JPH06178459A - Charging device for vehicle - Google Patents

Abstract

PURPOSE:To provide a charging device, for vehicles, wherein the power- generation current of a generator can be increased before a battery voltage is dropped when a short-time large-current load is used. CONSTITUTION:A boosting circuit 11 is operated when a control circuit 10 is operated and an electrification detection circuit 12 detects that an electric current is applied to a short-time large-current load 9. A prescribed voltage in which the portion of a boosting voltage has been added to the voltage of a battery 1 is applied to a field coil 3R, and the output current of a generator 2 is increased. A voltage to be applied to the field coil 3R so as to correspond to the operating state of the short-time large-current load 9 is set at a first prescribed voltage of 18 V when the electrification detection circuit 12 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for a vehicle, and in particular, when the vehicle is idling or traveling at a low speed, it is suitable for use with a large current load for a short time, and a voltage higher than a voltage generated by a generator is applied. The present invention relates to a vehicle charging device that applies a magnetic coil to increase an output current to charge a battery and supply a large current load for a short time.

[0002]

2. Description of the Related Art When a large-capacity electric load is used when a charging generator is rotating at a low speed such as when a vehicle is idling,
Since a current higher than the output of the charging generator is required and the battery is discharged, the battery voltage drops. The decrease in the battery voltage causes a decrease in the exciting current of the field coil, which reduces the output of the generator and promotes discharge from the battery.
Therefore, a device that detects battery discharge when the duty of the transistor that controls the exciting current of the rotor coil of the generator reaches 100% and a booster circuit that generates a boosted voltage when battery discharge is detected due to a decrease in battery voltage A vehicle charging device capable of suppressing the amount of discharge of a battery by operating is disclosed in JP-A-1-186.
No. 134 publication.

[0003]

[Problems to be Solved by the Invention]
For automobiles, an electric heating catalyst system as an exhaust gas countermeasure and a short-time large current load such as a windshield with a heater for ensuring safety have been developed. When these short-time high-current loads are mounted on the vehicle, the above-described vehicle charger significantly increases the generator current when the battery discharge is detected, and responds to the load. When the current increases, it is difficult to recover the battery voltage. In view of the above problems, the present invention provides a vehicle charging device capable of increasing the generated current of a generator before the battery voltage drops when a large current load is used for a short time. Let's take the first challenge.

Further, in the conventional vehicle charging device, the DC-DC converter used as the booster circuit has a primary side and a secondary side.
Since the voltage between the secondary side is insulated and voltage conversion is performed, only the boost voltage of the boost circuit is applied to the field coil, and the battery voltage is not applied.Therefore, the generator current slightly increases for the same boost voltage. Not possible, circuit efficiency is poor. The present invention is
In view of the above problems, a second object is to provide a vehicle charging device that improves the circuit efficiency of the booster circuit.

Further, the conventional vehicle charging device is wasteful and complicated because it is provided with a line for supplying current to the field coil from the booster circuit and a line for directly supplying from the battery. In view of the above problems, it is a third object of the present invention to provide a vehicle charging device having a simplified circuit configuration capable of continuously supplying current to the field coil without waste.

In addition, the conventional vehicle charging apparatus detects the discharge of the battery and then applies the voltage applied to the field coil to 18
Since it is continuously applied as V, there is a problem that the field coil causes abnormal heat generation. In view of the above problems, the present invention provides a vehicle charging device that suppresses the applied voltage of the battery to a small value for a short time in response to the use of a large current load to suppress abnormal heat generation of the field coil. It is an issue.

[0007]

In order to solve the above first problem, the present invention relates to an energization detection circuit for detecting energization of a large current load for a short time, and a battery voltage to a predetermined voltage detected by the energization detection circuit. A booster circuit for boosting the voltage and applying it to the field coil is provided. When the energization detection circuit detects the energization of the large current load for a short time, the booster circuit operates and applies a boosted voltage higher than the battery voltage to the field coil to increase the output current of the generator.

