JPH06261466A - Exciting current controller of generator for vehicle - Google Patents

Abstract

PURPOSE:To provide an exciting current controller of a generator for a vehicle which has a simple circuit configuration and needs no large capacitor but which can contol the stoppage of generation after an engine starts. CONSTITUTION:A switching means 11 allows exciting current of a generator 2 to flow intermittently. A counter (a generation start delaying means) 18 sends a generation stopping signal to the switching means 11 for a specified period of time after an engine starts up, making the generation voltage at a specified level, for example, the voltage at which a battery can be charged, or lower for a specified period of time after the engine starts up. A gradual exciting circuit (means for gradually increasing exciting current) 15 gradually increases a duty ratio of the switching means 11 by sending a duty control signal which changes gradually to the switching means 11 after a generation stoppage period is over. Since a counter 18 counts the number that the duty control signal changes from a first set value to a second set value, a capacitor or a large-scale counter is not necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exciting current controller for a vehicle generator, and more particularly to an exciting current controller for gradually increasing the exciting current after starting power generation.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 3-173324 discloses a switch means for intermittently controlling an exciting current of an engine-driven vehicle generator, and a power generation stop signal to be sent to the switch means for a predetermined period after the engine is started. A vehicle generator including a timer for prohibiting charging by setting the generated voltage to a chargeable voltage or less, and a gradually exciting circuit for gradually increasing the duty ratio of the switch means by sending a gradually changing duty control signal to the switch means. Proposed an exciting current control device.

As a result, the engine load is prevented from being applied to the engine during a period immediately after the engine is started and the torque generated by the engine is not sufficiently established, thereby stabilizing the engine speed. Further, the gradual increase of the generator load thereafter prevents the engine speed from dropping when the generator load suddenly increases.

[0004]

However, in the exciting current control device of the above-mentioned publication, it is necessary to add a timer as compared with the exciting current control device having only the gradually exciting circuit, but the delay time is several to several. Since it is as long as several tens of seconds, the analog type timer has a drawback that a large capacitor is required and the device becomes large. The use of such a large capacitor is not preferred because the excitation current controller is often built into the vehicle generator.

On the other hand, even a digital counter type timer requires a reference frequency oscillator and an extremely multistage frequency divider, which causes a problem that the circuit configuration becomes complicated and power consumption also increases. The present invention has been made in view of the above problems, and provides an exciting current control device for a vehicle generator that has a simple circuit configuration and can omit a large capacitor even though power generation stop control can be performed immediately after engine start. Its purpose is to provide.

[0006]

According to the present invention, there is provided an exciting current control device for a vehicular generator, a switch means for intermittently controlling an exciting current of an engine driven vehicular generator, and a power generation stop signal sent to the switch means. By doing so, the power generation start delay means for keeping the power generation voltage of the generator below a predetermined value for a predetermined period after the engine is started, and the duty ratio of the switch means by sending a gradually changing duty control signal to the switch means. In the exciting current control device for a vehicle generator, the exciting current control device includes a gradually increasing exciting current increasing control means, wherein the duty control signal of the power generation start delay means changes from a first set value to a second set value. It is characterized by including a counter that counts the number of times the power generation is stopped and sends the power generation stop signal until the count value reaches a predetermined value. .

[0007]

The switch means intermittently controls the exciting current of the engine-driven vehicle generator. The power generation start delay means sends a power generation stop signal to the switch means only for a predetermined period (power generation stop period) after starting the engine, and keeps the power generation voltage of the generator below a predetermined value for a predetermined period after starting the engine, for example, a battery chargeable voltage. Below.

The exciting current gradual increase control means gradually increases the duty ratio of the switch means by sending a gradually increasing duty control signal to the switch means after the end of the power generation stop period. In particular, the power generation start delay means includes a counter that counts the number of times the duty control signal changes from the first set value to the second set value, and this counter outputs the power generation stop signal until the count value reaches a predetermined value. Send out.

