The car charging system consists of a generator, battery, voltage regulator, charging indicator light and associated wires. The connection relationship between them is shown below. The functions of each component and the working principle of the system are as follows. as following.
1. Generator: Generator is the main power supply for automobile electrical equipment. During normal car operation, the alternator powers other electrical equipment except the starter and charges the battery. That is to say, when the engine is running normally, almost all of the car's electrical energy is supplied by the generator; when there is power left, the generator will charge the battery; Generally, the power of a car generator is 0.8 to 1.5 kilowatts, which can meet the power demand of the car in most cases. When energy production est insufficient, the battery completes it. For some small displacement engines, when the generator generates a large amount of electricity and the load is high, the engine vibrates due to the increased load. At this time, the engine automatically increases the speed to improve engine power.
Most generators used in automobiles are three-phase silicon rectified alternators, which use silicon diodes as rectifiers to convert alternating current to direct current. Its main structure is composed of rotor, stator, brush and slip ring mechanism, three-phase rectifier bridge, bearings, fans and front and rear covers. The rotor is used to generate a magnetic field, the stator is used to generate current. , and the rectifier converts the three-phase current. The alternating current is converted into a pulsating direct voltage. The powerance generated by the generator increases as the engine speed increases.
2. Battery: Battery is what we commonly call battery. This is the largest electrical equipment in the car. Its main function is to power the starter, ignition system and other major electrical equipment. the engine starts; when the engine does not run or runs at low speed, it powers various electrical equipment when there is too much electrical equipment and the power consumption exceeds the power supply capacity of the generator, the battery assists the generator; to power various electrical equipment; In addition, the battery also has the function of stabilizing the voltage of the power system. It is equivalent to a large capacitor and can absorb instantaneous surges in the circuit to protect electrical equipment.
Many people think that the battery is the main source of energycar management. In fact, this is not the case. The generator is the real source of power for the car. When the engine is running normally, the generator output voltage is higher than the car battery voltage. The generator powers all electrical equipment (except the starter) and at the same time charges the battery. internal storage when the engine starts. Electrical energy operates the starter and usually exists in the form of an electrical device.
3. Voltage Regulator: The voltage regulator is used to adjust the generator output voltage to maintain the generator output voltage between 13.8 and 14.4 volts. Since the generator output voltage increases with increasing engine speed, if the engine speed is too high, the generator output voltage will be too high, which will burn out the car's electrical system and some electronic components of the car. preciseif we. With a voltage regulator, these problems can be avoided. Car voltage regulators are now all electronic, most are built inside the generator and only a few are external. Most generator faults are all caused by a faulty voltage regulator.
4. Charging Indicator System: The charging indication system mainly refers to the voltmeter or charging light on the dashboard. They are used to indicate whether the operating condition of the generator is normal. If the charging light turns on or the voltmeter indicator is lower than 24V while the car is driving, it means the generator is not charging or the charging capacity is too low and the charging system needs to be repaired.
The working principle of the car charging system is: when we turn on the ignition switch, the battery provides a coexcitation current to the generator rotor, and the rotor generates a magnetic field, then the motor starts; , driving the generator to operate, and the stator winding cuts the rotor winding. The magnetic field lines generate three-phase alternating current, which is converted into direct current after rectification and output of the silicon at this time, because the generator speed is low, that is; The excitation current is supplied by the battery. This situation is called "other excitation", then as the generator speed becomes higher and higher, the power output becomes larger and larger, and the rotor winding current is supplied by the generated current by the battery. the generator itself. This situation is called “self-arousal.”
When the engine is operating normally, the generator also operates at high speed with the engine, emitting electrical energy for use by the engine.The car's electrical equipment, and the excess electrical energy is used to charge the battery. When the battery is fully charged, the voltage regulator cuts off the excitation current to the rotor and the generator stops producing electricity; When the battery voltage drops to a certain value, the voltage regulator reconnects the excitation current and the generator starts producing electricity again. This process is repeated again and again, which can not only ensure the normal operation of the car's electrical equipment, but also keep the battery in a fully charged state. In order to ensure that the car can produce electricity at low speed, the speed of the generator is generally 2.5-3 times that of the engine, so even if the engine is idling, the generator can produce electricity normally .
Common faults in automotive charging systemsinclude no load, overload and underload. The causes of faults are only two types: poor line contact and failure of the generator itself. Generally speaking, today's generators are highly integrated and cannot be disassembled and repaired under normal circumstances, and can only be replaced as a whole. When the car charging system is used, it is not allowed to use the instant grounding (grounding) method of the generator output end (fire test method) to determine whether the generator is producing electricity, nor remove the battery and other main electrical equipment when the generator is running at high speed, to avoid power surges caused by the breakdown of precision electronic components. During daily maintenance, it is necessary to frequently check the connection between the generator and the battery to ensureEnsure that the connection is firm and reliable and that the joints are free of rust. Additionally, the generator belt tension should also be checked. frequently. If the belt is too loose, the generator speed will be reduced. If it is too low, energy production will be insufficient. If the belt is too tight, it will easily damage the generator belt and bearings.
Generally, the engine belt refers to the accessory belt of the engine! Different from the timing belt, the accessory belt (hereinafter referred to as the belt) mainly operates the generator and the cooling water pump. Passenger cars normally have a warranty of three years and 100,000 kilometers, but many of our friends who buy. cars don't drive them every day. By running occasionally, few people can run 100,000 kilometers in three years. Therefore,During the warranty period, there are practically no situations in which the belt needs to be replaced. So, when should the belt be replaced? What are the serious consequences of not changing? Let me tell you about this problem today.
The engine accessory belt mainly drives the engine's cooling water pump and generator. Some hydraulically assisted cars also drive the power steering pump. If there is a problem with this belt, a slight slip will not have a substantial impact, but there will be a "heeheee" belt sliding noise when in use. In this case, except that the sound is not very pleasant, there is no other. impact, just open it with confidence. Go to the auto repair shop when you have time.
If the accessory belt breaks and completely loses its function, the car will not break down immediately. There will usually be no major problems if you stop the car in time for the repair. If the broken belt is not discovered and the car is still forced to drive, the most direct cause is that the generator is operating abnormally, the engine water temperature rises rapidly, and in severe cases, the engine can even be damaged by boiling.
The car belt replacement mileage is recommended to be 60,000 kilometers. The original car belt can be replaced at 80,000 kilometers. However, if you often park the car in the open for a long time after purchase. and drive it less, the engine The belt will age and cracks will appear on the surface. In severe cases, it will affect the life of the belt. A car is often said to be worn out rather than decommissioned. It's not just about the car's battery and tirese. Therefore, in this case, even if it is exposed to the sun. is less than 60,000 kilometers, the belt will make abnormal noise. It should be replaced as soon as possible.
It's like a kitchen knife at home. It is rarely used a few times a year. It rusts easily when left in the kitchen. Maybe it's already rusty when you come back and try to use it in the kitchen. end of the year. Hey, people use it every day. It's still good if I use it, and it won't be a problem if I use it for another year. Xiao Li, my car was often parked in an open-air parking lot exposed to the sun and rain for a while, and I basically drove it once or twice a month. Later the belt was replaced when it had aged further. more than 40,000 kilometers.
In general, the engine belt replacement cycle is usually 60,000 to 80,000 kilometers, butIt also depends on the actual vehicle situation. If a problem occurs, it should be replaced in time. I hope Xiao Li's explanation can help everyone