JP3089655B2 - Power supply for vehicles - Google Patents

Description

The present invention relates to a power supply device for a vehicle, and more particularly to a power supply device for supplying power to a plurality of load groups having different rated voltages.

2. Description of the Related Art As a power supply device for supplying power to a plurality of load groups having different rated voltages, a power supply device disclosed in JP-A-1-248933 is known. FIGS. 7A and 7B show the configuration of such an apparatus.

In FIG. 7, reference numeral 51 denotes a generator having a rated voltage of 24 [V], and the generator 51 has a voltage adjusting mechanism. A battery 56, for example, a motor 57 such as a fan motor, and another load 58 are connected to an output terminal of the generator 51. In addition,
The rated voltages of the battery 56, the motor 57, and the load 58 are 24 [V].

54 is a battery and 55 is a load group, which are connected in parallel with each other. The rated voltages of the battery 54 and the load group 55 are both 12 [V].

61 and 62 are capacitors having the same capacitance. One electrode of the capacitor 61 is connected to the switch S1, and the other electrode is connected to the switch S2. The two electrodes of the capacitor 62 are connected to the switch S3 and the ground, respectively.

53 is an oscillator, and the oscillator 53 outputs a voltage signal 繰 り 返 す that alternately repeats “H” and “L” at a constant cycle. Voltage signal Ψ is input to switches S1, S2, and S3, and periodically repeats the connection state shown in FIG. 7A and the connection state shown in FIG. 7B.

 Next, the operation will be described.

The voltage signal の of the oscillator 53 becomes “H”, and the switches S1, S2,
It is assumed that the connection state of S3 is as shown in FIG. At this time, the capacitors 61 and 62 are connected in series by the switches S2 and S3. Then, one electrode of the capacitor 61 is connected to the output terminal of the generator 51 by the switch S1.

In the above state, the battery 51 is
Motor 57, load 58, and capacitor connected in series
24 [V] power is supplied to 61 and 62. Therefore, battery 56 is charged, motor 57 and load 58 are driven, and electric charges are stored in capacitors 61 and 62. After a lapse of a predetermined time, the electric charges stored in the capacitors 61 and 62 become saturated, and the voltage between the electrodes of the capacitors 61 and 62 becomes 12 [V].

 The load 55 is driven by the battery 54.

Next, when the voltage signal Ψ output from the oscillator 53 becomes “L”, the connection state of the switches S1, S2, S3 becomes as shown in FIG. 7 (b). At this time, the capacitors 61 and 62 are connected in parallel. One electrode of each of the capacitors 61 and 62 is connected to the battery 54 and the load group 55, and the other electrode is connected to the ground.

In the above state, the battery 56, the motor 57, the load 58
In the same manner as in the state of FIG.
24 [V] power is supplied. On the other hand, capacitors 61 and 62
Discharges the stored charge, charges the battery 54, and serves as a power source for the load 55.

Thereafter, the voltage signal Ψ from the oscillator 53 periodically switches between “H” and “L”. Therefore, the state of FIG. 7A and the state of FIG. 7B are repeated.

As described above, one generator supplies power to each of the load groups having two different rated voltages.

<Problems to be solved by the invention> However, according to the above-described device, the rated voltage is 24 [V].
A high-voltage battery such as the battery 56 has problems that it is large, heavy, expensive, and has a short life.

On the other hand, when the battery 57 is not provided for the motor 57 and the load 58, and when the load changes abruptly such as when the motor 57 is started, there are the following problems. That is, the voltage generated by the generator 51 decreases with the change in the load. Even if the generator 51 has a voltage adjusting mechanism,
Since the current value of the field coil does not increase rapidly, the voltage drop of the generator 51 does not recover suddenly. As a result, the response at the time of starting the motor 57 may be deteriorated.

The present invention has been made to solve the above problems, and has as its object to provide a vehicle power supply device that can cope with a sudden change in load without using a high-voltage battery.