In order to solve the second problem, the present invention is characterized by supplying a predetermined voltage obtained by adding the boost voltage to the battery voltage to the field coil when the boost circuit operates. Provide a charging device. According to the above configuration, even if the boosted voltage is low, a predetermined voltage higher than the boosted voltage is applied to the field coil, so that the loss of the booster circuit is small and the circuit efficiency is improved.

Further, in order to solve the third problem, the present invention provides a vehicle charging device characterized in that the battery voltage is supplied to the field coil through the boosting circuit when the boosting circuit does not perform boosting operation. provide. Then, when the high current load is de-energized for a short time and the booster circuit stops operating, the voltage is applied to the field coil by applying the battery voltage from the power supply terminal of the booster circuit to the output terminal. The power supply terminal of the booster circuit is continuously shared regardless of the operation of the booster circuit to simplify the circuit configuration.

In order to solve the fourth problem, the present invention provides an energization detection circuit for detecting energization of a large current load for a short time, a discharge detection circuit for detecting discharge of a battery, and an application to the field coil. A boosting circuit for boosting a direct current voltage, the boosting circuit applies a first predetermined voltage to the field coil when the energization detecting circuit detects energization to a large current load for a short time, and the discharge detecting circuit Is detected, the second predetermined voltage set to be lower than the first predetermined voltage is applied to the field coil. Then, when the energization detection circuit detects energization to a large current load for a short time,
The booster circuit applies a high first predetermined voltage to the field coil to quickly eliminate the current shortage. When the discharge detection circuit detects the discharge of the battery, the second predetermined voltage lower than the first predetermined voltage is applied to the field coil. In this way, by changing the voltage applied to the field coil in response to the use of a large current load for a short time, abnormal heat generation of the field coil can be suppressed to a small level.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an electric circuit configuration diagram of the vehicle charging device of the first embodiment. In FIG. 1, the battery 1 has an ignition load 6
A series circuit of the general load 7, the control circuit 10 and the short-time high-current load 9, the boost control circuit 8, and the generator 2 are connected in parallel. The generator 2 is an electric load for the vehicle and the battery 1.
It is composed of an alternator 3 for generating electric power to charge the battery, a voltage regulator 5 for controlling the generated voltage, and a rectifier 4 for rectifying the generated voltage of the alternator 3. The alternator 3 excites the field coil 3R to generate a generated voltage in the stator coil 3S. The voltage regulator 5 is supplied with the battery voltage at the same time as the ignition load 6, detects the voltage of the battery 1 and outputs the exciting current of the field coil 3R to the transistor 5.
By a, the output voltage of the alternator 3 is controlled to a constant adjustment voltage.

The step-up control circuit 8 is composed of an energization detection circuit 12 for detecting energization of the large current load 9 for a short time and a step-up circuit 11 for starting the step-up in response to its operation signal. , The power source is connected to the ground terminal 8d, and the output terminal 8b is connected to one terminal of the field coil 3R. The input terminal 8c is connected to the current supply side of the large current load 9 for a short time. Boost circuit 11
Since the output side voltage adds the boosted voltage to the power supply voltage, the -OUT terminal on the secondary side and the + IN terminal on the primary side are connected to the power supply terminal 8a, and the + OUT terminal on the secondary side is connected to the output terminal 8
b, the -IN terminal on the primary side is grounded to the ground terminal 8d, and the detection signal of the energization detection circuit 12 is connected to the detection signal input terminal 8e. Energization detection circuit 12
Connects the input side to the input terminal 8c and the output side to the detection signal input terminal 8e of the booster circuit 11.

Before describing the operation, the relationship between the excitation voltage applied to the field coil 3R and the generator output current will be described with reference to FIG. FIG. 2 shows the dependence characteristics of the output current and the excitation voltage with the output voltage of the generator 2 as a parameter. In FIG. 2, the relationship between the excitation voltage and the output current is shown as the output voltage 1
The case of 1 V and 13.5 V is shown, and the output current of the generator 2 increases as the field coil excitation voltage increases. Moreover, since the low output voltage 11V of the generator 2 increases the output current, the output current can be further increased by increasing the field coil excitation voltage.