[0009]

As described above, the excitation current control device for a vehicle generator of the present invention counts the number of gradual increase cycles of the duty control signal output from the excitation current gradual increase control means, and starts the engine. After that, a circuit configuration is adopted in which the generated voltage of the generator is set to a predetermined value or less, for example, a battery chargeable voltage or less, until the count value (cumulative value of the number of gradual increase cycles) reaches a predetermined number.

Since a single gradual increase period of the duty control signal output from the exciting current gradual increase control means, that is, a gradual increase cycle, is a sufficiently long period such as several seconds,
The power generation start delay means can be configured by a small bit (for example, 1 bit) counter (counting means), and a large capacitor is required as compared with the case where the power generation start delay means is configured by a conventional analog timer. Therefore, the size of the circuit device is not increased.

Further, as compared with the case where the power generation start delay means is composed of a digital counter type timer, the reference frequency oscillator and the extremely multistage frequency divider can be omitted, so that the circuit structure can be simplified and the power consumption can be reduced. You can

[0012]

(Embodiment 1) An embodiment of an exciting current controller for a vehicle generator according to the present invention will be described with reference to FIG. An exciting current control device (hereinafter referred to as a regulator) 1 is a device for controlling an exciting current of a three-phase AC generator 2 with a built-in three-phase full-wave rectifier 22 driven by a vehicle engine, and is a key switch. Power is supplied from the battery 3 through 4, and the lighting control of the charge warning lamp 5 is also performed. The generated voltage rectified by the three-phase full-wave rectifier 22 of the three-phase AC generator 2 is supplied to the battery 3. Both low-order ends of the three-phase full-wave rectifier 22 and the battery 3 are grounded.

The high-level terminal potential of the battery 3 (hereinafter referred to as battery voltage) is divided by a voltage dividing circuit composed of resistors r1 and 2 and compared with a reference voltage V3 by a comparator 16, which compares the battery voltage with the reference voltage. When it is smaller than V3, a high level is output. Comparator 16
Is a comparison output S to the base of the switch 11 formed of a transistor through the AND circuits 14 and 191 and the OR circuit 13.
When the other input signals of the AND circuits 14 and 191 are at the high level and the other input signal of the OR circuit is at the low level, the switch 11 is intermittently controlled by the comparator 16 and the battery voltage is set to the reference voltage. Make it equal to V3.

The one-phase AC power generation voltage of the three-phase AC generator 2 is divided by a voltage dividing circuit composed of resistors r3 and r4 and input to the comparator 12, which then divides the AC power generation voltage S2. Is lower than the reference voltage V2, a high level is output. Reference numeral 197 is a capacitor that bypasses the high frequency component of the AC power generation voltage S2. The comparison output S3 of the comparator 12 is input to the OR circuit 13, and as a result, the comparator 12 outputs the switch 1 through the OR circuit 13 when the AC power generation voltage S2 is smaller than the reference voltage V2.
1 is conducted to generate electricity.

On the other hand, the resistor r5 and the capacitor 198 connected in series constitute a capacitor charging circuit, and the connection contact between the resistor r5 and the capacitor 198 is connected to the output terminal of the comparator 12 through the diode D2 which is the discharging means of this capacitor. It is connected. The voltage of the connection contact is divided by a voltage dividing circuit composed of resistors r6 and r7, and then input to a switch 17 composed of a grounded-emitter transistor through knot circuits 193 and 104. The switch 17 controls the lighting of the charge warning lamp 5.

As a result, the comparator 12 outputs a low level to discharge the capacitor 198 through the diode D2 when the one-phase voltage of the generator 2 averaged by the capacitor 197 exceeds a predetermined value, and the capacitor 198 is discharged. The low level output of 198 is a knot circuit 193, 19
The switch 17 is turned off through 4 and the charge warning lamp 5 is turned off.

