JPH11196535A - Battery application circuit - Google Patents

Abstract

(57) Abstract: To reduce a voltage rating of a load circuit connected to a series-connected capacitor and protect the load circuit, the capacitor, and the entire circuit. A series-connected battery pack, a first load circuit connected to both ends of the battery pack, and a second load connected to a smaller number of battery packs in series than the battery pack. In a circuit including a circuit, a protection circuit for preventing reverse bias of the second load circuit is provided in series with the second load circuit. [Effect] A small, safe and highly reliable power storage application circuit can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery application circuit using one or more capacitors connected in series, such as a lithium battery, an electric double layer capacitor, and a battery pack in which a plurality of unit cells are connected in series and parallel. In particular, the present invention relates to a charging / discharging device using a plurality of capacitors having an open-type protection element or a safety device in the battery, and a capacitor application circuit suitable for an electric device using these devices.

[0002]

2. Description of the Related Art Conventionally, there has been a lithium secondary battery having a built-in pressure switch for opening an electrode terminal and interrupting current when the internal pressure of the battery rises. For example, JP-A-6-215746.

FIG. 11 is a sectional view showing a conventional safety device. In the figure, 1101 is a metal safety valve, 11
02 is an insulating ring, 1103 is a perforated metal terminal plate, 11
04 is a metal lead mounting plate, 1105 is a bent part, 1
Reference numeral 106 denotes a welding portion.

[0004] When the internal pressure of the secondary battery rises due to short-circuiting, overcharging, or reverse charging, it is transmitted to the metal safety valve 1101 through a metal lead mounting plate 1104, a metal perforated terminal plate 1103, and a ventilation hole provided in an insulating ring 1102. Can be Since the outer peripheral portion of the metal safety valve 1101 is caulked by the secondary battery case, when the internal pressure of the secondary battery reaches a predetermined value, the central portion is lifted upward, the bent portion 1105 is inverted and the welded portion 1106 is peeled off. Perforated terminal plate 110 made of gold tatami
3 is disconnected and the current is interrupted.

[0005]

FIG. 12 is a diagram showing a capacitor application circuit using capacitors connected in series. In the figure, 1201 is a battery, 1202 is a built-in protection device,
1203, a secondary battery; 1204, a second load circuit;
05 is a first load circuit.

A built-in protection device 1202 and a secondary battery 1203
Are connected in series, and a first load circuit is connected to both ends thereof. The second load circuit 1204 is connected in parallel with a part of the battery 1201 connected in series.

In this circuit, even if the structure of the housing is devised so that the plus and minus of the battery are not mistakenly attached, the upper battery 1201 may be removed, or the battery may be attached to the lower battery. From the second, a reverse bias is applied to the second load circuit 1204,
The second load circuit 1204 will be damaged. Even if it is attached from the upper battery 1201 and fixed so that the battery 1201 is not removed, especially in the battery having the built-in protection device 1202 like a conventional lithium secondary battery, the battery of the upper battery 1201 Built-in protection device 120
When 2 is opened due to an overcurrent or the like, a reverse bias is similarly applied to the second load circuit 1204, and the second load circuit 1204 is damaged. Therefore, the second load circuit 1204 needs to be designed to withstand reverse bias.

Further, when the number of series of the capacitors 1201 increases or when the voltage of the lower battery 1201 is high,
When the connection of the upper battery 1201 is disconnected, a reverse bias is applied to the second load circuit 1204 and a voltage higher than the voltage of the upper battery 1201 is applied. Therefore,
The second load circuit 1204 needs to be designed to withstand reverse bias and withstand high voltage.

In addition, in a general battery application circuit using a chargeable battery, the first load circuit is a charge / discharge circuit. In this case, when the upper battery 1201 is shut off due to overcharging, a forward bias high voltage is applied to the second load circuit 1204. Therefore, the second load circuit 1204
Should be able to withstand the reverse bias minus the voltage of the capacitors connected in parallel from the total series voltage and the forward bias minus the voltage of the other capacitors minus the voltage that compensates for overcharging. Need to be designed. But,
When the voltage rating of the second load circuit 1204 is set so as to satisfy the above requirements, the size of the second load circuit 1204 increases and the cost increases. Further, in the case of a high-voltage battery in which a number of capacitors are connected in series, it is practically impossible to achieve a voltage rating that satisfies these requirements. If the battery is used before the voltage rating of the negative 2 load circuit 1204 is sufficiently obtained, the second load circuit 1204 is damaged when the upper storage battery 1201 is cut off, resulting in a dangerous state.

