JPH067733B2 - Voltage control device for vehicle alternator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage control device for a vehicular AC generator that controls the power generation of a vehicular AC generator to keep an appropriate charging voltage of a battery. .

[Conventional technology]

A voltage control device for a conventional vehicle alternator has an electric circuit diagram shown in FIG. 1, in which 1 is an armature winding, 2 is a three-phase full-wave rectifier, 3 is a battery, 4 is a charge lamp, Reference numeral 5 is a key switch, 6 is a field winding, and 16 is an auxiliary rectifier. This auxiliary rectifier 16 turns off the charge lamp 4 and supplies an exciting current to the field winding 6 (that is, a 3-diode excitation method). . The voltage adjusting circuit including the voltage dividing resistors 17 and 18, the resistor 21, the Zener diode 19, the transistors 8 and 20, and the flywheel diode 7 keeps the B terminal voltage constant by turning on or off the transistor 8.

Next, the operation of the conventional voltage control device having the above configuration will be described. When the key switch 5 is turned on, the battery 3
To key switch 5, charge lamp 4, field winding 6,
When an initial exciting current flows through the transistor 8 and the generator starts to rotate, a voltage is generated in the armature winding 1, an exciting current starts flowing in the field winding 6 through the auxiliary rectifier 16, and the charge lamp is turned off. . When the rotation speed of the generator further increases and the generated voltage increases, the Zener diode 19,
Since the transistor 20 is turned on and the transistor 8 is turned off, the exciting current gradually decreases and the generator output voltage decreases.
When the generator output voltage decreases, the Zener diode 19 and the transistor 20 are cut off and the transistor 8 is turned on, so that the exciting current increases and the generator output voltage increases. The above operation is repeated to control the generator output voltage to a constant value.

By the way, the conventional voltage control device shown in FIG. 1 has the following drawbacks.

(1) In FIG. 1, since the charge lamp 4 and the field winding 6 are connected in series, if the capacity of the charge lamp is increased, the voltage applied to the charge lamp becomes lower and the charge lamp becomes dark.

(2) Since the exciting current is supplied from the generator output through the auxiliary rectifier 16, compared to the method of directly exciting from the battery,
The rising speed of the generator is high.

[Object of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a voltage control device for a vehicle AC generator that is compatible with a voltage control device using a 3-diode excitation method.

[Structure of Invention]

The present invention relates to a voltage control device for an automotive alternator, which comprises voltage control means for maintaining a battery charging voltage at a constant value by controlling the field winding current of the alternator to control the power generation of the generator. It is composed of a semiconductor switch for driving a lamp, a semiconductor switch for power supply, and a semiconductor switch element for driving the semiconductor switch for power supply.

〔Example〕

The present invention will be described below with reference to the embodiments shown in the drawings. Second
FIG. 1 is an electric circuit diagram showing the configuration of an embodiment of a voltage control device for a vehicle AC generator according to the present invention. First in the figure
The same reference numerals as those of the conventional voltage control device shown in the drawing have the same parts and functions. In the figure, 10 is an IC that constitutes an internal circuit (voltage adjusting circuit) of the voltage control device
In the circuit, 10a is a terminal that outputs an on / off signal to the transistor 8 that controls the excitation current, 10b is a power generation detection terminal that detects a one-phase terminal voltage of the armature winding, and 10c is a charge lamp drive transformer 15. Terminals for supplying ON / OFF signals, 10d are power supply terminals, a power supply transistor 9 is a switch for supplying power to the IC circuit 10, 15 is a transistor for driving a charge lamp, and 13 and 14 are transistors. 9 is driven. Reference numeral 11 denotes an oscillation circuit, and a trigger pulse is generated at the terminal 11a, and the transistor 12 receives the trigger pulse from the oscillation circuit 11 to momentarily turn off the transistors 13 and 15. The Zener diode 22 sets the operating voltage of the transistor 14, and the resistor 23 is a leak protection resistor that suppresses the voltage generated by the leak voltage at the L terminal.

The oscillator circuit 11 and the transistors 12, 13 and 14 constitute a switch control means.

