The working principle of the vehicle speed sensor, where is the vehicle speed sensor

I believe that the speed sensor is no stranger to everyone. It is a sensor used to test the wheel speed of a car. But when it comes to the working principle of the vehicle speed sensor, many friends said that they are not very clear. Although this is something more professional people understand, wouldn't it be better for us to know more about our car?

Working principle of vehicle speed sensor

The vehicle speed sensor is composed of permanent magnets, magnetic poles, coils and ring gears. When the ring gear rotates in a magnetic field, the gap between the tooth tip of the ring gear and the electrode changes at a constant speed, causing the magnetic resistance in the magnetic circuit to change. Subsequently, the magnetic flux will increase and decrease periodically, and an induced voltage proportional to the increase and decrease speed of the magnetic flux is generated at both ends of the sensor coil, and this AC voltage signal will be directly transmitted to the control computer of the car to ensure the stable performance of the car.

As for the position of the vehicle speed sensor, it is generally installed in the drive axle housing or transmission housing, and the signal line of the sensor is installed in a shielded jacket. It is worth mentioning that the gap between the wheel speed sensor and the ring gear is exquisite. The normal standard value of the front wheel is 1.10-1.97mm, while the rear wheel is 0.42-0.80mm. If the gap is too large, it will directly affect the collection of the wheel speed sensor and the accuracy of the data.