JPH11113178A - Cutoff method of protection circuit, secondary battery device and secondary battery recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid an overcharged or an overdischarged state of a secondary battery by a method wherein, when the secondary battery is overcharged or overdischarged, the secondary battery is discharged or charged through an electric circuit. SOLUTION: In a protection circuit 11, the emitter of a P-N-P transistor Tr1 of an on-set circuit 12 is connected to a control circuit 13 and the collector of the P-N-P transistor Tr1 is connected to an electric circuit with which the cathode of a secondary battery BT is connected to a switch circuit 8. Thus, in the protection circuit 11, by supplying pulse control signals S5 continuously from a signal input terminal T, the on-set circuit 12 is kept on and hence the control circuit 13 can reset the switch circuit 8 through a drive circuit 7. With this constitution, the protection circuit 11 can charge or discharge the secondary battery BT by putting the transistors FET1 and FET2 of the switch circuit 8 into continuity the control circuit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order.

BACKGROUND OF THE INVENTION Prior Art (FIGS. 20 and 21) Problems to be Solved by the Invention Means for Solving the Problems Embodiments of the Invention (1) Configuration of Battery Pack (FIG. 1) (2) 1. First Embodiment (2-1) Configuration of Protection Circuit in First Embodiment (2-1-1) First Configuration of Protection Circuit (FIGS. 2 to 5) (2-1-2) (2) Second configuration of protection circuit (FIG. 6) (2-1-3) Third configuration of protection circuit (FIG. 7) (2-1-4) Fourth configuration of protection circuit (FIG. 8) (2) -2) Configuration of secondary battery return device (FIGS. 9 to 11) (2-3) Operation and effect in first embodiment (3) Second embodiment (3-1) Configuration of protection circuit (FIGS. 12 and 13) (3-2) Configuration of Secondary Battery Returning Device (FIGS. 14 and 17) (3-3) Operation and Effect in Second Embodiment (4) Other embodiments (FIGS. 18 and 19) the effect of the invention

[0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for releasing a protection circuit, a secondary battery device, and a secondary battery return device, for example, a secondary battery device containing a secondary battery such as a lithium ion battery, and the secondary battery device. This is suitable for application to a secondary battery return device that adjusts the voltage value of the above to a voltage value within a use range.

[0004]

2. Description of the Related Art In recent years, demand for small electronic devices such as a headphone stereo, a camera-integrated VTR (Video Tape Recorder), and a portable telephone has been increasing. These small electronic devices are equipped with a battery pack containing a high-capacity secondary battery (for example, a lithium ion battery), and operate with the battery pack as a power source to carry these small electronic devices. It has been made usable. Such a battery pack is charged by using a predetermined charging device while it is mounted on a small electronic device or by a single battery pack.

[0005] In practice, the battery pack is provided with a protection circuit in the battery pack to prevent overcharging of the secondary battery during charging or overdischarging from the secondary battery during discharging. The overcharge state and the overdischarge state are detected based on the voltage value of the secondary battery.

When such an overcharge state and an overdischarge state are detected, the protection circuit cuts off the electric path to the secondary battery, thereby excessively inputting the charging current to the secondary battery and discharging current from the secondary battery. Prevents excessive release.

[0007] In addition, since the charging power for the rechargeable battery is generally maintained while maintaining the charging voltage at a constant voltage, the current detecting device requires that the current value of the charging current fall below the reference current. Is detected to identify that the secondary battery has reached a fully charged state. Conventionally, such current detection is performed by arranging a resistor on the electric path to the secondary battery and measuring the voltage across the resistor.

For example, as shown in FIG. 20, reference numeral 1 denotes a battery pack as a whole, which comprises a voltage detection circuit 2, a current detection circuit 3, a protection circuit 4, and a secondary battery BT. The battery pack 1 connects the secondary battery BT to the input / output terminals A and B.
And a positive electrode of the secondary battery BT is connected to the input / output terminal A, and a resistor is provided on the electric path between the negative electrode of the secondary battery BT and the input / output terminal B. Element R1
And the protection circuit 4 are connected in series.

The voltage detection circuit 2 detects the voltage between both ends of the secondary battery BT and notifies the control circuit 6 in the protection circuit 4 of the voltage value of the secondary battery BT as a detection result signal S1. The current detection circuit 3 detects the value of the current supplied to the secondary battery BT by measuring the voltage across the resistance element R1 provided on the electric path, and detects the electric current based on the potential difference between the voltages across the resistance element R1. The direction of the current flowing in the path (that is, charging or discharging) is detected, and the detection result signal S2 is notified to the control circuit 6 in the protection circuit 4.

The protection circuit 4 includes a control circuit 6 and a drive circuit 7
And a switching circuit 8 composed of field effect transistors FET1 and FET2 whose gates are connected to the drive circuit 7. The field effect transistor FET
1 and FET2 are connected in series on an electric path connecting the input / output terminal B and the resistance element R1. The field effect transistors FET1 and FET2 are provided so that the connection direction between the source (S) and the drain (D) is opposed to each other.
The current is made to flow.

Thus, the field effect transistor FET1
Is turned on by a signal supplied from the drive circuit 7 to the gate under the control of the control circuit 6, so that a charging current flows from the secondary battery BT toward the input / output terminal B, and the field effect transistor FET2 is turned on. It is turned on by a signal supplied from the drive circuit 7 to the gate, and a discharge current flows from the secondary battery BT in the direction of the input / output terminal A.

Further, the field effect transistors FET1 and FET2 are respectively provided with parasitic diodes D1 and D2 whose rectification directions are opposite to the rectification direction when active, so that the field effect transistors FET1 and FET2 are turned off. Sometimes, the current flows in a direction opposite to the direction in which the current flows.

In practice, the protection circuit 4 turns on the field effect transistor FET1 and turns off the field effect transistor FET2 via the drive circuit 7 under the control of the control circuit 6 to charge the secondary battery BT when charging the secondary battery BT. When discharging from the control circuit 6, the field effect transistor FET1 is turned off and the field effect transistor FET2 is turned on via the drive circuit 7 under the control of the control circuit 6. When neither charging nor discharging is performed, the protection circuit 4 turns off both the field effect transistors FET1 and FET2 via the drive circuit 7 under the control of the control circuit 6.

As described above, the protection circuit 4 turns on the field-effect transistor FET1 and turns off the field-effect transistor FET2 at the time of charging, so that the protection circuit 4 passes from the input / output terminal A via the secondary battery BT, the parasitic diode D2 and the field-effect transistor FET1. As a result, a current flows through the input / output terminal B, and a charging current from a charging device (not shown) connected to the input / output terminals A and B is supplied to the secondary battery BT to be charged.

The protection circuit 4 turns off the field effect transistor FET1 during discharging,
By turning on 2, the current flows from the input / output terminal B to the input / output terminal A via the parasitic diode D1, the field effect transistor FET2, and the secondary battery BT,
Load device (not shown) connected to input / output terminals A and B
Is supplied from the secondary battery BT to the power supply.

Incidentally, the protection circuit 4 in this case may turn on both the field effect transistors FET1 and FET2 of the switching circuit 8 when charging or discharging. Next battery B
T, rectifier diode D2, field effect transistor FET
1 flows into the input / output terminal B, and the discharge current flows from the input / output terminal B to the rectifier diode D1 and the field effect transistor FE.
T2 flows to the input / output terminal A through the secondary battery BT.

Further, in the protection circuit 4, the control circuit 6 adjusts the operation of the switching circuit 8 based on the detection result signals S1 and S2 sent from the voltage detection circuit 2 and the current detection circuit 3, respectively. The on / off of the field effect transistors FET1 and FET2 is adjusted to perform charging or discharging when the voltage value of the battery pack 1 is within the normal use range, and when the voltage value is outside the use range, the field effect transistors FET1 and FET2 are set. Is turned off to cut off the electric path, thereby preventing overcharge and overdischarge of the secondary battery to protect the battery pack 1.

The range of use of the battery pack 1 is as follows.
As shown in FIGS. 21A to 21C, the normal use range is 2.7 [V] to 4.25 [V], and the charging voltage of the charger is 4.15.
[V] to 4.25 [V]. Therefore, when the detection result signal S1 from the voltage detection circuit 2 is 4.30 [V] to 4.40 [V], it is overcharged, and when it is 2.60 [V] to 2.50 [V], it is overdischarged. .

That is, the control circuit 6 performs the operation of the secondary battery BT based on the detection result signal S1 supplied from the voltage detection circuit 2.
Is determined to be in an overcharged state (4.30 [V] to 4.40 [V]) outside the operating range (for example, 2.7 [V] to 4.25 [V]), the switching circuit via the drive circuit 7 The field-effect transistors FET1 and FET2 of No. 8 are both turned off to interrupt the charging current.

