JP3137259B2 - Control device for AC generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator control device, and more particularly to a control device for controlling an AC generator mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art For example, as disclosed in JP-A-10-210796 and JP-A-10-229698, an AC generator having an armature coil and a field coil, and an output of the AC generator are rectified. 2. Description of the Related Art An AC generator control device including a full-wave rectifier for supplying a DC output to a storage battery and a voltage regulator having a switching element for controlling a field current flowing in a field coil of the AC generator is known.

As shown in FIG. 9, a conventional AC generator control device includes an AC generator (1) having an armature coil (101) and a field coil (102), and an AC generator (1). Rectifier circuit (2) that supplies full-wave rectified AC output and supplies DC output to storage battery (4)
And a voltage regulator (3) having a switch element (302) for controlling a field current flowing through a field coil (102) of the AC generator (1). The AC generator (1) is driven by, for example, an engine (not shown) mounted on a vehicle. The rectifier circuit (2) has a positive terminal (201) connected to the storage battery (4) and a negative terminal (202) grounded. The voltage regulator (3) is an alternator (1)
The maximum value of the field current flowing through the field coil (102) is controlled to a predetermined value by intermittently controlling the operation of the switching element (302) by detecting the AC voltage of the AC generator (1). Is controlled to a predetermined value.

For this reason, the voltage regulator (3) is provided with a field coil.
A flywheel diode (301) connected in parallel to (102) and regenerating an intermittent surge generated in the field coil (102);
A switching transistor (switch element) (302) for interrupting a field current flowing through the field coil (102); a bias resistor (303) connected between the switching transistor (302) and the rectifier circuit (2); Switching transistor (30
2) A control transistor (304) connected between the base and the ground, and a voltage dividing resistor (308, 30) for dividing the generated voltage.
9) and a non-inverting input terminal connected to the connection point of the voltage dividing resistors (308, 309) and an inverting input terminal connected to the reference voltage power supply (305). A comparator (306) that gives an output to the control transistor (304) when high
And

When an engine (not shown) is started, the AC generator (1) rotates, and the AC power output from the armature coil (101) is supplied to the rectifier circuit (2), rectified and converted as a DC current to the storage battery. Entered in (4). Thereby, the storage battery (4) is charged. By controlling the field current flowing through the field coil (102), the power generation output of the AC generator (1) is adjusted.

When the divided voltage at the connection point of the voltage dividing resistors (308, 309) is lower than the reference voltage (305), the comparator (306) generates a low level "L" output. (30
4) is off. For this reason, the switching transistor (302) to which the base current is supplied from the bias resistor (303)
Is turned on, a current flows through the field coil (102), and the generated voltage increases as the current of the field coil (102) increases. When the generated voltage rises and the divided voltage exceeds the reference voltage of the reference voltage power supply (305), the comparator (306) generates a high-level "H" output, and the control transistor (304) is turned on. Becomes For this reason, the base current of the switching transistor (302) is cut off, the field current is regenerated through the flywheel diode (303), and the generated voltage decreases. Or later,
The generated voltage is controlled through on / off control of the switching transistor (302). 10 (A) is a collector current waveform of the switching transistor (302), FIG. 10 (B) is a current waveform flowing through the field winding (102), and FIG. 10 (C) is an output voltage (battery) of the AC generator. Voltage) waveforms are shown.
FIG. 13 is a graph showing a smoothed input waveform to the comparator (306).

[0007]

By the way, since the rectifying ripple is applied to the output voltage of the AC generator (1) which is a three-phase full-wave rectifier, the connection point of the voltage dividing resistors (308, 309) is also shown in FIG. A voltage including a rectifying ripple shown in FIG. Therefore, the rectifier ripple is also input to the comparator (306), whereby the alternator (1) has an output characteristic falling to the right as shown in FIG. Conventionally, the capacitor (300)
And in parallel, and smoothes the input waveform to the comparator (306) to prevent the output voltage V ₀ from being reduced due to rectification ripple. When the output voltage V ₀ is smoothed by the capacitor (300),
The input of the waveform shown in FIG. 13 is given to the comparator (306).
However, the smoothing capacitor (300) used in the conventional circuit has a large capacitance of tens of thousands of pF, and is monolithic IC.
It was difficult to build in. For this reason, since an external component is used as the smoothing capacitor (300), the number of manufacturing steps and manufacturing costs are increased when manufacturing the control device for the AC generator.

An object of the present invention is to provide a control device for an alternator which can be built in a monolithic IC.

