JP2007042396A - Battery pack, and electric apparatus equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce wasteful consumption of a battery by positively detecting if a battery pack is attached to or detached from a main apparatus while making a very simple circuit configuration. <P>SOLUTION: This battery pack is equipped with a secondary battery 11, a shutdown circuit 12 to switch on and off power supply from the secondary battery 11 to a built-in electronic circuit, and a signal terminal 13 to the main apparatus 30 mounted with the battery pack. The shutdown circuit 12 detects if the battery pack is attached to or detached from the main apparatus 30 by detecting the voltage of the signal terminal 13, and the power supply from the secondary battery 11 to the electronic circuit is shut down with the battery pack removed from the apparatus body 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery pack that is attached to a main device so that it can be detached, and an electric device that is equipped with the battery pack.

The battery pack has a built-in electronic circuit for protecting the battery and can extend the battery life. This is because charging and discharging can be performed while preventing overdischarge and overcharge of the battery. However, since the electronic circuit consumes the power of the secondary battery, this causes overcharge of the secondary battery. In order for the electronic circuit to prevent overdischarge of the secondary battery, for example, a circuit has been developed that shuts down the battery discharge by shutting down the power supply circuit of the electronic circuit when the battery voltage drops below the minimum voltage. (See Patent Document 1)
2005-110425 gazette

  The battery pack can be shut down when the battery voltage falls below the minimum voltage, thereby preventing overdischarge. However, the electronic circuit for calculating the remaining capacity by calculating the charging / discharging current of the battery, the electronic circuit for the identification circuit such as the battery ID, or the electronic circuit for counting the number of times of charging / discharging is always in operation. Even in a state where the battery pack is not connected to the main device, the electronic circuit consumes power wastefully, and the remaining capacity of the battery is reduced. For this reason, there is a drawback that the usage time is shortened when the battery pack is set in the main device.

  This disadvantage can be solved by shutting down the power supply of the electronic circuit when the battery pack is not connected to the main device. However, to realize this, it is necessary to determine whether or not the battery pack is connected to the main device. This determination can be realized by mounting a circuit that outputs a “mounting signal” from the main device to the battery pack, and mounting a circuit that detects the “mounting signal” and controls the shutdown on the battery pack. Thus, if a circuit for detecting attachment is provided in both the main device and the battery pack, the circuit configuration becomes complicated. In addition, when the battery pack is mounted on the main device, it is necessary to specify the timing for transmitting the “mounting signal” in an electrical device that alternately transmits information between the battery pack and the main device. For this reason, not only the circuit configuration becomes complicated, but also timing control becomes complicated.

  The present invention has been developed for the purpose of solving such drawbacks. An important object of the present invention is to provide a battery pack capable of reliably detecting attachment / detachment to / from the main device and reducing wasteful consumption of the battery, and an electric device equipped with the battery pack, with an extremely simple circuit configuration. It is to provide.

The battery pack of the present invention has the following configuration in order to achieve the aforementioned object.
The battery pack includes secondary batteries 11 and 51, shutdown circuits 12 and 52 for turning on / off power supply from the secondary batteries 11 and 51 to the built-in electronic circuit, and signal terminals of the main devices 30 and 70 to be mounted. 13 and 53. The shutdown circuits 12 and 52 detect the voltage of the signal terminals 13 and 53 to detect the attachment / detachment with the main body devices 30 and 70, and the secondary battery 11 is removed in a state where the battery pack is removed from the main body devices 30 and 70. , 51 shuts down the power supply to the electronic circuit.

  The battery pack of the present invention includes a temperature sensor 16 that detects the battery temperature, and connects the temperature sensor 16 to the signal terminal 13 to detect the voltage of the temperature sensor 16 to detect attachment / detachment to the main body device 30. Can do.

  The battery pack of the present invention includes a memory 57 for storing battery information. The memory 57 is connected to the signal terminal 53, and the voltage of the signal terminal 53 connected to the memory 57 is detected to be attached to and detached from the main unit 30. Can be detected.

  In the battery pack of the present invention, the electronic circuit can include the microcomputers 14 and 54.