The output of the knot circuit 193 is capacitively coupled to the input terminal of the OR circuit 192 and the R terminal of the counter (power generation start delay means in the present invention) 18 through the capacitor 195. The capacitor 195 is used in the OR circuit 1 when the output of the knot circuit 193 becomes high level.
92 and the R terminal of the counter 18 for inputting a pseudo pulse voltage, the capacitor 195 and the R terminal of the counter 18 are connected through a base current limiting resistor (not shown), and similarly the capacitor 195 and the OR terminal are connected. Circuit 19
2 is preferably connected through a base current limiting resistor (not shown). Further, in this embodiment, the counter 1
The electrode of the capacitor 195 connected to the R terminal of 8 is charged through the emitter / base junction of the transistor described later connected to the R terminal of the counter 18,
It is also possible to ground the R terminal of 8 through a charging resistor having a predetermined resistance value.

The output of the OR circuit 192 is input to the R terminal of the gradual excitation circuit (excitation current gradual increase control means in the present invention) 15, and the F terminal output of the gradual excitation circuit 15 is connected to the S terminal of the counter 18 and the AND terminal. And input to the circuit 196. The output of the AND circuit 14 is input to the D terminal of the gradual excitation circuit 15, and the output of the Q terminal of the gradual excitation circuit 15 (duty control signal in the present invention) is input to the AND circuit 14.

The output of the Q terminal of the counter 18 (the power generation stop signal in the present invention) is input to the AND circuit 191 and also to the AND circuit 196 through the knot circuit 199. The output of the AND circuit 196 is input to the R terminal of the gradual excitation circuit 15 via the OR circuit 192. As shown in FIG. 2, reference numeral 10 is a power supply circuit that supplies reference voltages V1 to V4 to the respective parts of the voltage regulator 1 by turning on the ignition switch 4.

The gradual excitation circuit 1 will be described below with reference to FIGS. 3 and 4.
5 and the counter 18 will be described in more detail. The gradual excitation circuit 15 outputs the output of the AND circuit 14 to the knot circuit 151.
An inverter including a grounded-emitter transistor 152 that operates by the signal S4 formed by inverting and a collector resistance (load resistance) r8 thereof is provided, and this inverter charges or discharges the high-order end of the capacitor 153 through the resistance r9. The lower end of the capacitor 153 is grounded. The high-end voltage S5 of the capacitor 153 is applied to one end of the resistor 156 through the voltage follower 155, the other end of the resistor 156 is supplied with the current i from the constant current source 157, and the resistor 156 and the constant current source 157 are connected to the level shift circuit. Are configured. The voltage at the other end of the resistor 156 (hereinafter,
The added voltage) S6 is the comparator 158, 159.
Of the sawtooth wave generation circuit (not shown) is applied to the-input terminal of the comparator 158, and the reference voltage V3 is applied to the-input terminal of the comparator 159. Further, the capacitor 153 is reset by the reset transistor 154.

The high-order end of the capacitor 153 is discharged through r9 at the conduction rate of the transistor 152 corresponding to the duty ratio (= pulse width / pulse period) of the pulse signal input to the D terminal, and the capacitor 153 is turned off during the off period of the transistor 152. The high end of is charged through r8 and r9. As a result, the high-order voltage S5 of the capacitor 153 (hereinafter referred to as the storage voltage) coincides with the duty ratio of the pulse signal predetermined at the D terminal with a slight delay. That is,
The capacitor 153 discharges based on the time constant of the resistor r9 and the capacitor 153 when the transistor 152 is turned on, and as a result, the analog storage voltage S of the capacitor 153 is discharged.
Reference numeral 5 follows the duty ratio of the pulse signal input to the D terminal with a predetermined time delay.

An added voltage S level-shifted by a level shift voltage ΔV equal to the resistance value of the resistor 156 × the current value i of the constant current source 157 from the high-end voltage S5 of the capacitor 153.
6 is compared with the sawtooth voltage by the comparator 158,
As a result, the comparator 158 outputs the pulse signal S7 having a duty ratio obtained by adding the duty ratio of the D terminal by the duty ratio corresponding to the level shift voltage ΔV from the Q terminal. When a high level signal is input to the R terminal, the storage voltage of the capacitor 153 is instantly reset, the added voltage S6 becomes the minimum voltage, and the Q output becomes the pulse signal with the minimum duty ratio.