<Means for Solving the Problems> The present invention provides a generator, a first load, a second load,
A battery, a first capacitor group, a second capacitor group, a voltage drop detecting unit, an oscillating unit, a connecting unit,
Wherein the first load is one or more loads connected to an output terminal of the generator, and the second load is one or more loads connected in parallel with the battery. The first capacitor group and the second capacitor group are both composed of the same number of capacitors,
The voltage drop detection means outputs a drop signal when the voltage of the output terminal of the generator drops below a predetermined voltage, and the oscillation means outputs a replacement signal every predetermined period. The connection means connects the capacitors of the first capacitor group in series when the drop signal is not output and the switching signal is output, and connects the capacitors to an output terminal of the generator; , And the respective capacitors of the second capacitor group are connected in parallel and connected to the battery. When the falling signal is not output and the switching signal is not output,
Connecting each capacitor of the first capacitor group in parallel and connecting it to the battery, and connecting the capacitor of the second capacitor group in series and connecting it to the output terminal of the generator, When the falling signal is output and the switching signal is output, the capacitors of the first capacitor group and the second capacitor group are connected in parallel, and it is connected to the battery; When the falling signal is output and the switching signal is not output, all or a predetermined number of the capacitors of the first capacitor group and the second capacitor group are connected in series and connected to the generator. A power supply device for a vehicle, which is connected to an output terminal of the vehicle.

<Operation> According to the above configuration, when the falling signal is not output, that is, when the voltage of the transmitter does not drop, 1
After the capacitors of the two capacitor groups are connected in series and charged by the generator, they are connected in parallel to charge the battery, and at the same time, repeatedly operate as the power source of the second load group. When one of the capacitor groups is charged, the other capacitor group charges the battery, and at the same time serves as a power source for the second load group.

Therefore, the battery and the second load group are always supplied with power by one of the capacitor groups.

Also, when the falling signal is output, that is, when the voltage of the generator is falling, the capacitors of both capacitor groups are connected in parallel at the same time, and are connected in series after being charged by the battery. The operation of supplying power to the first load group is repeated. By this operation,
The generator voltage drop is quickly restored.

<Example> A first example will be described with reference to Figs. 1 to 4.

 First, FIG. 1 shows the configuration of the present embodiment.

1 is a generator provided with a voltage adjusting mechanism, and the output voltage is
36 [V].

Reference numeral 7 denotes a motor such as a fan motor, and reference numeral 8 denotes another load. The rated voltage is 36 [V]. The motor 7 and the load 8 are connected to the output terminal of the generator 1 via the wiring 31, and are supplied with power by the generator 1. Note that a first load group is configured by the motor 7 and the load 8.

Reference numeral 4 denotes a battery having an output voltage of 12 [V], and reference numeral 5 denotes a load group having a rated voltage of 12 [V] as a second load group, which are connected in parallel with each other.

11, 12, 13, 21, 22, and 23 are capacitors having the same capacitance. And, by the capacitors 11, 12, and 13,
A first capacitor group is formed, and a second capacitor group is formed by 21, 22, and 23.
Are formed.

SA1, SA2, SA3, SA4, SA5, SB1, SB2, SB3, SB4, SB5, SC1, SC2,
SC3 is a switch, which is switched by the voltage signal φ or.

Reference numeral 9 denotes an AND circuit. The AND circuit 9 outputs “H” when the voltage signal “H” is input to both of the two input terminals,
When "L" is input to at least one input terminal, "L" is output. The switches SA1, SA2, SA3, SA4, SA5,
The connection means is constituted by SB1, SB2, SB3, SB4, SB5, SC1, SC2, SC3 and the AND circuit 9.

Reference numeral 3 denotes an oscillation circuit, and the oscillation circuit 3 outputs a voltage signal φ and a switching signal. The voltage signal φ and the voltage signal φ have opposite phases, and switch between “H” and “L” at a fixed period (several tens [μsec] to several [msec]). Voltage signals φ and φ are switches SA1, SA2, SA3, SA4, SA
5, SB1, SB2, SB3, SB4, SB5, and the AND circuit 9.