[0009]

A control device for an alternator according to the present invention comprises: an alternator (1) for outputting an alternating current by driving an internal combustion engine; a generator connected to the alternator (1);
A rectifier circuit (2) for supplying DC to (4) and a voltage regulator (3) for controlling a field current of the AC generator (1) are included. The voltage regulator (3) is composed of a plurality of voltage-dividing resistors connected in parallel to the storage battery (4).
(307-309), a non-inverting input terminal connected to a connection point connecting the plurality of voltage dividing resistors (307-309) to each other, and an inverting input terminal connected to the reference voltage power supply (305). Piezoresistance
The divided voltage generated at the connection point (307-309) is the reference voltage power supply.
A comparator that generates an output when it is higher than the reference voltage of (305)
(306), and a switch element (302) for intermittently controlling the field current of the AC generator (1) based on the output of the comparator (306). In this AC generator control device, the voltage dividing resistor (307 to 30
A voltage limiting element (310) is connected in parallel with 9) to limit the magnitude of the divided voltage, and the upper limit of the divided voltage input to the comparator (306) is specified by the voltage limiting element (310). Therefore, the input voltage is limited, so that the output voltage of the AC generator (1) can be easily stabilized. The voltage limiting element (3
10) can be integrated as a Zener diode (310), a diode (330) or a Zener diode (331) and a transistor (333) into a monolithic IC by semiconductor elements, so that a control device for an alternator can be manufactured at low cost. be able to. In the embodiment of the present invention, the alternator (1)
May be detected by the voltage dividing resistors (307 to 309) of the voltage regulator (3).

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an AC generator control device according to the present invention will be described below with reference to FIGS.
In these drawings, the same portions as those shown in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, in the embodiment of the present invention, an additional voltage dividing resistor (307) is connected between the voltage dividing resistor (308) and the rectifier circuit (2), and at the same time, the voltage dividing resistor is connected. It is characterized in that a Zener diode (310) is connected as a voltage limiting element in parallel with (308) and (309). The Zener diode (310) constituted by a semiconductor element defines the upper limit of the divided voltage input to the comparator (306) to limit the input waveform,
As shown in FIG. 2, the output voltage of the AC generator (1) can be easily stabilized. FIGS. 2A to 2E show FIGS.
It corresponds to the voltage of different input setting levels shown in (e). The reason why the output voltage increases as shown in FIG. 2E is that the comparator (306) detects the detected voltage as an apparently lowered output voltage, which is cut by the Zener diode (310).

The embodiments of the present invention can be modified.
For example, a Zener diode (310) may be connected as a voltage limiting element in parallel with the resistor (309). Further, as shown in FIG. 4, the additional voltage dividing resistor (307) may be directly connected to the terminal of the storage battery (4).

As shown in FIG. 5, a rectifier circuit (2) is connected to a storage battery.
While connected to (4), a plurality of auxiliary rectifier diodes (203) connected to the rectifier circuit (2) can be directly connected to the voltage regulator (3).

FIG. 1 shows an example in which the voltage regulator (3) using the comparator (306) is used. However, instead of the comparator (306), as shown in FIG. A zener diode (312) is connected as a voltage detector (311) between the base of the voltage dividing resistor (308, 309) and the connection point of the voltage dividing resistor (308, 309). When the level exceeds a predetermined level, the control transistor (304) may be turned on through the Zener diode (312).

Further, as shown in FIG. 7, a band gap type voltage detector (311) which can use a low input voltage can be used. That is, the collector of the transistor (314) is connected to the rectifier circuit (2) via the resistor (313),
The base of the transistor (314) is connected to the connection point of the voltage dividing resistors (308, 309). Transistor (314) via resistor (315)
Is connected to the collector of the transistor (316) and at the same time to the base of the transistor (317). The emitter of the transistor (316) is grounded, and the base of the transistor (316) is connected to the connection point between the emitter of the transistor (317) and the ground resistor (318). Further, the collector of the transistor (317) is connected to the emitter of the transistor (314), and the collector of the transistor (320) is connected to the emitter of the transistor (314) via the resistor (319). The emitter of the transistor (320) is connected to the ground resistor (321), and the collector of the transistor (320) is connected to the base of the control transistor (304) composed of a Darlington transistor. When the voltage at the connection point of the voltage dividing resistors (308, 309) exceeds a predetermined level, the transistors (314, 316, 317, 320, 30
4) turns on.

