TWI797641B - protect the circuit - Google Patents

Abstract

The subject of the present invention is to realize a protection circuit and a battery pack for protecting a battery pack from overcharging and overheating with a simpler structure. The present invention provides a protection circuit, which protects a battery pack of a secondary battery such as a lithium ion battery from overcharging and overheating, and includes: a battery pack formed by connecting more than one secondary battery unit; The control unit outputs a control signal according to the voltage of the cell or the battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the battery pack and the external terminal, and receive signals from the signal control unit To perform on/off control; and a protection element, which has a built-in fuse assembly and a thermistor, the fuse assembly and the discharge circuit are connected in parallel, and the action of the thermistor is controlled by the third switching element connected to the signal control part control.

Description

protect the circuit

The present invention relates to a protection device, a protection circuit and a battery pack of a battery pack equipped with a protection element. The protection element has a thermistor and a fuse assembly.

Even if the lithium-ion battery is in the form of a single battery used in a mobile phone, it must be manufactured in the form of a battery pack. The form of the battery pack here refers to the combination of the lithium-ion battery and the protection circuit (Safety Unit) is assembled into the housing in a matching manner. The reason is that it is difficult to ensure the practical safety of a lithium-ion battery cell itself. The safety characteristics of lithium-ion batteries can be exemplified by poor tolerance to overcharging and overheating. Therefore, the battery pack is made by storing the protective circuit, protective element, fuse, etc. used to ensure safety and the battery in a plastic casing and other external cans. On the one hand, the voltage, current, temperature, etc. The control system (battery management system, BMS) controls the charge and discharge of the battery.

The battery pack of the secondary battery unit (cell) equipped with several lithium-ion batteries is connected in series with the protection element and the battery to prevent the battery from being charged and discharged under abnormal conditions. The protection element cuts off the current when the battery is charged and discharged in an abnormal state. In order to cut off the current of the battery in case of abnormality, the protective element contains a fuse component formed by a low-melting-point metal that will be melted due to the Joule heat of over-current. Furthermore, a thermistor is built into the protection element, and when there is an abnormality that the battery is overcharged, the thermistor can be energized to heat and fuse the low-melting-point metal fuse assembly in a short time. (refer to patent document 1) The above protection components are connected to the protection circuit of the battery pack, and the fuse components are controlled by control components such as Protection IC (Protection Integrated Circuit) and field effect transistor (FET, Field Effect Transistor) that monitor the voltage of each cell. action. For example, the protection element used in the charging and discharging control circuit of the battery pack described in Patent Document 2 senses the overcurrent of the battery pack and the rise in ambient temperature or energizes the thermistor under a predetermined condition, and forcibly turns on the fuse. actuation to cut off the circuit. That is, the protection element can heat the resistance element through the signal current when the protection circuit detects an abnormality in the machine, and use the heat to blow the fuse element (also called the fuse element) containing the fusible alloy to cut off the circuit. Break, or cut off the circuit by fusing the fuse assembly through overcurrent, so as to achieve machine safety.

The composition of the conventional battery pack is relatively complicated. That is, several protection elements are required in the protection circuit, at least different protection elements are used in the discharge system and the charge system. In addition, the protection circuit requires a plurality of semiconductor elements including FET (switching element) and diode (rectifying element) constituting the switch, of which at least two are used in the discharge circuit system and two are used in the charging circuit system , In addition, use one to control the action of the protection element. The two signals output from the switching control unit to the first and second switches must always be in opposite phases of each other. The reason is that if the signals are in the same phase, a loop will be formed between the two switches and the two protection elements, and therefore there is a risk of system failure. Conventional protection circuits have the above-mentioned risks when performing signal control. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-228379 [Patent Document 2] Japanese Patent Laid-Open No. 2012-231649

(Problem to be solved by the invention)

The present invention is proposed for the purpose of implementing a protection circuit and a battery pack for protecting a battery from overcharging and overheating with a simpler structure, thereby reducing the above-mentioned system risk. (technical means to solve the problem)

According to the present invention, a protection circuit is proposed, which protects the battery pack of secondary batteries such as lithium-ion batteries from overcharging and overheating, and has: A battery pack (battery), which is formed by connecting more than one secondary battery cell; a signal control unit, which outputs a control signal according to the voltage of the cell or the battery pack; the first switch element and the second switch element, which The current circuit connected in parallel between the battery pack and the external terminal, and receives the signal from the signal control part to perform on/off control; and the protection element, which has a built-in fuse assembly and thermistor, and the fuse assembly and The discharge circuit is connected in parallel, and the action of the thermistor is controlled by the third switch element connected to the signal control part.

