JPH0773412B2 - Charge control circuit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charge control circuit suitable for charging a nickel-cadmium storage battery or the like more safely and in a short time.

(Prior Art) Conventionally, as a charge control circuit for a nickel-cadmium storage battery or the like, as described in Yuasa Battery Co., Ltd. Technical Document No. 10 (B) page 13, a large current is supplied at the beginning of charging and at the end of charging. A charging method that switches to a safe minute current for the battery,
For example, the initial charging stage represents a multiple of numeric (C) when the 0.3 C _m A (the C _m A which represents the rated capacity of the battery are standardized in JIS in mAh, it referred to the following C _m A and C .0.3C _m a is the fact that 0.3 times the current value of a number of the rated capacity of the storage battery. quickly charged with), it detects when the charge voltage of the battery is a predetermined voltage value, or a predetermined temperature is reached , Then a charge control circuit that switches to trickle charge current (0.02-0.05C) is known.

(Problems to be Solved by the Invention) However, if the voltage detection and switching circuit fails
The rapid charge of 0.3C continues, overcharge occurs, and the battery temperature rises due to gas consumption. In the worst case, thermal runaway causes damage to the storage battery. Further, it takes a long time to charge the trickle in order to fully charge the battery by switching the charging from the quick charge to the trickle charge, and there is a drawback that the entire charging time becomes long.

An object of the present invention is to prevent thermal runaway and reduction of battery life due to overcharge, prevent damage to the storage battery and prolong life, and perform supplementary charging to obtain usable discharge capacity for a short time. Is to provide a charge control circuit for fully charging the storage battery.

(Means for Solving the Problems) The feature of the present invention for achieving the above-mentioned object is that in the charging control circuit for charging the storage battery, the storage battery (1) detects a voltage component that changes depending on the temperature. Temperature detection means (3) that has a temperature characteristic and outputs a voltage V _T proportional to the amount of change in the ambient temperature of the storage battery, voltage generation means (2) that generates a constant voltage V _S , and voltage V _T that is a constant voltage An adding means (4) for adding V _S and outputting as a reference voltage V _REF ;
The voltage of the storage battery is determined by distinguishing between V _REF and the storage battery voltage V _B.
A detection means (5) for detecting that V _B exceeds a predetermined value,
A timer (7) that starts timing by the output of the detection means and outputs the output after the start-up set time has elapsed, a first switch (SW1) switched by the timer, and a second switch opened and closed by the detection means. The switch (SW2) is inserted between the storage battery and the power supply, and sets the first, second and third current values when performing quick charging, supplementary charging and trickle charging. With resistances (R1, R2, R3) of
Until the voltage of the storage battery reaches a predetermined value, rapid charging is performed at the first current value set by the first switch, the first resistor and the closed second switch, and then the detection means The output of the detection means opens the second switch until an output is generated and the timer generates an output, and the first switch, the first and second switches are opened.
Replenishment charging is performed with the second current set by the resistance of the second switch, and thereafter, when the timer generates an output, the first switch is switched and set by the third switch. It is to perform trickle charging with the third current.

Further, the feature of the present invention is that, in the charge control circuit for charging the storage battery, the storage battery (1) has a negative temperature characteristic because the storage battery (1) detects a voltage component that changes depending on the temperature. Temperature detecting means (3) for outputting a voltage V _T proportional to the voltage and voltage generating means (2) for generating a constant voltage V _S
And an adding means (4) for adding the voltage V _T to the constant voltage V _S and outputting it as a reference voltage, and the voltage of the storage battery (1) by discriminating between the reference voltage and the voltage of the storage battery (1). A detection means (5) for detecting that the value exceeds a predetermined value, a timer (7) for starting timing by the output of the detection means, and issuing an output after the start set time has elapsed, and a first switchable by the timer. Switch (SW1), a second switch (SW2) that is switched by the detecting means, and a current setting means (11) that generates a voltage corresponding to the current when performing quick charging, replenishment charging and trickle charging, A constant current means (12) which is inserted between the storage battery and the power source and which generates a constant current proportional to the output voltage of the current setting means through the first switch and the second switch, Until the voltage of the storage battery reaches a predetermined value, Through the first switch and the second switch, the constant current means is provided with an output voltage corresponding to the current at the time of performing the rapid charge of the current setting means to perform the rapid charge at the first current value, and thereafter. Until the output of the detecting means is generated and the output of the timer is generated, the second switch is switched by the output of the detecting means, and the second switch is switched through the first switch and the second switch in the switched state. When the output voltage corresponding to the current at the time of performing the supplementary charging of the current setting means is given to the constant current means to perform the supplementary charging with the second current smaller than the first current, and thereafter the timer generates an output. The constant current means is provided with an output voltage corresponding to the current when trickle charging the current setting means through the first switch in a state where the first switch is switched. In performing the trickle charging in less than a third current current.

