1. Linear wheel speed sensor
Linear wheel speed sensor is mainly composed of permanent magnet, pole shaft, induction coil and gear ring. When the gear ring rotates, the tip of the gear and the backlash alternate opposite polar axis. During the rotation of the gear ring, the magnetic flux inside the induction coil changes alternately to generate the induced electromotive force, and this signal is fed to the ECU of ABS through the cable at the end of the induction coil. When the speed of the gear ring changes, the frequency of the induced electromotive force also changes.
2, ring wheel speed sensor
The ring wheel speed sensor is mainly composed of permanent magnet, induction coil and gear ring. The permanent magnet is composed of several pairs of magnetic poles. During the rotation of the gear ring, the magnetic flux inside the induction coil changes alternately to generate induced electromotive force, and the signal is input to the electronic control unit of ABS through the cable at the end of the induction coil. When the speed of the gear ring changes, the frequency of the induced electromotive force also changes.
3, Hall type wheel speed sensor
When the gear is located at the position shown in (a), the magnetic field lines passing through the Hall element are dispersed and the magnetic field is relatively weak; When the gear is in the position shown in (b), the magnetic field lines passing through the Hall element are concentrated and the magnetic field is relatively strong. As the gear rotates, the density of the magnetic field line passing through the Hall element changes, thus causing a change in the Hall voltage. The Hall element will output a millivolt (mV) level of quasi-sine wave voltage. The signal also needs to be converted by an electronic circuit into a standard pulse voltage.