The switching element of the present invention includes a field-effect transistor (FET), a metal-oxide-semiconductor field-effect transistor (MOSFET, Metal-Oxide-Semiconductor Field-Effect Transistor), an insulated gate bipolar transistor (IGBT, Insulated Gate Bipolar Transistor), etc. A switching transistor or a protection circuit module including the switching element.

The protection circuit of the present invention is applied to the charging and discharging device of the battery pack. That is, to provide a charging and discharging device, which is a charging and discharging device for a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack formed by connecting one or more single cells of the secondary battery; a signal control unit , which outputs a control signal according to the voltage of a single cell or a battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the battery pack and the external terminal, and receive signals from the signal control unit to perform On/off control; and a protection element, which contains a fuse assembly and a thermistor, the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by the third switch element connected to the signal control part; The signal control unit can turn off the first switching element and turn on the second switching element when charging, and turn on the first switching element and turn off the second switching element when discharging, so as to control the charging circuit and the discharging circuit. On/off control, and the protection element has a fuse assembly, which fuses when the value of the current flowing through the charging circuit of the second switching element exceeds the predetermined fusing current value, or when the voltage of the cell or battery pack exceeds When the predetermined voltage value is reached, the thermistor will be fused due to the heat generated by energization.

The protection circuit or charging and discharging device of the present invention is applied to a battery pack. That is, to provide a battery pack, which is a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack formed by connecting one or more secondary battery cells; Or the voltage output control signal of the battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the battery pack and the external terminal, and receive the signal from the signal control part to turn on/off Control; and protection components, the built-in fuse assembly and thermistor, the fuse assembly and the discharge circuit are connected in parallel, and the action of the thermistor is controlled by the third switch element connected to the signal control part; the signal control part is connected to When charging, the first switching element is turned off and the second switching element is turned on, and when discharging, the first switching element is turned on and the second switching element is turned off, and the charging circuit and the discharging circuit are turned on/off Control, the protection element is when the value of the current flowing through the charging circuit of the second switching element exceeds the predetermined fusing current value, the fuse assembly is blown to cut off the charging circuit, and through the signal control part, in the single cell or the battery pack When the voltage exceeds the predetermined value, the thermistor will heat up and the fuse assembly will be blown, thereby cutting off the charging circuit.

The battery pack of the present invention is used in electrical equipment such as mobile devices that do not use wires. That is, to provide an electric device that uses a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack that is formed by connecting one or more single cells of the secondary battery; a battery pack that controls the battery The protective circuit or charging and discharging device for charging and discharging of the battery pack; and the main body of the machine, which is detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack for driving; the battery pack has: a signal control unit , which outputs a control signal according to the voltage of a single cell or a battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the battery pack and the external terminal, and receive signals from the signal control unit to perform On/off control; and a protection element, which contains a fuse assembly and a thermistor, the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by the third switch element connected to the signal control part; The signal control unit turns off the first switching element and turns on the second switching element during charging, and turns on the first switching element and turns off the second switching element during discharging, so as to control the charging circuit and the discharging circuit. On/off control, the protection element is when the current value of the charging circuit flowing through the second switching element exceeds the predetermined fusing current value, the fuse assembly is blown to cut off the charging circuit, and through the signal control part, at When a single cell or a battery pack exceeds a predetermined voltage value, the thermistor will heat up and the fuse assembly will be blown, thereby cutting off the charging circuit.

According to another aspect of the present invention, a protection circuit is proposed, which protects a battery pack of a secondary battery such as a lithium ion battery from overcharging and overheating, and includes: a battery pack formed by connecting more than one single cell ; Signal control unit, which monitors the voltage of a single cell or a battery pack and outputs a control signal according to its measured value; a switching control element, which is connected to the discharge circuit and the charging circuit between the battery pack and the external terminal of the battery pack, and receives signals from The signal of the signal control part is thus on/off controlled; and the protection element has a built-in fuse assembly and a thermistor, and the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is connected to the signal control part. The switching element control.