Also, the control circuit 6 is in an overdischarge state (2.60 [V] to 2.50 [V]) where the voltage across the secondary battery BT is out of the usable range based on the detection result signal S1 supplied from the voltage detection circuit 2.
), The field effect transistors FET1 and FET2 of the switching circuit 8 are turned off via the drive circuit 7 to cut off the discharge current.

Further, the control circuit 6 determines, based on the detection result signal S2 supplied from the current detection circuit 3, that the current value of the charging current or the discharging current is not less than a predetermined reference current value (that is, the charging current or the discharging current is Even when the overcurrent state is determined, the field effect transistors FET1 and FET2 are turned off via the drive circuit 7 to interrupt the charging current and the discharging current, thereby protecting the secondary battery BT.

As described above, the protection circuit 4 includes the voltage detection circuit 2
By adjusting the on / off operation of the switching circuit 8 based on the detection result of the current detection circuit 3, the conduction state or the interruption state of the electric path can be controlled, and thus the battery pack 1 is protected.

The battery pack 1 receives the detection result signal S
When an overcharge state or an overdischarge state is detected based on 1 and S2, the protection circuit 4 operates to turn off the field effect transistors FET1 and FET2 of the switching circuit 8, but the circuit operates once to cut off the electric path. In this case, the protection circuit is a non-recoverable protection circuit that does not return the FETs 1 and 2 of the switching circuit 8 to the ON state.
ET1 and FET2 cannot be restarted to the ON state.

Therefore, once the protection circuit 4 of the battery pack 1 operates to cut off the electric path, the user again turns on the field effect transistors FET1 and FET2 of the switching circuit 8 at the service center of the manufacturer. At the same time, the battery pack 1 must be started up and the voltage value of the battery pack 1 must be adjusted so as to be within the range of use.

In this case, the serviceman sets the battery pack 1 to a predetermined secondary battery return device (not shown), and the predetermined voltage (input / output) is input via the signal input terminal T by the secondary battery return device. A DC control signal S3 of plus or minus DC (direct current) voltage between the terminal A and the signal input terminal T, or plus or minus DC voltage between the signal input terminal T and the input / output terminal B) 6

Thus, the control circuit 6 outputs the DC control signal S3
, The field effect transistors FET1 and FET2 of the switching circuit 8 are turned on again via the drive circuit 7 so that charging or discharging can be performed. Make the electrical path conductive.

[0027]

Although the protection circuit 4 having such a configuration is non-recoverable, it is not completely non-recoverable so that the protection operation can be restarted by the DC control signal S3. When the external overcharge state or the overdischarge state is reached, the field effect transistors FET1 and FET2 of the switching circuit 8 are turned off to cut off the electric path. There is a possibility that the field effect transistors FET1 and FET2 of the switching circuit 8 may be turned on by itself due to a short circuit with the signal input terminal T. In such a case, there is a problem that the battery pack 1 again causes an overcharged state or an overdischarged state and the secondary battery BT cannot be safely protected.

The present invention has been made in consideration of the above points, and proposes a method of releasing a protection circuit capable of safely restarting a secondary battery, a secondary battery device, and a secondary battery recovery device. It is.

[0029]

In order to solve the above-mentioned problems, the present invention relates to a method of charging or discharging a secondary battery connected between one and the other input / output terminals.
When the secondary battery is in an overcharged state or an overdischarged state, a method of releasing a protection circuit for protecting the secondary battery from an overcharged state or an overdischarged state by cutting off an electric path of the secondary battery by switching means. A first step of generating a DC voltage based on an AC voltage externally input through a predetermined signal input terminal, and driving an electrical path of the secondary battery by driving switching means based on the DC voltage. A second step of conducting, and discharging the secondary battery via an electrical path when the secondary battery is in an overcharged state, and discharging the secondary battery via an electrical path when the secondary battery is in an overdischarged state. And a third step of releasing the secondary battery from the overcharged state or the overdischarged state by charging the battery and releasing the protection operation for the secondary battery.

As described above, when the internal secondary battery is in an overcharged state or an overdischarged state, the secondary battery device is activated based on the AC voltage externally input through a predetermined signal input terminal. By making the electric path of the secondary battery conductive, it is possible to prevent the electric path of the secondary battery from being made conductive by an unintended signal, and to prevent the electrical path of the secondary battery from being applied only by an intentionally supplied AC voltage. By conducting the electric path of the secondary battery and charging or discharging the secondary battery in the conductive state of the electric path, the overcharge state or the overdischarge state can be eliminated.

Also, in the present invention, a secondary battery connected between one and the other input / output terminals, voltage detecting means for detecting a voltage value of the secondary battery, and a secondary battery provided on an electric path of the secondary battery are provided. Switching means, a rectifying means for generating a DC voltage based on an AC voltage inputted from the outside via a predetermined signal input terminal, and a secondary detecting means for charging or discharging a secondary battery and thereafter detecting the secondary voltage by a voltage detecting means. Detects the voltage value of the battery,
When it is detected that the secondary battery has entered an overcharged state or an overdischarged state, the switching means is switched to a cutoff state to protect the secondary battery, and when the protection operation is activated, the DC voltage is supplied from the rectifying means. Switching control means for switching the switching means to the conductive state when supplied is provided.

As described above, when the secondary battery device is in the overcharged state or the overdischarged state, the switching means is switched to the cutoff state to protect the secondary battery, and in this state, the DC voltage supplied from outside is used. As a result, the switching means is made conductive only by an AC voltage externally input through a predetermined signal input terminal without releasing the cut-off state of the secondary battery, whereby an unintended signal is output. Thus, it is possible to prevent the electric path of the secondary battery from being conducted, and to conduct the electric path of the secondary battery only by intentionally supplied AC voltage.

Further, in the present invention, the voltage value of the secondary battery connected between one input terminal and the other input / output terminal of the secondary battery device is detected by the first voltage detecting means, and the secondary battery is overcharged. When the battery is in the charged state or the overdischarged state, the switching means provided on the electric path of the secondary battery is shut off, and the switching means is switched to the conductive state by external control to discharge or charge the secondary battery. An AC voltage generating means for generating an AC voltage in the secondary battery restoring device for restoring the secondary battery to a voltage value within a use range.
Second voltage detecting means for detecting the voltage value of the secondary battery, voltage adjusting means for eliminating the overcharged or overdischarged state of the secondary battery by charging or discharging the secondary battery, The switching means is switched to a conductive state by supplying the power via a predetermined signal input terminal of the battery device, and the second
If the result of the detection by the voltage detecting means is an overcharged state or an overdischarged state, the secondary battery is charged or discharged by the voltage adjusting means, and the charged or discharged secondary battery has a voltage within a use range. And a control means for supplying an AC voltage to the secondary battery device until the value returns to a value.

As described above, when the secondary battery device is in the overcharged state or the overdischarged state, the switching means is turned on by supplying an AC voltage to the secondary battery device through a predetermined signal input terminal. By switching to the state, the secondary battery is charged or discharged, and the secondary battery after the charging or discharging is supplied with an AC voltage until the secondary battery returns to a voltage value within a normal use range, thereby protecting the secondary battery. The voltage can be released and the overcharged state or the overdischarged state can be eliminated to return to a voltage value within a normal use range.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Configuration of Battery Pack In FIG. 1 in which parts corresponding to those in FIG. 20 are assigned the same reference numerals, reference numeral 10 indicates a battery pack as a secondary battery device of the present invention as a whole, and is mainly a secondary battery. Battery BT, voltage detection circuit 2,
The protection circuit 11 includes a current detection circuit 3 and a protection circuit 11. The protection circuit 11 is provided with a new onset circuit 12 and a smoothing capacitor C1, and the protection circuit 11 is connected to the temperature detection thermistor 14 using a signal input terminal T. A pulse control signal S5 for restarting the switching circuit 8 is inputted, and the control circuit 1 as switching control means is provided.
Battery pack 1 except that the processing of step 3 was changed
It has almost the same configuration as (FIG. 20).

The protection circuit 11 turns on the on-set circuit 12 when a pulse control signal S5 composed of an AC voltage or a pulsed voltage is supplied via the signal input terminal T. The on-set circuit 12 supplies a reset signal S6 to the control circuit 13 after being turned on based on the pulse control signal S5. Accordingly, the control circuit 13 drives the drive circuit 7 based on the reset signal S6 to turn on both the FET1 and the FET2 of the switching circuit 8 (hereinafter, this is called a reset), so that the control circuit 13 can be charged or discharged. To return to.

