Introduction of Kunshan voltmeter manufacturer
The voltmeter is a large resistor, ideally considered open circuit. If there are no other electrical appliances in the trunk road, it can be considered that the power supply voltage is measured (because all the electrical appliances in the parallel circuit enjoy the power supply voltage); If other electrical appliances are connected in the trunk road, the electrical appliance will share part of the power supply voltage, and the voltmeter can only measure part of the voltage (the voltage of the electrical appliance connected is the voltage of the electrical appliance).
You should know that in the voltmeter, there is a magnet and a wire coil. After passing the current, the coil will produce a magnetic field. In this way, the coil will rotate under the action of the magnet. This is the head part of the ammeter and voltmeter.
The current that the meter can pass through is very small, and the voltage that both ends can bear is also very small (it must be far less than 1V, maybe only a few tenths of a volt or even less). In order to measure the voltage in the actual circuit, we need to connect a relatively large resistance in series to the voltmeter to make it into a voltmeter. In this way, even if a relatively large voltage is applied at both ends, most of the voltage will act on the large resistance, and the voltage on the meter head will be very small. Voltmeter is a kind of instrument with large internal resistance, which should be larger than several thousand ohm. The meter head is made according to the effect of the magnetic field force on the electrified conductor in the magnetic field. There is a permanent magnet inside the meter, which generates a magnetic field between the poles. In the magnetic field, there is a coil, and there is a hairspring at both ends of the coil. The spring is connected to a terminal of the meter. Between the spring and the coil, there is a rotating shaft, and there is a needle at the front end of the rotating shaft relative to the ammeter. When there is a current passing through, the current passes through the magnetic field along the spring and the rotating shaft, and the current cuts the magnetic induction line. Therefore, under the action of the magnetic field force, the coil deflects and drives the rotating shaft and the pointer to deflect. As the magnetic force increases with the current, the current can be observed by the deflection of the pointer.
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