In particular, when the second load circuit 1204 is formed of a semiconductor device, the state of the damage is a short-circuit type. Therefore, the upper battery 12
01 is bypassed, the short-circuit failure part of the remaining capacitor 1201 and the second load circuit 1204, and the first load circuit 12
The current path 05 is newly formed, and there is a high possibility that the other components will be further damaged.

For example, the first load circuit often includes a voltage regulator to keep the voltage obtained from the capacitor constant. Particularly, in a general lithium secondary battery, the voltage between terminals greatly changes from 2.5 V to 4.2 V, and therefore, a voltage regulator is almost indispensable.

In this case, the short-circuited second load circuit 120
4, the voltage regulator absorbs the reduced voltage of the upper battery 1201, and the circuit operates. Then
The current of the lower battery 1201 increases, and further damages the lower battery 1201 and the first load device 1205.

In a general capacitor application circuit, a connection point connected in series rarely connects a second load circuit. However, if the battery is difficult to handle like a lithium secondary battery and needs to monitor individual connections, and is used in series, the above-described various problems occur. In particular, when a large number of conventional lithium secondary batteries are connected in series and used, a protection device built therein and a voltage regulator required for a large voltage change become a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and reduces the voltage rating of a load circuit connected to a part of a series-connected capacitor to protect the load circuit, the capacitor, and the entire circuit. It is another object of the present invention to provide a low-cost, small-sized, safe, inexpensive, and highly reliable application circuit for a capacitor, which can be installed in any order.

[0015]

SUMMARY OF THE INVENTION According to the present invention, there is provided a capacitor application circuit comprising: a series of capacitors; first load circuits connected to both ends of the series; and less than the number of series of the series of capacitors. A second series connected to the series
A protection circuit for preventing a reverse bias of the second load circuit is provided in series with the second load circuit. Alternatively, a voltage detection circuit for detecting a voltage of the second load circuit is provided in parallel with the second load circuit, and a protection circuit including a switch that opens and closes in accordance with an output of the voltage detection circuit is provided in the second load circuit. In series with the load circuit. Alternatively, a voltage detection circuit for detecting the voltage of the second load circuit, and a bypass circuit for opening and closing in response to the output of the voltage detection circuit are provided in parallel with the second load circuit, and include a current-sensitive fuse. The protection circuit is connected to the second
In series with the load circuit. When a plurality of second load circuits are connected in series, the number of series connections is divided into predetermined groups. Further, a battery state communication circuit may be provided between the second load circuit or the grouped second load circuits and the protection circuit.

When a voltage exceeding the rated voltage is applied to the second load circuit at the time of attachment / detachment of the battery or at the time of the operation of the built-in protection device, the battery application circuit having the above-described configuration is adapted to operate according to the applied voltage. A protection circuit provided in series with the second load circuit electrically disconnects the second load circuit from the battery. Alternatively, a bypass circuit provided in parallel with the second load circuit is turned on in accordance with the applied voltage, and the second load circuit is turned on.
A current-sensitive fuse provided in series with the load circuit of (1) cuts off, and electrically disconnects the second load circuit from the battery. Further, the battery state communication circuit outputs that the second load circuit has been disconnected. With these, the voltage rating of the load circuit connected to the series-connected capacitors is reduced, the load circuit, the capacitor, and the entire circuit are protected. It is possible to realize a safe, easy to handle, and highly reliable power storage application circuit.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the figure, the same part is 2
The same reference numerals are given to those having more than one, and the description is omitted. FIG. 1 is a diagram showing a first embodiment of the present invention. In the figure, 101 is a battery, 102 is a built-in protection device, 103 is a secondary battery, 104 is a second load circuit,
05 is a first load circuit, and 107 is a protection circuit.