In this case, since the protection circuit 11 is provided with the smoothing capacitor C1, even when the DC control signal S3 of a predetermined voltage is supplied through the signal input terminal T as in the conventional case, the protection circuit 11 uses the smoothing capacitor C1. Thus, the DC component can be removed, so that the onset circuit 12 cannot be turned on by the DC control signal S3. Accordingly, in the protection circuit 11, the switching circuit 8 of the protection circuit 11 cannot be reset by static electricity or noise other than the pulse control signal S5 supplied intentionally.

(2) First Embodiment (2-1) Configuration of Protection Circuit in First Embodiment Next, four types of circuit configurations of the protection circuit 11 will be described. Here, the internal configuration of the on-set circuit 12 of the protection circuit 11 differs from the first configuration to the fourth configuration.
The other control circuit 13, drive circuit 7, switching circuit 8, and smoothing capacitor C1 are common.

(2-1-1) First Configuration of Protection Circuit First, as shown in FIG. 2, in the first configuration of the protection circuit 11, the PNP transistor Tr1 of the on-set circuit 12 is used.
Is connected to the control circuit 13, and the collector is connected to an electric path connecting the negative electrode side of the secondary battery BT and the switching circuit 8. The base of the PNP transistor Tr1 is connected to a signal input terminal T via a base resistor R2, a Zener diode TD1, a rectifier diode D3, and a smoothing capacitor C1.

The anode of a rectifier diode D4 is connected to one end of a smoothing capacitor C1 in a first electric path connecting the negative electrode side of the secondary battery BT and the signal input terminal T. Further, a smoothing capacitor C2 is provided in a second electric path connecting the negative electrode side of the secondary battery BT and the signal input terminal T, and one end of the smoothing capacitor C2 is connected to a rectifying diode D.
3 is connected to the anode.

As described above, the smoothing capacitor C1 and the rectifying diode D4 provided on the first electric path connecting the negative electrode side of the secondary battery BT and the signal input terminal T, and the smoothing capacitor provided on the second electric path. C2 and rectifier diode D
3 form a voltage doubler rectifier circuit.

The collector of the PNP transistor Tr1 is connected to a parasitic diode D5 for preventing a current from flowing backward from the collector to the base, the base resistor R2, the Zener diode TD1, the rectifier diode D3, and the smoothing capacitor C1 in this order. ing.

When the battery pack 10 is connected to a secondary battery return device to be described later, the input / output terminals A and B are connected by an impedance element R3 such as a resistor provided on the secondary battery return device side. As a result, a loop is formed between the input / output terminal A and the signal input terminal T.

In the protection circuit 11 having the on-set circuit 12 having such a configuration, the on-set circuit 12 is actually
When the transistor Tr1 of the switching circuit 8 is turned on and the FET1 and the FET2 of the switching circuit 8 are both turned on (reset) by the control circuit 13, the pulse control signal S5 having a predetermined potential (± ep) is applied between the input / output terminals A and B. Is supplied from outside through the signal input terminal T.

First, as shown in FIG. 3, when a negative low-level voltage (-ep) is first inputted from the signal input terminal T, since the FET1 and FET2 of the switching circuit 8 have not yet been turned on, they are turned on. The smoothing capacitor C1 and the rectifying diode D do not flow to the output terminal B but follow a loop formed between the signal input terminal T and the input / output terminal A.
4. Current flows in the order of the secondary battery BT (in the direction of the arrow). As a result, a potential difference (V _ep + V _BT ) obtained by adding the pulse voltage (V _ep ) and the voltage (V _BT ) of the secondary battery BT is generated at both ends of the smoothing capacitor C1.

Next, as shown in FIG.
When 5 changes from a negative low level voltage (-ep) to a positive high level voltage (+ ep), the secondary battery BT and the smoothing capacitor follow a loop formed between the input / output terminal A and the signal input terminal T. A current flows in the order of C2 and the rectifier diode D3 (in the direction of the arrow).

As a result, the current (V _ep + V _BT ) generated at both ends of the smoothing capacitor C 1 and the positive pulse voltage (V _ep ) in response to the current flowing in the opposite direction based on the current (V _ep + V _BT ) cause a pulse (P period) of one cycle. + Ep and -ep) are input, the smoothing capacitor C1 is connected to both ends of the smoothing capacitor C2.
Resulting double potential difference across the resulting potential (V _ep + V _BT) and by the current flowing in the reverse direction connexion resulting potential (V _ep -V _BT) and the pulse voltage (V _ep) (2V _ep) is Will be. Accordingly, a potential difference (2 V _ep ) exceeding the reference value of the Zener diode TD1 is generated between the base and the emitter of the PNP transistor Tr1, and the PNP transistor Tr1 is turned on (FIG. 2).

Incidentally, the PNP transistor Tr1 is turned on when a potential difference of 2 V _ep is generated between both ends of the smoothing capacitor C2 by the pulse control signal S5, but the secondary current is not supplied when the pulse control signal S5 is not supplied. Since the voltage (V _BT ) of the battery BT alone does not exceed the reference value of the zener diode TD1, the PNP transistor Tr1 does not turn on.

As described above, in the protection circuit 11, the pulse control signal S5 is continuously supplied from the signal input terminal T so that the on-set circuit 12 is maintained in the on state. Thus, the switching circuit 8 can be reset. Thus protection circuit 1
1 is the FE of the switching circuit 8 by the control circuit 13.
By making T1 and FET2 conductive, the secondary battery BT can be charged or discharged.

As shown in FIG. 5, the protection circuit 11
By providing the parasitic diode D5 having the anode connected to the collector of the NP transistor Tr1, even if a high voltage is applied between the input / output terminal A and the signal input terminal T due to some mistake, the input / output terminal A side From flowing through the base from the collector over the withstand voltage of the PNP transistor Tr1. Thus, the battery pack 10 can safely protect the secondary battery BT without being overcharged even when a high voltage is applied between the input / output terminal A and the signal input terminal T.

(2-1-2) Second Configuration of Protection Circuit Subsequently, as shown in FIG. 6, in the second configuration of the protection circuit 11, except for the internal configuration of the on-set circuit 12 in the first configuration. This is the same as the first configuration of the protection circuit 11 (FIG. 2). That is, the on-set circuit 12 of the protection circuit 11
Is arranged with an NPN transistor Tr2 instead of the PNP transistor Tr1, and rectifier diodes D6 and D6 whose rectification directions are opposite to each other instead of the rectifier diodes D3 and D4.
7 are arranged.

The smoothing capacitors C1 and C2 are the same as those in the first configuration of the protection circuit 11 (FIG. 2). However, in the second configuration, since the current directions are opposite, the smoothing capacitors C1 and C2 have the same configuration. The polarity is also reversed.

Further, a parasitic diode D8 for the same purpose as the parasitic diode D5 in the first configuration (FIG. 2) of the protection circuit 11 is connected to the emitter of the NPN transistor Tr2. To prevent the current from flowing backward. In the second configuration, the first
Although the Zener diode TD1 provided in the onset circuit 12 having the configuration described above has been removed, the Zener diode TD1 may be provided similarly to the first configuration.

By the way, also in the second configuration of the protection circuit 11, the smoothing capacitor C1 and the rectifying diode D7 provided on the first electric path connecting the negative electrode side of the secondary battery BT and the signal input terminal T, A voltage doubler rectifier circuit is formed by the smoothing capacitor C2 and the rectifier diode D6 provided in the electric path of FIG.

Therefore, in the second configuration of the protection circuit 11, when a positive high-level voltage (+ ep) is first input from the signal input terminal T, the FET of the switching circuit 8
1 and the FET 2 have not yet been turned on, so that they do not flow to the input / output terminal B side, but along the loop formed between the input / output terminal A and the signal input terminal T, the secondary battery BT and the rectifier diode D7. , A current flows in the order of the smoothing capacitor C1. Thus, both ends of the pulse voltage of the smoothing capacitor C1 (V _ep) and the secondary battery BT of the voltage (-V _BT) and is added the potential difference (V _ep -V _BT) occurs.

Next, the pulse control signal S5 changes from a positive high-level voltage (+ ep) to a negative low-level voltage (-e).
When the state changes to p), a current flows in the order of the rectifier diode D6, the smoothing capacitor C2, and the secondary battery BT along a loop formed between the input / output terminal A and the signal input terminal T.

Thus, a pulse for one cycle is generated by a current flowing in the reverse direction based on the potential (V _ep −V _BT ) generated at both ends of the smoothing capacitor C 1 and the negative pulse voltage (V _ep ). When (+ ep and -ep) are input, the smoothing capacitor C1 is connected to both ends of the smoothing capacitor C2.
Resulting double potential difference across the resulting potential (V _ep -V _BT) and reverse direction flow potential caused connexion by the current (V _ep + V _BT) and the pulse voltage (V _ep) (2V _ep) is Will be. Accordingly, a potential difference (2 V _ep ) is generated between the base of the NPN transistor Tr2 and the emitter, and the NPN transistor Tr2 is turned on.