Reference numeral 2 denotes a voltage drop detection circuit as voltage drop detection means, and the voltage drop detection circuit 2 outputs a voltage signal Φ. The voltage signal Φ is normally an “L” level signal, and becomes an “H” level signal when the voltage at the output terminal of the generator 1 drops. The voltage signal Φ is input to the switches SC1 and SC3 and the AND circuit 9.

FIG. 2 shows a detailed configuration of the voltage drop detection circuit 2.

Reference numeral 201 denotes an input terminal of the voltage drop detection circuit 2, and the generator 1 is connected to the input terminal 201. Input terminal 201
Is connected to the anode of the diode 210 for rectification,
The cathode of the diode 210 is connected to the output terminal 202. The output terminal 202 is connected to the motor 7 and the load 8.

The anode of the diode 211 is connected to the input terminal 201, and the cathode of the diode 211 is connected to one end of the resistor 212. The other end of the resistor 212 is connected to one electrode of the capacitor 213 and the cathode of the Zener diode 214, and the other electrode of the capacitor 213 and the anode of the Zener diode 214 are connected.

Note that the resistor 212 and the Zener diode 214 form a constant voltage circuit. Then, the reference voltage determined by the constant voltage circuit is held for a certain period of time by the diode 211 and the capacitor 213 even when the voltage of the input terminal 201 decreases.

Next, a connection point between the resistor 212, the capacitor 213, and the zener diode 214 is connected to an input terminal of the comparator 215. The anode of the diode 210 is connected to the input terminal of the comparator 215.

The output terminal of the comparator 215 is connected to the AND circuit 217 and the inverter 218. And the inverter 218
It is connected to the S input terminal of the R / S flip-flop 219.

The voltage signal φ from the oscillation circuit 3 is input to the input terminal 203, and the input terminal 203
Connected to D circuit 217.

The output terminal of the AND circuit 217 is the R terminal of the R / S flip-flop 219.
Connected to the input terminal, the Q of the R / S flip-flop
The output terminal is connected to the output terminal 204. Then, a voltage signal Φ is output from the output terminal 204.

Next, the operation of the voltage drop detection circuit 2 shown in FIG. 2 will be described.

FIG. 3 is a time chart showing voltage signals at main terminals of the voltage drop detection circuit 2.

First, an operation when the voltage of the output terminal of the generator 1 has not dropped will be described.

At this time, since the voltage at the anode of the diode 210 in FIG. 2 is higher than the voltage determined by the constant voltage circuit, the output of the comparator 215 becomes “H” level (third level).
A in the figure).

A comparator is connected to one input terminal of the AND circuit 217.
An “H” level voltage signal is input from 215. Then, as the voltage signal φ inputted from the input terminal 203 switches between “H” and “L”, the voltage signals inputted to the R input terminal of the R / S flip-flop 219 become “L” and “H”. "And switch.

On the other hand, an “L” level signal is input from the inverter 218 to the S input terminal of the R / S flip-flop. Therefore, the output of the R / S flip-flop 219 becomes “L”.

As described above, when the voltage of the output terminal of the generator 1 has not dropped, the voltage signal Φ goes to the “L” level.

Next, the operation when the voltage at the output terminal of the generator 1 drops will be described.

At this time, since the voltage at the anode of the diode 210 in FIG. 2 becomes lower than the voltage determined by the constant voltage circuit, the output of the comparator 215 once becomes "L" level (see B in FIG. 3). Therefore, an “H” level signal is input from the inverter 218 to the S input terminal of the R / S flip-flop.

A comparator is connected to one input terminal of the AND circuit 217.
An “L” level voltage signal is input from 215. Therefore, an “L” level signal is input from the AND circuit 217 to the R input terminal of the R / S flip-flop 219.

As a result, the output of the R / S flip-flop 219 becomes “H”.

As described above, when the voltage at the output terminal of the generator 1 drops, the voltage signal Φ goes to the “H” level.

 Next, the operation of the circuit of FIG. 1 will be described.

First, the operation when the voltage signal Φ output from the voltage drop detection circuit 2 is “L”, that is, when the voltage at the output terminal of the generator 1 has not dropped will be described.