Furthermore, the protection circuit including the switching control element described above is applied to a charging and discharging device. That is, to provide a charging and discharging device, which is a charging and discharging device for a battery pack of a secondary battery such as a lithium ion battery provided with the above-mentioned switching control element, and includes: a battery pack formed by connecting one or more monomers; The control unit outputs the control signal according to the voltage of the single cell or the battery pack; the switching control element is connected to the discharge circuit and the charging circuit between the battery pack and the external terminals of the battery pack, and receives the signal from the signal control unit to perform On/off control; and a protection element, which has a built-in fuse assembly and a thermistor, the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by a switching element connected to the signal control part; switching control When the element is charged, the discharge circuit can be disconnected and the charging circuit can be connected by the signal control part, and the discharge circuit can be connected and the charging circuit can be disconnected by the signal control part when discharging, so that the charging circuit and the discharging circuit can be connected. On/off control, and the protection element has a fuse assembly, which fuses when the value of the current flowing through the charging circuit of the switching control element exceeds the predetermined fusing current value, or when the voltage of the cell or battery pack exceeds the predetermined value When the voltage value is higher, the thermistor will be fused due to the heat generated by energization.

The protection circuit and charging and discharging device including the switching control element mentioned above can be used in a battery pack. That is, to provide a battery pack, which is a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack formed by connecting one or more secondary battery cells; Or the voltage output control signal of the battery pack; the switching control element, which is connected to the discharge circuit and the charging circuit between the battery pack and the external terminal of the battery pack, and receives the signal from the signal control part to perform on/off control; And the protection element, which has a built-in fuse assembly and a thermistor, and the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by a switching element connected to the signal control part; the signal control part is used to discharge when charging The circuit is disconnected and the charging circuit is connected. When discharging, the discharging circuit is connected and the charging circuit is disconnected, and the charging circuit and the discharging circuit are connected/disconnected. The protection element is connected to the switching control element. When the current value of the charging circuit exceeds the predetermined fusing current value, the fuse assembly will be blown to cut off the charging circuit, and the signal control part will make the thermistor heat up when the voltage value of the single cell or the battery pack exceeds the predetermined value. Blow the fuse assembly, thereby disconnecting the charging circuit.

The battery pack including the switching control element of the present invention can be used in electric machines such as mobile devices that do not use wires. That is, to provide an electric device that uses a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack that is formed by connecting one or more single cells of the secondary battery; a battery pack that controls the battery The protective circuit or charging and discharging device for charging and discharging of the battery pack; and the main body of the machine, which is detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack for driving; the battery pack has: a signal control unit , which outputs a control signal according to the voltage of a single cell or a battery pack; a switching control element, which is connected to the discharge circuit and the charging circuit between the battery pack and the external terminal of the battery pack, and receives a signal from the signal control unit to switch on /disconnection control; and a protection element, which has a built-in fuse assembly and a thermistor, and the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by a switching element connected to the signal control part; the signal control part is When charging, the discharge circuit is turned off and the charging circuit is turned on; when discharging, the discharge circuit is turned on and the charging circuit is turned off, and the charging circuit and the discharging circuit are turned on/off controlled, and the protection element is connected to the current When the current value of the charging circuit of the switching control element exceeds the predetermined fusing current value, the fuse element will be blown to cut off the charging circuit, and through the signal control part, when the voltage value of the single cell or the battery pack exceeds the predetermined value, the heat will be generated. The varistor heats up and blows the fuse assembly, thereby cutting off the charging circuit. (compared to the effect of previous technology)

The invention provides a protection device for forming a simpler battery pack.

As shown in FIG. 1 , the protection circuit 10 of the present invention is a protection circuit for protecting secondary battery packs such as lithium-ion batteries from overcharging and overheating, and includes: a battery pack 12 consisting of more than one secondary battery The cells 11 of the battery are connected in series; the signal control unit 13 outputs control signals according to the voltage of the cells 11 or the battery pack 12; a first switch element 15-1 and a second switch element 15-2, They are connected in parallel to the current circuit between the battery pack 12 and the external terminal 14, and receive the signal from the signal control unit 13 to perform on/off control; and a protection element 16, which has a built-in fuse assembly 16- 1 and the thermistor 16-2, the fuse assembly 16-1 is connected in parallel with the discharge circuit, and the action of the thermistor 16-2 is controlled by the third switching element 15-3 connected to the signal control unit 13. As shown in FIG. 1 , the protection circuit 10 can only use the signal control unit 13 to control the switching of the charging and discharging circuit, thereby simplifying the circuit configuration and reducing the risk of failure (error) of the control unit. The protection circuit 10 can delay the applied voltage by providing a delay circuit 89 including a resistance element 89-1 and a capacitor element 89-2 as shown in FIG. .