Next, the operation of the first embodiment will be described.
When the vehicle is operated to operate the control circuit 10 and the energization of the large current load 9 from the battery 1 is started for a short time, the energization detection circuit 12 detects the energization and the boost control circuit 8 operates. At the same time, the booster circuit 11 operates to apply a high predetermined voltage obtained by adding the boosted voltage to the battery voltage to the field coil 3R to increase the output current of the generator 2. For example, when a shortage of current due to the large current load 9 occurs for a short time, the boost control circuit 8 boosts the power supply voltage to a predetermined voltage of 18 V and applies it to the field coil 3R to supply a large exciting current, thereby generating the generator 2. Increase the output current of.

When the control circuit 10 stops energizing the large-current load 9 for a short time, the boost control circuit 8 stops the boosting of the booster circuit 11 because there is no energization signal from the energization detection circuit 12. On the output side of the boost control circuit 8, the battery voltage is supplied from the power supply terminal 8a, and in the forward direction toward the output side, from the -OUT terminal of the boost circuit 11 to the + OUT terminal, through the output terminal 8b to the field coil 3R. The battery voltage is supplied, and the generated voltage is controlled by the voltage regulator 5.

The vehicle charging apparatus of the first embodiment described above applies the boosted predetermined voltage to the field coil 3R only when the large current load 9 is energized for a short time and the boost control circuit 8 operates. The output current of the generator 2 is increased, the amount of discharge of the battery 1 is suppressed, and the voltage is quickly recovered before the battery voltage drops. The set value of the predetermined voltage to be boosted is
It is determined from the amount of current of the large-current load 9 for a short period of time and the duration of its energization, with due consideration given to heat generation due to the temperature rise of the field coil 3R.

Next, a concrete embodiment of the booster circuit 11 will be described with reference to the drawings. FIG. 3 is a basic circuit diagram showing an embodiment of the booster circuit 11. In the configuration of the booster circuit 11 of FIG. 3A, the input side of the oscillation circuit 13 is connected to the detection signal input terminal 8e, and the output side is connected to the base side of the transistor TR1. + One end of the primary winding L1 of the transformer 14
The other end of the primary winding L1 is connected to the IN terminal and the oscillation circuit 13
Is connected to the collector side of the transistor TR1 for on-off control. The secondary winding L2 of the transformer 14 has one end connected to the anode side of the diode D1 connected to the + OUT terminal and the other end connected to the diode D2 connected to the + OUT terminal.
Connected to the anode side of, and connected to the -OUT terminal from the central tap.

The operation of the booster circuit 11 shown in FIG. 3A will be described. When the energization detection signal of the electric load is input to the detection signal input terminal 8e and the oscillation circuit 13 is operated and the transistor TR1 is driven, the transformer 14 turns the secondary winding L2.
Boosting voltage induced from the primary winding L1 to the boosting circuit 11
To obtain a predetermined voltage. The predetermined voltage is
It is output from the + OUT terminal through the diode D1 or the diode D2. If the oscillation circuit 13 is stopped without the electric load energization detection signal, the battery voltage is + OU through the parallel circuit formed by the secondary winding L21, the diode D1, and the secondary winding L22 and the diode D2 of the illustrated transformer 14.
Supply to the T terminal.

The structure of the booster circuit 11 shown in FIG. 3B is as follows.
As compared with the booster circuit 11 of FIG.
The secondary winding L2 has one end connected to the cathode side of the diode D1 connected to the -OUT terminal, the other end connected to the cathode side of the diode D2 connected to the -OUT terminal, and the central tap connected to the + OUT terminal. . Regarding the operation, although the direction of the current flowing through the secondary winding of the transformer 14 is different, it is omitted because it is the same as in FIG.

