China Neodymium Magnets Some Introduction of ABS wheel speed sensor ABS, also known as anti-lock braking system, is an automotive safety system which avoid the wheels from locking and maintain the adhesive force between wheel and road in maximum value. ABS can calculate the speed, wheel angular deceleration, and wheel slip ratio according to wheel angular speed signal. ABS wheel speed sensor magnet is a typical application of Neodymium and AlNiCo magnets in the sensor area. ABS is consists of the wheel speed sensor, hydraulic control unit, and electronic control unit. Electrical control unit will determine to start anti-lock brake according to the wheel speed which tested by wheel speed sensor. Wheel speed sensor can be divided into electromagnetic-type and hall-type. Electromagnetic-type wheel speed sensor is still widely applied in ABS due to its simple structure and low cost. For electromagnetic-type wheel speed sensor, ABS wheel speed sensor magnet is an essential part. Addendum and backlash of the trigger wheel will face to pole pin alternately during the rotating of the trigger wheel and thus generate the induced electromotive force due to alternative variation of magnetic flux inside the inductive coil. This induced electromotive force will be input to the electronic control unit as a signal. The frequency of the induced electromotive force will be changed with the wheel speed, therefore, vehicle speed can be measured by the electronic control unit. Working Principle of ABS wheel speed sensor The magnetoelectric wheel speed sensor is composed of two parts: permanent magnetic core and coil. Relative to the magnetic line of force, it comes out through one end of the magnetic core and enters the other end of the magnetic core through its ring gear and corresponding air. For the magnetic core, it is surrounded by coils, which are wound around the outside of the magnetic core. It is precisely because of this structure that the magnetic line of force can completely pass through the coil. Once the wheel of the car starts to rotate at high speed, because the ring gear rotates synchronously with the wheel, its corresponding teeth and gap will quickly pass through the corresponding magnetic field of the sensor in sequence, which will change the magnetic resistance corresponding to the corresponding magnetic circuit. About ABS wheel speed sensor magnet The magnet of ABS wheel speed sensor generally adopts Neodymium magnet or AlNiCo magnet. Different customers have different customized schemes for magnet material, performance, shape and size. If you are looking for ABS wheel speed sensor magnet, Hongyu team will serve you wholeheartedly.China Neodymium Magnets website:http://www.neodymium-mag.com/neodymium-magnets/