  The battery pack of the present invention includes regulator circuits 15 and 55 for stabilizing the voltage of the secondary batteries 11 and 51 and supplying them to an electronic circuit, and shuts down between the regulator circuits 15 and 55 and the secondary batteries 11 and 51. Circuits 12 and 52 can be connected.

  The electric device to which the battery pack according to claim 6 of the present invention is mounted includes the battery packs 10 and 50 and the main body devices 30 and 70 to be mounted so as to be removable. The battery packs 10, 50 include secondary batteries 11, 51, shutdown circuits 12, 52 for turning on / off power supply from the secondary batteries 11, 51 to the built-in electronic circuit, and main devices 30, 70 to be mounted The signal terminals 13 and 53 are provided. The main body devices 30 and 70 include connector terminals 33 and 73 connected to the signal terminals 13 and 53 of the battery packs 10 and 50. The connector terminals 33 and 73 are connected to the power supply units of the main body devices 30 and 70 via the pull-up resistors 32 and 72. In this electrical device, when the battery packs 10 and 50 are connected to the main body devices 30 and 70, the pull-up resistors 32 and 72 make the voltage of the signal terminals 13 and 53 higher than the set voltage, The shutdown circuits 12 and 52 detect a voltage higher than the set voltage to detect that they are attached to the main devices 30 and 70, and the battery packs 10 and 50 are removed from the main devices 30 and 70, and the signal terminals 13, When the voltage of 53 falls below the set voltage, the shutdown circuits 12 and 52 detect the voltage of the signal terminals 13 and 53 and shut down the power supply from the secondary batteries 11 and 51 to the electronic circuit.

  The present invention has a feature that it is possible to reliably detect the attachment / detachment of the battery pack to / from the main body device and reduce the wasteful consumption of the battery while having a very simple circuit configuration. This is because the battery pack of the present invention detects the voltage of the signal terminal provided for transmitting the battery temperature and information to the main device, and detects the attachment / detachment to the main device. That is, the connection from the battery pack side to the main device is detected by using the signal terminal provided on the main device side to detect the information of the battery pack, and the attachment / detachment is determined. In this structure, it is not necessary to provide a special circuit for detecting the attachment / detachment of the battery pack on the main device side, and the attachment / detachment can be reliably detected on the battery pack side. This is because the voltage of the signal terminal changes when the battery pack is attached to the main device.

  Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below exemplify the battery pack 10 and the electric device for embodying the technical idea of the present invention, and the present invention does not specify the battery pack 10 and the electric device as follows. .

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

FIG. 1 is a circuit diagram of the battery pack 10 and the main device 30 that are mounted so as to be removable from the main device 30. The battery pack 10 in this figure is connected to a secondary battery 11, a shutdown circuit 12 for turning on and off the power supply from the secondary battery 11 to the built-in electronic circuit, and a connector terminal 33 of the main device 30 to be mounted. And a signal terminal 13. A protection circuit necessary for constituting an actual battery pack is not shown.
The main device 30 is a load such as an electric tool that uses the battery pack 10 as a power source. The main device 30 may be a power source such as a charger, or may be a device that serves both as a load and a charger, such as a notebook computer.

  The secondary battery 11 is a lithium ion secondary battery. However, the secondary battery may be another secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The illustrated battery pack 10 has a plurality of secondary batteries 11 connected in series to increase the output voltage.

  The electronic circuit includes a one-chip microcomputer (MPU) 14. The one-chip microcomputer 14 is connected to a current and voltage detection circuit (not shown) of the secondary battery 11 and calculates the remaining capacity from the charge / discharge current and voltage of the secondary battery 11, or the secondary battery 11. The initial information such as the type and rating, the number of charge / discharge cycles and the usage history are counted, and the information is transmitted to the main device 30. The electronic circuit is supplied with power from the secondary battery 11 via the regulator circuit 15. The regulator circuit 15 stabilizes the voltage of the secondary battery 11 and supplies power for driving the electronic circuit. The battery pack 10 including the regulator circuit 15 can stably operate the electronic circuit by supplying a power supply voltage with little voltage change to the electronic circuit even when the voltage of the secondary battery 11 changes. However, the battery pack does not necessarily require a regulator circuit, and can supply the power of the secondary battery without going through the regulator circuit.