The comparator 159 brings the F terminal output to a high level when the added voltage S6 exceeds the reference voltage V3. The counter 18 resets the Q output to a low level by a reset signal input to the R terminal through the capacitor 195 when the comparator 12 detects power generation, and when the F terminal output of the gradual excitation circuit 15 becomes a high level. This is a hold circuit of the RS flip-flop circuit type that sets the Q output to a high level by the set signal input to the S terminal.

The operation of this device will be described below. When the ignition switch 4 is turned on and the reference voltage V2 is supplied to the comparator (hereinafter, also referred to as a power generation detection circuit) 12, the generator 2 is not generating power before the engine is started, so the output of the comparator 12 is high. And the switch 11 becomes normally closed through the OR circuit 13,
An exciting current flows through the field coil 21, and as the generator 2 rotates, power can be generated.

In the star cranking state, the generator 2
Since the number of revolutions is low, the generated voltage of the generator 2 is low, and the reference voltage V2 is determined so that the output of the power generation detection circuit 12 remains at the high level. When the engine starts,
The power generation voltage increases as the rotation speed increases, the output of the power generation detection circuit 12 becomes low level, and the power generation command from the power generation detection circuit 12 to the OR circuit 13 is also canceled. And
The capacitor 198 is discharged through the diode D2,
The output of the knot circuit 193 is high level, and the knot circuit 19
The output of 4 becomes low level, the transistor 17 is turned off, and the charge warning lamp 5 is turned off.

Further, since the output of the knot circuit 193 is inverted to the high level, the R of the 1-bit counter 18 is changed.
A pseudo pulse voltage is applied to the terminal through the capacitor 195, the counter 18 is reset, and its Q output becomes low level. Further, this Q output is input to the AND circuit 191 to set the output of the AND circuit 191 to the low level, whereby the switch 11 is turned off and the excitation current is cut off.

D1 is a flywheel diode, and when the current of the field coil 21 decreases, the power generation voltage decreases, the output of the power generation detection circuit 12 becomes high level, and the switch 11 becomes conductive through the OR circuit 13 to generate the power generation voltage S2. The exciting current is controlled so that is equal to V2. By setting V2 so that the generated voltage S2 at this time is lower than the battery voltage, the generator 2
The output current from the battery to the battery 3 can be stopped.

On the other hand, when the engine is at a normal idling speed or higher, the generated voltage S2 can be obtained even if the exciting current is small, so that the conduction period of the switch 11 is short. Therefore, the output of the power generation detection circuit 12 is a signal having a short high level, a long low level, and a small duty ratio, and the output of the knot circuit 193 after being smoothed by the capacitor 198 remains at the high level. Therefore, the capacitor 195
Through this, the reset pulse signal is input to the R terminal of the hold circuit 18 only once when the generator 2 starts power generation and the charge warning lamp 5 is turned off.

Along with the above-mentioned reset signal to the counter 18, the reset signal is also input to the R terminal of the gradually exciting circuit 15 through the OR circuit 192, whereby the capacitor 1
53 is discharged and the stored value is reset to zero. As a result, the Q terminal output of the gradual excitation circuit 15 has the level shift voltage ΔV.
The pulse voltage has a duty (ratio + α) corresponding to
Here, since the power generation is suppressed so that the power generation voltage of the generator 2 becomes a value lower than the battery voltage, the output of the comparator 16 is at the high level, so the output of the AND circuit 14 is the Q terminal output. And the Q terminal output (here, the pulse voltage with a duty ratio of + α) is input to the D terminal of the gradual excitation circuit 15 through the AND circuit 14, and the potential S5 of the capacitor 153, that is, the analog storage value has the above-mentioned time delay. Hold and approach the value ΔV corresponding to + α. The increase of the charging voltage (stored value) S5 of the capacitor 153 is further level-shifted to increase the output of the Q terminal, the stored value gradually increases, and the duty ratio of the pulse signal as the Q terminal output increases. Go.

When the stored value S5 of the capacitor 153 reaches a predetermined value, S6 exceeds V3 and a high level signal is output from the F terminal. As described above, when the engine is started, the power generation voltage increases as the rotation speed increases, the output of the power generation detection circuit 12 becomes low level, and the knot circuit 19
3 becomes high level, the counter 18 is reset through the capacitor 195, and then the gradual excitation circuit 15
Since the F terminal output of was at low level, the counter 18
Q output remains low.

