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how to read a car voltage gauge
Car voltmeter is an instrument for measuring car voltage. The symbol isv. there's a endless attraction in the sensitive galvanometer. A coil composed of cables is connected in series between the two outstations of the galvanometer. The coil is placed in the glamorous field of the endless attraction and connected with the pointer of the cadence through the transmission device. Utmost voltmeters are divided into two ranges. The voltmeter has three outstations, one negative terminal and two positive outstations. The positive pole of the voltmeter is connected with the positive pole of the circuit, and the negative pole is connected with the negative pole of the circuit. The voltmeter must be connected in resemblant with the tested appliance. The voltmeter is a considerable resistor. Immaculately, it's considered as open circuit. In the resemblant circuit, the voltmeter (in resemblant with other consumers) and consumers are connected inparallel.However, it can be considered to measure the power force voltage, If there are no other consumers in the main circuit.
There are generally two ranges of voltmeter - 0 ~ 3V and 0 ~ 15V.Because the same voltmeter has different ranges, corresponding to different ranges, the voltage value represented by each small cell is different, so the reading of the voltmeter is complex, and the number of significant digits of the measured value is easy to make mistakes. If it refers to a position in the middle between the two scale lines, it can be read as 10.1v, 10.2v, 10.3v, or 10.4v respectively according to the degree that the pointer is close to the two scale lines. Even if it refers to the center, it can not be read as 10.25v. In this case, two inaccurate numbers, i.e. 2 and 5 after the decimal point, do not comply with the reading rules.
In fact, there is still a certain idea to change the voltmeter, that is, to get an on-board power supply for use in the car. In addition, I listen to music to pass the time when I stop and wait, but I'm afraid of battery power loss, so I turn it off when I see that the voltage is too low to avoid battery power loss and failure to start. Car drivers often observe the instrument during driving and judge the working condition of the car according to the changes of instrument numbers. Use voltmeter and ammeter to detect the circuit conditions, such as whether the alternator generates power, whether the fan battery loses power, whether the charging current is normal, whether the circuit is short-circuit or open circuit, etc.
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