  The illustrated battery pack 10 includes a temperature sensor 16 that detects the battery temperature. The temperature sensor 16 is connected to the signal terminal 13. The battery pack 10 detects the voltage of the temperature sensor 16 connected to the signal terminal 13 to detect attachment / detachment to / from the main device 30. When the battery pack 10 is connected to the main unit 30, the voltage at the signal terminal 13 rises to “High”. When the battery pack 10 is removed from the main device 30, the voltage at the signal terminal 13 is lowered to "Low". This is because when the battery pack 10 is connected to the main device 30, the temperature sensor 16 is connected to the power supply line 31 as a power supply unit via the pull-up resistor 32 of the main device 30. The main device 30 has a connector terminal 33 connected to the signal terminal 13 of the battery pack 10 connected to the power line 31 of the main device 30 via a pull-up resistor 32. The pull-up resistor 32 can also be connected to another power supply unit (not shown) of the main device 30.

  The one-chip microcomputer 14 detects the battery temperature by detecting the voltage of the temperature sensor 16. The temperature sensor 16 is a temperature element such as a thermistor whose electric resistance changes with battery temperature. The thermistor is a temperature element whose electrical resistance decreases rapidly as the temperature increases. When the battery temperature changes and the electrical resistance of the temperature sensor 16 changes, the voltage at the signal terminal 13 changes. In the main device 30, the divided voltage at the connection point between the pull-up resistor 32 and the temperature sensor 16 is detected by the voltage detection circuit 35 to detect the battery temperature. Alternatively, in the battery pack 10, the one-chip microcomputer 14 can detect the battery temperature by detecting the voltage of the signal terminal 13, in other words, the voltage of the temperature sensor 16.

  In order to change the voltage of the temperature sensor 16 with the battery temperature, the main device 30 is connected to the power supply line 31 via the pull-up resistor 32 to the connector terminal 33 connected to the signal terminal 13. The voltage of the temperature sensor 16 is a voltage that divides the power supply voltage of the main device 30 by the ratio of the pull-up resistor 32 and the electrical resistance of the temperature sensor 16. Therefore, when the battery temperature increases and the electrical resistance of the thermistor that is the temperature sensor 16 decreases, the voltage of the temperature sensor 16 decreases.

  The shutdown circuit 12 is controlled to be turned on and off by the first input switching element 21 and the first input switching element 21 connected to the temperature sensor 16 connected to the signal terminal 13 and the first input switching element 21. And a control switching element 24 that is controlled to be turned on / off by the one-chip microcomputer 14 of the electronic circuit and controls the main switching element 23 to be turned on / off. The battery pack 10 shown in the drawing uses an FET as a switching element of the shutdown circuit 12. However, a transistor can be used as the switching element instead of the FET.

  The first input switching element 21 and the second input switching element 22 have a gate which is an input side terminal connected to the signal terminal 13 and a source which is a ground side terminal connected to the ground. Since the first input switching element 21 and the second input switching element 22 have their input side gates connected to the signal terminal 13, they are turned on when the voltage of the signal terminal 13 is “High”. It turns off in the "" state. Further, the first input switching element 21 has a drain which is an output side terminal connected to a gate which is an input side of the main switching element 23. Therefore, when the first input switching element 21 is turned on, the main switching element 23 is turned on. The second input switching element 22 has a load resistor 25 connected to the drain on the output side, and is connected to the MPU that is the one-chip microcomputer 14. The second input switching element 22 outputs “Low” to the one-chip microcomputer 14 when the signal terminal 13 is “High”, and outputs “High” to the one-chip microcomputer 14 when the signal terminal 13 is “Low”. Output.

