JPH0479218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a charging generator, and more particularly to a circuit with an alarm function that issues an alarm when a terminal of a generator is disconnected.

[Conventional technology]

Regarding the alarm function in the control device of the charging generator, there is a technology that detects disconnection of the voltage detection terminal of the storage battery and issues an alarm, as described in Japanese Patent Application Laid-Open No. 56-25342, etc., and a technology that issues an alarm by detecting disconnection of the voltage detection terminal of the storage battery, as described in Japanese Patent Application Laid-Open No. 58-25342. As described in No. 163238, etc., there is a technology that detects the generation of overvoltage due to disconnection of the output terminal of a generator and issues an alarm.

[Problem that the invention seeks to solve]

The conventional technique described above has the problem that the circuit becomes complicated because it is necessary to disconnect the generator terminal in two ways: () disconnect the voltage detection terminal () disconnect the output terminal.

An object of the present invention is to provide a control device for a charging generator that can detect both of the above-mentioned malfunctions with a simple circuit.

[Means for solving problems]

Conventionally, a control device for a charging generator used in automobiles, etc. has a first voltage voltage divider circuit that detects the voltage of a storage battery, and an auxiliary operation that operates when the input to the first voltage voltage divider circuit is not optimal. having a second voltage divider circuit;
This solved the problem of the generated voltage rising even if the terminal was disconnected. In the present invention, using these two voltage dividing circuits, a diode connection is used to preferentially transmit the voltage at the voltage dividing point of the first and second voltage dividing circuits to the comparison circuit, The circuit is simplified by providing a current mirror circuit in parallel with the diode used for transmission of the first voltage divider circuit.

[Effect]

When the storage battery is being charged normally without any terminal disconnection, voltage is detected from the first voltage divider circuit, and current flows through the current mirror circuit. However, if the storage battery voltage detection terminal is disconnected, or if the output terminal of the generator becomes disconnected,
Since the voltage from the second voltage dividing circuit is detected, no current flows through the current mirror circuit.

The present invention focuses on the above-mentioned difference, and when there is no output current from the current mirror circuit, it is determined that there is an "abnormality" and an alarm is issued.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a circuit diagram of an automobile charging power generation system. 1 is a charging generator, 2 is a storage battery, 3 is a key switch, and 4 is a charging indicator light. The charging generator 1 includes a control device 10, an armature winding 11, a three-phase full-wave rectifier 12 that rectifies the output of the armature winding 11, and a field winding that supplies magnetic flux to the armature winding 11. It is. In addition, the control device 10 is a hybrid thick film IC.
A power transistor 20 and a flywheel diode 2 for controlling the field current.
1, resistors 22, 23, 24, 25, a transistor 26 that drives the charging indicator light 4, a capacitor 2
7, 28, 29 Resistor 30 by first voltage divider circuit
a, 30b, resistor 31 by second voltage divider circuit
It consists of a and 31b. 100 is monolithic IC
, Zener diode 101, comparator 1
02, OR gate 103, oscillation circuit 104, reference voltage generation circuit 105, AND gate 106, NPN
Transistors 107, 108, 109, 110
PNP transistor 111, 112, 113 Diode 114, 115, 116, 117 Resistor 1
Consists of 18.

With the above configuration, when the key switch 3 is turned on, current is supplied from the storage battery 2 to the Zener diode 101 via the resistor 23, and the power supply voltage Vcc for driving the monolithic IC 100 is established. When the generator rotor (not shown) is stationary, no voltage is generated in the armature winding 12 and the diode 117 is cut off, so no charge is stored in the capacitor 29. Then, the input d of the AND gate becomes "0" level, the output f becomes "0" level, transistor 109 is turned off, transistor 26 is turned on, and charging indicator lamp 4 is turned on.
On the other hand, the output voltage of the storage battery 2 is low, and the comparator 102
The output c of the oscillation circuit 104 is at “0” level.
The oscillation signal is transmitted to power transistor 20 via transistors 107 and 108. Then, the power transistor 20 becomes conductive at a constant conduction rate, and a constant field current flows through the field winding 13.
"Initial excitation" is performed.

Next, when the rotor of the generator starts rotating, an alternating voltage is generated in the armature winding, and the peak value of the alternating voltage is passed through the diode 117 to the capacitor 29.
is charged to. When this value exceeds a certain value, a signal is applied to the input terminal a of the oscillation circuit 104, oscillation is stopped, the output terminal b becomes the "0" level, and the signal at the input terminal c of the OR gate is applied to the power transistor 20. The initial excitation is completed. on the other hand,
Since the input terminal d of the AND gate 106 is at the "1" level and the e terminal is at the "1" level (the reason will be explained later), the output terminal f is at the "1" level, the transistor 109 is turned on, and the transistor 26 is turned on. It turns off.