(Operation) According to the present invention, the charging current can be switched in three stages.

When the voltage of the storage battery is lower than the predetermined value, rapid charging is performed with the first large current.

When the voltage of the storage battery reaches a predetermined value, replenishment charging is performed for a predetermined time with a second current smaller than the first current,
After that, trickle charging is performed with a smaller third current.

By the above current switching and time monitoring, charging can be performed in a short time without causing deterioration of the battery.

(Embodiment) FIG. 1 shows a first charge control circuit with a battery protection circuit according to the present invention.
It is a block diagram showing an example of.

1 is a nickel-cadmium storage battery (hereinafter referred to as a nicad battery) that can be charged and discharged at a nominal voltage of 1.2V. Reference numeral 2 is a voltage generator that is stable against changes in temperature and input voltage and generates a constant voltage V _S. 3, since the nickel-cadmium batteries 1 detects a voltage component which varies with the ambient temperature, using a varistor semiconductor temperature sensor such as a thermistor, once per -3 _m
Ni-Cd battery with negative temperature characteristics that changes V voltage 1
It is a temperature detector that generates a voltage V _T proportional to the change in the ambient temperature of. 4 is a constant voltage V _S output from the voltage generator 2.
And a voltage V _T that is the output of the temperature detector 3, and is an adder for adding the voltages V _S and V _T. The output voltage V _REF of the adder 4 as the reference voltage becomes (V _S + V _T ), and becomes 1.5V, 1.56V and 1.44V when the ambient temperature of the Nicad battery 1 is 20 ° C, 0 ° C and 40 ° C, respectively. Become. 5 is the detection voltage V _B of the NiCd battery 1 and the reference voltage V output by the adder 4
_This is a comparator having a hysteresis width that _{receives REF} as an input and determines the magnitude of the detection voltage V _B reference voltage V _REF . The output becomes L level when V _B <V _REF , and becomes H level when V _B V _REF . Reference numeral 6 is a short pulse generator which is composed of a differentiating circuit, a monostable multivibrator, etc., receives the output of the comparator 5 and generates a short pulse of H level when the output of the comparator 5 changes from L level to H level. is there. 7 is a charge amount at a current of 0.3C and a current of 0.1C after an external DC power source (not shown) is connected to the input terminal IN or an H level short pulse is input from the short pulse generator 6. Fully charged according to the amount of charge. It is a timer for determining the amount of charge (charging time) of 0.1 C among them. In this embodiment, the set time of the timer 7 is selected to be 4 hours. R
1, R2 and R3 are resistors that determine the charging current from the external DC power supply to the nicad battery 1, and are current limiting resistors that define the quick charging current, the safe maximum charging current and the trickle charging current, respectively. The rapid charging current is set to a current (0.3 C or more) that causes a chemical change inside the Nicad battery 1 due to the influence of the charging current and causes a rapid increase in the charging voltage at the end of charging of the Nicad battery 1. In the present embodiment, the charging current is 0.3 C. Have been elected. The safe maximum charging current is set to a current (0.05 to 0.2C) that does not cause the deterioration of the nickel-cadmium battery 1 even when a constant current is passed for a long time, and is selected as 0.1C in this embodiment. The trickle charging current is generally used in the range of 0.02 to 0.05C, but in the present embodiment, it is 0.033.
Selected as C. The trickle charge compensates for the self-discharged portion of the nicad battery 1, and is not always necessary and can be omitted. SW1 and SW2 are analog switches,
The switch is composed of semiconductor switches, relays, etc., and operates according to the level of the control terminal C. switch
The external DC power supply is connected to the common terminal CO of SW1 via the input terminal IN. The output of the timer 7 is connected to the control terminal C of the switch SW1. When the output of the timer 7 is L level, the common terminal CO of the switch SW1 and the normally closed (hereinafter referred to as NC) terminal are connected, and the NC terminal is connected through the resistor R1 and the switch SW2 or the resistors R1 and R2. Connected to Nicad battery 1 via an external DC
Charge the NiCd battery 1 with a charging current of 0.3C or 0.1C from the power supply. When the output of timer 7 is H level, switch SW
1 common terminal CO and normally open (hereinafter referred to as NO)
The terminal is connected, and the NO terminal is connected to the nicad battery 1 via the resistor R3, and trickle charges the nicad battery 1 with a charging current of 0.033C from an external DC power supply. The output of the comparator 5 is connected to the control terminal C of the switch SW2. When the output of the comparator 5 is L level,
Since the common terminal CO and NC terminal of the switch SW2 are connected and the resistor R2 is short-circuited, a charging current of 0.3 C flows through the nickel-cadmium battery 1. When the output of the comparator 5 is at H level, the common terminal CO and NC terminal of the switch SW2 are opened, and a charging current of 0.1 C flows to the nickel-cadmium battery 1 through the resistors R1 and R2. The external DC power source is a DC power source that generates a voltage that is 2 to 5 times the initial charging voltage of the NiCd battery 1. In this embodiment, the initial charging voltage of the NiCd battery 1 is approximately 1V.
The voltage of the DC power supply is selected as 5V.