  The main switching element 23 has an input side gate connected to the drain of the first input switching element 21, a source connected to the secondary battery 11, and a drain connected to the regulator circuit 15. In the main switching element 23 (because it is a p-channel FET, the gate voltage is turned on when Low), either the first input switching element 21 or the control switching element 24 is turned on, and the gate is set to “Low”. In the state it is switched on. The main switching element 23 in the on state connects the secondary battery 11 to the regulator circuit 15 and supplies power from the secondary battery 11 to the regulator circuit 15. When power is supplied to the regulator circuit 15, power is supplied to the one-chip microcomputer 14 and the upper resistance terminal of the second input switching element 22 through another circuit (not shown). The main switching element 23 is turned off in a state where the gate is set to “High”. The gate of the main switching element 23 becomes “High” when both the first input switching element 21 and the control switching element 24 are turned off.

  The control switching element 24 is controlled to be turned on / off by the one-chip microcomputer 14. The one-chip microcomputer 14 turns on the control switching element 24 when in the operating state. Therefore, when the main switching element 23 is switched on and the one-chip microcomputer 14 is in an operating state, the control switching element 24 is switched on. The control switching element 24 in the on state keeps the main switching element 23 on.

  As shown in FIG. 2, the main switching element 23 is controlled to be turned on and off by a first input switching element 21 and a control switching element 24. These switching elements perform the following operation to switch the main switching element 23 on and off.

(1) When the battery pack 10 is connected to the main unit 30, the voltage at the signal terminal 13 increases, and “High” is input to the gates of the first input switching element 21 and the second input switching element 22. And turned on. The voltage at the signal terminal 13 varies with the electrical resistance of the temperature sensor 16. However, even if the electric resistance of the temperature sensor 16 decreases to the minimum voltage, a “High” voltage that can switch the first input switching element 21 and the second input switching element 22 on is input. When the battery pack 10 is removed from the main device 30, the voltage of the signal terminal 13 becomes 0V and becomes “Low”.

(2) When either the first input switching element 21 or the control switching element 24 is turned on, the source of the main switching element 23 is connected to the ground. The main switching element 23 in this state is switched on because a bias voltage for turning on the FET is input between the source and the gate. The main switching element 23 that is turned on connects the secondary battery 11 to the regulator circuit 15 and puts the regulator circuit 15 into an operating state. The regulator circuit 15 in the operating state stabilizes the voltage of the secondary battery 11 and activates the one-chip microcomputer 14.
(3) When the one-chip microcomputer 14 is activated, the one-chip microcomputer 14 switches on the control switching element 24. Therefore, the main switching element 23 is kept on and the regulator circuit 15 is kept in the operating state.
(4) When the battery pack 10 is removed from the main device 30, the voltage at the signal terminal 13 decreases. This is because the signal terminal 13 is not connected to the power supply line 31 by the pull-up resistor 32. For this reason, the first input switching element 21 and the second input switching element 22 are switched off. Even in this state, the one-chip microcomputer 14 in the operating state keeps the control switching element 24 on and puts the regulator circuit 15 in the operating state.
(5) The second input switching element 22 switched to the OFF state inputs a “High” OFF signal to the one-chip microcomputer 14. When the battery pack 10 is connected to the main device 30 and the second input switching element 22 is on, the second input switching element 22 is on and outputs “Low” to the one-chip microcomputer 14. Therefore, when “Low” is input from the second input switching element 22, the one-chip microcomputer 14 determines that the battery pack 10 is attached to the main device 30, and when “High” is input, the battery pack 10 10 is determined to be removed from the main device 30. The one-chip microcomputer 14 detects that the battery pack 10 has been removed by a “High” off signal input from the second input switching element 22, performs end processing such as data saving, and then performs control. The switching element 24 is switched off. In this state, since both the control switching element 24 and the first input switching element 21 are turned off, the main switching element 23 is switched off. Instead of such an embodiment, a circuit that switches off the main switching element 23 with a “High” off signal input from the second input switching element 22 may be used.
(6) When the main switching element 23 is switched off, power is not supplied from the secondary battery 11 to the regulator circuit 15, and the operation of the regulator circuit 15 is stopped. For this reason, the regulator circuit 15 does not supply the power of the secondary battery 11 to the one-chip microcomputer 14. In other words, when the battery pack 10 is removed from the main body device 30, the shutdown circuit 12 is turned off to cut off the power supply from the secondary battery 11 to the one-chip microcomputer 14.

