What is the difference between ammeters in series and parallel?

Are the ammeters connected in series or parallel? An ammeter is connected in series in a circuit. An ammeter refers to an instrument used to measure current in AC and DC circuits. In the circuit diagram, the symbol for the ammeter is; circled with an "a";. The current value is represented by "a", or "A"; it is the standard unit in which the current meter is based on the action of magnetic field forces on a charged conductor in a magnetic field.

There is a permanent magnet inside the ammeter that creates a magnetic field between the two poles. There is a coil in the magnetic field and a spring at both ends of the coil. Each spring is connected to one terminal of the ammeter. There is a rotating shaft connected between the spring and the coil, and the rotating shaft is related to the current. There is a pointer on the front of the instrument. When the current passes through the magnetic field along the spring and rotating shaft, the current cuts off the magnetic induction line. Therefore, under the action of the magnetic field force, the coil deflects and drives the rotating shaft and pointer to deflect.

Since the magnitude of the magnetic field force increases with the current, the magnitude of the current can be observed through the deflection of the pointer. This is called a magnetoelectric ammeter, and it's what we usually use in the laboratory. In junior high schools, the use range of ammeters is generally 0~0.6A and 0-3a. Precautions for using ammeters:

1. Wiring is correct. When measuring current, the ammeter should be connected in series with the circuit under test; when measuring voltage, the voltmeter should be connected in parallel with the circuit under test. When measuring DC current and voltage, you must pay attention to the polarity of the instrument to ensure the accuracy of the instrument. The polarity should be consistent with the measured polarity.

2. High voltage and large current measurement. When measuring high voltage or large current, a voltage transformer or current transformer must be used. The range of the voltmeter and ammeter should be consistent with the secondary rating of the transformer. Generally, the voltage is 100V and the current is 5A.

3.Expand the range. When the voltage measured in the circuit exceeds the range of the meter, an external shunt or voltage divider can be used, but note that its accuracy level should be consistent with that of the meter.

4. In addition, it should be noted that the use environment of the instrument should meet the requirements and be kept away from external magnetic fields.