As described above, in the protection circuit 11, the pulse control signal S 5 is continuously supplied from the signal input terminal T, so that the on-set circuit 12 is maintained in the on state, whereby the control circuit 13 is controlled via the drive circuit 7. Thus, the switching circuit 8 can be reset. Thus protection circuit 1
1 is the FE of the switching circuit 8 by the control circuit 13.
By making T1 and FET2 conductive, the secondary battery BT can be charged or discharged.

(2-1-3) Third Configuration of Protection Circuit Next, FIG. 7 in which parts corresponding to those in FIG.
The third configuration of the protection circuit 11 is the same as the onset circuit 12 in the first configuration except that the connection point of the rectifier diode D4 is different. That is, in the on-set circuit 12 of the protection circuit 11, a rectifier diode D4 is provided on an electric path connecting the input / output terminal A and the signal input terminal T, an anode of the rectifier diode D4 is connected to one end of the smoothing capacitor C1, and a cathode is provided. Are connected to the input / output terminal A side.

In the third configuration of the protection circuit 11 in this case, the smoothing capacitor C1 and the rectifying diode D4 provided on the first electric path connecting the input / output terminal A and the signal input terminal T also include the secondary battery. Negative side of BT and signal input terminal T
Capacitor C provided in a second electric path connecting
2 and the rectifier diode D3 form a voltage doubler rectifier circuit.

Accordingly, in the third configuration of the protection circuit 11, when a negative low-level voltage (-ep) is first input from the signal input terminal T, a voltage between the input / output terminal A and the signal input terminal T is established. A current flows in the order of the smoothing capacitor C1 and the rectifier diode D4 along the formed loop.

Next, the pulse control signal S5 is changed from a negative low level voltage (-ep) to a positive high level voltage (+ e
When the state changes to p), a current flows in the order of the smoothing capacitor C2 and the rectifier diode D3 along a loop formed between the input / output terminal A and the signal input terminal T.

As a result, when one cycle of the pulse (+ ep and -ep) is input, the potential difference (2V _ep ) twice the pulse voltage (V _ep ) is applied across the smoothing capacitor C2.
Is generated, a potential difference (2 V _ep ) is generated between the base of the PNP transistor Tr1 and the emitter, and the PNP transistor Tr1 is turned on.

As described above, in the protection circuit 11, the pulse control signal S 5 is continuously supplied from the signal input terminal T, so that the on-set circuit 12 is maintained in the on state, whereby the control circuit 13 is controlled via the drive circuit 7. Thus, the switching circuit 8 can be reset. Thus protection circuit 1
1 is the FE of the switching circuit 8 by the control circuit 13.
By making T1 and FET2 conductive, the secondary battery BT can be charged or discharged.

(2-1-4) Fourth Configuration of Protection Circuit Next, FIG. 8 in which parts corresponding to those in FIG.
In the fourth configuration of the protection circuit 11, the connection point of the rectifier diode D7 is different from that of the second configuration (FIG. 6) on the first electric path connecting the input / output terminal A and the signal input terminal T. It is the same as the onset circuit 12 in the second configuration except that the rectifier diode D7 is provided with a zener diode TD2 in series.

Incidentally, also in the fourth configuration of the protection circuit 11, the smoothing capacitor C1 and the rectifying diode D7 provided on the first electric path connecting the input / output terminal A and the signal input terminal T, and the secondary battery BT Capacitor C provided on a second electric path connecting the negative electrode side of the
2 and the rectifier diode D6 form a voltage doubler rectifier circuit. The zener diode TD2 connected in series with the rectifier diode D7 is turned on when the pulse voltage of the pulse control signal S5 exceeds the reference voltage of the zener diode TD2.

Accordingly, in the fourth configuration of the protection circuit 11, when a positive high-level voltage (+ ep) exceeding the reference voltage of the Zener diode TD2 is first input from the signal input terminal T, the input / output terminal A and the signal A current flows in the order of the Zener diode TD2, the rectifier diode D7, and the smoothing capacitor C1 along a loop formed between the input terminal T and the input terminal T.

Next, the pulse control signal S5 changes from a positive high level voltage (+ ep) to a negative low level voltage (-e).
When the state changes to p), a current flows in the order of the rectifier diode D6 and the smoothing capacitor C2 along a loop formed between the input / output terminal A and the signal input terminal T.

As a result, when one cycle of the pulse (+ ep and -ep) is input, the potential difference (2V _ep ) twice the pulse voltage (V _ep ) is applied across the smoothing capacitor C2.
Is generated, a potential difference (2 V _ep ) is generated between the base of the NPN transistor Tr2 and the emitter, and the NPN transistor Tr2 is turned on.

In the fourth configuration of the protection circuit 11, current does not flow unless the pulse voltage of the pulse control signal S5 exceeds the reference voltage of the zener diode TD2. If the signal S5 is not supplied, the NP of the on-set circuit 12
The N transistor Tr2 cannot be turned on. Therefore, in the fourth configuration of the protection circuit 11, the switching circuit 8 can be reset only when the pulse control signal S5 having a predetermined potential exceeding the reference voltage of the Zener diode TD2 is supplied. The switching circuit 8 cannot be reset simply by supplying a control signal.

As described above, the protection circuit 11 keeps the on-set circuit 12 in the ON state by continuously supplying the pulse control signal S5 having a predetermined potential exceeding the reference voltage of the zener diode TD2 from the signal input terminal T. And
Thus, the control circuit 13 can reset the switching circuit 8 via the drive circuit 7. Thus, the protection circuit 11 is switched by the control circuit 13 to the switching circuit 8.
FET1 and FET2 are made conductive,
The secondary battery BT can be charged or discharged.

(2-2) Configuration of Secondary Battery Returning Device In FIG. 9, reference numeral 20 denotes a battery pack 1 which resets a protection circuit 13 provided inside the battery pack 10 as a whole.
FIG. 5 shows a secondary battery return device for returning a voltage value of 0 to a use range, provided on input / output terminals A and B and a signal input terminal T of the battery pack 10 and a holder (not shown) for setting the battery pack 10; And a pulse control signal S for resetting the protection circuit 11 provided inside the battery pack 10.
5, a pulse control signal generating unit 22 for generating the battery pack 10, a voltage adjusting unit 23 for charging or discharging the battery pack 10 in an overcharged state or an overdischarged state to adjust the battery pack 10 within a use range, and the voltage and the voltage of the battery pack 10. A detection unit 24 for detecting a current;
It comprises a control unit 25 having a microcomputer configuration for controlling the battery pack connection unit 21, the pulse control signal generation unit 22, the voltage adjustment unit 23 and the detection unit 24, and a display unit 35 for displaying each state of the battery pack 10. I have.

The battery pack connection unit 21 is connected to the battery pack 10.
Switch SW1 is connected to the signal path connected to the input / output terminal A of the switch.
Are provided, and on / off is controlled by the control unit 25. The battery pack connection unit 21 connects the input / output terminal A and the input / output terminal B of the battery pack 10 by an impedance element R3, and connects the input / output terminal B and the signal input terminal T to a battery pack connection detection circuit. 26 are connected.

The battery pack connection detecting circuit 26 detects the current flowing through the thermistor 14 (FIG. 2) connected between the input / output terminal B and the signal input terminal T when the battery pack 10 is set in the holder. Is used to detect whether or not the battery pack 10 is set in the holder, and the detection result is used as a detection result signal S11 in the control unit 2.
5 is output.

The pulse control signal generating section 22 as an AC voltage generating means is constituted by a pulse control signal generating circuit 27 and a stop circuit 28, and generates a pulse control signal based on a control signal S12 from the control section 25. The circuit 27 generates a pulse control signal S5 for resetting the protection circuit 11 of the battery pack 10, and supplies the pulse control signal S5 to the battery pack 10 via the signal input terminal T.

In the pulse control signal generating section 22, the stop circuit 28 supplies a stop command signal S 14 to the pulse control signal generating circuit 27 based on the control signal S 13 sent from the control section 25, thereby controlling the pulse control signal. The supply of the signal S5 is stopped.

The voltage adjusting section 23 includes a switching circuit 29, a switching switch 30, a charger 31, and a discharger 32. The switching circuit 29 connects the terminal of the switching switch 30 to the charger 31 based on the control signal S15 from the control unit 25.
Side or the discharger 32 side. The charger 31 is a control unit 2
5, the battery pack 10 is charged and the discharger 32 is charged.
By discharging the battery pack 10 under the control of the control unit 25, the battery pack 10 in an overcharged state or an overdischarged state has a voltage value within a use range (2.7 [V] to 4.25 [V]). Adjust as follows.