A battery 101 composed of a built-in protection device 102 and a secondary battery 103 is connected in series, and a first load circuit is connected to both ends thereof. Also, a second load circuit
104 is connected in parallel with a part of the battery 101 connected in series. The protection circuit 107 is connected to the second load circuit 1
04 and in series.

Here, the protection circuit 107 is formed of an N-type MOS transistor, and its gate is connected to the second load circuit 10.
4 is connected to the positive side of the battery 101 connected in parallel.

When the upper battery 101 is removed first, or when the lower battery 101 is attached first, and when the built-in protection device 1 of the upper battery 101 is removed.
02 is opened due to an overcurrent or the like, the protection circuit 107
The gate potential of the N-type transistor becomes low, and the transistor turns off. Conversely, when the upper battery 101 is attached and the built-in protection device 102 is conducting,
The gate potential of the N-type MOS transistor becomes high, and the transistor turns on. That is, the second load circuit 10
When a reverse bias is applied to No. 4, the protection circuit 107 cuts off the connection and prevents the reverse bias of the second load circuit. Then, in the forward bias, the connection is made conductive and the connection is made effective.

Here, protection circuit 1 for preventing reverse bias
07 can also be achieved with diodes. However, MOS transistors are more suitable than diodes because of their smaller voltage drop.

As described above, in the capacitor application circuit, the voltage rating of the second load circuit 104 can be reduced to a value of only forward bias, and the cost and size of the second load circuit 104 can be reduced. it can. In addition, the protection circuit 107 has one N
It can be realized at low cost and small size as a MOS transistor. The battery 101 can be freely attached and detached, so that the ease of handling can be improved.

FIG. 2 is a diagram showing a second embodiment of the present invention. Voltage detection circuit 201 constituted by operational amplifier
Are connected in parallel with the second load circuit 104. The protection circuit 107 includes an N-type MOS transistor and a P-type M transistor.
It is composed of OS transistors connected in series. The output of the voltage detection circuit 201 is connected to the gates of an N-type MOS transistor and a P-type MOS transistor.

When the upper battery 101 is removed first, or when the lower battery 101 is attached first, and when the built-in protection device 1 of the upper battery 101 is removed.
02 is opened due to an overcurrent or the like, the voltage detection circuit 2
The input of 01 becomes negative, and its output also outputs an amplified negative value. Then, the N-type MOS transistor is turned off
Then, the connection of the second load circuit 104 is cut off.

When the battery 101 is a chargeable battery and the first load circuit is a charge / discharge circuit, the built-in protection device 102 of the upper battery 101 is cut off by overcharging, and the second load circuit 104 When a forward bias high voltage is applied to the P-type MOS transistor,
F, the connection of the second load circuit 104 is cut off.

The voltage value at which the connection of the second load circuit 104 is cut off by the reverse bias and the forward bias exceeding the rating can be adjusted by the threshold voltage of the MOS transistor or the gain of the operational amplifier. Therefore, the value of the rated voltage of the forward bias, which is guaranteed when the second load circuit 104 is abnormal, can be reduced.

On the other hand, when a voltage within the rating is applied to the second load circuit 104, both the N-type MOS transistor and the P-type MOS transistor are turned on, and the connection of the second load circuit 104 is enabled.

As described above, in the present capacitor application circuit, the reverse bias of the second load circuit 104 can be prevented, the value of the rated forward bias voltage ensured in the event of an abnormality can be reduced, and the low load of the second load circuit 104 can be reduced. Cost and size can be reduced. Further, the battery 101 can be freely attached and detached, so that it is possible to improve ease of handling, safety, and reliability.

FIG. 3 is a diagram showing a third embodiment of the present invention. Reference numeral 301 denotes a comparator, and 302 denotes a reference voltage generation circuit. Comparator 301 and voltage detection circuit 20
1 (operational amplifier) is connected in parallel with the second load circuit 104, and these outputs are connected to a control terminal of a protection circuit 107 formed by an N-type MOS transistor. The reference voltage generating circuit 302 is configured by a Zener diode, and is set to a forward bias rated voltage of the second load circuit 104. In addition, the comparator 301 compares the applied voltage of the second load circuit 104 with the voltage of the reference voltage generation circuit 302. When the voltage applied to the second load circuit 104 exceeds the voltage of the reference voltage generation circuit 302, that is, the rated voltage of the forward bias of the second load circuit 104, the comparator 301 inverts the output to a low potential. Is turned off, and the connection of the second load circuit 104 is cut off.