Below, Fig. 1 and the second diagram showing the charging characteristic diagram at 20 ° C
The operation of this embodiment will be described with reference to the drawings.

When an external DC power supply is connected to the input terminal IN, the charging control circuit with a battery protection circuit shown in FIG. 1 is activated, the timer 7 is started (at this time, the output is at the L level), and the voltage V of the nicad battery 1 _B is compared with the reference voltage V _{REF generated} by the adder 4, and since V _B <V _REF , the L level is output to the output. Therefore, the Ni-Cd battery 1 is switched from the external DC power supply.
Charging is initiated at a charge current of 0.3 C (as shown by charge current curve 9 in FIG. 2) via SW1, resistor R1 and switch SW2. As shown in the charging voltage curve 8 in FIG. 2, the charging voltage characteristic at this time is such that the voltage rises rapidly for about 1 hour from the beginning, and after that, the voltage gradually decreases with a low gradient. The voltage rises and the voltage starts to rise sharply at the end of charging due to a change in the internal state of the nicad battery 1. Charge voltage V _B of Ni-Cd battery 1
Suddenly rises and becomes higher than the reference voltage V _REF generated by the adder 4 (at point A on the charging voltage curve 8 in FIG. 2), the output of the comparator 5 becomes H level and the switch SW2 is opened. To Therefore, the charging current of the nickel-cadmium battery 1 flows through the resistor R2 (as shown by the charging current curve 9 in FIG. 2).
It becomes 1C. Further, since the output of the comparator 5 becomes H level, the short pulse generator 6 generates a short pulse, resets the timer 7, and restarts the time counting.

If the charging voltage V _B of the nickel-cadmium battery 1 does not become higher than the reference voltage V _REF within the set time of the timer 7, the timer 7 times up, its output becomes H level, and the switch SW
The common terminal C and N terminal of 1 are connected, and the charge current of 0.3C is changed to trickle charge of 0.033C via the resistor R3.

When the charging current changes from 0.3C to 0.1C, as shown in Fig.2, it first drops rapidly by about 0.1V and then gradually decreases by about 0.1V. When 4 hours (in other words, the time between A and B of the charging voltage curve 8 in FIG. 2) have elapsed from the start of charging with the charging current of 7, the timer 7 has timed up and the supplementary charging has been completed, Outputs H level. Therefore, the common terminal CO of switch SW1
And N terminal are connected, and the Ni-Cd battery 1 is trickle charged via the resistor R3.

FIG. 3 shows a second embodiment in which the charge control circuit of the present invention is incorporated in a portable device.

