JPH0445409Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a control device for a vehicle alternator, and particularly to an alarm device thereof.

[Conventional technology]

FIG. 2 shows a conventional device, in which 1 is an alternating current generator driven by an engine (not shown) installed in a vehicle, and includes an armature coil 101 and a field coil 102.
It is made up of. 2 is a rectifier that full-wave rectifies the AC output of the AC generator 1; 201 is a main output terminal that outputs a main output; 202 is a main output terminal that excites the field coil 102; and a voltage regulator 3 and an alarm 4 that will be described later. 203 is an auxiliary output terminal to which the rectified output voltage of the generator is applied.
3 is a voltage regulator that controls the output voltage of the generator 1 to a predetermined value, and 301 and 302 are storage batteries 5, which will be described later.
It is a voltage dividing resistor that detects the terminal voltage of and constitutes the first voltage detection means, and the predetermined detection value is set to the optimum value for charging the storage battery 5. 30
3, 304 is a voltage dividing resistor that detects the output voltage from the auxiliary output terminal 202 of the rectifier 2, which constitutes a second voltage detection means, and the predetermined detection value is 1 to 2 V lower than the first predetermined detection value. It is set high. 30
5, 306 is a separation diode that separates the outputs of the first voltage detection means and the second voltage detection means;
7 is a Zener diode, and 308 is a transistor, which is turned on and off depending on whether the Zener diode 307 is conductive or non-conductive. 309 is an output transistor,
It is controlled intermittently by a transistor 308 to control the field current of the field coil 102. 310 is the base resistance of the output transistor 309; 311 is connected in parallel to the field coil 102;
This is a diode that absorbs intermittent surges that occur in 2. Further, 4 is an alarm device for diagnosing and alarming an abnormality in the generator 1, 401 is an alarm lamp driving transistor that drives an alarm lamp 9, which will be described later, 402 is a control transistor that controls the transistor 401, and 403 is the generator 1 404 is the base resistance of the transistor 401, and 405 is the base resistance of the transistor 402. 5 is a storage battery mounted on the vehicle and charged by the generator 1; 6 is a key switch; 7 is a backflow prevention diode; 8 is a resistor for initial excitation of the field coil 102; 9 is a warning lamp; B is a main output terminal 201. The wiring terminal S is a voltage detection terminal of the storage battery 5.

Next, the operation will be explained. When the key switch 6 is closed when starting the engine, the storage battery 5
From there, an initial excitation current flows to the field coil 102 via the key switch 6, the backflow prevention diode 7, and the initial excitation resistor 8, and the generator 1 becomes ready to generate electricity. Auxiliary output terminal 2 of rectifier 2 in this state
The potential 02 is a value obtained by dividing the voltage of the storage battery 5 by the resistance of the initial excitation resistor 8 and the field coil 102, and is a relatively low potential. On the other hand, in the alarm device 4, a base current flows from the storage battery 5 to the transistor 401 via the key switch 6 and the resistor 404, the transistor 401 becomes conductive, and the alarm lamp 9 lights up, indicating a non-power generation state.

Next, when the engine is started and the generator 1 starts generating electricity, the alarm 4 detects that the output voltage of the generator 1 is connected to the Zener diode 40 via the resistor 405.
3, the Zener diode 403 becomes conductive due to the rise in the generated voltage, which causes the transistor 402 to become conductive and the transistor 401 to become non-conductive, the alarm lamp 9 to turn off, and the generator 1 to generate power normally. to indicate that it has started. On the other hand, the voltage regulator 3 includes a first voltage detection means for detecting the terminal voltage of the storage battery 5 and an auxiliary output terminal 2 of the rectifier 2.
02, and since the predetermined detection value is lower for the former, the first voltage detection means usually takes priority and the second voltage detection means is disabled. It is becoming. Therefore, usually
Voltage dividing resistors 301 and 30 as first voltage detection means
2 and Zener diode 307,
The storage battery 5 is charged and its terminal voltage is applied to the voltage dividing resistor 3.
When the first voltage detection predetermined value set in 01 and 302 is exceeded, the Zener diode 307 becomes conductive.
Transistor 308 conducts and transistor 30
9 becomes non-conductive. Conversely, when the terminal voltage of the storage battery 5 becomes lower than the first voltage detection predetermined value, the Zener diode 307 becomes non-conductive, and the transistor 30
8 becomes non-conductive. Such a transistor 30
8, the output transistor 309 is turned on and off, the field current flowing through the field coil 102 is controlled on and off, the output voltage of the generator 1 is controlled, and the terminal voltage of the storage battery 5 is adjusted to the first predetermined value. . or,
If the voltage detection terminal S of the storage battery 5 is disconnected, the first voltage detection means becomes disabled and the output voltage of the generator 1 increases, but it is 1 to 2 V higher than the first voltage detection predetermined value. When the set second voltage detection predetermined value is reached, this is detected by the second voltage detection means, the field current is cut off due to the non-conduction of the transistor 309, and the output voltage of the generator 1 is reduced. Conversely, when the output voltage of the generator 1 becomes equal to or lower than the second voltage detection predetermined value, the field current flows and the output voltage of the generator 1 increases, and is eventually adjusted to the second predetermined value.