Further, by comparing the reference voltage generation circuit 302 with the comparator 301, the protection circuit 107 can be more accurately controlled.

When a reverse bias is applied to the second load circuit 104, the output of the voltage detection circuit 201 outputs an amplified negative value. Then, the N-type MOS transistor is turned off, and the connection of the second load circuit 104 is cut off.

On the other hand, when a voltage within the rating is applied to the second load circuit 104, the N-type MOS transistor is turned on to enable the connection of the second load circuit 104.

As described above, in the present capacitor application circuit, the reverse bias of the second load circuit 104 can be prevented, and the value of the rated forward bias voltage guaranteed in the event of an abnormality can be reduced with high accuracy.
The cost and size of the second load circuit 104 can be reduced. In addition, the battery 101 can be freely attached and detached, so that the ease of handling, safety, and reliability can be improved.

FIG. 4 is a diagram showing a fourth embodiment of the present invention. A bypass circuit 401 composed of an N-type MOS transistor and a P-type MOS transistor connected in series and a voltage detection circuit 201 composed of an operational amplifier are both connected in parallel with the second load circuit 104. Further, a protection circuit 107 including a current-sensitive fuse is connected in series with the second load circuit 104.

When a voltage within the rating is applied to the second load circuit 104, the bypass circuit 401 is off, and the connection of the second load circuit 104 is enabled.

However, when a reverse bias or a forward bias exceeding the rated voltage is applied to the second load circuit 104, the N-type MOS transistor and the P-type MOS transistor are turned on, and the connection between the second load circuits 104 is established. Short circuit. Then, a current exceeding the rated current flows through the current-sensitive fuse,
The current-sensitive fuse is blown, and the connection of the second load circuit 104 is cut off. Then, even if the abnormality is avoided and the voltage becomes normal, the connection of the second load circuit 104 is not restored unless the protection circuit 107 is replaced. Therefore, it is effective for an electric device that needs to deal with abnormality more carefully.

The bypass circuit 401 of the present circuit can be used in common with a balance compensating circuit used for equalizing the voltage difference between the capacitors connected in series. Cost can be reduced.

As described above, in the present capacitor application circuit, the reverse bias of the second load circuit 104 can be prevented, and the value of the rated forward bias voltage ensured in the event of an abnormality can be reduced. Cost reduction of the circuit 401,
The size can be reduced. Further, the battery 101 can be freely attached and detached, so that it is possible to improve ease of handling, safety, and reliability. In particular, the present invention is effective for an electric device that needs to be handled more carefully with respect to an abnormality.

FIG. 5 is a diagram showing a fifth embodiment of the present invention. Bypass circuit 4 composed of N-type MOS transistors
01, a voltage detection circuit 201 comprising an operational amplifier, a second
Applied voltage of load circuit 104 and reference voltage generation circuit 302
Are connected in parallel with the second load circuit 104. Further, a protection circuit 107 formed of a current-sensitive fuse is connected in series with the second load circuit 104.

When a voltage within the rating is applied to the second load circuit 104, the bypass circuit 401 is OFF, and the second load circuit 104 enables the connection.

However, when a reverse bias or a forward bias exceeding the rated voltage is applied to the second load circuit 104, the N-type MOS transistor turns on and the second load circuit 1
04 is short-circuited. Then, a current exceeding the rated current flows through the current-sensitive fuse, and the current-sensitive fuse blows,
The connection of the second load circuit 104 is cut off. Then, even if the abnormality is avoided and the voltage becomes normal, the connection of the second load circuit 104 is not restored unless the protection circuit 107 is replaced. Therefore, it is effective for an electric device that needs to deal with abnormality more carefully.

Further, the bypass circuit 401 of this circuit can be shared with a balance compensation circuit used for equalizing the voltage difference between the capacitors connected in series, so that the number of parts, the size, and the size can be reduced. Cost can be reduced.