In the present embodiment, instead of the current limiting resistors R1, R2 and R3 of the first embodiment, the charging control circuit 21 using a current setting device and a constant current circuit is used instead. Blocks that move in the same way as are labeled with the same numbers.

Reference numeral 11 is a current setting device that generates a voltage (for example, a voltage of 1.5V, 0.5V and 0.165V) corresponding to a current of 0.3C, 0.1C and 0.033C. Reference numeral 12 is a constant current circuit that generates a constant current proportional to the output voltage of the current setting device 11. Reference numeral 22 is a small portable device (hereinafter referred to as a load) that can be carried by a battery and is portable, such as a portable computer, a portable radio, and a radio cassette. Reference numeral 23 is an AC adapter for converting a commercial power supply into a DC power supply and supplying an operating current and a charging current to the load 22 and the charging control circuit 21, respectively. SW3 is a switch for connecting / disconnecting the power supply and is also used for detecting the power-on.

First, the configuration of the charge control circuit 21 of this embodiment will be described.
However, the description of the same configuration as that of the first embodiment will be omitted.

The 0.3C and 0.1C output of the current setting device 11 is the N of switch SW2.
Connected to C terminal and NO terminal respectively. The 0.033C output of the current setting device 11 and the CO terminal of the switch SW2 are connected to the NO terminal and NC terminal of the switch SW1, respectively. The CO terminal of the switch SW1 is connected to the control terminal C of the constant current circuit 12. Current output of constant current circuit 12
I.OUT is connected to the nickel-cadmium battery 1 through the reverse current blocking diode D1. One of the inputs of the OR gate 15 is connected to the output of the single pulse generator 6, and the other one is connected to the resistor R4.
The switch SW3 is normally pulled up by the
It is grounded via -2. The output of the timer 7 is connected to one input of the OR gate 16, and the other one is connected to the OR gate 15
Connected to one of the inputs. The voltage detection input of the comparator 5 is connected to the nickel-cadmium battery 1 via the switch SW3-3 which is normally short-circuited.

In this embodiment, due to the use of nickel-cadmium batteries 1 connected to the battery nominal voltage 1.2V to four series, has a negative temperature characteristic of a voltage change of one degree per -12 _m V, Ni-Cd battery 1 Is changed to a temperature detector 3 that generates a voltage V _T proportional to the change in ambient temperature. Also, the adder 4 as the reference voltage
Output voltage V _REF of NiCd battery 1 ambient temperature is 20 ℃, 0 ℃
6V, 6.24V and 5.76V at 40 ℃ and 40 ℃ respectively.

Next, the overall configuration of this embodiment will be described.

One output OUT1 of the AC adapter 23 is input to the charge control circuit 21
The other output OUT2 is connected to the load 22 through the reverse blocking diode D3 and the switch SW3-1. The output OUT of the charge control circuit 21 is a reverse blocking diode D.
It is connected to the load 22 via 2 and the switch SW3-1.

Fig. 4 shows the AC drive for long-term use at home.
It is a figure which shows an example of the time chart at the time of AC drive.

FIG. 5 is a diagram showing an example of a time chart when used in a place where there is no commercial power source, such as in a vehicle or outdoors, driven by a battery.

The operation during AC drive will be described below with reference to FIGS. 3 and 4.

When the AC adapter 23 is connected to a commercial power source, the charging control circuit 21
Starts and starts timer 7 (at this time, the output is L
As well as a level), 'compares the reference voltage V _REF produced by the adder 4 and _B, V' voltage V of a nickel-cadmium battery 1 _B
Since it is <V _REF , L level is output. Therefore,
NiCd battery 1 has the 0.3C output of the current setting device 11
It is sent to the control terminal C of the constant current circuit 12 via the NC terminal-CO terminal of SW2 and the NC terminal-CO terminal of the switch SW1, and the constant current circuit 12 (shown in the charging current curve 9a of FIG. 4 is shown. Like) starts charging with a charging current of 0.3C. As shown in the charging voltage curve 8a of FIG. 4, the charging voltage characteristic at this time is such that the voltage rises rapidly for 1 hour from the beginning,
After that, the voltage gradually rises with a low gradient.