The protection circuit 10 described above is applied to a charging and discharging device of a battery pack. That is, a charging and discharging device is provided, which is a charging and discharging device for a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack 12, which is formed by connecting in series the cells 11 of more than one secondary battery; A signal control unit 13, which outputs a control signal according to the voltage of the cell 11 or the battery pack 12; a first switching element 15-1 and a second switching element 15-2, which are connected in parallel between the battery pack 12 and the external The current circuit between the terminals 14, and receives the signal from the signal control unit 13 to perform on/off control; and the protection element 16, which has a built-in fuse assembly 16-1 and a thermistor 16-2, and the fuse assembly 16-1 is connected in parallel with the discharge circuit, and the action of the thermistor 16-2 is controlled by the 3rd switch element 15-3 connected to the signal control part 13; the signal control part 13 can make the 1st switch element 15 -1 is turned off and the second switching element 15-2 is turned on, and when discharging, the first switching element 15-1 is turned on and the second switching element 15-2 is turned off, and the charging circuit and the discharging circuit are connected. On/off control, the protection element 16 has a fuse assembly 16-1, and the fuse assembly 16-1 is blown when the value of the current flowing through the charging circuit of the second switching element 15-2 exceeds a predetermined fusing current value, or when When the voltage of the single cell 11 or the battery pack 12 exceeds a predetermined voltage value, the thermistor 16-2 will be fused due to the heat generated by energization.

In the above protection circuit or charge and discharge device, the second switching element 15 - 2 is arranged between the cell 11 or the battery pack 12 and the protection element 16 . Alternatively, in another example of the protection circuit or the charge-discharge device of the present invention, the protection element 16 is arranged between the cell 11 or the battery pack 12 and the second switch element 15-2.

Also, in the protection circuit or the charging and discharging device of the present invention, the first switching element 15-1 is connected between the battery pack 12 and the external terminal 14 of the battery pack, and includes a switching transistor, which receives signals from The signal of the signal control part 13 of the voltage output control signal of the monomer 11 is thus on/off controlled, and the second switch element 15-2 is connected in parallel with the first switch element 15-1, including receiving the signal The signal thus performs on/off control of a switching transistor, and the first switching element 15-1 and the second switching element 15-2 are configured so that the bias directions of the internal diodes in the switching transistor are opposite to each other, The signal control unit 13 performs on/off control such that the first switching element 15-1 is turned off and the second switching element 15-2 is turned on during charging, and the first switching element 15-1 is turned on during discharging. 1 turns on and turns off the second switching element 15-2. For example, the first switching element 15-1 and the second switching element 15-2 may respectively include a field effect transistor, if the first switching element 15-1 and the second switching element 15-2 are formed as a field effect transistor The bias directions of the internal diodes are opposite to each other, and the following on/off control can be performed by the signal control unit 13, that is, the first switching element 15-1 is turned off and the second switching element is turned off during charging. 15-2 is turned on to turn on the first switching element 15-1 and turn off the second switching element 15-2 at the time of discharge.

The protection circuit 10 can also be modified like the protection circuit 20 shown in FIG. 2 . That is, it is equipped with: a battery pack 22, which is formed by connecting in series the cells 21 of more than one secondary battery; a signal control unit 23, which outputs a control signal according to the voltage of the cells 21 or the battery pack 22; The switching element 25-1 and one second switching element 25-2 are connected in parallel to the current circuit between the battery pack 22 and the external terminal 24, and are turned on/off by receiving a signal from the signal control unit 23 Control; and the protection element 26, which has a built-in fuse assembly 26-1 and a thermistor 26-2, the fuse assembly 26-1 is connected in parallel with the discharge circuit, and the action of the thermistor 26-2 is controlled by the signal connected The 3rd switching element 25-3 control of part 23; Signal control part 23 can also branch its signal circuit and arrange inverter element (inverting amplifying element) 27 in any signal circuit, in the signal circuit of this branch One side is connected to the gate of the first switching element 25-1, and the other side is connected to the gate of the second switching element 25-2. In this case, since one of the first switching element 25-1 and the second switching element 25-2 has the inverter element 27, one signal path can be shared. In this modified example, as shown in FIG. 2 , switching of the charging and discharging circuit can be controlled by a single signal from the signal control unit 23 , thereby simplifying the circuit configuration and reducing the risk of errors in the control unit.