In the above case, when the voltage signals φ and “H” are “H” and “L”, respectively, the connection state of each switch is as shown in FIG. That is, the capacitors 11, 12, and 13 are connected in series between the wiring 31 and the ground, and the capacitors 21, 22, and 23 are connected to the battery 4
And load group 5 in parallel.

FIG. 4A shows an equivalent circuit in this state. At this time, the capacitors 11, 12, and 13 are charged by the generator 1,
The voltage between the electrodes of capacitors 11, 12, and 13 is 12 [V]
become. Further, the batteries 4 are charged by the capacitors 21, 22, and 23, and at the same time, power is supplied to the load group 5.

Thereafter, when the voltage signal φ switches to “L” and “H”, respectively, the switches SA1, SA2, SA3, SA4, SA5, SB1, SB2,
SB3, SB4, and SB5 are connected to terminals on the opposite side of the state shown in FIG. That is, the capacitors 11, 12, 13 are connected in parallel with the battery 4 and the load group 5, and the capacitors 21, 22,
23 is connected in series between the wiring 31 and the ground.

FIG. 4B shows an equivalent circuit in the above state. At this time, the capacitors 11, 12, and 13 are discharged, charging the battery 4 and serving as a power source for the load 5. In addition, capacitor 2
1,22,23 are charged by the generator 1 and the capacitors 21,
The voltage between the electrodes 22 and 23 becomes 12 [V]. The batteries 4 are charged by the capacitors 11, 12, and 13, and power is supplied to the load group 5 at the same time.

Thereafter, when the voltage signal φ is switched again, the connection state becomes as shown in FIG. And capacitor 1
1,12,13 are charged, capacitors 21,22,23 are discharged,
The battery 4 is charged and serves as a power source for the load group 5.

As described above, power is always supplied to the battery 4 and the load group 5.

Next, the operation when the voltage signal Φ output from the voltage drop detection circuit 2 is “H”, that is, when the voltage at the output terminal of the generator 1 drops will be described.

In the above case, the connection state of the switches SC1 and SC3 is on the opposite side to FIG. As a result, the switches SA1, SA2, SA3, SA4, SA
5, SB1, SB2, SB3, SB4, and SB5 are switched by the voltage signal φ.

In this state, when the voltage signal φ is "L", the connections of the switches SA1, SA2, SA3, SA4, SA5, SC1, SC3 are opposite to those in FIG. That is, all of the capacitors 11, 12, 13, 21, 22, and 23 are connected in parallel to the battery 4 and the load group 5.

FIG. 4C shows an equivalent circuit in this state. At this time, the capacitors 11, 12, 13, 21, 22, and 23 are charged by the battery 4, and the voltage between the electrodes of the capacitors 11, 12, 13, 21, 22, and 23 becomes 12 [V].

Thereafter, when the voltage signal φ switches to “H”, the connection states of the switches SA1, SA2, SA3, SA4, SA5, SB1, SB2, SB3, SB4, SB5, and SC2 are switched. As a result, the capacitors 11,1
2, 13, 21, 22, and 23 are connected in series between the wiring 31 and the ground to provide a 72 [V] power supply.

FIG. 4D shows an equivalent circuit in the above state. At this time, the capacitors 11, 12, 13, 21, 22, and 23 discharge, and the motor 7
And the load 8 is driven.

Thereafter, when the voltage signal φ switches again, the connection state becomes as shown in FIG. 4 (c). And capacitors 11, 12,
13,21,22,23 are charged by the battery 4.

As described above, when the output voltage of the generator 1 drops, the battery 4 of 12 [V] and the capacitors 11, 12, 13, 21, 2, 2
A high voltage power supply is constituted by 2,23. Therefore, 36
The voltage drop of the generator 1 is promptly recovered without using the high voltage battery of [V].

As shown in FIG. 4 (d), capacitors 11, 12, 13, 21,
When the motors 22 and 23 are connected in series, the voltage at the output terminal of the generator 1 increases even when the operation of the motor 7 or the load 8 is not normal (see C in FIG. 3). Therefore, an “H” level voltage signal is output from the output terminal of the comparator 215 in the voltage drop detection circuit 2.

