Ammeter - a device operating principle and scope
Dec 20, 2019
Ammeter - a measuring device that performs current measurement function in the circuit in amps. Thus, each device is designed to measure a specific value. In this article I want to tell you about the structure of data measuring instruments and their varieties. So, let's begin.
Ammeters are divided into two broad classes:
Let's talk about the analog meter, which had also referred to the arrow:
Operate such devices due to the magneto-electric system, which works as follows:
Ammeter located in the housing of the thinnest wire coil disposed in the permanent magnets and is associated with a special spring.
Once the coil begins to flow electric current, is formed around the electromagnetic field which enters into interaction with the magnetic field of permanent magnets, and coil changes its position under the action of torque, and a spring attached inhibits it.
Once the rotation and braking moments are balanced coil stops, and with it, and an arrow that indicates a proportional current which now passes through measuring device.
Sometimes, increasing the limit of measurement in the ammeter circuit with switched resistor whose parameters are calculated in advance. And such a resistor is called - a shunt.
Ammeter mounted in series (in the gap), so it is crucial internal resistance and the smaller it is, the better for it.
After all, if the internal resistance ammeter is large, then it (ammeter) to an existing network, a resistor, resulting in a decrease in the current circuit and the data will not reflect the real parameters.
Internal resistance is taken into account in the production of an ammeter and in view of its magnet system and configured spring.
The undoubted advantages of analog gauges include the fact that no separate power supply is required for their functioning and they work by directly flowing current, but disadvantage is that such meters are quite inertia.
That is, we see the value of current flowing immediately, but with a delay, which is connected with the fact that the internal system takes some time to make a balance.
This type ammeter is a more complicated construction, which includes an analog to digital converter (ADC), where the current is converted into digital data, reflecting on LCD.
Such meters have such a drawback as the inertia and speed of delivery of information directly related to frequency characteristics set by the processor. In a fairly expensive counterparts refresh rate can be more than 1,000 updates per second.
By cons include ammeters such that for the normal operation of individual power is required. Of course, there are ammeters that use circuit power supply, but because of its high cost are quite rare.
In addition, meters are classified into ammeters:
- to calculate the DC.
- to calculate ac.
Of course, in the house alone ammeter almost nobody wants, but if you need to measure the force of the current, it is best all will be available multimeter to measure DC and AC, and lots of other useful functions. I personally I buy here.
That's all I wanted to tell you about ammeters, their unit and variety. If you liked this article, then vote her huskies and thank you very much for your attention!