A universal speedometer, one of the gauges on a vehicle's instrument panel, displays the speed at which the vehicle is traveling. The mechanical type is usually circular, with a pointer indicating the real-time speed; the digital type is a direct display of the speed. In China, the speed in kilometers per hour is often mistakenly called "mai" or "yard", and the speedometer is often mistakenly called "mai speed meter" or "stopwatch".

The driving shaft of the speedometer is driven by the transmission or transfer gear through the flexible shaft. The speedometer consists of a permanent magnet fastened to the driving shaft, an aluminum bowl with a shaft and a pointer, a cover, and a dial fastened to the case. When not in operation, the aluminum bowl keeps the pointer at the zero position of the scale under the action of the disc spring (hairspring).

When the vehicle is running, the driving shaft rotates with the permanent magnet, and the magnetic field lines of the permanent magnet generate eddy currents on the aluminum bowl, and the eddy currents interact with the magnetic field of the permanent magnets to generate torque to overcome the elastic force of the disc spring so that the aluminum bowl rotates in the direction of the permanent magnets. Deflection, so the aluminum bowl turns an angle with the pointer. Since the strength of the eddy current is proportional to the speed of the vehicle, the rotation angle of the pointer is proportional to the speed of the vehicle, and the pointer indicates the corresponding speed on the dial.

Taizhou Yongchang Electric Vehicle Manufacturing Co., Ltd. not only has a universal speedometer but also a pulsar speedometer and other products, welcome to visit our official website.