As shown in FIG. 8, the voltage limiting element (3
10) can use a substitute circuit of the Zener diode. That is, in FIG. 8A, a plurality of diodes (330) are connected in series, and the upper limit of the divided voltage can be defined by the internal impedance of the diodes (330). As shown in FIG. 8B, a series circuit of a Zener diode (331) and a ground resistor (332) and the collector and the emitter of the transistor (333) are connected in parallel to the voltage dividing resistors (308, 309). At the same time, the base of the transistor (333) is connected to the connection point between the Zener diode (331) and the ground resistor (332). When a voltage exceeding the specified value is applied to the voltage dividing resistor (308), the Zener diode (331) and the transistor (333) are turned on, and the voltage inputted to the comparator (306) or the voltage detector (311) is turned on. An upper limit value of the voltage can be defined.

[0017]

As described above, since the output characteristics of the AC generator can be adjusted by adjusting the voltage dividing resistance ratio with the semiconductor element without using an external capacitor, the control device for the AC generator can be changed to a monolithic IC. It can be integrated and manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a control device for an alternator according to the present invention.

FIG. 2 is a graph showing output characteristics of the AC generator control device according to the present invention.

FIG. 3 is a graph showing a voltage waveform cut by a voltage limiting element.

FIG. 4 shows a second embodiment according to the present invention showing a connection state to a storage battery.
Circuit diagram showing an embodiment of the present invention.

FIG. 5 is a circuit diagram showing a third embodiment according to the present invention using an auxiliary rectifier circuit.

FIG. 6 is a circuit diagram showing a fourth embodiment of the present invention in which a Zener diode is connected as a voltage detector.

FIG. 7 is a circuit diagram showing a fifth embodiment according to the present invention using a bandgap type voltage detector.

FIG. 8 is a circuit diagram showing another embodiment of the voltage limiting element.

FIG. 9 is a circuit diagram of a conventional control device for an alternator.

FIG. 10 is a graph showing waveforms of various parts generated when the AC generator control device operates.

FIG. 11 is a graph showing output characteristics of a conventional AC generator control device.

FIG. 12 is a graph showing a waveform input to a comparator.

FIG. 13 is a graph showing a smoothed input waveform to a comparator.

[Explanation of symbols]

(1) ... AC generator, (101) ... armature coil, (10
2) ... field coil, (2) ... rectifier circuit, (201) ... main rectifier output terminal, (202) ... ground terminal, (203) ... auxiliary rectifier diode (auxiliary rectifier circuit), (3 ) ・ ・ Voltage regulator,
(301) ・ ・ Flywheel diode, (302) ・ ・ Switching transistor (switch element), (303) ・ ・
Bias resistor, (304) Control transistor, (30
7) Additional voltage dividing resistor, (308, 309)
(306) ・ ・ Comparator, (305) ・ ・ Reference voltage power supply, (310)
..Zener diodes (voltage limiting elements),

Claims (2)

(57) [Claims] 1. An alternating current generator that outputs alternating current by driving an internal combustion engine, a rectifier circuit that is connected to the alternating current generator and supplies direct current to a storage battery, and a voltage regulator that controls a field current of the alternating current generator. A voltage regulator, a plurality of voltage dividing resistors connected in parallel to the storage battery, a non-inverting input terminal connected to a connection point connecting the plurality of voltage dividing resistors to each other, and a reference voltage power supply. A comparator having an inverting input terminal connected to the comparator and generating an output when a divided voltage generated at a connection point of the voltage dividing resistor is higher than a reference voltage of the reference voltage power supply; A control device for an alternator comprising a switch element for intermittently controlling a field current of the alternator, wherein a voltage limiting element is connected in parallel with the voltage dividing resistor to limit the magnitude of the divided voltage. And input to the comparator A control device for an AC generator, wherein an input waveform is limited by defining an upper limit value of a divided voltage to be performed by the voltage limiting element. 2. An AC generator that outputs AC by driving an internal combustion engine, a rectifier circuit that is connected to the AC generator and supplies DC to a storage battery, and an auxiliary rectifier circuit that is connected to the AC generator. A voltage regulator for controlling a field current of the alternator, wherein the voltage regulator comprises a plurality of voltage dividing resistors connected in parallel to the storage battery, and a connection connecting the plurality of voltage dividing resistors to each other. A non-inverting input terminal connected to a point and an inverting input terminal connected to a reference voltage power supply, and output when a divided voltage generated at a connection point of the voltage dividing resistors is higher than a reference voltage of the reference voltage power supply. And a switch element for intermittently controlling the field current of the AC generator based on the output of the comparator, wherein the voltage limiting element is provided in parallel with the voltage dividing resistor. Connect the divided voltage While limiting the size of the AC generator control device an upper limit value of the divided voltage input to the comparator and limits the input waveform defined by the voltage limiting element.