How does a car generator work? Design and signs of breakdown in the car

The generator is used to generate alternating current in cars. And not only in them, because the alternator is designed to simply convert mechanical energy into electrical energy. It turns out to be much more efficient than a DC generator, and in addition, it can work efficiently from low speeds. The genius Nikola Tesla invented the alternator. It is such a great invention that in vehicles so incredibly complex and advanced, an element created in 1891 still works today.

Generator design

Do you want to know what the construction of an alternator looks like? Well, the most noticeable element for the car user is the pulley. It is on him that a poly-V-belt or a V-belt is put on, which provides a drive. The following elements of the generator are already hidden from the view of the average user.

If we want to create a generator circuit, the following design elements must be placed on it. Each generator consists of the following parts:

• rotor;
• stand;
• rectifier unit;
• brush holder with brushes;
• voltage regulator;
• front and rear cases;
• pulley;
• goylatora.

Generator - the principle of operation of a car generator

What do all these elements, enclosed in one body, give? Without the work of the pulley, in principle, in any way. It all starts when you turn the key in the ignition. When the belt starts to turn the wheel and this sets the rotor in motion, a magnetic field is created between the stator and the magnet on the rotor. These are alternately located claw poles, the tops of which have different polarities. Under them is a coil. Brushes with slip rings connected to the ends of the toothed poles supply power to the alternator.. So the alternator produces alternating current.

Generator and generator, or how to get direct current in a car

Are you wondering why you need alternating current in a car? It is basically useless, so it needs to be “straightened”. For this, rectifier diodes are used, installed in the generator on the rectifier bridge. Thanks to them, the current received by the car generator is converted from alternating to direct.

Is it possible to check the alternator in the car yourself?

If the car starts, what's the problem? Well, if the generator does not charge the battery, then after a few minutes of driving with the lights on, it will be completely discharged. And then it will be impossible to start the engine. Luckily, testing a generator is very easy and doesn't require any technical knowledge or skills.

How to check the car generator step by step?

If you want to check the generator in the car, first get a multimeter, or rather a voltmeter. At the very beginning, check what voltage is transmitted from the battery. Do not start the engine while doing this. The value should be above 13 V. Then start the engine and let it run for a while (about 2 minutes). At this time, make sure the battery charging indicator next to the watch is off. The next step is to re-measure the voltage from the battery with the engine running. The value must be greater than 13 V.

The last step in checking the generator is the load on the engine and battery. Turn on the fan to maximum power, turn on the radio, lights and anything else that can consume electricity. If the car's alternator is working properly, the battery voltage should be about 13 volts at this load.

How to connect a generator?

There are several connectors marked with letters on the generator housing. One of them is "B +", which is responsible for transmitting voltage to the battery and is the main connector on the generator. Of course, not the only one, because besides it there is also “D +”, which is responsible for powering the generator diode, and “W”, which transmits information to the tachometer. After installing the generator at the assembly site, it is very easy to connect it.

What should I pay special attention to when connecting the generator?

Although connecting the generator is not difficult, care must be taken not to confuse the sensors with neighboring components. Motor accessories have very similar power plugs. It may happen that instead of connecting the generator, you put a plug from the sensor of another component there. And then you will not have a charge, and additionally a diode will appear on the dashboard, informing, for example, about low oil pressure in the engine.

Generator - signs of failure of the car generator

It is very easy to determine the malfunction of the generator - the battery simply does not receive the required current. To accurately diagnose what happened, you need to look at the device itself. The generator is made up of various components and many of them can fail. First, you can remove the belt from the pulley and turn the impeller. If you hear interfering noises, you can start disassembling the element and finding an electrician. If the rotor does not want to spin at all, the generator is also suitable for regeneration.. The belt itself can also be the cause, because its incorrect tension can lead to a low value of the mechanical force transmitted to the pulley.

Automotive alternator and brush condition and faults. When is a replacement needed?

Brushes are another matter, i.e. element that excites the current. They are made of carbon and wear out with constant contact with the rings. When the material has been rubbed to a minimum, no excitation current will be transmitted and hence the alternator will not generate current. Then simply unscrew the brush holder, usually fastened with two screws, and check the condition of the brushes. They just need to be replaced if necessary.

How to excite a generator in a car?

In the vast majority of cases, the car's generator has external excitation.. This means that the carbon brushes must supply it with excitation current. However, a self-excited generator can also be found in cars, and the good old Polonez is an example of this. This design has an auxiliary rectifier responsible for self-exciting the alternator. In any other case, if the alternator has a 6-diode rectifier bridge, then this is a separately excited element. How to excite a car generator? You have to add tension to it.