Nippondenso Co., Ltd.

Tooru Aoyama

Kouzi Tanaka

Kouji Tanaka

Hidetoshi Kato

Hiroshi Shibata

Shigeru Tanaka

A vehicular generator unit includes an alternator and a generator control system that controls the alternator. The alternator is driven by an engine to achieve the power generation for charging a battery. The generator control system includes a transistor for intermitting a field current therethrough so as to control the power generation of the alternator. The system further includes a switching circuit which suppresses the duty of the transistor to a low value, where the alternator can not perform the power generation for the battery, until complete engine start-up or self-rotation is detected. On the other hand, when start-up is detected, the duty of the transistor is switched to a value where the alternator can perform the power generation for the battery. The duty of the transistor is then increased gradually to 100%.

Vehicle generator control system

Voltage of a terminal at a high impedance is set to a fixed voltage (2.5 V) by a constant current source and a resistor, and whether the voltage of the terminal is a fixed voltage which is between 3.5 V and 5.5 V or not is detected by comparators and a NOR circuit. A control signal is sent from an ECU to the terminal to turn on a switching transistor to lower a divided voltage so that the alternator generates a high voltage only when the voltage of the terminal is the special voltage, and generates normal voltage otherwise. In case of disconnection of the communication line or grounding of the communication line, or when the battery voltage is applied to the communication line, the voltage of the terminal does not become abnormal voltage but become the normal voltage. Thus, abnormal voltage may not applied to the battery.

Voltage regulator of vehicle alternator

A power generation control system for a generator is provided with a smoothing circuit, a voltage control circuit and an exciting current control circuit including a delaying circuit. When a terminal voltage of a smoothing capacitor is higher than a first reference voltage of a first comparator, a switching element is closed to supply current to an exciting coil. When a divided voltage of a voltage detecting circuit is lower than a second reference voltage of a second comparator, the smoothing capacitor is charged so that the terminal voltage thereof is gradually raised. When a detection voltage of the exciting current control circuit is higher than a third reference voltage of a third comparator, the smoothing capacitor is rapidly discharged so that the terminal voltage thereof is rapidly lowered down to a value not higher than the first reference voltage of the first comparator. Thereafter, the smoothing capacitor is charged again, in a manner as mentioned above, so that the terminal voltage thereof is gradually raised.

Power generation control system for generator

In a charging control apparatus for a vehicle for controlling generation of electric power from a vehicle's generator charging a battery, the rate of increase in the field current of the generator is increased when an electrical load is connected to the generator. A switch is connected in series with the field winding, and a mean conduction rate detector detects the mean conduction rate of the switch and generates an output signal having a value which is a function of the mean conduction rate of the switch. A maximum signal generator generates an output signal having a value larger by a predetermined value than that of the output signal of the mean conduction rate detector, and a comparator is enabled to operate while the maximum signal generator is generating the maximum signal. The comparator is preferably enabled again when the value of the mean output signal of the conduction rate detector exceeds a preset value. The predetermined value is preferably increased with the increase in the mean conduction rate of the switch. By enabling the comparator operate depending on the value of the maximum signal, the mean conduction rate of the switch can be gradually increased after it is increased by a predetermined value. The comparator is enabled when the value of the output signal of the mean conduction rate detector attains preset value, and the battery can be quickly charged when the mean conduction rate exceeds the preset value. Because the predetermined value is increased with an increase in the mean conduction rate, the battery can be quickly charged according to the mean conduction rate while decreasing the burden on the engine.

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Okazaki, Japan

Tooru Aoyama