  The battery pack 50 of FIG. 3 includes a memory 57 that stores battery information. The memory 57 is an EEPROM. The memory 57 is connected to a pair of signal terminals 53. The battery pack 50 detects the voltage of one signal terminal 53 </ b> A (SDA), and detects attachment / detachment to / from the main device 70. When the battery pack 50 is connected to the main device 70, the voltage at the signal terminal 53A (SDA) rises to “High”. When the battery pack 50 is removed from the main device 70, the voltage at the signal terminal 53A (SDA) decreases and becomes “Low”. This is because when the battery pack 50 is connected to the main device 70, the memory 57 is connected to the power supply line 71 via the pull-up resistor 72 of the main device 70. In the main device 70, a connector terminal 73 connected to the signal terminal 53 of the battery pack 50 is connected to the power line 71 of the main device 70 via a pull-up resistor 72.

  The one-chip microcomputer 54 outputs information stored in the memory 57 to the main device 70. When the battery pack 50 is attached to the main device 70, a signal requesting information in the memory 57 is output from the main device 70 to the battery pack 50. The one-chip microcomputer 54 detects this signal and outputs the information stored in the memory 57 to the main device 70.

The battery pack 50 and the main device 70 operate as follows to turn off the shutdown circuit 52.
(1) When the battery pack 50 is connected to the main device 70, the voltage of the signal terminal 53A (SDA) is increased by the pull-up resistor 72 of the main device 70, and the first input switching element 61 and the second input device 61 “High” is input to the gate of the input switching element 62 to be turned on.
(2) When either the first input switching element 61 or the control switching element 64 is turned on, the gate of the main switching element 63 is connected to the ground. The main switching element 63 in this state is switched on because a bias voltage for turning on the FET is input between the source and the gate. The main switching element 63 that is turned on connects the secondary battery 51 to the regulator circuit 55 and puts the regulator circuit 55 into an operating state. The regulator circuit 55 in the operating state stabilizes the voltage of the secondary battery 51 and activates the one-chip microcomputer 54.
(3) When the one-chip microcomputer 54 is activated, the one-chip microcomputer 54 switches the control switching element 64 on. Therefore, the main switching element 63 is kept on and the regulator circuit 55 is kept in the operating state.
(4) When the battery pack 50 is removed from the main device 70, the voltage at the signal terminal 53A (SDA) decreases. This is because the signal terminal 53A (SDA) is not connected to the power supply line 71 by the pull-up resistor 73. For this reason, the first input switching element 61 and the second input switching element 62 are switched off. Even in this state, the one-chip microcomputer 54 in the operating state keeps the control switching element 64 on and puts the regulator circuit 55 into the operating state.
(5) The second input switching element 62 switched to the OFF state inputs a “High” OFF signal to the one-chip microcomputer 54. When the battery pack 50 is connected to the main device 70 and the second input switching element 62 is on, the second input switching element 62 is on and outputs “Low” to the one-chip microcomputer 54. Therefore, when “Low” is input from the second input switching element 62, the one-chip microcomputer 54 determines that the battery pack 50 is attached to the main device 70, and when “High” is input, the battery pack 50 Is removed from the main device 70. The one-chip microcomputer 54 detects that the battery pack 50 has been removed by the “High” off signal input from the second input switching element 62 and switches the control switching element 64 off. In this state, since both the control switching element 64 and the first input switching element 61 are turned off, the main switching element 63 is switched off.
(6) When the main switching element 63 is switched off, power is not supplied from the secondary battery 51 to the regulator circuit 55, and the operation of the regulator circuit 55 is stopped. For this reason, the regulator circuit 55 does not supply the power of the secondary battery 51 to the one-chip microcomputer 54. That is, when the battery pack 50 is removed from the main device 70, the shutdown circuit 52 shuts down and cuts off the power supply from the secondary battery 51 to the one-chip microcomputer 54.