The detecting section 24 comprises a voltage detecting circuit 33 as a second voltage detecting means and a current detecting circuit 34, and the voltage detecting circuit 33 as the second voltage detecting means makes the voltage value of the battery pack 10 And outputs the detection result to the control unit 25 as a detection result signal S17. Further, in the detection unit 24, the current detection circuit 34
The charging current to the battery and the discharging current from the battery pack 10 are detected, and the detection result is output to the control unit 25 as a detection result signal S18.

The display unit 25 is composed of a light emitting diode, a liquid crystal display, or the like, and displays a connection state as to whether or not the battery pack 10 is correctly set in the holder under the control of the control unit 25. Is displayed within the range of use so that the user can easily recognize it.

Subsequently, as shown in FIG. 10 and FIG. 11, the protection circuit 11 of the battery pack 10 is actually reset in the secondary battery return device 20, and the voltage value of the battery pack 10 is adjusted to be within the range of use and then returned. To do so, the process enters the reset procedure from the start step of RT1 and moves to step SP1.

In step SP1, the control unit 25 detects the connection state of the battery pack 10 by the battery pack connection detection circuit 26, and proceeds to step SP2. Step SP
2, the control unit 25 controls the battery pack connection detection circuit 26.
It is determined whether or not the battery pack 10 is connected to the holder on the basis of the detection result signal S11 sent from the device.

If a negative result is obtained, this means that no signal is sent through the input / output terminal B and the signal input terminal T of the battery pack 10, and the battery pack 10 is not connected to the holder. At this time, the control unit 25
Returns to step SP1 and repeats the above processing until the battery pack 10 is connected to the holder. On the other hand, if an affirmative result is obtained, it indicates that the battery pack 10 is connected to the holder.
5 moves to step SP3.

In step SP3, the control unit 25 prepares for operation so that the battery pack 10 can be charged or discharged by connecting the terminal of the switch SW1.
Move on to In step SP4, the control unit 25 supplies the pulse control signal S5 generated by the pulse control signal generation circuit 27 through the signal input terminal T of the battery pack 10. Thereby, the battery pack 10 is connected to the internal protection circuit 11.
Is reset, and the electric field drop transistors FET1 and FET2 of the switching circuit 8 are both turned on, and the electric path between the input / output terminals A and B is conducted. That is, the battery pack 10 returns to a state where charging or discharging can be performed.

When the protection circuit 11 (FIG. 2) is reset by the pulse control signal S5 and restarted, it is based on the detection result signals S1 and S2 sent from the voltage detection circuit 2 and the current detection circuit 3. Start the protection operation again. For this reason, if the current secondary battery BT is in an overcharged state or an overdischarged state outside the range of use, the protection circuit 11
Turns off the field-down transistors FET1 and FET2 again to protect the battery pack 10.
Accordingly, the secondary battery return device 20 maintains the battery pack 10 in a chargeable or dischargeable state by continuously outputting the pulse control signal S5 to the battery pack 10 under the control of the control unit 25.

At step SP5, the control unit 25 detects the current voltage value of the battery pack 10 by the voltage detection circuit 33, and proceeds to step SP6.

At step SP6, the control unit 25 determines whether or not the current voltage value of the battery pack 10 is 2.70 [V] or less within the use range. If a negative result is obtained here, this indicates that the current voltage value of the battery pack 10 is 2.70 [V] or more.
Since there is a possibility that the voltage value is 4.25 [V] or more within the use range, the control unit 25 proceeds to step SP10.

On the other hand, if a positive result is obtained, it indicates that the current voltage value of the battery pack 10 is 2.70 [V] or less (that is, an overdischarged state). Move to step SP7.

At step SP7, the control unit 25 switches the terminal of the switch 30 to the charger 31 side via the switching circuit 29 and shifts to the charging mode because the battery pack 10 is in the overdischarged state. In step SP8, the control unit 25
Charge the battery pack 10 by the charger 31 and proceed to step SP9. In step SP9, the control unit 25
, The charging current is detected by the current detection circuit 34, and the routine proceeds to step SP14.

On the other hand, in step SP10, the control unit 2
5 indicates that the current voltage value of the battery pack 10 is within the operating range.
It is determined whether it is 5 [V] or more. If a negative result is obtained here, it means that the current voltage value of the battery pack 10 is 4.2.
5 [V] or less. At this time, the control unit 25
Determines that the current voltage value of the battery pack 10 is within the usable range, moves to step SP23, and ends the process.

On the other hand, if a positive result is obtained, it indicates that the current voltage value of the battery pack 10 is 4.25 [V] or more (that is, an overcharged state). Move to step SP11. Step SP11
Since the battery pack 10 is in the overcharged state, the control unit 25 switches the terminal of the switch 30 to the discharger 32 side via the switching circuit 29 and shifts to the discharge mode.

In step SP12, the control unit 25 discharges the battery pack 10 by the discharger 32. In step SP13, the control unit 25 controls the current detection circuit 34.
, The discharge current is detected, and the routine goes to step SP14.

In step SP14, the control unit 25 determines whether or not a charging current or a discharging current is flowing based on the detection result signal S18 sent from the current detection circuit 34. If a negative result is obtained here, it indicates that the charging current or the discharging current is not flowing (that is, charging or discharging is not performed), and at this time, the control unit 25 proceeds to step SP15.

At step SP15, the control unit 25
Determines that the connection failure has occurred in the battery pack 10 because the charging current or the discharging current does not flow, and proceeds to step SP22. In step SP22, the control section 25 displays on the display section 35 that the battery pack 10 has a connection failure, and ends the processing in step SP23.

On the other hand, if a positive result is obtained in step SP14, it means that the charging current or the discharging current is flowing (that is, the protection circuit 11 of the battery pack 10).
Has been reset and charging or discharging has been performed). At this time, the control unit 25 proceeds to step SP16.

In step SP16, the control section 25 detects the voltage value of the battery pack 10 by the voltage detection circuit 33, and proceeds to step SP17. In step SP17, the control unit 25 determines whether the current voltage value of the battery pack 10 is within the use range (2.70 [V] to 4.25 [V]) based on the detection result signal S17 sent from the voltage detection circuit 33. Determine whether or not.

If a negative result is obtained here, it means that the voltage value of the battery pack 10 has not yet fallen within the usable range, and
This indicates that the battery is in the overcharged state or the overdischarged state. At this time, the control unit 25 returns to step SP8 or step SP12 and performs charging or discharging again until the voltage value of the battery pack 10 falls within the use range.

On the other hand, if an affirmative result is obtained, it indicates that the voltage value of the battery pack 10 is already within the use range (that is, a normal state that is neither overcharged nor overdischarged), At this time, the control unit 25
Move to 18.

In step SP18, when the voltage value of the battery pack 10 falls within the range of use, the control circuit 25 activates the protection circuit 11 provided in the battery pack 10 to activate the electric field drop transistor FET1 of the switching circuit 8.
Further, since it is no longer necessary to turn off the FET 2 again, it is determined that there is no need to supply the pulse control signal S5, and the supply of the pulse control signal S5 to the pulse control signal generation circuit 27 via the stop circuit 28 is performed. The operation is stopped and the process proceeds to step SP19.

In step SP19, the control unit 25 detects a charging current or a discharging current based on the detection result signal S18 from the current detection circuit 34, and proceeds to step SP20. In step SP20, the control unit 25 determines whether a charging current or a discharging current is flowing.

If a negative result is obtained here, it means that no charging current or discharging current flows between the input / output terminals A and B. At this time, the control unit 25 proceeds to step S
The process proceeds to step P15, where it is determined that the battery pack 10 has a connection failure, and the process proceeds to step SP22 to display the connection failure on the display unit 35, and then the process proceeds to step SP2.
The process ends in 3.

On the other hand, if an affirmative result is obtained in step SP20, it indicates that a charging current or a discharging current is flowing between the input / output terminals A and B, and at this time, the control unit 25 performs the charging or discharging operation. It is determined that the discharge has been performed normally, and the process proceeds to step SP21.

At step SP21, the control unit 25 stops charging or discharging the battery pack 10, and proceeds to step SP22. In step SP22, the control unit 25 displays on the display unit 35 that the voltage value of the battery pack 10 has fallen within the use range and charging or discharging has been completed, and proceeds to step SP23 to complete the processing.

(2-3) Operation and Effect of First Embodiment In the above configuration, the protection circuit 11 of the battery pack 10
FIG. 2 shows that the DC voltage (2 V _ep ) generated by the voltage doubler rectifier circuit including the smoothing capacitor C1 and the rectifying diode D4 and the smoothing capacitor C2 and the rectifying diode D3 is applied only when the pulse control signal S5 is input. Based on this, the on-set circuit 12 can be turned on, and thus the switching circuit 8 can be reset by the control circuit 13.

