Waveform results When the wheel starts to rotate, the Hall effect sensor begins to generate a series of signals, and the number of pulses will increase with the increase of vehicle speed, similar to the legend, which recorded about 30 mph at that time. The pulse signal frequency of the vehicle speed sensor will increase with the increase of vehicle speed, but the duty ratio of the position will remain unchanged at any vehicle speed.
Extended data
The higher the speed sensor, the more waveform pulses appear on the oscilloscope. Confirm that the amplitude, frequency and shape from one pulse to another are consistent, that is, the amplitude is large enough and usually equal to the power supply voltage of the sensor, and the interval between the two pulses is consistent and the shape is consistent, as expected. Ensure that the frequency of the waveform is synchronized with the vehicle speed and the duty ratio is unchanged. Also note the following points:
Observe the consistency of the waveform and check the sharp corners at the top and bottom of the waveform. Observe the consistency of amplitude: the wave heights should be equal, because the power supply voltage of the sensor is constant. Some examples show that there are gaps or irregularities at the bottom or top of the waveform. The key here is the stability of waveform. If the potential of the waveform to the ground is too high, it means that the resistance is too high or the sensor is poorly grounded.
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