Alnico Odometer Magnet and Speedometer Magnet

AlNiCo Odometer magnet is a magnet made by AlNiCo which used in automobile odometers, including an outer AlNiCo magnet ring, and a magnetic injection molded body with a shaft hole is fitted in the hole of the outer magnetic ring. The outer magnetic ring is an interference fit, the magnetic injection molding body and the outer magnet ring are cylindrical bodies, the outer magnet ring is a AlNiCo permanent magnet, and the diameter of the hole in the outer magnet ring is the corresponding magnetic The diameter of the shaft hole of the injection body is 3 times that of the injection molded body. The production process of the AlNiCo Odometer magnet is simple and easy, the raw material AlNiCo are relatively cheaper than rare earth Neodymium or SmCo, and the use performance of the product is equal to or better than that of the existing similar products, thereby reducing the production cost and saving a lot of expensive rare earth permanent magnet materials reduce the production cost of enterprises and have huge economic benefits.

How a purely electronic Odometer works?

The pure electronic odometer sensor is not in direct contact with the mechanical parts, and there is a certain gap between the sensor probe and the target wheel, which is generally controlled at 1.4+0.6mm. When the car is driving, the rotor of the odometer rotates together with the output shaft of the transmission. When a certain tooth of the rotor of the odometer rotates to the position corresponding to the sensor probe, the sensitive device in the probe is affected by the magnetic field of the odometer rotor and outputs a low level. The teeth of the odometer rotor are not aligned with the sensor probe, and the sensitive device in the probe is not affected by the magnetic field and outputs a high level, so that every time the output shaft of the transmission rotates one revolution, the odometer sensor has a square wave pulse signal output, which is transmitted through the connecting wire harness. For the speedometer, the magnetoelectric pulse signal sent by the sensor can be processed by the microcomputer inside the meter, and the vehicle speed can be displayed on the display screen. The odometer is processed by the computer to calculate and display the mileage according to the vehicle speed and the accumulated running time.

If the AlNiCo magnet magnet is demagnetized, the pointer of the speedometer only swings slightly when driving at high speed. It often points to zero at medium and low speeds, or the pointer index is too large at medium and low speeds, and the indication value is inaccurate. 

Solution: You can remove the speedometer, take out the rotor, and re-magnetize