Thus, the protection circuit 11 of the battery pack 10
Can remove the DC current by the smoothing capacitor C1 even when a DC voltage is temporarily input from the outside due to static electricity, noise, or a short circuit between the input / output terminal A and the signal input terminal T. As a result, the on-set circuit 12 will not be turned on, and thus the switching circuit 8 will not be reset.

The protection circuit 11 of the battery pack 10 receives the pulse control signal S5 from the signal input terminal T continuously, so that the voltage value of the battery pack 10 is in an overcharged state or an overdischarged state. , The on-set circuit 12 can be always turned on, and the control circuit 13 can maintain the field-down transistors FET1 and FET2 of the switching circuit 8 via the drive circuit 7 in the on state. In this state, the battery pack 10 is charged or discharged by the external charger 31 or discharger 32, so that the battery pack 10 is in an overcharged state or an overdischarged state.
It easily returns to the voltage value within the use range.

In the secondary battery return device 20 for resetting the protection circuit 11 of the battery pack 10 having such a configuration, when the battery pack 10 is confirmed by the battery pack connection unit 21 that the battery pack 10 is set in the holder, the pulse By continuously outputting the control signal S5 to the signal input terminal T, the switching circuit 8 of the battery pack 10 is turned on to enable charging or discharging.

At this time, if the current voltage value of the battery pack 10 is in an overcharged state or an overdischarged state, the secondary battery return device 20 is charged by the charger 31 or the discharger 32 of the voltage adjusting unit 23. Alternatively, it is possible to return to a voltage value within a use range by discharging. As a result, when the voltage value of the battery pack 10 returns to the range of use, the protection circuit 11 activates the field-down transistors FET1 and FET2 of the switching circuit 8 based on the detection result signals S2 and S3 from the voltage detection circuit 2 and the current detection circuit 3. Are not turned off, the secondary battery return device 20 stops supplying the pulse control signal S5. In this way,
The secondary battery return device 20 is a protection circuit 11 for the battery pack 10.
The battery pack 10 can be safely restarted by resetting the voltage of the battery pack 10 to return the voltage value of the battery pack 10 to the use range.

According to the above configuration, the protection circuit 11 of the battery pack 10 can be reset by the pulse control signal S5 input through the signal input terminal T, so that the protection circuit 11 can be externally generated for some reason. Even if a DC voltage is input, the protection circuit 11 will not be reset, and thus a secondary battery device that can safely restart can be realized.

Further, the pulse control signal S5 of a predetermined voltage level is continuously supplied intentionally through the signal input terminal T of the battery pack 10, and the electric path of the battery pack 10 is returned to the conductive state to charge or discharge. Thereby, the battery pack 10 can be released from the overcharged state or the overdischarged state and the secondary battery BT can be returned to the use range. Thus, a secondary battery return device capable of safely restarting the secondary battery device can be provided. realizable.

(3) Second Embodiment (3-1) Configuration of Protection Circuit As shown in FIG. 12, the circuit configuration of the battery pack 40 is completely the same as the configuration shown in FIG. In this case, a pulse control signal S5 composed of an AC voltage or a pulse-like voltage is supplied between the input / output terminal B and the signal input terminal T via the signal input terminal T.

In practice, first, when a negative low-level voltage (-ep) is inputted from the signal input terminal T, since the FET1 and FET2 of the switching circuit 8 have not yet been turned on, the input / output terminal B side , A current flows in the order of the smoothing capacitor C1, the rectifier diode D4, and the secondary battery BT along a loop formed between the signal input terminal T and the input / output terminal A. As a result, the pulse voltage (V _ep ) and the secondary battery BT are connected across the smoothing capacitor C1.
Voltage (V _BT) and is added the potential difference (V _ep + V _BT) occurs.

Next, the pulse control signal S5 is changed from a negative low level voltage (-ep) to a positive high level voltage (+ e
When the state changes to p), a current flows in the order of the secondary battery BT, the smoothing capacitor C2, and the rectifier diode D3 along a loop formed between the input / output terminal A and the signal input terminal T.

Thus, one cycle of the pulses (+ ep and -ep) is generated by the current flowing by the voltage (V _ep + V _BT ) generated at both ends of the smoothing capacitor C1 and the plus pulse voltage (V _ep ). ) will be twice the potential difference of the pulse voltage (V _ep) (2V _ep) occurs across the smoothing capacitor C2 as it is entered. Therefore, a Zener diode T is connected between the base of the PNP transistor Tr1 and the emitter.
A potential difference (2V _ep ) that exceeds the reference value of D1 occurs,
Thus, the PNP transistor Tr1 is turned on.

As described above, in the protection circuit 11, the on-set circuit 12 is turned on by the continuous supply of the pulse control signal S5 from the signal input terminal T, whereby the control circuit 13 sends the control circuit 13 via the drive circuit 7. Switching circuit 8
Can be reset. Thus, the protection circuit 11
The secondary battery can be charged or discharged by turning on the electric field drop transistors FET1 and FET2 of the switching circuit 8 by the control circuit 13.

In the battery pack 40 according to the second embodiment, the protection circuit 11 is reset when the pulse control signal S5 is input for one cycle, but the voltage value of the battery pack 40 at that time is used. If the current is out of the range (overcharged state or overdischarged state), the protection circuit 11 operates again and the field-down transistor FET of the switching circuit 8
Since the FET 1 and the FET 2 are turned off, it is necessary to continuously supply the pulse control signal S5 until the voltage value of the battery pack 40 falls within the use range.

At this time, as shown in FIG. 13, in the battery pack 40, the protection circuit 11 is reset by the pulse control signal S5 for the first cycle, and the electric field drop transistors FET1 and FET2 of the switching circuit 8 are turned on. Then, a loop is formed between the input / output terminal B and the signal input terminal T.

Accordingly, in the protection circuit 11, when a negative low level voltage (-ep) of the next pulse control signal S5 is input from the signal input terminal T, the smoothing capacitor C
1. Rectifier diode D4, field drop transistor FET
A current flows in the order of 1 and FET2 (in the direction of arrow Y1).
Thereby, the pulse voltage (V) is applied across the smoothing capacitor C1.
_ep ) occurs.

Next, the pulse control signal S5 is changed from a negative low level voltage (-ep) to a positive high level voltage (+ e
p), the field-down transistor FE follows a loop formed between the input / output terminal B and the signal input terminal T.
A current flows in the order of T1, FET2, smoothing capacitor C2, and rectifier diode D3 (in the direction of arrow Y2).

[0120] Thereby, the double voltage of the pulse voltage across the smoothing capacitor _{C2 (V ep) (2V ep} ) occurs. Accordingly, a potential difference (2 V _ep ) exceeding the reference value of the Zener diode TD1 is generated between the base and the emitter of the PNP transistor Tr1, and the PNP transistor Tr1 is also turned on in this case.

As described above, once the field-drop transistors FET1 and FET2 of the switching circuit 8 are turned on, a loop is formed between the input / output terminal B and the signal input terminal T, and the input is started from the next pulse control signal S5. Output terminal A
No current flows through the impedance element R3 via the switch (FIG. 12). For this reason, the protection circuit 11 can turn on the PNP transistor Tr1 by a voltage obtained by subtracting the voltage drop generated by the impedance element R3 from the potential (2V _ep ) generated at both ends of the smoothing capacitor C2.

Therefore, in the battery pack 40 according to the second embodiment, once the field-down transistors FET1 and FET2 of the switching circuit 8 are turned on, the amplitude of the pulse control signal S5 is thereafter changed to a predetermined level. Will be able to lower.

Therefore, in the battery pack 40, since the amplitude of the pulse control signal S5 continuously inputted can be reduced after the FET1 and the FET2 of the switching circuit 8 are turned on, the pulse control signal S5 is controlled by the pulse control signal S5. Thus, the amount of current flowing through the thermistor 14 can be reduced, and the thermal load can be reduced accordingly. The configuration of the secondary battery return device capable of adjusting the amplitude of the pulse control signal S5 will be described below.

(3-2) Configuration of Secondary Battery Returning Apparatus In FIG. 14, in which parts corresponding to those in FIG. 9 are assigned the same reference numerals, 50 is the secondary battery returning apparatus in the second embodiment as a whole. As shown, a pulse-like voltage is supplied as a pulse control signal S5 between the input / output terminal B and the signal input terminal T via the signal input terminal T, so that a battery pack 40 is provided.
Of the protection circuit 11 is reset.
In this case, the secondary battery return device 50 has substantially the same configuration as the secondary battery return device 20 except that a new pulse control signal generator 51 is provided instead of the pulse control signal generator 22.