Further, since voltage signal φ at this time is at “H” level, a voltage signal at “L” level is input from inverter 216 to AND circuit 217. As a result, an “L” level voltage signal is input from the AND circuit 217 to the R input terminal of the R / S flip-flop, and the output from the Q output terminal, ie, the voltage signal Φ
Becomes "H" level.

Therefore, when the operation of the motor 7 or the load 8 is not normal, the voltage signal Φ is always at "H" level.

Then, when the operation of the motor 7 and the load 8 becomes normal, the voltage of the output terminal of the generator 1 becomes high even if the capacitors 11, 12, 13, 21, 22, and 23 are connected in parallel (No. 3
(See FIG. D). At this time, the voltage signal φ is “L” level,
Since the output of the comparator 215 is at “H” level, voltage signals of “H” and “L” level are input to the R input terminal and the S input terminal of the R / S flip-flop 219, respectively. As a result, the voltage signal Φ becomes “L” level, and FIG.
The operation returns to the normal operation shown in (b) (see E in FIG. 3).

As described above, according to this embodiment, the motor 7 and the load 8 are connected to the generator 1, and the battery 4 and the load group 5 are connected.
Are connected, a voltage drop of the generator 1 is detected by the voltage drop detection circuit 2, a switching signal is output by the oscillation circuit 3, and capacitors 11, 12, and 12 are output according to the output from the voltage drop detection circuit and the oscillation circuit 3. 13,21,22,23 connection state is switched. Therefore, an effect is obtained that power can always be supplied to batteries 4 and 5 during normal operation.

Further, when the output voltage of the generator 1 drops, the voltage drop can be quickly recovered by the battery 1, and the effect of improving the responsiveness of the motor 7 and the load 8 can be obtained. Further, since it is not necessary to use a 36 [V] battery, it is possible to obtain an effect that weight and cost can be reduced.

 Next, FIG. 5 and FIG. 6 show a second embodiment.

When the load 8 of the first embodiment is a semiconductor element having no constant voltage circuit, the semiconductor element may be broken by applying a high voltage. Therefore, the present embodiment is a device in which the voltage supplied to the motor 7 and the load 8 becomes lower than that of the first embodiment when the voltage of the generator 1 drops.

First, the configuration of this embodiment will be described with reference to FIG.

SC4 is a switch. One terminal of the switch SC4 is connected to the wiring 31, one terminal is connected to the switch SA1, and the other terminal is connected to a wiring between the switches SA4 and SA5. The switch SC4 is switched to the voltage signal Φ from the voltage drop detection circuit 2.

Note that other configurations are the same as those of the first embodiment, and thus detailed description is omitted.

 Next, the operation will be described.

First, the operation when the voltage signal Φ output from the voltage drop detection circuit 2 is “L”, that is, when the voltage at the output terminal of the generator 1 has not dropped will be described.

In this case, the switch SC4 is connected to the opposite side of FIG. 5, that is, to the switch SA1. The operation at this time is the same as the normal operation of the first embodiment.

Next, the operation when the voltage signal Φ output from the voltage drop detection circuit 2 is “H”, that is, when the voltage at the output terminal of the generator 1 drops will be described.

In this case, the connection state of the switches SC1, SC3, SC4 is as shown in FIG.

When the voltage signal φ is “L”, the switches SA1, SA2,
Connections of SA3, SA4, SA5, SC2, SB1, SB2, SB3, SB4, and SB5 are opposite to those in FIG. That is, capacitors 11, 12, 13, 21, 22, 22,
All three are connected in parallel to battery 4 and load group 5.

FIG. 6A shows an equivalent circuit in this state. At this time, the capacitors 11, 12, 13, 21, 22, and 23 are charged by the battery 4, and the voltage between the electrodes of the capacitors 11, 12, 13, 21, 22, and 23 becomes 12 [V].