The configuration of the booster circuit 11 shown in FIG. 3C is as follows.
The primary winding L1 and the secondary winding L2 of the transformer 14 are coupled with opposite polarities. The input side of the oscillator circuit 13 is connected to the input terminal 8e.
And the output side of the oscillation circuit 13 is connected to the transistor TR1.
Connect to the base side of. Primary winding L1 of transformer 14
Has one end connected to the + IN terminal and the other end connected to the transistor T
The collector side of R1 and the anode side of the diode D1 are connected, and the cathode side of the diode D1 is connected to the + OUT terminal. The secondary winding L2 has one end connected to the −OUT terminal and the other end connected to the anode side of a diode D2 connected to the + OUT terminal.

The operation of the booster circuit 11 shown in FIG. 3C will be described. When the energization signal of the electric load is input to the detection signal input terminal 8e and the oscillation circuit 13 operates, the transistor TR1 is driven on-off. When the transistor TR1 is turned on, the primary winding L1 is energized to generate an induced voltage in the secondary winding L2, and the booster circuit 11 is passed through the diode D2.
+ OUT is a specified voltage that is the induced voltage added to the power supply voltage of
Supply to the terminal. When the transistor TR1 turns off,
The booster circuit 11 supplies the voltage generated by the energy stored in the primary winding L1 during the on time to the + OUT terminal through the diode D1 to add it to the power supply voltage.
If the oscillation circuit 13 is stopped without the electric load energization detection signal, the circuit for passing the battery voltage from the + IN terminal to the diode D1 through the primary winding L1 and the -OUT terminal to the diode D2 through the secondary winding L2. It is supplied to the + OUT terminal through a parallel circuit with a circuit that communicates. Then, the voltage is supplied to the field coil 3R and the voltage regulator 5 controls the output voltage of the generator 2 to the regulated voltage. If the winding ratios of the primary winding L1 and the secondary winding L2 of the transformer 14 are the same, the generated magnetic field is canceled and the resistance can be approximated to a pure resistance.

[0022] above, the booster circuit 11 described, since the output voltage V ₀ becomes the sum of the boost voltage of ΔV due to the battery voltage V _B and the transformer 14, the difference between the battery voltage V _B and a predetermined output voltage V ₀ As for the voltage ΔV, only the boosted voltage ΔV to which ΔV = V _O −V _B is added needs to be converted, so that the circuit loss due to the transistor TR1 or the like is reduced and the booster circuit 1
The efficiency of 1 can be improved. If the boosting does not work,
Field coil 3 through diodes D1 and D2 of the converter
Since the battery voltage can be supplied to R and the output side is in the forward direction, it is not necessary to provide a special circuit and wiring. Furthermore, in consideration of the thermal effect due to the heat generation of the field coil 3R, the applied voltage is set by the energization time only when energizing in response to the use of the large current load 9 for a short time, so that the generator 2 can be effectively used. It is also possible to increase the amount of power generation and suppress the amount of discharge of the battery 1. The booster circuit 11 may be integrally formed in the voltage regulator 5 of the generator 2. The energization detection circuit 12 can be substituted with an operation signal of the control circuit 10.

Next, a second embodiment will be described. Figure 4
FIG. 4 is an electric circuit configuration diagram of a vehicle charging device of a second embodiment. This embodiment has the same main configuration as that of the first embodiment, but one end of the field coil 3R is connected to the common cathode side of the rectifier 4, the power supply voltage of the battery 1 is supplied, and the other end is a boost control circuit. 8 is connected to the output terminal 8f. Then, the current flows from the common cathode side of the rectifier 4 to the field coil 3R, and further flows from the output terminal 8f to the voltage regulator 5 via the -OUT terminal of the booster circuit 11 and the + OUT terminal to the voltage regulator 5b. Connect so that it plugs in. The booster control circuit 8 includes a booster circuit 1 from the battery 1 through a power supply terminal 8a.
Power is supplied to the + IN terminal of 1 and grounded from the ground terminal 8d to the ground through the -IN terminal. The input terminal 8c is
It is connected to the current supply side of the high-current load 9 for a short time. Further, the booster circuit 11 has a configuration using the embodiment of FIG.