When switch SW3 is turned on about 2 hours after the start of charging, A
Output OUT2 of C adapter 23 to diode D3 and switch S
Power is supplied to the load 22 via W3-1, and the load 22 operates.

At this time, the switch SW3-2 is opened and the OR gate 1
One of the inputs of 5 and 16 becomes H level respectively, and the timer 7 is reset and the switch SW1 is operated.
The switch SW1 operates and the 0.033C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12 via the NO terminal-CO terminal of the switch SW1, and the current output I.OU of the constant current circuit 12 is output.
Trickle charge of 0.033C is applied to the nickel-cadmium battery 1 while the load 22 is operating from T via the diode D1. The switch SW3-3 becomes an open state, to become V 'B _{<V REF,} the output of the comparator becomes the L level.

When the switch SW3 is operated after the load 22 is operated for about 5 hours (see FIG. 17a in FIG. 4), the switch SW3-2 becomes conductive and the NC terminal and the CO terminal of the switch SW1 are connected. The switch SW3-3 also becomes conductive, the comparator 5 'compares the _B and the reference voltage V _REF, V' voltage V of a nickel-cadmium battery 1 is to output the L level to the output for a B _{<V REF,} Switch SW2 does not change. Therefore, in the nickel-cadmium battery 1, the 0.3C output of the current setting device 11 is the N of the switch SW2.
It is sent to the control terminal C of the constant current circuit 12 through the C terminal-CO terminal and the NC terminal-CO terminal of the switch SW1, and the constant current circuit 12 has the charging current curve 9a shown in FIG. , Start charging with a charging current of 0.3C. As shown in the charging voltage curve 8a in Fig. 4, the charging voltage characteristic at this time increases rapidly during the first 20 minutes, and after that, the voltage gradually increases with a low gradient. Then, due to the change in the internal state of the Ni-Cd battery 1, the voltage starts to rapidly increase at the end of charging. Soared the charging voltage V _'B of nickel-cadmium batteries 1, and is higher than the reference voltage V _REF generated by the adder 4 (becomes point A of the charging voltage curve 8a of FIG. 4), the output of the comparator 5 is H It becomes a level and activates the switch SW2, and the 0.1C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12 via the NO terminal-CO terminal of the switch SW2 and the NC terminal-CO terminal of the switch SW1. . Therefore, from the current output I.OUT of the constant current circuit 12, the nickel-cadmium battery 1 is charged with a charging current of 0.1 C (as shown in the charging current curve 9a in FIG. 4). Further, since the output of the comparator 5 becomes H level, the short pulse generator 6 generates a short pulse, resets the timer 7, and restarts the time counting.

When the charging voltage V _'B of nickel-cadmium batteries 1 is not higher than the reference voltage V _REF within the set time of the timer 7, the timer 7
Has timed out, its output becomes H level, the common terminal C and N terminal of the switch SW1 are connected, the 0.033C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12, and the nicad battery 1 Changes from the current output I.OUT of the constant current circuit 12 to a trickle charge of 0.033C instead of the charge current of 0.3C.

When the charging current changes from 0.3C to 0.1C, as shown in Fig. 4, the voltage drops sharply by about 0.4V first, and then gradually decreases by about 0.4V. When 4 hours (in other words, the time between A and B of the charging voltage curve 8a in FIG. 4) have elapsed from the start of charging with the charging current of C,
The timer 7 times up, completes the supplementary charge, and outputs the H level at its output. Therefore, the common terminal CO and N terminal of the switch SW1 are connected, the 0.033C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12, and the nicad battery 1 has a constant charging current of 0.1C instead. It is charged by the trickle charge of 0.033C from the current output I.OUT of the current circuit 12.

Next, a case where the load 22 is driven by the NiCd battery 1 will be described below with reference to FIGS. 3 and 5.