Again, the protection circuit 10 of the present invention can also be deformed like the protection circuit 30 shown in Figure 3, that is, it has: a battery pack 32, which is formed by connecting in series the monomers 31 of more than one secondary battery; Part 33, which outputs a control signal according to the voltage of the cell 31 or the battery pack 32; a first switching element 35-1 and a second switching element 35-2, which are connected in parallel to the battery pack 32 and the external terminal 34 The current circuit between them, and receives the signal from the signal control part 33 to perform on/off control; and the protection element 36, which has a built-in fuse assembly 36-1 and a thermistor 36-2, and the fuse assembly 36- 1 is connected in parallel with the discharge circuit, and the action of the thermistor 36-2 is controlled by the third switch element 35-3 connected to the signal control part 33; the signal control part 33 branches its signal circuit and sets it in any signal circuit The inverter element (inverting amplification element) 37 is connected to the gate of the first switching element 35-1 on one side of the branched signal circuit, and connected to the gate of the second switching element 35-2 on the other side. In this case, since one of the first switching element 35-1 and the second switching element 35-2 has the inverter element 37, one signal circuit can be shared. The protection element 36 is disposed between the battery pack 32 and the second switch element 35-2, and when the thermistor 36-2 and the fuse assembly 36-1 exceed a predetermined fusing temperature, or through the second switch element 35-2 When the value of the current flowing through the fuse assembly 36-1 exceeds the predetermined fusing current value, the charging circuit is cut off, and the above-mentioned thermistor 36-2 outputs a control signal according to the voltage of the cell 31 or the battery pack 32. The signal control unit 33 is energized to generate heat when the cell 31 or the battery pack 32 exceeds a predetermined voltage value, and the fuse unit 36-1 is connected in parallel to the first switching element 35-1. As shown in FIG. 3 , the protection circuit 30 can control the switching of the charging and discharging circuit by a single signal from the signal control unit 33 , thereby simplifying the circuit configuration and reducing the risk of failure of the control unit.

The signal control part 13 of the protective circuit or the charging and discharging device of the present invention is when the voltage value of the single cell 11 or the battery pack 12 exceeds a predetermined value, by controlling the signal output according to the voltage of the single cell 11 or the battery pack 12, the second 1. The switching transistor of the switching element 15-1 is turned from off to on, and the switching transistor constituting the second switching element 15-2 is changed from on to off, when the monomer 11 or the battery pack 12 is not full At a predetermined voltage value, the switching transistor constituting the first switching element 15-1 is turned off from on by the control signal of the signal control unit 13, and the switching transistor constituting the second switching element 15-2 is turned off. The crystal turns from off to on.

The first switch element 15-1 of the protection circuit or the charge-discharge device of the present invention includes a switch transistor, and the switch transistor is connected to the discharge circuit in such a way that the bias direction of the internal diode becomes positive relative to the discharge direction. Above, the second switching element 15-2 includes a switching transistor, and the switching transistor is connected to the charging circuit so that the bias direction of the internal diode becomes forward with respect to the charging direction.

The protection circuit or charging and discharging device of the present invention can delay the applied voltage by setting a delay circuit 89 including a resistance element 89-1 and a capacitor element 89-2 as shown in FIG. 8 as needed, thereby buffering the surge when switching Incoming current and other overshoot current.

The protection circuit or charging and discharging device of the present invention is applied to a battery pack. That is, a battery pack is provided, which is a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack 12 formed by connecting in series one or more single cells 11 of the secondary battery; a signal control unit 13, It outputs a control signal according to the voltage of the cell 11 or the battery pack 12; a first switching element 15-1 and a second switching element 15-2 are connected in parallel between the battery pack 12 and the external terminal 14 A current circuit, and receives a signal from the signal control part to perform on/off control; and a protection element 16, which contains a fuse assembly 16-1 and a thermistor 16-2, a fuse assembly 16-1 and a discharge circuit connected in parallel, and the action of the thermistor 16-2 is controlled by the third switch element 15-3 connected to the signal control part 13; the signal control part 13 is to disconnect the first switch element 15-1 and make the The second switching element 15-2 is turned on, and when discharging, the first switching element 15-1 is turned on and the second switching element 15-2 is turned off, so as to control the charging circuit and the discharging circuit on/off, The protection element 16 is when the current value of the charging circuit flowing through the second switching element 15-2 exceeds a predetermined fusing current value, the fuse assembly 16-1 is blown to cut off the charging circuit, and by the signal control part 13, When the voltage of the cell 11 or the battery pack 12 exceeds a predetermined value, the thermistor 16-2 is heated and the fuse assembly 16-1 is blown, thereby cutting off the charging circuit.

