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what does a speedometer measure physics
What does a speedometer measure physics is:
1. When the car is running, the drive 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 current interacts with the magnetic field of the permanent magnet to generate a torque to overcome the elastic force of the disc spring, so the aluminum bowl will carry the pointer turn an angle.
2. The function of the speedometer is to indicate the driving speed and the accumulated mileage. It consists of two parts: the speedometer and the odometer. The driving shaft is driven by the transmission or transfer gear through the flexible shaft;
3. The speedometer is composed of permanent magnet fixed on the drive shaft, aluminum bowl with shaft and pointer, a case, and a dial fastened on the case. When not working, the aluminum bowl keeps the pointer at the zero position of the scale under the action of the disc spring (hairspring). When the car is running, the drive shaft rotates with the permanent magnet, and the magnetic force lines of the permanent magnet generate eddy currents on the aluminum bowl, and the eddy current interacts with the magnetic field of the permanent magnet to generate a moment to overcome the elastic force of the disc spring, so that the aluminum bowl is turned in the direction of the permanent magnet. Deflection, so the aluminum bowl rotates through an angle with the pointer. That is the working principle of the differential: when the car goes straight, the two planetary gears only revolve, not rotate. According to the principle of mechanics, the inner wheel will inevitably turn slower when turning. At this time, the speed of the drive shaft remains unchanged. At this time, the planetary wheel revolves around the half axis and rotates itself. The speedometer indicates the speed at which the vehicle is traveling, it shows the instantaneous speed. The indication of the speedometer depends on the vehicle speed sensor (rear wheel driving wheel). The sensor is installed on the gearbox. Through different speeds, different pulse signals are obtained, and then converted into pointer output, which is the current speed you see.
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