Because when the car is running normally, the engine speed varies widely, which will definitely have a great impact on the output voltage of the generator, and the motor regulator plays a very important role in regulating the voltage to keep the voltage within a certain range. What is the working principle of the car generator regulator? What is the schematic diagram of the car generator regulator? What is the method of judging the fault of the automobile generator regulator? Let’s take a look at the following.
TITLE AUTOMOTIVE GENERATOR REGULATOR FUNCTIONS
The voltage regulator is an important part that assists the generator to work. Because when the car is running normally, since the rotor of the alternator is driven by the engine to rotate through the belt, the speed of the engine changes from a minimum of about 800 rpm to a maximum of about 6,000 rpm, and the engine speed changes in a wide range. The size of the output voltage of the generator will definitely have a great impact, causing a large change in the output voltage of the generator, which cannot meet the working requirements of automotive electrical equipment. In order to keep the generator voltage constant at different speeds, and to automatically adjust with the change of the generator speed, so that the voltage value remains within a certain range, a voltage regulator must be installed to make the output voltage of the engine It remains basically constant under all operating conditions.
The normal operation of the voltage regulator has a great relationship to ensure the normal operation of the entire automotive electrical system and to prolong the service life of the automotive electrical equipment. The output voltage (or charging voltage) of the automobile generator regulator has a great influence on the service life of the battery. Its function is to protect the battery and a charging protection device of the battery, so as to avoid overcharging and affecting the service life.
For 12V automotive electrical systems, the regulator regulates the output voltage of the generator between 13.8-14.4 volts.
The basic principle of TITLE voltage regulator
The output voltage of the generator depends on the number of turns of the generator stator coil, the speed of the generator and the strength of the magnetic field generated by the rotor coil, and we can only adjust the rotor coil The strength of the generated magnetic field. The voltage regulator controls the strength of the magnetic field by controlling the energization current to the rotor coils.
Automotive Generator Voltage Regulator Schematic
Automotive Generator Voltage Regulator Schematic
TITLE Power Generation Types and principles of generator regulators
From the perspective of the development of generator regulators, there are three types of contact type and electronic type microcomputer control. The contact type uses mechanical contacts to control the on and off of the rotor coil; the electronic voltage regulator uses triodes or integrated circuits to control the on and off of the rotor coil; and the microcomputer control type is controlled by the engine control unit or a separate power management system Turning on and off the rotor coil.
When it comes to voltage regulators, it is necessary to mention external grounded voltage regulators and internal grounded voltage regulators. The inner grounding voltage regulator controls the grounding point of the rotor coil inside the generator; the outer grounding voltage regulator controls the grounding point of the rotor coil outside the generator. During this period of definition, the generator voltage regulator adopts an external design, so the essence is: the inner ground type voltage regulator controls the power supply of the rotor coil; and the outer ground type voltage regulator controls the rotor coil grounding.
The schematic diagram of the external ground voltage regulator of the automobile generator
The external ground voltage regulator of the automobile generator Schematic diagram
The principle of voltage regulation of TITLE electronic voltage regulator
The basic circuit of the external ground electronic regulator: The basic circuit is composed of three resistors R1, R2, R3, two transistors VT1, VT3, composed of a Zener diode VS.
Resistors R1 and R2 form a voltage divider, and the voltage across the voltage divider R1 and R2 is the generator voltage.
VT3 is a high-power triode (NPN type), which is connected in series with the field winding of the generator and acts as a switch to switch on and off the excitation circuit of the generator;
VT1 is a Low-power triode (NPN type), used to amplify the control signal;
The voltage regulator VS is a sensing element, which is connected in series in the base circuit of VT1, and the resistors R1 and R2 are selected to match VS: when the generator When the output voltage UB reaches the specified adjustment value (such as when Santana is 14V), the voltage on R2 is exactly equal to the reverse breakdown voltage of the voltage regulator VS.
(1) When the generator voltage is lower than the set value, VS cannot be reversely broken down, and the triode VT1 has no base current, so VT1 is turned off; the resistor R3 provides the base current for the triode VT3, The triode VT3 is turned on, the ground terminal of the control rotor coil is connected, and the current of the rotor coil is connected.