First of all, to fully charge Nicad Battery 1, AC adapter
Connect 23 to utility power. Then, the charge control circuit 21 operates, compared (at this time, the output is at the L level) to the timer 7 is started with and the reference voltage V _REF produced by the adder 4 and the voltage V _'B of cadmium battery 1 And _V'B <V
_Since it is _REF , L level is output. Therefore, in the NiCd battery 1, the 0.3C output of the current setting unit 11 is the switch SW2.
Sent to the control terminal C of the constant current circuit 12 through the NC terminal-CO terminal of the switch and the NC terminal-CO terminal of the switch SW1,
The constant current circuit 12 starts charging with a charging current of 0.3C as shown in the charging current curve 9b of FIG. As shown in the charging voltage curve 8b of FIG. 5, the charging voltage characteristic at this time is that the voltage rises rapidly for 1 hour from the beginning, and after that, the voltage gradually drops with a low gradient. Rising and Nicad Battery 1
Due to the change of the internal state of, the voltage starts to rise sharply at the end of charging. Soared the charging voltage V _'B of nickel-cadmium batteries 1, and is higher than the reference voltage V _REF generated by the adder 4 (becomes point A1 of the charge voltage curve 8b of FIG. 5), the output of the comparator 5 is It becomes H level and activates the switch SW2, and the 0.1C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12 via the NO terminal-CO terminal of the switch SW2 and the NC terminal-CO terminal of the switch SW1. To be done. Therefore, the constant current circuit 12
The nickel-cadmium battery 1 is charged with a charging current of 0.1 C from the current output I.OUT (as shown in the charging current curve 9b of FIG. 5). Further, since the output of the comparator 5 becomes the H level, the short pulse generator 6 generates a short pulse, resets the timer 7 and restarts the time counting.

When the charging current changes from 0.3C to 0.1C, as shown in 8b of Fig. 5, it first drops sharply by about 0.4V and then gradually drops by about 0.4V. When 4 hours (in other words, the time of winding A1−B1 of the charging voltage curve 8b in FIG. 5) have elapsed from the start of charging with the charging current of 0.1C,
The timer 7 times up, completes the supplementary charge, and outputs the H level at its output. Therefore, the common terminal CO and N terminal of the switch SW1 are connected, the 0.033C output of the current setting device 11 is sent to the control terminal C of the constant current circuit 12, and the nicad battery 1 has a constant charging current of 0.1C instead. It is charged by the trickle charge of 0.033C from the current output I.OUT of the current circuit 12.

After charging the nickel-cadmium battery 1 for about 11 hours (see FIG. 5), the AC adapter 23 is not removed for use inside or outside the vehicle.

When the switch SW3 is activated (see FIG. 5b, 5b), a current of 0.2C flows from the nicad battery 1 through the diode D2 to the load 22, as shown in FIG. 5b. At this time, the voltage of the nickel-cadmium battery 1 is switched as shown in FIG. 5b.
When SW3-1 is turned on, the voltage drops by about 0.15V, then drops by about 0.01V / min until it reaches a constant voltage (about 5.2V) for about 40 minutes, and then gradually drops.

Here, when the switch is turned off (see FIG. 17b, FIG. 5), the voltage of the nickel-cadmium battery 1 rises by about 0.15 V and is maintained until it is charged again.

When the AC adapter 1 is again connected to the commercial power source, the Ni-Cd battery is charged again and operates almost in the same way as when AC is driven.

Note that in FIG. 1 or FIG. 3, the comparator 5 is configured to generate an output not only when the voltage of the storage battery exceeds a predetermined value but also when the ambient temperature of the storage battery exceeds the predetermined value. When the temperature rises due to charging, it is possible to switch to supplementary charging.

(Effect of the invention) According to the present invention, the charging current of the storage battery can be switched to three stages in accordance with the ambient temperature of the storage battery, and the deterioration of the battery can be prevented by an appropriate charging current. And the charging time can be shortened.