The battery pack of the present invention is used in electrical equipment such as mobile devices that do not use wires. That is, to provide an electric machine, which utilizes a battery pack of a secondary battery such as a lithium ion battery, and has: a battery pack 12, which is formed by connecting in series one or more cells 11 of the secondary battery; and a battery pack, which has A protection circuit or a charge-discharge device for controlling the charging and discharging of the battery pack 12; and a machine body, which is detachably connected to the battery pack for charging the battery pack or receiving power supply from the battery pack for driving; the above-mentioned battery The package includes: a signal control unit 13, which outputs a control signal according to the voltage of the cell 11 or the battery pack 12; a first switching element 15-1 and a second switching element 15-2, which are connected in parallel to the battery pack 12 and the current circuit between the external terminal 14, and receives the signal from the signal control part 13 to perform on/off control; and the protection element 16, which has a built-in fuse assembly 16-1 and thermistor 16-2 , the fuse assembly 16-1 is connected in parallel with the discharge circuit, and the action of the thermistor 16-2 is controlled by the 3rd switching element 15-3 connected to the signal control part 13; The switching element 15-1 is turned off and the second switching element 15-2 is turned on. When discharging, the first switching element 15-1 is turned on and the second switching element 15-2 is turned off, and the charging circuit and the discharging The circuit is on/off controlled, and the protection element 16 is when the current value of the charging circuit flowing through the second switching element 15-2 exceeds the predetermined fusing current value, the fuse assembly 16-1 is blown to cut off the charging circuit. And through the signal control part 13, when the voltage value of the cell 11 or the battery pack 12 exceeds a predetermined value, the thermistor 16-2 is heated and the fuse assembly 16-1 is blown, thereby cutting off the charging circuit.

As shown in FIG. 4 , the protection circuit 40 of the present invention is a protection circuit for protecting secondary battery packs such as lithium-ion batteries from overcharging and overheating, and has: a battery pack 42 consisting of more than one monomer 41 are connected in series; the signal control part 43 monitors the voltage of the monomer 41 or the battery pack 42 and outputs a control signal according to the measured value; the switching control element 45 is connected between the battery pack 42 and the external terminal 44 of the battery pack between the discharge circuit and the charging circuit, and receive the signal from the signal control unit 43 to perform on/off control; and a protection element 46, which contains a fuse assembly 46-1 and a thermistor 46-2, The fuse assembly 46 - 1 is connected in parallel with the discharge circuit, and the action of the thermistor 46 - 2 is controlled by the switch element 48 connected to the signal control unit 43 . As shown in FIG. 4 , the protection circuit 40 can control the switching of the charging and discharging circuit by a single signal from the signal control unit 43 , thereby simplifying the circuit configuration and eliminating the risk of errors caused by switching the control unit. The protection circuit 40 can delay the applied voltage by providing a delay circuit 89 including a resistance element 89-1 and a capacitor element 89-2 as shown in FIG. .

Furthermore, the protection circuit including the switching control element described above is applied to a charging and discharging device. That is, the charging and discharging device possessing the switching control element of the present invention has: a battery pack 42, which is formed by connecting in series more than one single cell 41; Control signal; switching control element 45, which is connected to the discharge circuit and charging circuit between the battery pack 42 and the external terminal 44 of the battery pack, and receives a signal from the signal control part 43 to perform on/off control; and protection Component 46 has a built-in fuse assembly 46-1 and a thermistor 46-2, the fuse assembly 46-1 is connected in parallel with the discharge circuit, and the action of the thermistor 46-2 is controlled by a switch connected to the signal control unit 43 Component 48 control; switching control component 45 can disconnect the discharge circuit and connect the charging circuit by the signal control part 43 when charging, and connect the discharging circuit and disconnect the charging circuit by the signal control part 43 when discharging , and the on/off control of the charging circuit and the discharging circuit is carried out, and the protection element 46 has a fuse assembly 46-1, and the value of the current flowing through the charging circuit of the switching control element 45 exceeds a predetermined When the fusing current value is cut off, or when the voltage of the cell 41 or the battery pack 42 exceeds a predetermined voltage value, the thermistor 46-2 is energized to generate heat.

The switching control element 45 of the present invention includes a selector, a switch controller, a complementary metal oxide semiconductor (CMOS, Complementary Metal Oxide Semiconductor) transistor, MOSFET, IGBT, FET or a protection circuit module including the switching element. The switching element 48 includes switching elements such as MOSFET, IGBT, and FET, or a protection circuit module including the switching element.

In the protection circuit or charging and discharging device including the switching control element 45 of the present invention, the protection element 46 is arranged on the charging circuit between the cell 41 or the battery pack 42 and the switching control element 45 . Also, although not shown, in another example of a protection circuit or a charging/discharging device including the switching control element, the protection element 46 may also be disposed between the switching control element 45 and the external terminal 44 of the battery pack.