Then, by comparing with the reference voltage generating circuit 302 by the comparator 301, the bypass circuit 401 can be controlled with higher accuracy.

As described above, in the capacitor application circuit, the reverse bias of the second load circuit 104 can be prevented, and the value of the rated forward bias voltage guaranteed in the event of an abnormality can be accurately reduced.
The cost and size of the second load circuit 104 and the bypass circuit 401 can be reduced. In addition, the battery 10
1 can be freely attached and detached, so that handling, safety and reliability can be improved. In particular, the present invention is effective for an electric device that needs to be handled more carefully with respect to an abnormality.

FIG. 6 is a diagram showing a sixth embodiment of the present invention. In the figure, reference numeral 601 denotes a piezoelectric switch. The piezoelectric switch 601 includes a piezoelectric element and a switch. The piezoelectric element is connected in parallel with the second load circuit 104, and the switch unit is inserted in series with the second load circuit 104.
When a voltage is applied, the piezoelectric element expands and contracts in a certain direction according to the voltage value. The switch is opened and closed by the expansion and contraction movement. Therefore, when the rated voltage of the second load circuit 104 is exceeded, the moving amount of the piezoelectric element is set so that the switch is opened.

As a result, in the present capacitor application circuit, the second
The voltage rating of the load circuit 104 can be reduced, and the cost and size of the second load circuit 104 can be reduced. Also, the protection circuit 107 can be realized at low cost and small size.
Then, the battery 101 can be freely attached and detached, so that the ease of handling can be improved, and the safety and reliability can be improved.

FIG. 7 is a diagram showing a seventh embodiment of the present invention. A Zener diode 701 having a cathode connected to the plus side of the second load circuit 104 is connected to the second load circuit 10.
4 and a protection circuit 107 composed of a current-sensitive fuse is inserted in series with the second load circuit 104.

A forward bias is applied to the Zener diode 701,
Alternatively, when a reverse bias equal to or higher than the breakdown voltage is applied, that is, a reverse bias is applied to the second load circuit 104, or
When a forward bias equal to or higher than the rated voltage is applied, the Zener diode 701 conducts, and short-circuits between the second load circuits 104. Then, a current higher than the rated current flows through the current-sensitive fuse, the current-sensitive fuse blows, and the connection of the second load circuit 104 is cut off.

Then, even if the abnormality is avoided and the voltage becomes normal, the connection of the second load circuit 104 is not restored unless the protection circuit 107 is replaced. Therefore, it is effective for an electric device that needs to deal with abnormality more carefully.

As described above, in the present capacitor application circuit, the voltage rating of the second load circuit 104 can be reduced, and the cost and size of the second load circuit 104 can be reduced.
Also, the protection circuit 107 can be realized at low cost and small size. Then, the battery 101 can be freely attached and detached, so that the ease of handling can be improved, and the safety and reliability can be improved.

FIG. 8 is a diagram showing an eighth embodiment of the present invention. A Zener diode 701 having a cathode connected to the plus side of the second load circuit 104 is connected to the second load circuit 10.
4 and a protection circuit 107 made of PTC is inserted in series with the second load circuit 104.

When a current exceeding the rated current flows, the PTC
This is an element whose resistance rapidly increases due to self-heating.

A forward bias is applied to the Zener diode 701,
Alternatively, when a reverse bias equal to or higher than the breakdown voltage is applied, that is, when a reverse bias or a forward bias equal to or higher than the rated voltage is applied to the second load circuit 104, the Zener diode 701 is turned on, and the second load circuit 104 is turned on. 104 are short-circuited. Then, a current higher than the rated current flows through the PTC,
The resistance of TC rapidly increases, and the second load circuit 104 cuts off the connection. Then, when the abnormality is avoided and the voltage becomes a normal voltage and the temperature of the PTC decreases, the resistance decreases and the connection of the second load circuit 104 is restored.

As described above, in the present capacitor application circuit, the voltage rating of the second load circuit 104 can be reduced, and the cost and size of the second load circuit 104 can be reduced.
Also, the protection circuit 107 can be realized at low cost and small size. Then, the battery 101 can be freely attached and detached, so that the ease of handling can be improved, and the safety and reliability can be improved.