Also, the charging of the quick charging current is monitored over time, and if the charging voltage does not reach the predetermined voltage within the fixed time, the trickle charging or the charging control circuit is protected by switching to trickle charging or ending the charging. You can plan.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 2 is a graph showing a charging current vs. charging voltage characteristic. FIG. 3 is a block diagram showing a second embodiment of the present invention. FIG. 4 and FIG. 5 are operation time charts when the AC power source and the battery of the second embodiment are driven, respectively. 1; storage battery, 2; voltage generator, 3; temperature detector, 4; adder, 5; comparator, 7; timer SW1, SW2; switch, R1, R2, R3; resistance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Matsumoto 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Masatake Nagai 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Yasuyuki Hiraiwa 2-3-3 Higashisakura, Higashi-ku, Nagoya, Aichi Prefecture Hagiwara Electric Co., Ltd. (72) Inventor Akiyoshi Yoshizawa 2-3-3, Higashisakura, Higashi-ku, Nagoya, Aichi Prefecture Hagiwara Electric Incorporated (72) Inventor Ichiro Obata 2-3-3 Higashisakura, Higashi-ku, Nagoya, Aichi Prefecture Hagiwara Electric Co., Ltd. (56) Reference JP-A-56-98341 (JP, A) JP, U)

Claims (4)

[Claims] 1. In a charge control circuit for charging a storage battery, (a) the storage battery (1) has a negative temperature characteristic because it detects a voltage component that changes with temperature, and is proportional to the amount of change in the ambient temperature of the storage battery. Temperature detection means for outputting voltage V _T (3)
And (b) voltage generating means (2) for generating the constant voltage V _S , and (c) adding means (4) for adding the voltage V _T to the constant voltage V _S and outputting the reference voltage V _REF . (D) a detecting means (5) for discriminating between the reference voltage V _REF and the voltage V _B of the storage battery to detect that the voltage V _{B of} the storage battery has exceeded a predetermined value; A timer (7) that starts timing by the output and outputs the output after the start set time has elapsed, and (f) a first switch (SW) that is switched by the timer.
1), (g) a second switch (SW2) which is opened and closed by the detecting means, and (h) is inserted between a storage battery and a power supply, and is used for quick charging, supplementary charging and trickle charging. , Second and third
The first, second and third resistors (R1, R2,
R3), and rapid charging with a first current value set by the first switch, the first resistor and the closed second switch until the voltage of the storage battery reaches a predetermined value. The second switch is opened by the output of the detecting means until the output of the detecting means is generated and then the timer generates the output, and the second switch is opened by the first switch and the first and second resistors. Replenishment charging is performed with the set second current, and thereafter, when the timer generates an output, the first switch is switched and the third switch is set by the third resistor. The charge control circuit is characterized in that trickle charging is performed with the current of. 2. In a charge control circuit for charging a storage battery, (a) the storage battery (1) has a negative temperature characteristic because it detects a voltage component that changes depending on the temperature, and a change amount of the ambient temperature of the storage battery (1). Temperature detection means (3) that outputs a voltage V _T proportional to, (b) voltage generation means (2) that generates a constant voltage V _S , and (c) voltage V _T and constant voltage V _S And (d) detection for detecting that the voltage of the storage battery (1) exceeds a predetermined value by discriminating the magnitude of the reference voltage and the voltage of the storage battery (1). Means (5), (e) a timer (7) which starts timing by the output of the detection means and outputs the output after the start set time has elapsed, and (f) a first switch (SW) which is switched by the timer.
1), (g) a second switch (SW2) which is switched by the detecting means, and (h) a current setting means (11) for generating a voltage corresponding to the current at the time of performing quick charging, replenishment charging and trickle charging. )
(I) a constant current means (1) that is inserted between a storage battery and a power source and that generates a constant current proportional to the output voltage of the current setting means via the first switch and the second switch.
2) and, until the voltage of the storage battery reaches a predetermined value, the output voltage corresponding to the current when the rapid charging of the current setting means is performed is performed through the first switch and the second switch. The second switch is switched by the output of the detecting means until the output of the detecting means is generated and the output of the timer is generated. An output voltage corresponding to the current at the time of performing supplementary charging of the current setting means is applied to the constant current means via the first switch and the switched second switch, and the output voltage is less than the first current. Replenishment charging is performed with a current of 2, and when the timer generates an output thereafter, trickle charging of the current setting means is performed via the first switch in a state in which the first switch is switched. A charging control circuit, characterized in that an output voltage corresponding to the current is applied to the constant current means to perform trickle charging with a third current smaller than the second current. 3. The charge control circuit according to claim 1, wherein the set time of the timer is adjustable. 4. The set time of the timer is adjusted according to the operating time of the load.
The charge control circuit according to the item.