolver or optical encoder can be used. If a resolver is used then an ADC must be used. An optical encoder provides a digital output which eliminates the need for an ADC. The position loop is the back-EMF signal feedback loop, which is required for commutation.

feedback_llop_slva654.gifFigure 10. Feedback Loops for Sensorless Control