FIG. 9 is a diagram showing a ninth embodiment of the present invention. In the figure, reference numeral 901 denotes a capacitor circuit row group;
02 is a battery status communication circuit, 903 is a PWM inverter
A converter 904 is a step-up / step-down chopper, and 905 is a control microcomputer.

Second load circuit 104 and capacitor 101
Are connected in series in units of four, respectively, and these are connected in parallel in a ladder shape via a protection circuit 107. Also, 4
A voltage detection circuit 201 and a comparator 301 for comparison with a reference voltage generation circuit 302 are connected in parallel to each of the second load circuits 104 grouped in units.
It is connected to the control terminal of each protection circuit 107. The battery state communication circuit 902 is connected to both ends of the second load circuit 104 connected in series in units of four. Then, the first load circuit 105 is connected to both ends of the capacitor circuit row group 901 and the capacitor row formed by these components that are further connected in series.

Here, the protection circuit 107 is an N-type MOS transistor, and its control circuits are a voltage detection circuit 201, a reference voltage generation circuit 302, and a comparator 301.
Other circuit configurations described above may be used.

The first load circuit 105 is a charging / discharging device, and mainly includes a PWM inverter / converter 903,
It comprises a step-up / step-down chopper 904 and a control microcomputer 905. And, in the whole circuit, it converts AC into DC,
It has the function of storing power and the function of converting stored DC to AC and outputting it.

Now, assuming that the storage device 101 is a lithium secondary battery, the second load circuit 104 includes a detection circuit for detecting overcharge, overdischarge, and temperature of each storage device 101, and a detection circuit for each storage device 10.
1 corresponds to a balance compensation circuit that corrects the current and voltage variations. In particular, the detection circuit corresponds to a dedicated IC corresponding to connection of four or less series. These detection circuits can also be used as the voltage detection circuit 201 and the comparator 301, the reference voltage generation circuit 302, or the bypass circuit 401.

In this circuit, when outputting an alternating current,
The DC of the battery 101 is stepped up by the step-up / step-down chopper 904 and converted into AC by the PWM inverter / converter 903. At this time, the voltage per unit cell of the lithium secondary battery generally changes from 2.5 V to 4.2 V,
As shown in the figure, the difference is further increased to 13.6 V as a whole in eight series. Therefore, the output voltage of the step-up / step-down chopper 904 is detected and fed back to the step-up chopper operation to stabilize the output voltage.

When assembling this circuit, a certain capacitor 101
Is removed, or when the last battery 101 can be attached, or when the built-in protection device 102 of the battery 101 during the output operation is opened due to an overcurrent or the like, the operation is as follows.

First, the remaining capacitor 104 is connected to the second load circuit 104 connected in parallel with the capacitor 101 of interest.
(Approximately -29.4 V at maximum) is likely to be applied. However, at the moment when the reverse bias is applied to the second load circuit 104, the voltage detection circuit 201 outputs a low voltage, turns off the protection circuit 107 composed of an N-type MOS transistor, and cuts off the connection. However, the remaining capacitor 101 and the second load circuit 104 connected in series
The connection of the second load circuit 104 to which the reverse bias is applied next is cut off. Then, similarly, the next second load circuit 104 is sequentially cut off, and eventually,
The respective second load circuits 104 grouped in units of four are cut off. Further, the connection between the storage battery array and the second load circuit 104 and the first load circuit 105 is completely disconnected.

Next, when charging the battery bank, the PWM inverter / converter 903 converts an AC input into a DC. The converted DC is stepped down by a step-up / step-down chopper to reduce the rated voltage of the battery array and charged.

If the step-up / step-down chopper 904 malfunctions or malfunctions and a voltage exceeding the rated voltage of the second load circuit 104 and the capacitor 101 is applied, the comparator 30
1 outputs a low potential, and the protection circuit 107 cuts off the connection between the second load circuit 104 and the capacitor 101. Then, if there is a path passing through the remaining second load circuits 104, the next second load circuit 104 is similarly sequentially cut off, and eventually, each of the second second load circuits 104 is divided into groups of four. Is shut off. Further, the connection between the storage battery array and the second load circuit 104 and the first load circuit 105 is completely disconnected.