The protection circuit and charging and discharging device including the switching control element mentioned above can be used in a battery pack. That is, the battery pack equipped with switching control elements of the present invention is a battery pack of secondary batteries such as lithium-ion batteries, and includes: a battery pack 42, which is formed by connecting in series single cells 41 of more than one secondary battery; Control part 43, it outputs control signal according to the voltage of monomer 41 or battery pack 42; The signal of the control part 43 thus performs on/off control; and the protection element 46 has a built-in fuse assembly 46-1 and a thermistor 46-2, and the fuse assembly 46-1 is connected in parallel with the discharge circuit, and the temperature sensitive The action of the resistor 46-2 is controlled by the switching element 48 connected to the signal control part 43; the signal control part 43 is to disconnect the discharge circuit and connect the charging circuit when charging, and to connect the discharging circuit and make the charging circuit connect when discharging. The charging circuit is disconnected, and the on/off control of the charging circuit and the discharging circuit is carried out, and the protection element 46 is when the value of the current flowing through the charging circuit of the switching control element 45 exceeds the predetermined fusing current value, and the fuse assembly is blown 46-1 to cut off the charging circuit, and through the signal control part 43, when the monomer 41 or the battery pack 42 exceeds a predetermined voltage value, the thermistor 46-2 is heated and the fuse assembly 46-1 is blown, thereby Cut off the charging circuit.

The battery pack including the switching control element 45 can be used in electrical equipment such as mobile devices without wires. That is, the electric machine equipped with the switching control element of the present invention uses a battery pack of a secondary battery such as a lithium ion battery, and has: a battery pack 42, which is formed by connecting in series one or more single cells 41 of the secondary battery; A battery pack, which has a protection circuit or a charge-discharge device for controlling the charging and discharging of the battery pack 42; and a machine body, which is detachably connected to the battery pack for charging the battery pack or receiving power supply from the battery pack And drive; above-mentioned battery pack has: signal control part 43, it outputs control signal according to the voltage of monomer 41 or battery pack 42; The discharge circuit and the charging circuit receive the signal from the signal control part 43 to perform on/off control; and the protection element 46 has a built-in fuse assembly 46-1 and a thermistor 46-2, and the fuse assembly 46- 1 is connected in parallel with the discharge circuit, and the action of the thermistor 46-2 is controlled by the switch element 48 connected to the signal control part 43; the signal control part 43 is to disconnect the discharge circuit and connect the charge circuit when charging, When discharging, the discharge circuit is connected and the charging circuit is disconnected, and the charging circuit and the discharging circuit are connected/disconnected, and the protection element 46 is when the value of the current flowing through the charging circuit of the switching control element 45 exceeds When the predetermined fusing current value is reached, the fuse assembly 46-1 will be blown to cut off the charging circuit, and the thermistor 46-2 will be activated when the voltage of the cell 41 or the battery pack 42 exceeds the predetermined voltage value through the signal control unit 43. The fuse assembly 46-1 is blown by heat generation, thereby cutting off the charging circuit. [Example]

As shown in Figure 5, the protection circuit 50 of Embodiment 1 has: a battery pack 52, which is formed by connecting four cells 51 of lithium-ion batteries in series; Voltage output control signal; a first switch element 55-1 and a second switch element 55-2, which are connected in parallel to the current circuit between the battery pack 52 and the external terminal 54, receive signals from the control unit 53 The signal is thus on/off controlled, and each includes an N-channel MOSFET; and a protection element 56, which contains a fuse assembly 56-1 including a fusible metal material and a thermistor including a film resistor 56-2, the fuse assembly 56-1 is connected in parallel with the discharge circuit, and the action of the thermistor 56-2 is controlled by a third switching element 55-3 that is connected to the signal control part 53 and includes an N-channel MOSFET. . The protection circuit 50 is applied to the charging and discharging device of the battery pack. The signal control unit 53 turns off the first switch element 55-1 and turns on the second switch element 55-2 when charging, and turns the first switch element 55-2 on when discharging. The element 55-1 is turned on and the second switching element 55-2 is turned off to perform on/off control of the charging circuit and the discharging circuit.