Here, if the voltage division ratios of the first voltage dividing circuits 30a, 30b and the second voltage dividing circuits 31a, 31b are set so that the voltage dividing ratio of the second voltage dividing circuit is larger, If the first voltage dividing ratio is set to be larger, the voltage at the voltage dividing point of the first voltage dividing circuit will be higher than the voltage at the voltage dividing point of the second voltage dividing circuit. Then, the PNP transistor 111 becomes conductive,
From the voltage dividing point of resistors 30a and 30b, comparator 10
A small current is passed to the non-inverting input terminal of No.2. At this time, since the voltage at the voltage dividing point of the second voltage dividing circuit is lower than that of the first voltage dividing circuit, the PNP transistor 112 is cut off. At this time, due to the operation of the current mirror circuit by the PNP transistors 111 and 113, approximately the same current as the current flowing through the transistor 111 flows through the transistor 113.
The current is amplified through the transistor 110, raising the voltage at the e terminal to the "1" level.

Next, when the rotational speed of the generator becomes higher, the voltage of the storage battery 2 becomes higher, and the first voltage dividing circuit 30
The voltage at the dividing point of a and 30b increases, and the comparator 102
When the voltage at the non-inverting input terminal of the transistor becomes higher than the reference voltage 105, the output C of the comparator 102 becomes "1" level, the output of the OR gate 103 becomes "1", transistors 107 and 108 are turned on, and the power transistor 20 is turned on. It is turned off and the field current decreases through the flywheel diode 21. Then, the voltage at output terminal B of the charging generator decreases, and storage battery 2
voltage also decreases. When the voltage of the storage battery 2 decreases, the voltage at the voltage dividing points of the first voltage dividing circuits 30a and 30b also decreases, the output of the comparator 102 returns to the "0" level, and the output of the OR gate 103 becomes "0". Transistors 107 and 108 are turned off and power transistor 20 is turned on, energizing the field current and increasing the output voltage of the charging generator.

By repeating the above operations, the voltage at the voltage detection terminal S of the charging generator 1 is controlled to a constant value.

Next, consider the case where the terminal S is disconnected. When the terminal S is disconnected, no voltage is generated at the voltage dividing points of the first voltage dividing circuits 30a and 30b, so the PNP transistor 111 is cut off. instead,
The PNP transistor 112 becomes conductive, the second voltage dividing circuits 31a and 31b operate as voltage dividing circuits, and the voltage at the output terminal B of the charging generator 1 is controlled to a constant value. On the other hand, since no current flows through the PNP transistor 111, the PNP transistor 111 forms a current mirror.
No current flows through the transistor 113 either, and the voltage level at the e terminal becomes "0". Then, the output of the AND gate 106 also becomes “0”, and the transistor 1
09 is turned off, the transistor 26 is turned on, the charging indicator light is turned on, and a warning can be issued to the driver of the car.

Furthermore, if the output terminal B of the charging generator 1 is disconnected, the storage battery 2 will not be charged even if the output voltage of the charging generator 1 increases. At this time, since the voltage at the terminal S is lower than the control voltage in the normal state, voltage detection is performed via the second voltage dividing circuits 31a and 31b. Then, as in the case above,
PNP transistor 112 becomes conductive, PNP transistors 111 and 113, and NPN transistor 1
10 is cut off, and the input e of the AND circuit 106 is “0”
Then, the charging indicator light 4 lights up.

As described above, according to this embodiment, disconnection of the S and B terminals can be detected using a simple circuit, so the circuit can be simplified and costs can be reduced.

〔Effect of the invention〕

According to the present invention, a malfunction in the charging system due to disconnection of the terminal of the charging generator can be detected and alarmed using a simple circuit, so that the reliability of the device can be improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a charging power generation system according to an embodiment of the present invention. 100... Monolithic IC, 111, 112,
113...PNP transistor, 2...Storage battery,
4... Charging indicator light, 30a, b... First voltage dividing circuit, 31a, b... Second voltage dividing circuit, 106...
AND gate.

Claims (1)

[Scope of Claims] 1. A generator, a storage battery charged by the generator, a first voltage dividing circuit that divides the output voltage of the storage battery, and a second voltage divider that divides the output voltage of the generator. a first diode having an anode connected to a voltage dividing point of the first voltage dividing circuit; and a first diode having an anode connected to a voltage dividing point of the second voltage dividing circuit, and a cathode of the first diode; a second diode having a common cathode; a comparator circuit that compares the cathode voltage of the first and second diodes with a preset voltage; and an output of the generator based on the output of the comparator circuit. a first power element that controls a battery, a charge alarm means whose one end is connected to a storage battery, and a second power element that conducts or interrupts the charge alarm means.
a power element; and a power generation voltage detection circuit that detects the generated voltage of the generator and makes the second power element conductive when the detected voltage is below a certain value. a PNP type transistor in which the anode of the first diode and its emitter are shared, and the cathode of the first diode and its base are shared; and a logic in which the collector voltage of the PNP type transistor and the generated voltage of the generator are input. A control device for a charging generator, characterized in that a product circuit and a drive circuit that cuts off the second voltage element when the output of the AND circuit is "1" are provided in the generated voltage detection circuit. 2. In claim 1, the first diode is configured by shorting the base and collector of a PNP transistor, and the first diode and the PNP transistor are integrated into a monolithic IC.
A control device for a charging generator, characterized in that the control device is arranged at a position where thermal coupling is large on the top and operates as a current mirror circuit.