P4.1 - Rotational Speed Direction Detection Based on the Output Duty Cycle of a Differential Hall Effect Gear Tooth Sensor
- AMA Conferences 2015
2015-05-19 - 2015-05-21
- Proceedings SENSOR 2015
- P4 - Magnetic Sensors
- C. Lui, J. Liu - ChenYang Technologies GmbH & Co. KG, Finsing (Germany), J. Qiu - University of Shanghai for Science and Technology, Shanghai (China)
- 780 - 785
In this paper, a new method is proposed to use the duty cycle of the output signal from a differential Hall Effect gear tooth sensor for determining the rotational direction. The magnetic polarization of the detected differential magnetic field density is changed by changing the rotational direction of the target wheel. Therefore a variation in duty cycle of the electrical output signal is visible when the geometric duty cycle of the target wheel is designed about 70%. This method works with special target gears which are designed and optimized by magnetic field simulation and experiments. The presented method is applied to the differential Hall Effect gear tooth sensor CYGTS101DC-S, which has a large sensing gap of 3.5mm, a relatively stable duty cycle of 61.24% in clockwise direction and of 38.76% in counter-clockwise direction under using the designed target wheel.