By the way, in the conventional device as described above, when the voltage detection terminal S of the storage battery 5 is disconnected due to vibrations of the vehicle or engine, the output voltage of the generator 1 is switched from the first predetermined value to the second predetermined value. Although the output voltage of the generator 1 is prevented from becoming uncontrolled, the abnormality cannot be displayed as a warning to the driver of the vehicle. Therefore, if the operation continues as it is, the storage battery 5 will be charged at a voltage 1 to 2 V higher than the optimal value.
The storage battery 5 becomes overcharged, causing an electrical load (not shown)
lifespan becomes shorter. In addition, if the main output wiring terminal B of the generator 1 is disconnected due to vibration or the like, the generator 1 is controlled to the second predetermined value, but the abnormality cannot be displayed as a warning to the driver, and the storage battery 5 becomes discharged without being charged.

[Problem that the invention attempts to solve]

Conventional vehicle alternator control devices are configured as described above, and if the storage battery voltage detection terminal S or main output wiring terminal B is disconnected, it is not possible to alert the driver of an abnormality, and the electric load There were problems in that it shortened the lifespan of vehicles and made vehicles inoperable.

This idea was created to solve the problems mentioned above, and it can display a warning to the driver if the storage battery voltage detection terminal or main output wiring terminal is disconnected, and can prevent excessive electrical loads. An object of the present invention is to obtain a control device for a vehicle alternator that can prevent a load and a vehicle from becoming inoperable.

[Means for solving problems]

The control device for a vehicle alternator according to this invention includes a voltage dividing resistor that detects the terminal voltage of the storage battery, and a first voltage dividing resistor that conducts when the field coil is deenergized to reduce the voltage at the dividing point of the voltage dividing resistor. The alarm is provided with a switching element and a second switching element that operates when the voltage at the dividing point drops and forcibly lights up the alarm lamp.

[Effect]

In the alarm according to this invention, when the voltage detection terminal of the storage battery is disconnected, the voltage at the dividing point of the voltage dividing resistor decreases, and the second switching element operates to light up the alarm lamp. In addition, if the connection between the generator and the storage battery is disconnected, the voltage at the dividing point of the voltage dividing resistor of the alarm will drop due to the voltage drop in the storage battery when the first switching element becomes conductive due to the deenergization of the field coil. and lights up the alarm lamp.

〔Example〕

Examples of this invention will be described below with reference to the drawings. In FIG. 1, 410 is the transistor 40
2 is a transistor for detecting battery terminal voltage connected in series, 411 is a Zener diode which is a voltage detecting element connected to the base of transistor 410, 412 and 413 are voltage dividing resistors for detecting battery terminal voltage, and 414 is a voltage dividing resistor. transistors connected in series with 412 and 413; 415 a Zener diode for detecting disconnection of the field coil 102;
16 is a base resistance of the transistor 414.
The voltage at which the transistor 410 becomes non-conductive is set to be approximately 2V lower than the first predetermined value of the voltage regulator 3.