After that, when the F terminal of the gradual excitation circuit 15 becomes high level, the output of the AND circuit 196 becomes high level, and the high level output of the AND circuit 196 becomes OR circuit 19.
2, the gradual excitation circuit 15 is reset, the potential (stored value) of the capacitor 153 of the gradual excitation circuit 15 is reset, and the capacitor 153 of the gradual excitation circuit 15 starts charge accumulation again.
The Q terminal output again outputs a pulse signal whose duty ratio gradually increases. The stored value of the gradual excitation circuit 15 is 0.
Since it is reset to, the high level signal output from the F terminal becomes a pulse signal. Then, this pulse signal is also input to the S terminal of the counter 18, and the counter 18
Q terminal output becomes high level.

In this way, the output of the F terminal from the gradual excitation circuit 15 becomes high level, the reset signal is input to the R terminal of the gradual excitation circuit 15, and the counter 18 is set. When the high level signal is output, the low level signal is input to the AND circuit 196, so that the reset signal is prohibited from being input to the R terminal of the gradual excitation circuit 15 again. Furthermore, the Q of the counter 18
The high-level signal from the terminal is input to the AND circuit 191, which causes the output of the AND circuit 14 to switch.
Applied to. That is, since the battery voltage is low and the comparator 16 outputs a high level as described above, the Q terminal output of the gradual excitation circuit 15, that is, a pulse signal whose duty ratio gradually increases is applied to the switch 11,
The intermittent excitation current having a duty ratio equal to this duty ratio is supplied, and the output current of the generator 2 increases. As a result, when the battery 3 is charged, the comparator 16 becomes low level, the outputs of the AND circuits 14 and 191 become low level, the output current of the generator 2 decreases, and the output voltage of the generator 2 decreases. The control is performed so that the predetermined value is obtained.

By the above operation, after the engine starts and after the power generation of the generator 2 is started, the output current of the generator 2 is stopped for a time necessary for the stored value of the gradual excitation circuit 15 to increase to a predetermined value. After that, it is possible to increase the duty ratio of the switching means 11 at the duty ratio increasing speed determined by the gradual excitation circuit 15 to gradually increase the output current.

As a result, the drive torque of the generator can be reduced with respect to the engine immediately after starting, and the drive torque can be gradually increased after the start of output. Further, since the timer is not required for setting the current output stop period of the generator 2 described above, and only the simple counter 15 is provided, the circuit configuration is remarkably simple.

Since the output of the AND circuit 14 follows the comparison output of the comparator 16 after the end of the gradual excitation period, that is, the duty ratio gradual increase period, the comparison output of the comparator 16 is connected to the D terminal of the gradual excitation circuit 15. The duty ratio is input, and as a result, the Q output of the gradual excitation circuit 15 becomes a duty ratio obtained by adding a predetermined duty ratio to this duty ratio, and the comparison output of the AND circuit 14 (the duty ratio of the switch 11) is obtained by the gradual excitation circuit 15. The logical product of the duty ratio of the Q output and the duty ratio of the comparator 16 is obtained. If the duty ratio of the switch 11 is lower than the duty ratio of the comparator 16 due to the influence of the Q output of the gradual excitation circuit 15, the comparator voltage is lowered and the comparator is lowered. Since the duty ratio of 16 increases, there is no problem. (Embodiment 2) Another embodiment of the exciting current control device of the present invention will be described with reference to FIG.

The main feature of this circuit is that the gradual excitation circuit 15 of the first embodiment is formed of a digital circuit, and its operation will be described below. Ignition switch 4
Is turned on, the RS flip-flops (1 bit counter) 18, 201 are designed to be in a reset state (Q output is low level, anti-Q output is high level).