Next, the operation of the second embodiment will be described. When the energization detection circuit 12 detects the energization of the large current load 9 for a short time, the booster circuit 11 operates to generate a voltage of -ΔV between the output terminal 8f and the output terminal 8b of the booster control circuit 8. The power supply voltage V _B is applied to the field coil 3R, and the voltage −ΔV of the booster circuit 11 is further applied, which means that V _B + ΔV is applied to the field coil 3R.
The exciting current flowing through the field coil 3R is increased as in the first embodiment. When the large current load 9 is not energized for a short time, only the battery voltage V _B is applied to the field coil 3R, and the current passes through the field coil 3R and the voltage regulator 5 passes through the −OUT terminal and the + OUT terminal of the booster circuit 11. To control the output of the generator 2 to a constant voltage. As described above, in the second embodiment as well, it is only necessary to convert the voltage corresponding to the boosted voltage ΔV, so that the first embodiment
The efficiency can be improved as in the embodiment.

Further, a third embodiment will be described. Figure 5
[Fig. 6] is an electric circuit configuration diagram of a vehicle charging device of a third embodiment. In the first embodiment of FIG. 1 and the second embodiment of FIG. 4, there is a voltage drop in the booster circuit 11, and the voltage regulator 5 needs to adjust for the voltage drop. Therefore, as shown in FIG. In the third embodiment, a booster control circuit 8 has a built-in relay that operates in synchronization with an energization detection signal in the main configuration of FIG.
In this configuration, the normally closed contact 15 of the relay is inserted between the -OUT terminal and the + OUT terminal of 1. In the operation of the above configuration, the power supply voltage is normally closed contact 15 when the large current load 9 is not energized for a short time.
Is supplied to the field coil 3R via the
Is energized, the energization detection circuit 12 detects the energization and opens the normally closed contact 15 to operate the booster circuit 11 to supply a predetermined voltage to the field coil 3R.

In the third embodiment described above, the battery voltage is applied to the field coil 3R when the large-current load 9 is not energized for a short time.
Since the voltage drop due to the resistance component can be eliminated and the voltage can be directly applied, the voltage regulator 5 can be used without adjustment during normal operation, and the power generation output is not reduced. Similarly, FIG. 1 and FIG.
The same effect is obtained by adding the normally closed contact 15 between the -OUT terminal and the + OUT terminal of the booster circuit 11 shown in FIG.
If a high voltage may be applied to the transistor 5a of the voltage regulator 5, a large-capacity transistor may be changed or a parallel circuit of transistors that operates only when the large-current load 9 is energized for a short time is added. it can.

Next, a fourth embodiment will be described with reference to the drawings. FIG. 6 is an electric circuit configuration diagram of the boost control circuit 8. FIG. 7 shows an electric circuit configuration diagram of the vehicle charging device shown in the fourth embodiment. As shown in FIG. 6, the boost control circuit 8 is
Energization detection circuit 12 for detecting energization of the large current load 9 for a short time
And a discharge detection circuit 20 for detecting the discharge state of the battery 1.
And a booster circuit 1 for boosting a power supply voltage based on those detection signals and outputting a first predetermined voltage V1 and a second predetermined voltage V2.
It consists of 1. In FIG. 7, in addition to the main configuration of FIG. 1, the + power supply of the battery 1 is connected to the power supply terminal 8a, the − power supply is connected to the ground terminal 8d, and the output terminal 8b is connected to one side terminal of the field coil 3R. The input terminal 8c is connected to the current supply side of the large current load 9 for a short time, and the discharge detection input terminal 8g is connected.
Is connected to the collector side of the transistor 5a.