Thereafter, when the voltage signal φ switches to “H”, the connection states of the switches SA1, SA2, SA3, SA4, SA5, SB1, SB2, SB3, SB4, SB5, and SC2 are switched. As a result, capacitors 13,2
1, 22, and 23 are connected in series between the wiring 31 and the ground.

FIG. 6B shows an equivalent circuit in the above state. At this time, the capacitors 13, 21, 22, and 23 discharge and drive the motor 7 and the load 8. In addition, since the capacitors 11 and 12 do not operate in a state of storing electric charges, they do not appear on the equivalent circuit.

As described above, when the output voltage of the generator 1 drops, a high-voltage power supply is constituted by the battery 4 of 12 [V] and the capacitors 13, 21, 22, and 23. Therefore, 36 [V]
, The voltage effect of the generator 1 is quickly restored.

As described above, according to the present embodiment, in addition to the configuration of the first embodiment, the switch SC4 is provided between the wiring 31 and the switch SA1. Therefore, in addition to the effects obtained in the first embodiment, the voltage supplied to the motor 7 and the load 8 when the voltage of the generator 1 drops can be made lower than in the first embodiment, and the load 8 can be reduced. In the case of a semiconductor element having no constant voltage circuit, an effect is obtained that the destruction of the semiconductor element can be prevented.

<Effect of the Invention> As described above, according to the present invention, the first power generator is provided.
, The battery and the second load are connected, the voltage drop of the generator is detected by the voltage drop detecting means, the switching signal is output by the oscillating means, and the output from the voltage drop detecting means and the oscillating means is output. Accordingly, the connection states of the capacitors of the first capacitor group and the second capacitor group are switched.

Therefore, during normal operation, the effect is obtained that the battery can be charged and power can be supplied to the second load at the same time.

Also, when the voltage at the output terminal of the generator drops,
The voltage drop of the generator can be quickly recovered by the battery and the capacitor, and the effect of improving the responsiveness of the first load can be obtained. further,
Since it is not necessary to use a high-voltage battery, the size, weight, and cost of the device can be reduced, and the durability can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment, FIG. 2 is a circuit diagram showing a configuration of a voltage drop detection circuit of FIG. 1, and FIG. 3 is a time chart showing outputs of respective terminals of the voltage drop detection circuit. FIG. 4 is an equivalent circuit diagram of the first embodiment, and FIG.
FIG. 6 is an equivalent circuit of the second embodiment, and FIG. 7 is a circuit diagram showing a conventional example. 1 ... generator, 2 ... voltage drop detection circuit, 3 ... oscillation circuit, 4 ... battery, 5 ... load group of 12 [V], 7
…… 36 [V] motor, 8 …… 36 [V] load, 11, 12,
13,21,22,23 …… Capacitors.

Claims (1)

(57) [Claims] 1. A generator, a first load, a second load,
A battery, a first capacitor group, a second capacitor group, a voltage drop detecting unit, an oscillating unit, a connecting unit,
Wherein the first load is one or more loads connected to an output terminal of the generator, and the second load is one connected in parallel with the battery.
Or a plurality of loads, wherein both the first capacitor group and the second capacitor group are composed of the same number of capacitors, and the voltage drop detecting means is configured such that a voltage at an output terminal of the generator is lower than a predetermined voltage. The oscillation means outputs a switching signal every predetermined period, and the connecting means does not output the falling signal, and outputs the switching signal. Is output, each capacitor of the first capacitor group is connected in series and connected to the output terminal of the generator, and each capacitor of the second capacitor group is connected in parallel. When the drop signal is not output and the switching signal is not output, the capacitors of the first capacitor group are connected in parallel. Connected to the battery, connected in series to the capacitors of the second capacitor group and connected to the output terminal of the generator, the down signal is output, and the switching signal is output The first capacitor group and the second capacitor group
When the capacitors are connected in parallel to each other and connected to the battery, and when the falling signal is output and the switching signal is not output, the first capacitor group and the second A power supply device for a vehicle, wherein all or a predetermined number of capacitors in a capacitor group are connected in series and connected to an output terminal of the generator.