After the engine is started, the one-phase voltage of the generator 2 is P
The voltage is input to the comparator 121 from the terminal through the resistor r11, and the comparator 121 converts the one-phase voltage to the reference voltage V2.
The pulse is shaped by comparison with and input to the frequency comparator 122. The frequency comparator 122 sends a high level signal to the knot circuit 208 through the OR circuit 203 when the frequency f of the input pulse shaping one-phase voltage is higher than the predetermined frequency fo, and the knot circuit 208 inverts it and switches it. 17, the charge warning lamp 5 is turned off.

Further, the OR circuit 203 includes a capacitor 195.
Is capacitively coupled to the set terminals of the RS flip-flops 18 and 201 and the input terminal of the OR circuit 192 through
When the OR circuit 203 becomes high level (the generated voltage rises and the engine rotation is established), the RS flip-flops 18, 201 are set (Q output becomes high level, anti-Q output becomes low level).

Also in this embodiment, it is preferable to install a base current limiting resistor individually between the capacitor 195 and each set terminal of the RS flip-flops 18, 201 and the input terminal of the OR circuit 192, and the capacitor 19 is also provided.
It is also preferable to ground the electrode on the RS flip-flop side of No. 5 through a resistor when the input resistance value of the set terminals of the RS flip-flops 18 and 201 is high.

In this way, the RS flip-flop 1
Since the anti-Q output of 8 becomes low level, the AND circuit 19
1 cuts off the switch 11 to stop the power generation (the power generation stop period is started). Also, the RS flip-flop 20
Since the Q output of 1 becomes the high level, even if the output of the frequency comparator 122 becomes the low level due to the stop of the power generation, the turning off of the charge warning lamp 5 is continued.

The gradual excitation circuit 15 receives the signal S1 from the comparator 16 which outputs a high level when the divided voltage of the battery voltage is lower than the reference voltage V3, and when the signal S1 is a high level, counts up in a predetermined cycle, An up-down counter 151 that counts down in a predetermined cycle when the signal S1 is at a low level, and a fixed-cycle pulse signal having a duty ratio corresponding to the count value (stored value) of the up-down counter 151 is output to the switch 11 through the AND circuit 191. And a PWM (pulse width modulation) circuit 152 that operates.

The count value of the up / down counter 151 is reset when the frequency comparator 122 outputs a pulse to the reset terminal of the up / down counter 151 through the OR circuit 203, the capacitor 195, and the OR circuit 192. At this time, since the F terminal of the gradual excitation circuit 15 is still at the low level, the AND circuit 196 does not output the reset signal to the gradual excitation circuit 15. At this time, as described above, the anti-Q output of the RS flip-flop 18 is at a low level, and power generation is stopped. Therefore, the S terminal voltage which is the terminal voltage of the battery 3 is low, the output S1 of the comparator 16 becomes high level, and the stored value (count value) of the up / down counter 151 gradually increases at the count speed determined inside the counter. go. When the stored value increases to a predetermined value, a high level is output from the F terminal of the counter 151 to the reset terminal of the RS flip-flop 18 and the AND circuits 196 and 204, and RS
The anti-Q output of the flip-flop 18 is reset to the high level, and the RS flip-flop 18 outputs the AND circuit 1
A high level signal is sent to 91.

As described above, the up / down counter 15
Immediately after the high level is output from the F terminal of 1, RS is still
Before the flip-flop 18 is reset, RS
Since the low level anti-Q output of the flip-flop 18 is inverted by the knot circuit 199 and input to the AND circuit 196, the AND circuit 196 outputs a high level signal to the reset terminal of the up / down counter 151 through the OR circuit 192. The up / down counter 151 is reset, and its F terminal becomes low level.

In addition, the up / down counter 15 described above
When a high level is output from the F terminal of 1 and the RS flip-flop 18 is reset, and its anti-Q output becomes high level, the knot circuit 199 outputs a low level to the AND circuit 196, and thereafter the up / down counter 15
1 is not reset. At the time when the up-down counter 151 is reset, the battery voltage is still low, so the output S1 of the comparator 16 becomes high level,
The up / down counter 151 restarts counting up again, and the PWM circuit 152 outputs a pulse with a gradually increasing duty ratio to the AND circuit 191. AND circuit 191
Receives the high-level anti-Q output from the RS flip-flop 18 as described above, and the switch 11 is intermittently switched by the gradual excitation circuit 15 in the mode in which the duty ratio gradually increases.