(2) When the generator voltage reaches the set value, VS can be reversely broken down to provide base current for the triode VT1, so VT1 is turned on; VT1 is turned on and the resistor R3 is directly grounded , Because the triode VT3 has no base current, the triode VT3 is cut off, and the ground end of the control rotor coil is cut off, and the rotor coil current is cut off. Reduce the generator output voltage.
TITLE’s typical built-in voltage regulator
Now we talk about voltage regulators, many places are TITLE’s voltage regulators, and many times this voltage regulator is called IC regulator, compared with the traditional discrete components, this voltage regulator should have an integrated control chip inside, which realizes the control of turning on and off the rotor coil, and also realizes the control of the charging indicator of the meter. Xiali is free from Japan, and this control idea is the design idea of many cars.
Voltage Regulator Structure Schematic
Xiali Voltage Regulator Circuit Diagram
Power Generation The advantages of the machine voltage detection circuit: The distance between the generator and the detection circuit is close, and it can be connected directly to the output end of the generator without wires, and the connection is reliable, so that the detection circuit cannot detect the signal.
Disadvantages of the generator voltage detection circuit: When the connection resistance between the generator and the battery is large, the charging voltage of the battery will be low, making the battery insufficiently charged.
The regulator has 6 terminals F, P and E. The three terminals are directly connected to the generator with screws. The B terminal is fixed on the output terminal “B” of the generator with a nut. IG, L The two terminals lead wires to the external wiring socket of the regulator.
Field current control: VT2 is a high-power triode, which is connected in series with the magnetic field, and the on and off of VT2 is controlled by the integrated chip IC, thereby controlling the on-off of the magnetic field circuit, making the generator Voltage is controlled.
Xiali charging indicator circuit diagram
Charging indicator: The charging indicator is connected to the VT1 collector in series, and the VT1 leads The charging indicator light is on, and the charging indicator light when VT1 is off is off. In the integrated chip IC, there is a circuit that controls the turn-on and turn-off of VT1. The control signal is provided by point p, which provides the AC signal of the single-phase voltage of the generator. The amplitude of the signal can reflect the output voltage of the generator.
Xiali charging indicator circuit diagram
When generating electricity When the output voltage of the generator is lower than the battery voltage, the control circuit in the IC turns on VT1, and the charging indicator light is on. When the output voltage of the generator is higher than the battery voltage, the control circuit in the IC turns off VT1 and the charging indicator goes out.
Voltage Regulator Control Circuit with Field Diode:
Santana Charge Indicator Circuit Diagram
TITLE Voltage Use and maintenance of the regulator
Generally, the regulator is not allowed to remove the protective cover during use. Normally, a comprehensive inspection and maintenance should be carried out every 200 hours of operation. The contents are as follows:
1. Remove the protective cover. shell, and inspect the contact surfaces for dirt and burns. If there is dirt, wipe the contact surface with a relatively clean paper. If the contact is ablated or the plane is uneven, resulting in poor contact, generally use “00” sandpaper or sand strip to smooth it, and finally wipe it with clean paper.
2. Check the firmness of each joint, measure the resistance and the resistance of each coil. If it is damaged, it should be repaired or replaced in time.
3. Check the closing voltage and reverse current of the circuit breaker, the limit voltage of the voltage regulator, the limit current of the limiter, and the gap and air gap of various contacts. If it does not meet the requirements, it should be adjusted.
4. Check the adjusted regulator, and pay attention to the indication of the pointer of the charging ammeter when starting the diesel engine. If the pointer of the ammeter still points to the “-” side when the diesel engine is running at a medium or higher speed, it means that the contact of the circuit breaker is not disconnected, and the grounding switch should be disconnected quickly; otherwise, it will damage the battery, regulator and charging generator, etc. . If the pointer of the ammeter still points to “0” after the diesel engine is started to the rated speed, the adjustment has not been adjusted according to the technical requirements, and should be checked and adjusted again.