Next, the operation will be explained. key switch 6
When the storage battery 5 is closed, the storage battery 5 is charged to a first predetermined value by the voltage regulator 3 during normal operation as in the conventional case. The warning lamp 9 is turned on and off in the same way as in the conventional case. Here, due to vibrations of the vehicle or engine, etc., the storage battery 5
When the terminal voltage detection terminal S is disconnected, the output voltage of the generator 1 is switched from the first predetermined value to the second predetermined value, and the generator 1 is prevented from becoming uncontrolled. On the other hand, the voltage dividing resistors 412 and 413 for detecting the voltage at the storage battery terminals of the alarm device 4 become unable to detect voltage. Therefore, Zener diode 411 and transistor 410 become non-conductive, and transistor 401 becomes non-conductive.
becomes conductive and the warning lamp 9 lights up to notify the driver of the abnormality. In addition, if the main output wiring terminal B is disconnected due to vibration or the like, the generator 1 is controlled to the second predetermined value as in the past, but it is in no-load operation, and the field coil 102 is energized during the energization time. The duty is short and the de-energization time is long. (The conduction time of the transistor 309 is short.) Therefore, the conduction time of the transistor 414 is long and the non-conduction time is short. That is, the terminal voltage of the storage battery 5 is divided by the voltage dividing resistor 41.
2,413, the detection time is long. On the other hand, since the storage battery 5 is not charged, the terminal voltage of the storage battery 5 continues to decrease. Therefore, when the terminal voltage of the storage battery 5 drops to a predetermined value that is set approximately 2V lower than the first predetermined value, the field coil 1
When 02 is deenergized, the transistor 414 becomes conductive, the voltage at the dividing point of the voltage dividing resistors 412 and 413 decreases, the transistor 410 becomes non-conductive, the alarm lamp 9 lights up, and the field coil 102 is energized. When this happens, the light goes out and lights up intermittently. However, since the intermittent frequency of the field coil 102 is from several tens of hertz to several hundreds of hertz, the dimming phenomenon is not felt, a sufficient lighting condition can be confirmed, and the driver can detect an abnormality.

In addition, if a large electrical load is connected during normal operation, especially when the generator 1 is rotating at low speed, an overload will occur, and the terminal voltage of the storage battery 5 will be reduced by the voltage dividing resistors 412, 4
13, but in this case the field coil 102 is energized due to the overload condition and therefore the transistor 4
14 is in a non-conducting state, and the voltage dividing resistor 41
2, 413 is not configured, the terminal voltage of the storage battery 5 is directly detected by the resistor 412, the Zener diode 411 and the transistor 410 remain conductive, and the alarm lamp 9 is not erroneously lit.

[Effect of idea]

As described above, according to this invention, when the voltage detection terminal of the storage battery or the connection between the generator and the storage battery is disconnected, the partial voltage resistance of the alarm decreases and the second switching element operates to turn on the alarm lamp. Force the light on. Therefore, the driver can detect an abnormality, and can prevent damage to the load due to overcharging of the storage battery and inability to operate due to a drop in voltage of the storage battery.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a control device according to this invention, and FIG. 2 is a circuit diagram of a conventional control device. 1... Alternator, 2... Rectifier, 3... Voltage regulator, 4... Alarm, 5... Storage battery, 9... Alarm lamp, 301 to 304, 412, 413...
Voltage dividing resistor, 402, 410, 414...transistor.

Claims (1)

[Scope of utility model registration request] A storage battery charged by a rectified output of an alternating current generator having a field coil, a first voltage detection means for detecting a terminal voltage of the storage battery, and a second voltage detection means for detecting a rectified output voltage of the alternator. , a voltage regulator that adjusts the output voltage of the alternator to a predetermined value by intermittent control of the current in the field coil, and an alternating current for vehicles equipped with an alarm having a warning lamp that is turned off by the rectified output of the alternator. A control device for a generator includes a voltage dividing resistor that detects a terminal voltage of a storage battery, a first switching element that becomes conductive when a field coil is deenergized, and lowers a voltage at a dividing point of the voltage dividing resistor; 1. A control device for an alternator for a vehicle, characterized in that the alarm is provided with a second switching element that operates when the pressure point voltage decreases and lights up an alarm lamp even during output from the alternator.