The indication of the speedometer depends on the vehicle speed sensor. The sensor is installed on the gearbox. Through different speeds, different pulse signals are obtained, and then converted to pointer output, which is the current speed you see. The law requires the speedometer to display more than the actual speed. Slightly higher, this is for safety. There is also a liquid crystal display speed, the principle is similar to the above, the indication output is replaced by a liquid crystal digtal speedometer display.
The analog meter pointer can visually display the trend of speed change. Although the real-time vehicle speed can be accurately known through the digital display, it is not very intuitive to know whether the vehicle is accelerating or decelerating, or even what range the current vehicle speed is in. For example, some current models can be driven at different speeds through technology. The color of the instrument panel is different, which can be used as a safety warning for the driver. However, the digital display is not able to achieve such a clear effect.
Advantage of digital speedometer for car:
1. The reading is simple and intuitive;
2. High degree of integration: one meter can measure three-phase current, three-phase voltage, active and reactive power, active and reactive power, power factor, frequency, phase and other electric quantities;
3. Diversified functions: can perform power quality management functions such as harmonic measurement and analysis;
4. It is easy to realize remote monitoring: it can monitor the state of the circuit and output it to a remote place, and can also accept and execute remote control instructions;
5. Various communication methods: RS232/485 output, analog output, and even optical fiber output can be realized
However, with the development of science and technology, the analog meters displayed by these pointers may eventually be replaced with digital displays, and even automatic driving modules will be added to free your hands and directly give the computer more authority to control the vehicle. At that time, for faster operation, of course, the computer was directly connected to the display instead of the traditional pointer dial.