TITLE Auto Generator Regulator Fault Judgment
The regulator has three columns, one is the positive pole, the other is the ground pole, and the other is the magnetic field column. The test method: the positive pole is connected to the positive pole of the regulator, Connect the grounding iron to the grounding pole of the regulator, and connect the magnetic field pole of the regulator to one of the carbon brushes with a wire, and connect the other carbon brush to the grounding iron. Use a test lamp to test whether the carbon brush has electricity. The light bulb is good, but not bright. It’s the regulator that’s broken.
Another method for judging the quality of the regulator:
1. The generator does not generate electricity, use a test lamp to measure the magnetic field end without electricity, and the regulator F has no electricity, but B There is electricity, and E grounding is normal, that is, the regulator is broken and needs to be replaced.
2. If the power generation of the generator is too large and exceeds 15.0v or even higher, the regulator is generally broken and needs to be replaced.
3. Use a meter to measure the power generation of the generator. It is normally about 14.8. If it is high, the regulator is damaged. If the bulb often burns and you can’t find other problems, except for high battery temperature and fast consumption, the voltage regulator is broken.
TITLE Auto alternator and regulator failure maintenance
1. The alternator does not charge: the engine is running at a medium speed or above, the ammeter indicates discharge, and the charging indicator light does not go out. Measure the generator terminal voltage to be ≯ battery voltage.
Causes: generator belt break or serious slippage; generator excitation circuit or charging circuit open circuit; generator fault; regulator fault
fault diagnosis and repair
(1) Check the belt tightness and wire connection (loose or wrong connection) in turn.
(2) If it is normal, perform electromagnetic suction test on the generator, if not, check the excitation circuit. It should first be distinguished whether it is the fault of the generator or the fault of the regulator (provide by energizing the rotor winding of the generator and testing whether it has electromagnetic attraction). If normal, go to the next step.
(3) Check the armature circuit. Use a test light to check for power at the generator “B” terminal to determine if the fault is on the outside line or inside the generator.
(4) When diagnosing circuit faults, the resistance or voltage range of a test lamp or a multimeter can be used.
2. The charging current of the generator is too small: when the battery is running low, the charging current is very small when the engine is running at high speed, or the battery is often running low.
Reason: Poor contact of the charging line; slippage of the drive belt; faulty generator; too low or faulty regulator voltage.
Troubleshooting and maintenance:
(1) Check the tightness or oil pollution of the generator drive belt, and check the connection of the wires;
(2) Remove the generator” Connect the “B” and “F” terminals of the generator with both ends of the test light, start the engine and gradually increase the speed, if the test light turns red, it means that the generator is faulty; if the increase of two degrees is larger, the generator is normal , the fault is in the regulator. There is an ammeter to observe the charging current in this case, and distinguish whether it is the fault of the generator or the regulator.
3. The charging current of the generator is too large: when the battery does not lose power, the ammeter indicates that the charging is still above 10A, or the electrolyte is consumed too quickly.
Reasons: The regulator voltage value is too high; the high-power triode of the transistor regulator cannot be effectively cut off or short-circuited; the magnetizing coil or the adjustment resistor of the electromagnetic vibration regulator is disconnected, the high-speed contact is dirty, etc.; The excitation circuit of the machine is short-circuited with “B+”.
Troubleshooting Repair: Remove regulator field wiring, gradually increase generator speed and observe ammeter. If charging is still indicated, the generator is faulty; otherwise, the regulator is faulty, and the electromagnetic vibration regulator can be adjusted and repaired; if it is a transistor regulator, it should be replaced.
4. Unstable alternator charging: When the engine is running above idling speed, the ammeter indicates unstable or flashes after turning on the light.
Causes: The rotating belt is loose and sometimes slips; the lead of the charging system is in poor contact; the generator is faulty; the adjusting contact of the regulator is ablated or dirty, the spring of the contact arm is too soft, etc.
Troubleshooting and maintenance:
1) First, eliminate external faults such as belt slippage and poor wire foundation.
2) Check the failure of the regulator first and then check the failure of the generator.
3) Generator failure: ① Bearing failure; ② The rotor collides with the stator; ③ Too much wear of the brushes or poor contact with the slip ring; ④ The rotor shaft is bent, etc.