The main structure of the booster circuit 11 is a voltage conversion circuit 21 for outputting a boosted voltage, an output voltage detection circuit 22,
The voltage smoothing circuit 23. Further, the booster circuit 11 includes a drive circuit 26 that drives the transistor TR1 of the voltage conversion circuit 21, and a PWM that controls the duty of the drive circuit 26.
The control circuit 25 is provided, and the pulse generation circuit 24 inputs the logical sum of the detection signals from the detection signal input terminal 8e and the discharge detection input terminal 8h by the logic circuit 27 and supplies a pulse to the PWM control circuit 25. The voltage smoothing circuit 23 is
The output voltage of the voltage conversion circuit 21 is smoothed, and the smoothed voltage is supplied to the output voltage detection circuit 22. The output voltage detection circuit 22 detects the voltage and outputs a detection signal to the PWM control circuit 25. Then, the base side of the transistor TR2 of the output voltage detection circuit 22 and the detection signal input terminal 8e for inputting the energization detection signal are connected, the + IN terminal and the -OUT terminal are connected to the power supply terminal 8a, and the -IN terminal is connected to the ground terminal 8.
and the discharge detection input terminal 8h is connected to the discharge detection circuit 2
Connect to the output side of 0. Further, the detection signal input terminal 8e is connected to the output side of the energization detection circuit 12. The output voltage detection circuit 22 includes an amplifier 28, a reference voltage Vref, and resistors R1 to R3 in addition to the transistor TR2. The discharge detection circuit 20 may be one that detects discharge when the drive duty of the drive transistor 5a that controls the field coil 3R of the known technology is 100%, or one that detects battery discharge due to a decrease in battery voltage.

When the energizing signal to the large current load 9 is input for a short time, the step-up control circuit 8 having the above-mentioned configuration preferentially applies the step-up voltage to the field coil 3R as the first predetermined voltage V1 = 18.
If the electric power generation output is insufficient due to vehicle idling and the discharge detection circuit 20 operates, it is not possible to apply the high first predetermined voltage V1 for a long time. Therefore, the boosted voltage applied to the field coil 3R is the second predetermined voltage. The voltage V2 is set so that V1> V2.

Next, the operation of the fourth embodiment will be described.
When the boost control circuit 8 energizes the large-capacity short-time high-current load 9 that exceeds the power generation capacity, the energization detection circuit 12 detects the energization, and a detection signal is input to the booster circuit 11 to operate the booster circuit 11. . Then, when the energization detection circuit 12 detects the energization, the pulse generation circuit 24 is sent to the PWM control circuit 25.
The pulse supply is started from. At the same time, the transistor TR2 operates to change the output voltage of the voltage conversion circuit 21 to
The voltage is divided by the parallel resistance of the resistors R2 and R3 and R1, and the amplifier 2
8 and the arithmetic signal with the reference voltage Vref is input to the PWM control circuit 25.

As described above, when the large current load 9 is energized for a short time, the input voltage V ₋ of the amplifier 28 of the output voltage detection circuit 22 is V ₋ = V ₀ (R ₂ · R ₃ / (R ₁ · R ₂ + R ₂ · R ₃ + R ₁ · R ₃ )), and the input voltage V ₋ decreases, so PWM is given priority.
The output voltage V of the voltage conversion circuit 21 is controlled by the control circuit 25.
_O is controlled to a first predetermined voltage V1 higher than the battery voltage. The voltage conversion circuit 21 is omitted because the same operation is performed by the circuit configuration shown in FIG. Output voltage V
_{After 0} is smoothed by the smoothing circuit 23, the voltage detecting circuit 22
The detection signal detected by is input to the PWM control circuit 25 and fed back, and the first predetermined voltage V1 having a high voltage is applied to the field coil 3R to increase the output current of the generator 2 and greatly increase the power generation output. To do.

