Wheel speed sensor

Components – Wheel speed sensors

Most of these devices are inductance sensors and work in conjunction with a toothed wheel. They consist of a permanent magnet and a soft iron rod around which is wound a coil of wire. As the toothed wheel rotates the changes in inductance of the magnetic circuit generates a signal. The frequency and voltage of the signal are proportional to wheel speed. The frequency is the signal used by the electronic control unit

The wheel speed sensors provide information on distance covered. The sensors on the non-driven wheels are used because the driven wheels slip when accelerating. ABS wheel speed sensors have become smaller and more efficient. Recent models not only measure the speed and direction of rotation but can be integrated into the wheel bearing. On some systems turn angle is calculated by comparing left and right-hand signals. This is not necessary when a turn angle sensor is used.