SLIA097 March   2022 DRV5011 , DRV5011 , DRV5012 , DRV5012 , DRV5013 , DRV5013 , DRV5015 , DRV5015 , DRV5021 , DRV5021 , DRV5023 , DRV5023 , DRV5032 , DRV5032 , DRV5033 , DRV5033 , TMAG5110 , TMAG5110 , TMAG5111 , TMAG5111 , TMAG5123 , TMAG5123 , TMAG5231 , TMAG5231 , TMAG5328 , TMAG5328

 

  1.   Trademarks
  2. 1Introduction
  3. 2Flow Meter Design
    1. 2.1 Mechanical Considerations
    2. 2.2 Magnetic Considerations
      1. 2.2.1 Material
      2. 2.2.2 Geometry
      3. 2.2.3 Magnetic Deign Tools
    3. 2.3 Hall-Effect Sensor Considerations
      1. 2.3.1 Device Sensitivity
      2. 2.3.2 Unipolar Switch
      3. 2.3.3 Omnipolar Switch
      4. 2.3.4 1D Latch
      5. 2.3.5 2D Integrated Latch
      6. 2.3.6 Bandwidth
      7. 2.3.7 Package
      8. 2.3.8 Power Consumption
  4. 3Flow Meter Development
    1. 3.1 3D-Print Recommendations
    2. 3.2 Flow Meter Assembly Considerations
    3. 3.3 Flow Meter Assembly Guide
      1. 3.3.1 Shaft Installation
      2. 3.3.2 Bearing Installation
      3. 3.3.3 Magnet Installation
      4. 3.3.4 Impeller Installation
      5. 3.3.5 O-ring Installation
      6. 3.3.6 Flow Meter Top Installation
      7. 3.3.7 PCB Mounting
      8. 3.3.8 Cover Installation
  5. 4Flow Meter Evaluation
    1. 4.1 Flow Meter Testing
  6. 5Error Sources
    1. 5.1 Mechanical Error
    2. 5.2 Sampling Error
    3. 5.3 Magnetic Error
  7. 6Flow Meter PCB
    1. 6.1 PCB Schematic
    2. 6.2 PCB Layout
  8. 7Bill of Materials (BOM)
  9. 8References

2.3.3 Omnipolar Switch

Omnipolar switches act as two opposite polarity unipolar switches connected together. Therefore, the switch still operates using BOP and BRP; however, the polarity of the B-field no longer influences the output of the sensor. This implementation requires the magnets be positioned far enough apart to allow the B-field to fall below the BRP threshold between magnets. Use of the omnipolar switch enables the magnets to be positioned in any orientation (North facing or South facing) with no polarity influence to the sensor operation. Magnets can be positioned in either orientation, simplifying overall mechanical assembly of the flow meter. Omnipolar switch operation is displayed in Figure 2-4.

Figure 2-4 Omnipolar Switch Operation