  The battery pack 50 of FIG. 3 operates the shutdown circuit 52 with the voltage of the signal terminal 53A (SDA). However, the shutdown circuit 52 can be controlled to be turned on / off by the voltage of the other signal terminal 53B (SCL).

It is a circuit diagram of the electric equipment with which the battery pack concerning one Example of this invention is mounted | worn. It is an enlarged view of the shutdown circuit of the battery pack shown in FIG. It is a circuit diagram of the electric equipment with which the battery pack concerning the other Example of this invention is mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pack battery 11 ... Secondary battery 12 ... Shutdown circuit 13 ... Signal terminal 14 ... Microcomputer 15 ... Regulator circuit 16 ... Temperature sensor 21 ... 1st input switching element 22 ... 2nd input switching element 23 ... Main switching element 24 ... Control switching element 25 ... Load resistance 30 ... Main unit 31 ... Power supply line 32 ... Pull-up resistor 33 ... Connector terminal 35 ... Voltage detection circuit 50 ... Pack battery 51 ... Secondary battery 52 ... Shutdown circuit 53 ... Signal terminal 53A ... Signal Terminal
53B ... Signal terminal 54 ... Microcomputer 55 ... Regulator circuit 57 ... Memory 61 ... First input switching element 62 ... Second input switching element 63 ... Main switching element 64 ... Control switching element 70 ... Main equipment 71 ... Power supply line 72 ... Pull-up resistor 73 ... Connector terminal

Claims (6)

Secondary battery (11), (51), shutdown circuit (12), (52) for turning on / off the power supply from the secondary battery (11), (51) to the built-in electronic circuit, and main body to be mounted A battery pack comprising signal terminals (13) and (53) for the devices (30) and (70),
The shutdown circuit (12), (52) detects the voltage at the signal terminals (13), (53), detects the attachment / detachment with the main unit (30), (70), and the battery pack (30 ), A battery pack that is configured to shut off the power supply from the secondary battery (11), (51) to the electronic circuit in a state where it is removed from the (70).   It is equipped with a temperature sensor (16) that detects the battery temperature, and this temperature sensor (16) is connected to the signal terminal (13) and detects the voltage of the temperature sensor (16) to detect attachment / detachment to the main unit (30) The battery pack according to claim 1.   It has a memory (57) for storing battery information, and this memory (57) is connected to the signal terminal (53), and detects the voltage of the signal terminal (53) connected to the memory (57) to detect the main device ( The battery pack according to claim 1, wherein the battery pack is detected to be attached to or detached from 70).   The battery pack according to claim 1, wherein the electronic circuit comprises a microcomputer (14), (54).   It has regulator circuits (15) and (55) that stabilize the voltage of the secondary batteries (11) and (51) and supply them to the electronic circuit.The regulator circuits (15) and (55) and the secondary battery ( The battery pack according to claim 1, wherein a shutdown circuit (12), (52) is connected between 11) and (51). A battery pack (10), (50), and an electric device comprising a main body device (30), (70) to be attached so as to be removable,
The battery packs (10) and (50) include a secondary battery (11) and (51), and a shutdown circuit (12 for turning on and off the power supply from the secondary battery (11) and (51) to the built-in electronic circuit. ), (52), and signal terminals (13), (53) for the main devices (30), (70) to be mounted,
Main unit (30), (70) has connector terminals (33), (73) connected to signal terminals (13), (53) of battery pack (10), (50), connector terminal (33) , (73) are connected to the power supply of the main unit (30), (70) via the pull-up resistors (32), (72),
When the battery packs (10) and (50) are connected to the main unit (30) and (70), the pull-up resistors (32) and (72) set the voltage at the signal terminals (13) and (53) to the set voltage. The shutdown circuit (12), (52) of the battery pack (10), (50) detected a voltage higher than the set voltage and was installed in the main unit (30), (70) Detect
When the battery packs (10) and (50) are disconnected from the main unit (30) and (70) and the voltage at the signal terminals (13) and (53) drops below the set voltage, the shutdown circuits (12) and (52 ) Detects the voltage at the signal terminals (13) and (53) and shuts off the power supply from the secondary batteries (11) and (51) to the electronic circuit. .

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