The rules of how to connect an ammeter should be known to everyone. For example, such knowledge is often used in the preparation of assignments for experimental rounds of school olympiads or laboratory work.
Let's start with the principle of operation of the ammeter. The fact that it measures the current is obviously just from the title. This happens as follows: an electric current moving along a circuit passes through the device. This creates a torque, which causes the deviation of the dynamic (moving) part of a certain angle. Such a deviation is directly proportional to the strength of the current. This is then displayed visually, for example, by moving the arrow or by drawing a number.
Recall the concepts of parallel and serial connection. If you need to measure the current strength on any receiver, then its value should coincide with the fact that it passes through the ammeter. This is specific to serial communication.
However, the method of connection is not the only important condition for how to connect an ammeter. No less important is the resistance of the ammeter. If it suddenly turns out to be higher than the resistance of the receiver, when the device is connected, the system of the circuit will fail, and the value of the current acting on the receiver will change.
When connected to a break, it doesn’t matter whether the “plus” is connected to a power source or an instrument. The main thing is to consistently and not in parallel.
There are several types of ammeters. Among them are analog and digital. With the help you can measure both direct and alternating current. However, for any of them, the rules for connecting an ammeter remain unchanged. One has only to check which current is measured by a specific device. This is indicated on the device itself. If the current is constant, “=” is indicated, if the variable is “~”. This must be done, otherwise the ammeter will not work.
In addition, when working with electricity, you must follow the safety rules. When in contact with bare wires and carelessly, there is a chance that if you do not get an electric burn, then it will be very unpleasant sensations. This is especially true of real installations, because in a school laboratory, as a rule, the circuit runs on batteries, and the current is not too high.
Thus, the characteristic feature of the ammeter is its serial connection. This limits the number of ways to connect an ammeter.
Ammeter. Current Measurement - Video
Catalog Number: 3811010-АП111Б
Specifications Ammeter Ap-111
Applicability
Tractors T-150 K, 158, DT-175S, 75 U, T-130 MG, PAZ-672, GAZ-71, 66-01, UAZ-469RH, URAL-479
Ammeter Installation
On most cars, to monitor the operation of the power supply system, only the charge indicator lamp is used, which does not monitor the state of the battery, charging current, voltage in the on-board network and, moreover, does not allow to determine a number of faults in the circuits. Full information on the operation of the generator and the battery can be obtained by equipping the car ammeter and a voltmeter.
Ammeter It is usually connected to a wire break from the generator to the battery. For example, on VAZ machines between the terminals "B +" of the generator and "+" of the battery. Connection Ammeter must be made with a suitable cross-section wire. For example aP-111 ammeter It is necessary to connect the wire with a cross section of at least 20kV, otherwise the wire will heat up. Himself Ammeter In the process of work, it can also get warm a little, because a shunt is installed inside it, on which, with a large current, heat is also released, this is not a malfunction.
The voltmeter is connected much easier, in any place where there is a "+". Accordingly, one contact is connected to the body of the other, it is more convenient to connect to the terminal of the ignition lock where the "+" appears when the ignition is turned on. The illustration shows a typical wiring diagram. Ammeter and voltmeter
Ammeter connection diagram and voltmeter:
1 - rechargeable battery
2 - generator
3 - mounting block
4 - ignition switch
5 - battery charge indicator lamp located in the instrument cluster
6 - ammeter
Drivers of cars and trucks are interested in how to connect an ammeter and a voltmeter in the car. The need to install these indicators is explained by the desire to have complete control over the state of the battery and the generating set. Most modern cars and previously released do not have such indicators installed by the manufacturer. True, in cars with on-board computers, there is a possibility to control the voltage in the circuits of the car, in the rest of the models the owners are involved in installing the instruments.
How to connect the ammeter and voltmeter in the car Especially interesting for owners of cars with mileage, since many components and assemblies, including the generator set, have already been worn out in order, so they can work with violations. The test lamp only signals the absence of onboard voltage, and this is clearly not enough. So, for example, if you do not notice in time the increased voltage of the battery charging, it can lead to its failure.
About the functions of these pointers
Each control or measuring device installed in the instrument panel of the car informs the driver about the performance of a particular vehicle system. This allows you to operate the machine without compromising its technical condition. However, the power supply system of many cars is deprived of the opportunity for such control. Owners of cars are trying to solve such problems on their own by installing an ammeter or a voltmeter, and some owners install both of these pointers.
An ammeter installed in an electrical circuit will indicate the current consumed by the system. From these data, you can judge the process of charging the battery and in a timely manner to identify and eliminate the problems encountered. The voltmeter also allows you to keep this process under the control of the driver, which increases the service life of electrical equipment. Here are the main reasons for installing these devices on the car.
What products are used?
Some time ago, finding and installing such a device was a big problem. Motorists installed ammeters from trucks on their cars, and those drivers who were on "you" with radio electronics selected measuring instruments themselves. The first domestic cars in which the voltmeter took its permanent place on the dashboard were the VAZ 2105, and a little later they appeared on other models.
Today, such a problem does not exist, since there is a large selection of such products in retail chains. You can install an electronic clock in the panel, which simultaneously with the current time shows the voltage of the on-board network. There are electronic tachometers, which, after pressing the desired button, perform the functions of a voltmeter. Such devices do not cause any problems with the owners.
Also today automobile ammeters and voltmeters are on sale, and individual drivers independently adjust the devices used in electronic devices. The installation of such signs poses some difficulties, since it is necessary to select shunts for them, to perform calibration or to make new scales. Therefore, we will not dwell on this.
How to install such indicators? We will assume that you managed to purchase an ammeter or voltmeter designed for use in automobiles; now we will consider the process of their installation. It should be recalled features of connecting them to the electrical circuit.
The ammeter is connected only in series between the current source and the consumers, and the polarity of the connection must be observed, plus from the source to the plus of the device and so on. The voltmeter is connected only in parallel to the power source, also subject to polarity.
We connect the ammeter
Let's start with the fact that the work can be started only after disconnecting the battery. A significant current flows through this device, so you need to pick up wires of the appropriate cross section. It should be connected to an open wire that supplies power to the ignition switch. At the ends of the wires should be installed and crimp tips with pliers, otherwise due to poor contact there will be a heating of the junction.
After installing the wires should check the connection. To do this, turn on the load, such as dipped or main beam. The ammeter should show the discharge, if it shows the opposite value, then the connection wires should be swapped. Next, you should start the engine and make sure that the battery is charging.