The pulse control signal generation section 51 is composed of a pulse control signal generation circuit 27, a stop circuit 28, and a newly provided pulse adjustment circuit 52. Based on the control, the electric field drop transistors FET1 and FET of the switching circuit 8
Adjustment is made so that the amplitude of the pulse control signal S5 after the time when the signal 2 is turned on is reduced to a predetermined level.

[0126] Namely as shown in FIG. 15, the pulse adjusting circuit 52 is initially Onsetsuto circuit 12 pulse control signal voltage difference between the base and emitter in order to the PNP transistor Tr1 is turned on amplitude such that 2V _ep of S5
From the pulse control signal generation circuit 27 to the signal input terminal T.

Thus, the PNP of the on-set circuit 12
The transistor Tr1 is turned on, and accordingly, the field-down transistors FET1 and FET2 of the switching circuit 8 are both turned on, so that a loop is formed between the input / output terminal B and the signal input terminal T. Therefore, the pulse adjusting circuit 52 can reduce the amplitude of the pulse control signal S5 to a predetermined level for turning on the PNP transistor Tr1 after a predetermined time t1 when the electric field drop transistors FET1 and FET2 of the switching circuit 8 are turned on. .

Next, the processing procedure of the secondary battery return device 50 capable of adjusting the amplitude of the pulse control signal S5 will be described with reference to FIG.
And the flowchart shown in FIG. First, the secondary battery return device 50 enters from the start step of RT2 and moves to step SP31. In this case, step SP
The processing from step 31 to step SP44 is the same as the processing from step SP1 to step SP14 in the secondary battery return device 20, and the processing from step SP49 to step SP44.
The processing up to 56 is the same as the processing from step SP16 to step SP23 in the secondary battery return device 20, so that the description is omitted here.

In step SP44, when the control unit 25 is charging or discharging current in the charging mode or discharging mode, this indicates that both the field-down transistors FET1 and FET2 of the switching circuit 8 are in the ON state, that is, the input / output terminal B and This indicates that a loop has been formed between the control unit 25 and the signal input terminal T.
Moves to step SP45.

In step SP45, the control unit 25 outputs a pulse control signal S5 to the impedance element R3 because a loop is formed between the input / output terminal B and the signal input terminal T.
As a result, the voltage of the pulse control signal S5 is reduced to a predetermined level via the pulse adjusting circuit 52.

At step SP46, the control section 25 starts counting by the timer 25A. Step SP47
In step (2), the control unit 25 calculates the charge / discharge time estimated to take from the voltage value in the first overcharged state or the overdischarged state to the voltage value within the use range by charging or discharging the battery pack 40. Then, whether or not the charge / discharge time has elapsed is determined based on the count value of the timer 25A.

Here, if a negative result is obtained, it indicates that the charging / discharging time has not yet elapsed, and at this time, the control unit 25 returns to step SP47 again and continues until the charging / discharging time elapses. Repeat the process. On the other hand, if a positive result is obtained, it indicates that the charging / discharging time has already elapsed, and at this time, the control unit 25 proceeds to step S
Proceeding to P49, the voltage value of the battery pack 40 is detected, and if it is within the use range, the supply of the pulse control signal S5 is stopped at step SP51, and thereafter, the processing of steps SP52 to SP56 is performed and the processing is terminated.

(3-3) Operation and Effect in the Second Embodiment In the above configuration, the protection circuit 11 of the battery pack 40 is provided with the smoothing capacitor C1 and the rectifying diode D4 only when the pulse control signal S5 is input. Also, the on-set circuit 12 can be turned on based on the DC voltage (2 V _ep ) generated by the voltage doubler rectifier circuit including the smoothing capacitor C2 and the rectifier diode D3, and thus the switching circuit 8 is controlled by the control circuit 13. Can be reset.

As a result, the protection circuit 11 of the battery pack 40 is
Can remove the DC current by the smoothing capacitor C1 even when a DC voltage is temporarily input from the outside due to static electricity, noise, or a short circuit between the input / output terminal A and the signal input terminal T. Therefore, the onset circuit 1
2 is not turned on, and thus the switching circuit 8 is not reset.

The battery pack 40 sets both the field-down transistors FET1 and FET2 of the switching circuit 8 to the ON state by the pulse control signal S5 for the first cycle, thereby setting the field-down transistors FET1 and FET1 of the switching circuit 8 to ON. Since a loop is formed between the signal input terminal T and the input / output terminal B via the FET 2, even if the voltage level of the pulse control signal S5 supplied subsequently is reduced to a predetermined level, the electric field of the switching circuit 8 is reduced. The falling transistors FET1 and FET2 can be kept on.

Accordingly, the secondary battery return device 50 is provided with the electric field drop transistor F of the switching circuit 8 of the battery pack 40.
After the ET1 and the FET2 are both turned on, the pulse control signal S5 is supplied at a reduced voltage level, so that the thermistor 14 is supplied by the pulse control signal S5.
And the thermal load can be reduced by reducing the amount of current supplied to the power supply.

After that, when the overcharge state or the overdischarge state of the battery pack 40 is eliminated and the battery pack 40 returns to the range of use, the protection circuit 11 switches the electric field drop transistors FET1 and FET2 of the switching circuit 8 to the secondary battery return device 50. The supply of the pulse control signal S5 is stopped so as not to be turned off. In this way, the secondary battery return device 50 can reset the protection circuit 11 of the battery pack 40, adjust the voltage value of the battery pack 40 within the use range, and return it.

According to the above configuration, the protection circuit 11 of the battery pack 40 can be reset by the pulse control signal S5 input through the signal input terminal T, so that the protection circuit 11 can be externally generated for some reason. Even if a DC voltage is input, the protection circuit 11 will not be reset, and thus a secondary battery device that can safely restart can be realized.

Further, the pulse control signal S5 of a predetermined voltage level is intentionally continuously supplied through the signal input terminal T of the battery pack 40, and the electric path of the battery pack 40 is returned to the conductive state to charge or discharge. Thereby, the battery pack 40 can be released from the overcharged state or the overdischarged state and the secondary battery BT can be returned to the use range, and thus the secondary battery return device capable of safely restarting the secondary battery device can be provided. realizable.

(4) Other Embodiments In the above-described first and second embodiments, the parasitic diode D5 is provided on the collector side of the PNP transistor Tr1 of the onset circuit 12 as the rectifier, so that the input is not changed. Although the case where the high voltage current is prevented from flowing back from the collector of the PNP transistor Tr1 to the base even when a high voltage is applied by mistake between the output terminal A and the signal input terminal T has been described in the present invention, Not only
As shown in FIG. 18, a parasitic diode D10 and a zener diode TD10 for controlling a current in the charging direction between the smoothing capacitor C1 and the base of the PNP transistor Tr1.
May be further added. In this case, double backflow can be prevented, and thus overcharge of the secondary battery BT can be more reliably prevented.

In the second embodiment described above,
Although the case where the pulse voltage is lowered to a predetermined level by adjusting the amplitude of the pulse control signal S5 by the pulse adjusting circuit 52 has been described, the present invention is not limited to this, and the pulse control is performed as shown in FIG. The pulse width of the signal S5 may be reduced. In this case, since the amount of current of the pulse control signal S5 can be reduced as the pulse width is shortened, when the battery pack 10 is set in the reset device 50 and the pulse control signal S5 is supplied from the signal input terminal T, The thermal load on the thermistor 14 can be reduced. Further, the pulse adjusting circuit 52 may simultaneously control the voltage level and the pulse width of the pulse control signal S5.

Further, in the above-described first and second embodiments, the case where the field-down transistors FET1 and FET2 are used as the first and second switches in the switching circuit 8 as the switching means has been described. However, the present invention is not limited to this, and switches having other various configurations may be used.

Further, in the first and second embodiments described above, the case where a DC voltage of a predetermined potential is generated by the onset circuit 12 as rectifying means has been described, but the present invention is not limited thereto. The present invention is not limited to this. A DC voltage is generated from an AC voltage, and the control circuit 1
As long as 3 can be turned on, rectification means of other various configurations may be used.

Further, in the first and second embodiments described above, the field-down transistors FET1, which switch the charging current for the secondary battery BT between the conductive state and the cutoff state,
A case has been described in which charging or discharging is controlled by using a switching circuit 8 including a field-down transistor FET2 that switches a discharging current to a secondary battery BT between a conducting state and a blocking state. However, the present invention is not limited to this. ,
A switching circuit 8 including only one of the field-down transistors FET1 and FET2 may be used.

