Overview

If the power of electricity consumers in the vehicle carried out only from the battery, at the expense of current consumption of its large discharge occurs very rapidly. To maintain the battery in its charged state is charged by a generator driven by the engine crankshaft.

The car is equipped with an alternator. When installing additional electrical equipment, make sure that there is enough generator power for its supply. The main elements are the generator rotor, stator, a rectifier brush collector, electronic voltage regulator, bearing and belt pulley.

The generator drive belt carried by the engine crankshaft pulley.

The generator produces a three-phase alternating current, which can not be used to the vehicle and to charge the battery. Therefore, in the generator are three diode rectifier that convert three-phase alternating current to pulsating direct. The voltage is regulated integrated electronic controller.

When the generator is an electric current flowing through the field winding creates around the poles of the rotor flux. When the rotor under each stator tooth passes the south, the north pole of the rotor - the working magnetic flux passing through the stator teeth, changes in size and voltage. This creates an alternating magnetic flux in the stator winding electromotive force. The wedge shape of the pole pieces of the rotor is selected in such a way to provide an electromotive force waveform close to a sine wave.

At high speed the rotor of the generator when the generator voltage is greater than 13,6-14,6 In, the voltage regulator is locked, and the current through the field winding does not pass. The voltage generator falls, the regulator opens and again passes a current through the field winding. The higher the speed of the rotor of the generator, the longer the controller locked state, therefore, the more decreases the output voltage of the generator. The process of locking and unlocking the controller comes with a high frequency, so the fluctuations in the output voltage of the generator quickly, and it can be considered almost constant, is maintained at 13,6-14,6 V.

The generator produces a voltage of about 14 V, and for the vehicle electrical system is sufficient voltage 12 V, so a small voltage difference is used for constant recharging of the battery. The gear ratio of the crankshaft pulley and the generator is selected such that even when the frequency of rotation of the crankshaft of the engine idling is responsible for charging the battery.

When checking the operation of the generator and the vehicle must be followed some simple rules that do not derive from the generator system:

- Do not operate the generator with the generator disconnected from the battery clip. Without a battery in the vehicle electrical system having dangerous surge pulses when disconnecting any power consumers. These surge voltages can damage the electronics of the car, including a voltage regulator and diode rectifier unit generator;

- Do not check the operation of the generator "to spark", even short-term connection "plus" generator terminals with "weight". In this case, through the diodes substantial current flows, and they are damaged. Monitor the voltage of the generator can only be a voltmeter;

- Negative terminal of the battery must always be connected to the "weight" of the car, and the positive - with a clip generator. Wrong (reverse) switch batteries immediately cause the passage of high current through the diodes of the generator, and they will fail;

- It does not check diodes pressure more than 12 or Megger, as it is too high for the diode voltage - checking they are punched (a short circuit). When checking the insulation of the wiring Megger necessary to disconnect all wires from the generator;

- It is necessary to disconnect all wires from the generator and battery when electric welding of any parts of the body;

- Check the chain and electrical components, you need to troubleshoot the engine stopped and the battery disconnected. Malfunction of the charging system shown in the Table. 10.1.

Table 10.1

Faults electrical system, their possible causes and remedies