On the other hand, while the abnormality occurs as described above and the connection of the second load circuit 104 is cut off, the power supply of the battery state communication circuit 902 is cut off, and the information is stored in the control microcomputer.
Conveyed to 905. Upon receiving this information, the control microcomputer 905 stops the PWM inverter / converter 903 and the step-up / step-down chopper 904. This allows
It is also possible to protect the entire device. In particular, for the maximum output voltage of a single cell of 4.2 V, the output fluctuation of the battery
In a circuit that fluctuates as large as 13.6 V, even if several cells are cut off, the first load circuit 105 operates normally and further destroys other circuits. Therefore, when the connection of the battery 101 is disconnected as described above, detecting the information and stopping the entire device is not only a partial circuit protection, but also the safety, reliability and handling of the entire device. It greatly contributes to the improvement of performance. As described above, in the present capacitor application circuit, even if the second load circuit 104 is connected in series, the second load circuit can be cut off and protected in units of four series divided into groups. Then, the withstand voltage of the second load circuit 104, the voltage detection circuit 201, and the comparator 301 can be reduced to four series. In particular, the voltage of four series is 16.8 V at the maximum, which is compatible with the rated voltage of general-purpose semiconductor devices. For this reason,
The second load circuit and the voltage detection circuit 201, the reference voltage generation circuit 302, the comparator 301, or the bypass circuit 401 can be realized by the same IC. Further, the cost and size of the second load circuit 104 can be reduced. Further, the battery 101 can be freely attached and detached, so that it is possible to improve ease of handling, safety, and reliability.

FIG. 10 is a diagram showing a tenth embodiment of the present invention. In the figure, 1001 is an analog switch,
1002 is an insulation amplifier.

The input of the isolation amplifier 1002 is connected via an analog switch 1001 to each connection point of the capacitors 101 connected in series in units of four. The output of the isolation amplifier 1002 and the input of the analog switch 1001 are connected to the control microcomputer 905. And
A first load circuit 105 is connected to both ends of the capacitor circuit row group 901 and the capacitor row formed by these components that are further connected in series.

The insulated amplifier 1002 detects the voltage between terminals of each battery 101, and the analog switch 1001 also serves to select the battery 101 for detecting the voltage and to perform balance compensation.

In this circuit, at the time of assembly, a certain capacitor 1
01 is removed, or the last battery 101 is attached, the built-in protection device 102 of the battery 101 during output operation is opened due to overcurrent, or the buck-boost chopper 904 malfunctions or malfunctions. When an abnormal voltage is applied, the control microcomputer 905
An abnormality is determined from the voltage of the insulation amplifier 1002, and all the analog switches 1001 are shut off. Further, the PWM inverter / converter 903 and the step-up / step-down chopper 904 are stopped. Thus, the input rating of the insulated amplifier 1002 can reduce the voltage for four series. In addition, the isolation amplifier 1002 includes the voltage detection circuit 201 and the battery state communication circuit 902, the analog switch 1001 includes the selection switching circuit, the balance compensation circuit, and the protection circuit 107, and the control microcomputer 905 includes the reference voltage generation circuit 302 and the comparator 301. It is possible to use both. Therefore, the number of parts, cost, and size can be reduced.

As described above, in the capacitor application circuit, the withstand voltage of the insulating amplifier 1002 can be reduced to four series, and the cost and size can be reduced by sharing the circuits. Further, the battery 101 can be freely attached and detached, so that it is possible to improve ease of handling, safety, and reliability.

[0071]

As described above, according to the present invention, the voltage rating of a load circuit connected to a series-connected capacitor is reduced, the load circuit, the capacitor, and the entire circuit are protected. It is possible to provide a low-cost, small-sized, safe, easy-to-handle, and highly reliable power storage application circuit that can be installed in any order.

Therefore, in particular, a charge / discharge device using a lithium battery or an electric double layer capacitor, a battery pack in which a plurality of cells are connected in series and parallel, an open type protection element or a safety device connected in series in a battery, It is useful in an electric device using them.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a seventh embodiment of the present invention.