Next, the operation of the voltage control device of the present invention having the above configuration will be described. First, when the key switch 5 is turned on, a current flows from the battery 3 through the key switch 5 and the charge lamp 4, and since the transistor 15 is still off, the transistor 14 is turned on. Then, a base current flows from the battery 3 to the transistor 9 to turn on the transistor 9 to supply current to the IC circuit 10, and the IC circuit starts operating. Then, the IC circuit detects the voltage applied to the 10d terminal, and a high voltage is applied to the 10c terminal to turn on the transistor 15 to turn on the choge lamp 4. At this time, the transistor 13 is also turned on. Therefore, even if the transistor 15 is turned on and thus the transistor 14 is turned off, the base current of the transistor 9 flows through the transistor 13 and the transistor 9 is kept in the on state, so that the power supply to the IC circuit is maintained. There is no interruption of supply. When the generator rotates to start power generation, the 10b terminal voltage rises, and the IC circuit detects this and sets the 10c terminal to a low voltage to turn off the transistors 13 and 15, turning on the transistor 14 and turning on the charge lamp. Turn off the light. At this time, IC circuit 1
The base current of transistor 9, which supplies power to 0, flows through transistor 14. When the generator speed further increases and the generator output voltage exceeds the rectified value, the IC circuit 10
Detects this at the terminal 10d and turns off the transistor 8. As a result, the exciting current decreases and the generator output voltage decreases. When this becomes less than the adjustment value, the IC circuit 1
0 detects this and turns on the transistor 8 again. As a result, the exciting current increases and the generator output voltage rises.
Thereafter, this operation is repeated to control the generator output voltage to a constant value.

Here, when the charge lamp is turned on, the transistor 13 for turning on the power supply transistor 9 and the charge lamp driving transistor 15 are on, and the transistor 14 is off. At this time, even if the key switch 5 is opened, the charge lamp driving switch 15 is on, and the base current of the power supply transistor 9 continues to flow through the transistor 13. Therefore, simply opening the key switch 5 does not turn off the power-supply transistor 9, and power continues to be supplied.

Therefore, the embodiment of the present application employs a configuration in which the oscillation circuit 11 is used to momentarily turn on the transistor 12 at regular intervals. According to this configuration, the charge lamp driving transistor 15 and the transistor 13 are momentarily turned off, and the transistor 14 is not turned on when the key switch 5 is opened, so that the transistor 9 is turned off.
The power supply to the C circuit 10 is stopped.

〔The invention's effect〕

As described above, in the voltage control device for the vehicle alternator according to the present invention, the charge lamp is a circuit separate from the excitation circuit, as compared with the diode excitation method in which the excitation current is supplied through the conventional auxiliary rectifier. It has a large effect that it can be made brighter when the charge lamp is turned on, the starting rotation speed of the generator is lowered, and it is compatible with the voltage control device by the three-diode excitation method.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a conventional 3-diode excitation type voltage control device, and FIG. 2 is an electric circuit diagram of a voltage control device for a vehicle alternator according to the present invention. 9 ... Power supply semiconductor switch (transistor), 15 ... Charge lamp driving semiconductor switch (transistor),
13, 14 ... Semiconductor switch elements (transistors) for driving the semiconductor switch 9 for power supply, 10 ... IC circuits (voltage adjusting circuits), 11 ... Oscillation circuits, 12 ... Transistors.

Claims (1)

[Claims] 1. A voltage control device for a vehicle alternator, comprising voltage control means for controlling a field winding current of an alternator to control power generation of the generator to keep a battery charging voltage at a constant value. A charge lamp driving semiconductor switch for driving the charge lamp, a power semiconductor switch for controlling supply of power for driving the charge lamp driving semiconductor switch, and a terminal voltage of the charge lamp driving semiconductor switch Is equal to or more than a predetermined set value, or when the charge lamp driving semiconductor switch is controlled to be in an ON state, the power semiconductor switch is turned on, and the charge lamp driving semiconductor is periodically turned on for a predetermined set time. Control of a vehicle alternator, comprising: a switch control means for turning off the switch. apparatus.