[0145]

As described above, according to the present invention, by charging or discharging a secondary battery connected between one and the other input / output terminals, the secondary battery is brought into an overcharged state or an overdischarged state. In the case where the protection circuit is released from the overcharge state or the overdischarge state by switching off the electric path of the secondary battery by the switching means, the external circuit is connected via a predetermined signal input terminal. A first step of generating a DC voltage based on an AC voltage input from the DC power supply, a second step of driving a switching means based on the DC voltage to make an electric path of the secondary battery conductive, and a secondary battery. If the battery is overcharged, the secondary battery is discharged via the electrical path, and if the battery is overdischarged, the secondary battery is charged via the electrical path to overcharge the secondary battery. Condition By providing a third step for eliminating the overdischarge state and canceling the protection operation for the secondary battery, it is possible to prevent the electrical path of the secondary battery from being made conductive by an unintended signal and to perform the intended operation. The electrical path of the secondary battery is made conductive only by the alternating voltage supplied in a specific manner, and the overcharge state or the overdischarge state can be eliminated by charging or discharging the secondary battery in the conductive state of the electrical path. Thus, a method of releasing the protection circuit that can safely restart the secondary battery can be realized.

Further, according to the present invention, a secondary battery connected between one input terminal and the other input / output terminal, voltage detecting means for detecting a voltage value of the secondary battery, A switching means provided; a rectifying means for generating a DC voltage based on an AC voltage externally input through a predetermined signal input terminal; and a voltage detecting means for charging or discharging the secondary battery. When the voltage value of the secondary battery is detected, and when it is detected that the secondary battery has entered an overcharged state or an overdischarged state, the switching means is switched to a cutoff state to protect the secondary battery, and the protection operation operates. And a switching control means for switching the switching means to a conductive state when a DC voltage is supplied from the rectifying means in a state in which the electric path of the secondary battery is turned on by an unintended signal. Electrical path by connexion only two battery intentionally supplied AC voltage is prevented to be able to conduct, thus can safely restart the secondary battery 2
A secondary battery device can be realized.

Further, according to the present invention, the voltage value of the secondary battery connected between one and the other input / output terminals of the secondary battery device is detected by the first voltage detecting means, and the secondary battery is detected. When the battery is in the overcharge state or the overdischarge state, the switching means provided on the electric path of the secondary battery is shut off, and the switching means is switched to the conductive state by external control to discharge or discharge the secondary battery. An AC voltage generating means for generating an AC voltage, and a second voltage detecting means for detecting a voltage value of the secondary battery, in a secondary battery restoring device for returning the secondary battery to a voltage value within a use range by charging. Means, voltage adjusting means for eliminating an overcharged or overdischarged state of the secondary battery by charging or discharging the secondary battery, and supplying an AC voltage through a predetermined signal input terminal of the secondary battery device. Switch by The charging means is switched to a conductive state, and when the result of detection by the second voltage detecting means is an overcharged state or an overdischarged state, the secondary battery is charged or discharged by the voltage adjusting means, and after the charging or discharging, Control means for supplying an AC voltage to the secondary battery device until the secondary battery returns to a voltage value within the use range, thereby releasing the protection operation for the secondary battery and overcharging or overdischarging the battery. Can be restored to a voltage value within a normal use range, and thus a secondary battery return device capable of safely restarting the secondary battery can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a battery pack according to the present invention.

FIG. 2 is a block diagram showing a first configuration of the protection circuit according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an operation (1) of the protection circuit according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating an operation (2) of the protection circuit according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram for controlling a current flow through a parasitic diode D5 according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a second configuration of the protection circuit according to the first embodiment of the present invention.

FIG. 7 is a block diagram showing a third configuration of the protection circuit according to the first embodiment of the present invention.

FIG. 8 is a block diagram showing a fourth configuration of the protection circuit according to the first embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a secondary battery return device according to the first embodiment of the present invention.

FIG. 10 is a flowchart (1) showing a processing procedure of the secondary battery return device according to the first embodiment of the present invention.

FIG. 11 is a flowchart (2) showing a processing procedure of the secondary battery return device according to the first embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a protection circuit according to a second embodiment of the present invention.

FIG. 13 is a schematic diagram showing a current flow according to the second embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a secondary battery return device according to a second embodiment of the present invention.

FIG. 15 is a graph showing a change in an amplitude state of a pulse control signal according to the second embodiment of the present invention.

FIG. 16 is a flowchart (1) showing a processing procedure of the secondary battery return device according to the second embodiment of the present invention.

FIG. 17 is a flowchart (2) showing a processing procedure of the secondary battery return device according to the second embodiment of the present invention.

FIG. 18 is a block diagram showing a configuration of a protection circuit according to another embodiment of the present invention.

FIG. 19 is a graph showing a pulse width state of a pulse control signal according to another embodiment of the present invention.

FIG. 20 is a block diagram showing a configuration of a conventional battery pack.

FIG. 21 is a schematic diagram showing a use range voltage of a battery pack and various voltage states.

[Explanation of symbols]

1, 10, 40 ... battery pack, 2 ... voltage detection circuit,
3 ... Current detection circuit, 4, 11 ... Protection circuit, 6, 13
... Control circuit, 8 ... Switching circuit, 12 ... Onset circuit, C1, C2 ... Smoothing capacitors, D3, D
4 ... Rectifier diode, A, B ... Input / output terminal, T ...
Signal input terminal, BT ... secondary battery, 20, 50 ... secondary battery return device, 21 ... battery pack connection, 22, 51
…… Pulse control signal generator, 23 …… Voltage adjuster, 24
... Detector, 25 Control unit.

Claims (8)

[Claims] When the secondary battery is overcharged or overdischarged by charging or discharging a secondary battery connected between one and the other input / output terminals, the electric power of the secondary battery is changed. In a method of releasing a protection circuit for protecting a secondary battery from an overcharged state or an overdischarged state by interrupting a path by switching means, a method is provided based on an AC voltage externally input through a predetermined signal input terminal. A first step of generating a DC voltage by driving the switching means on the basis of the DC voltage so as to make an electrical path of the secondary battery conductive.
And discharging the secondary battery via the electric path when the secondary battery is in an overcharged state, and discharging the secondary battery via the electric path when the secondary battery is in an overdischarged state. A third step of releasing the secondary battery from the overcharged state or the overdischarged state by charging the battery and releasing the protection operation for the secondary battery. Method. 2. A secondary battery connected between one and the other input / output terminals, voltage detecting means for detecting a voltage value of the secondary battery, and switching provided on an electric path of the secondary battery. Means, a rectifying means for generating a DC voltage based on an AC voltage inputted from the outside via a predetermined signal input terminal, and a charging / discharging means for charging or discharging the secondary battery. When the voltage value of the battery is detected, and when it is detected that the secondary battery is in an overcharged state or an overdischarged state, the switching means is switched to a cutoff state and
A secondary battery device for protecting the secondary battery, and switching control means for switching the switching means to a conductive state when the DC voltage is supplied from the rectifying means in a state where the protection operation is activated. . 3. The secondary battery device according to claim 2, wherein the signal input terminal is a temperature detection terminal. 4. The rectifying means comprises a voltage doubler rectifying circuit for generating the DC voltage based on the AC voltage, and a transistor circuit activated based on the DC voltage. 3. The secondary battery device according to claim 2, wherein a parasitic diode for preventing a reverse flow of the current when the occurrence of the electric current occurs is connected. 5. The switching means according to claim 1, wherein said switching means switches a charging current for said secondary battery between a conductive state and a cut-off state.
3. The secondary battery device according to claim 2, further comprising a switch for switching a discharge current from the secondary battery to a conduction state or a cutoff state. 6. The voltage value of a secondary battery connected between one input terminal and the other input / output terminal of a secondary battery device is detected by a first voltage detecting means, and the secondary battery is in an overcharged state or When the battery is overdischarged, the switching means provided on the electric path of the secondary battery is shut off, and the switching means is switched to a conductive state by external control to discharge or charge the secondary battery. An AC voltage generating means for generating an AC voltage; and a second voltage detecting means for detecting a voltage value of the secondary battery. Means, voltage adjusting means for eliminating the overcharged state or overdischarged state of the secondary battery by charging or discharging the secondary battery; and applying the AC voltage to a predetermined signal input terminal of the secondary battery device. Supply via The switching means is switched to the conducting state, and if the result of detection by the second voltage detecting means is an overcharged state or an overdischarged state, the secondary battery is charged or discharged by the voltage adjusting means. Control means for supplying the AC voltage to the secondary battery device until the secondary battery after charging or discharging returns to a voltage value within the use range. apparatus. 7. The secondary battery return device according to claim 6, wherein the AC voltage is a pulse signal, and the pulse width of the pulse signal is controlled by the control means. 8. The secondary according to claim 6, wherein the AC voltage is a pulse signal, and the amplitude of the pulse signal is controlled by the control means when the switching means is turned on. Battery return device.