Thereafter, the comparison output S1 of the comparator 16
The up / down counter 151 counts up or down in accordance with the above, and the PWM circuit 152 outputs the pulse signal of the duty ratio corresponding to the count value to the switch 1
1 and the normal excitation current control is performed. next,
The operation of the RS flip-flop 201 will be described.

As described above, the RS flip-flop 201 is set by the high level output of the frequency comparator 122, continuously outputs the high level to the knot circuit 208, and keeps the charge warning lamp 5 off.
This is because the frequency comparator 122 sets the RS flip-flop 18 through the capacitor 195, and the low-level anti-Q output cuts off the switch 11 during the power generation stop period, the frequency comparator 122 outputs the low level and the charge signal is output. This is to prevent the awning lamp 5 from being erroneously turned on.

The resetting of the RS flip-flop 201 is carried out as follows. First, after the start of power generation, if the divided voltage of the battery voltage (rectified voltage output from the generator 2) exceeds the reference voltage V3, the signal S1 is sent to the knot circuit 207.
Then, it is inverted and input to the reset terminal of the RS flip-flop 201 through the OR circuit 202, thereby resetting the RS flip-flop 201. As a result, if the output of the frequency comparator 122 becomes low level after that due to the disconnection of the field coil 21, for example, the switch 17
Is turned on, and the charge warning lamp 5 can be turned on.

When the up / down counter 151 counts a predetermined number of digits and the output of the F terminal thereof becomes high level, the RS flip-flop 18 is reset and the anti-Q output thereof becomes high level, the AND circuit 2 operates.
04 becomes high level and RS is transmitted through the OR circuit 202.
The flip-flop 201 is reset and the charge warning lamp 5 can be turned on. That is, lighting is possible after the start of the gradual excitation period.

However, at the early stage of the gradual excitation period immediately after the RS flip-flop 18 inverts from the low level to the high level, that is, immediately after the switching from the power generation stop period to the gradual excitation period, the duty ratio of the switch 11 is still small and the frequency It is easy for the comparator 122 to output a low level,
Since the charge warning lamp 5 is likely to erroneously light up,
The low-pass filter including the resistors r12 and r13 and the capacitor 205 delays the high-level output of the AND circuit 204 to prevent lighting at an early stage of the gradual excitation period immediately after the switching point.

In each of the embodiments described above, the counter (R
Although the S flip-flop) 18 is 1 bit, it is a counter of a plurality of digits for counting the output pulse from the F terminal. Until the counter output reaches a predetermined number, the F terminal output (high Depending on the level, the counting of the up / down counter 151 may be restarted or the capacitor 153 may be reset.

In this way, it is possible to set a power generation stop period that is a multiple of the interval at which the high level is output from the F terminal output of the gradual excitation circuit 15, by simply adding a counter.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment.

FIG. 2 is a circuit diagram of the power supply circuit shown in FIG.

3 is a circuit diagram of the gradual excitation circuit of FIG.

FIG. 4 is a circuit diagram of the counter shown in FIG.

FIG. 5 is a circuit diagram showing another embodiment.

[Explanation of symbols]

 2 generator (vehicle generator) 11 switch (switch means) 15 gradual excitation circuit (excitation current gradual increase control means) 18 counter (power generation start delay means).

Claims (1)

[Claims] 1. A switch means for intermittently controlling an exciting current of an engine-driven vehicular generator, and a power generation stop signal sent to the switch means so that a generated voltage of the generator is predetermined only for a predetermined period after engine start. A generator for a vehicle, which includes a power generation start delay means for setting a value equal to or less than a value, and an exciting current gradual increase control means for gradually increasing the duty ratio of the switch means by sending a gradually changing duty control signal to the switch means. In the exciting current control device, the power generation start delay means counts the number of times the duty control signal changes from the first set value to the second set value, and stops the power generation until the count value reaches a predetermined value. An exciting current control device for a vehicle generator, comprising: a counter that sends out a signal.