In the idling state of the vehicle, when the load is known about the amount of electricity generated by the generator, the discharge detection circuit 20 detects the discharge state and the booster circuit 11 starts operating. To the PWM control circuit 25, the pulse signal of the pulse generation circuit 24 and the amplifier 28 of the output voltage detection circuit 22 are connected to the resistors R1 and R2.
The output voltage V _O is divided by and and the operation signal of the reference voltage V ref is input. When the discharge detection circuit 20 operates, the amplifier 2
The potential of the input voltage V ₋ of 8 becomes V ₋ = V ₀ · (R ₂ / (R ₁ + R ₂ )), and the PWM control circuit 25 causes the voltage conversion circuit 21
Controlling the output voltage V _O of the second boosted voltage V2. When operating for a long time, the second boosted voltage V2 is set and V1>
Since it becomes V2, the problem of abnormal heat generation of the field coil 3R is solved. In each of the above-described embodiments, only the case where the booster control circuit boosts the power supply voltage to 18V is described, but the invention is not limited to this, and 14V is used.
The above is sufficient.

[0033]

As described above, according to the present invention, the operating condition of the on-vehicle electric load and the discharging condition of the battery are grasped, and the boosted voltage is added to the battery voltage and the predetermined voltage is applied to the field voltage. The structure applied to the coil simplifies the circuit, and by switching and using a predetermined voltage according to the load, the generated current is increased while the battery voltage does not drop, and abnormal heat generation of the field coil is suppressed. It has an excellent effect in practice.

Further, since the booster circuit obtains a predetermined voltage higher than the power supply voltage, the boosted voltage is added to the power supply voltage, so that the voltage conversion efficiency can be remarkably improved.
When the boosting operation is not performed, there is an effect that a vehicle charging device having a simple circuit configuration capable of supplying the battery voltage to the field coil through the output terminal can be realized and the circuit efficiency thereof can be improved.

[Brief description of drawings]

FIG. 1 is an electric circuit configuration diagram of a vehicle-mounted charging device according to a first embodiment.

FIG. 2 is a characteristic diagram of an output current and an exciting voltage with respect to an output voltage of a generator.

FIG. 3 is a basic circuit diagram showing an embodiment of a booster circuit.

FIG. 4 is an electric circuit configuration diagram of a second embodiment.

FIG. 5 is an electric circuit configuration diagram of a third embodiment.

FIG. 6 is an electric circuit configuration diagram of a boost control circuit according to a fourth embodiment.

FIG. 7 is an electric circuit configuration diagram of a vehicle-mounted charging device of a fourth embodiment.

[Explanation of symbols]

1 ... Battery, 2 ... Generator, 3R ... Field coil, 3S ...
Stator coil, 6 ... Ignition load, 7 ... General load, 9 ... Short-time large current load, 11 ... Booster circuit, 12 ... Energization detection circuit, 20 ... Discharge detection circuit.

Claims (4)

[Claims] 1. A vehicle charging device for charging a battery by a generated voltage generated in a stator coil of a generator to supply a large current load, a general load and an ignition load for a short time, and detecting energization of a large current load for a short time. A vehicle charging device comprising: an energization detection circuit; and a booster circuit that boosts a battery voltage to a predetermined voltage by detection by the energization detection circuit and applies the boosted voltage to the field coil. 2. The vehicle charging apparatus according to claim 1, wherein when the booster circuit operates, a predetermined voltage obtained by adding the boosted voltage to the battery voltage is supplied to the field coil. 3. The vehicle charging apparatus according to claim 1, wherein the battery voltage is supplied to the field coil through the booster circuit when the booster circuit does not perform boosting operation. 4. An energization detection circuit for detecting energization of a large current load for a short time, a discharge detection circuit for detecting battery discharge, and a booster circuit for boosting a DC voltage applied to the field coil, The booster circuit applies a first predetermined voltage to the field coil when the energization detection circuit detects energization to a large current load for a short time, and sets it lower than the first predetermined voltage when the discharge detection circuit detects it. The vehicle charging device according to claim 1, wherein a second predetermined voltage that applies is applied to the field coil.