FIG. 8 is a diagram showing an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a ninth embodiment of the present invention.

FIG. 10 is a diagram showing a tenth embodiment of the present invention.

FIG. 11 is a sectional view of a conventional safety device.

FIG. 12 is a diagram showing a capacitor application circuit using a capacitor connected in series.

[Explanation of symbols]

101, 1201 ... electric storage device, 102, 1202 ... built-in protection device, 103, 1203 ... secondary battery, 104, 1204 ...
Second load circuit, 105, 1205 ... first load circuit,
201: voltage detection circuit, 301: comparator, 302
... Reference voltage generation circuit, 401, bypass circuit, 601
Piezoelectric switch, 701 ... Zener diode, 901 ...
Battery circuit row group, 902... Battery status communication circuit, 9
03: PWM inverter / converter, 904: step-up / step-down chopper, 905: control microcomputer, 1001: analog switch, 1002: insulating amplifier, 1101: metal safety valve, 1102: insulating ring, 1103: metal perforated terminal board, 1104 Metal lead mounting plate, 1105: bent portion, 1106: welded portion.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akihiro Takanuma 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Pref.

Claims (10)

[Claims] 1. A series of capacitors connected in series, a first load circuit connected to both ends of the series of capacitors, and a second series connected to the series of capacitors smaller in number than the series of the series of capacitors. A storage capacitor application circuit comprising a load circuit, wherein a protection circuit for preventing reverse bias of the second load circuit is provided in series with the second load circuit. 2. The switch according to claim 1, wherein a voltage detection circuit for detecting a voltage of the second load circuit is provided in parallel with the second load circuit, and a switch that opens and closes according to an output of the voltage detection circuit. Wherein the protection circuit is provided in series with the second load circuit. 3. A voltage detection circuit for detecting a voltage of said second load circuit, a reference value generation circuit for generating a predetermined voltage, an output of said reference value generation circuit and said second load circuit. A comparator for comparing the applied voltage of the load circuit with the second load circuit, and a protection circuit comprising a switch that opens and closes in accordance with the output of the voltage detection circuit and the comparator; A battery application circuit, which is provided in series with a capacitor. 4. A circuit according to claim 1, further comprising: a voltage detection circuit for detecting a voltage of said second load circuit, and a bypass circuit for opening and closing in response to an output of said voltage detection circuit, in parallel with said second load circuit. And a protection circuit comprising a current-sensitive fuse provided in series with said second load circuit. 5. A voltage detecting circuit according to claim 1, wherein a voltage detecting circuit for detecting a voltage of said second load circuit, a reference value generating circuit for generating a predetermined voltage, an output of said reference value generating circuit, A comparator for comparing the applied voltage of the load circuit,
A bypass circuit that opens and closes according to the output of the voltage detection circuit and the comparator is provided in parallel with the second load circuit, and a protection circuit including a current-sensitive fuse is provided with the second load circuit. Characteristic capacitor application circuit. 6. A storage capacitor application circuit according to claim 1, further comprising a protection circuit comprising a piezoelectric switch to which an applied voltage of said second load circuit is input, said protection circuit being connected in series with said second load circuit. . 7. A circuit according to claim 1, wherein a Zener diode having a cathode connected to a positive side of said second load circuit is provided in parallel with said second load circuit, and a protection circuit comprising a current fuse is provided in said second load circuit. A capacitor application circuit, which is provided in series with a circuit. 8. A circuit according to claim 1, wherein a Zener diode having a cathode connected to a positive side of said second load circuit is provided in parallel with said second load circuit, and a protection circuit comprising PTC is provided in said second load circuit. A battery application circuit, which is provided in series with a capacitor. 9. The battery according to claim 1, wherein the battery, a second load circuit connected in parallel with the battery, and a protection circuit connected in series with the second load circuit are connected in series in a ladder shape. A battery comprising: a circuit array; and first load circuits connected to both ends of the battery circuit array, wherein the number of series-connected second load circuits in the battery circuit array is divided into a predetermined group. Application circuit. 10. The storage state communication circuit according to claim 1, wherein a storage state communication circuit is provided between the second load circuit or the grouped second load circuits and the protection circuit. A capacitor application circuit.