As shown in Figure 6, the protection circuit 60 of Embodiment 2 has: a battery pack 62, which is formed by connecting four cells 61 of lithium ion batteries in series; Voltage output control signal; a first switch element 65-1 and a second switch element 65-2, which are connected in parallel in the current circuit between the battery pack 62 and the external terminal 64, and receive signals from the control unit 63 The signal is thus on/off controlled, and each includes an N-channel MOSFET; and a protection element 66, which contains a fuse assembly 66-1 including a fusible metal material and a thermistor including a film resistor 66-2, the fuse assembly 66-1 is connected in parallel with the discharge circuit, and the action of the thermistor 66-2 is controlled by a third switching element 65-3 including an N-channel MOSFET connected to the signal control part 63 . The protection circuit 60 is applied to the charging and discharging device of the battery pack. The signal control part 63 branches the signal circuit, and connects the gate of the first switching element 65-1 on one side, and connects the second switching element 65-2 on the other side. The gate of the second switching element 65 - 2 is connected to the signal circuit of the signal control unit 63 via the inverter element 67 . The gate of the first switching element 65 - 1 is not connected to the signal control unit 63 via the inverter element 67 . Since the second switching element 65-2 has the inverter element 67, it can share a signal circuit with the first switching element 65-1. Furthermore, in Embodiment 2, the inverter element 67 is connected to the side of the second switching element 65-2, but the inverter element 67 only needs to be provided in any one of the first or second switching element, Instead of being arranged on the side of the second switching element 65-2, it may be appropriately arranged on the side of the first switching element 65-1.

As shown in Figure 7, the protection circuit 70 of Embodiment 3 has: a battery pack 72, which is formed by connecting four cells 71 of lithium-ion batteries in series; voltage and output a control signal according to the measured value; a switching control element 75, which is connected to the discharge circuit and the charging circuit between the battery pack 72 and the external terminal 74 of the battery pack, and receives the signal from the signal control unit 73 to perform connection. On/off control, and includes a CMOS transistor with an inverter (inverting amplifier); and a protection element 76, which contains a fuse assembly 76-1 including a fusible metal material and a fuse assembly including a film resistor The thermistor 76-2 and the fuse assembly 76-1 are connected in parallel with the discharge circuit, and the action of the thermistor 76-2 is controlled by a switching element 78 including an N-channel MOSFET connected to the signal control unit 73 . The protection circuit 70 is applied to the charging and discharging device of the battery pack, the signal control part 73 is connected to the input terminal (IN) of the switching control element 75, the discharge circuit is connected to the drain of the switching control element 75, and the charging circuit passes through the fuse assembly of the protection element 76-1 is connected to the source of the switching control element 75.

As shown in Figure 8, the protection circuit 80 of Embodiment 4 has: a battery pack 82, which is formed by connecting four cells 81 of lithium ion batteries in series; Voltage output control signal; a first switch element 85-1 and a second switch element 85-2, which are connected in parallel to the current circuit between the battery pack 82 and the external terminal 84, and receive signals from the control unit 83 The signal is thus on/off controlled, and includes an N-channel MOSFET; a protection element 86, which contains a fuse assembly 86-1 including a fusible metal material and a thermistor 86 including a film resistor -2, the fuse assembly 86-1 is connected in parallel with the discharge circuit, and the action of the thermistor 86-2 is controlled by a third switching element 85-3 including an N-channel MOSFET connected to the signal control part 83; and The delay circuit 89 includes a resistor element 89 - 1 connected in series with the battery pack 82 and a capacitor 89 - 2 connected in parallel with the resistor element 89 - 1 and the battery pack 82 . The protection circuit 80 can delay the applied voltage through the delay circuit 89, so as to buffer the inrush current during the switch generated in the unit of several μ seconds, and it is applied to the charging and discharging device of the battery pack. The signal control part 83 can be used during charging. The first switching element 85-1 is turned off and the second switching element 85-2 is turned on. When discharging, the first switching element 85-1 is turned on and the second switching element 85-2 is turned off, and the charging circuit On/off control with discharge circuit. (Refer to Figure 9)

Furthermore, the protection circuit 80 of the fourth embodiment can also be modified like the protection circuit 100 shown in FIG. 10 . That is, it is equipped with: a battery pack 102, which is formed by connecting in series the cells 101 of more than one secondary battery; a signal control unit 103, which outputs a control signal according to the voltage of the cells 101 or the battery pack 102; a protection element 106, Its built-in fuse assembly 106-1 and thermistor 106-2 are connected in series with the charge and discharge circuit including one path, and the action of thermistor 106-2 is connected to the signal control part A switch element 105 control of 103; and a delay circuit 109, which includes a resistance element 109-1 connected in series with the battery pack 102 and a capacitor element 109-2 connected with the resistance element 109-1 and connected in parallel with the battery pack 102; The protection circuit 100 uses the delay circuit 89 to delay the applied voltage to buffer the inrush current when switching, and when the value of the current flowing through the above-mentioned charging and discharging circuit exceeds a predetermined fusing current value, the fuse unit 106-1 is blown and the Cut off the charging and discharging circuit, and use the signal control unit 103 to make the thermistor 106-2 generate heat and blow the fuse assembly 106-1 when the voltage value of the cell 101 or the battery pack 102 exceeds a predetermined value, so that the above-mentioned The charging and discharging circuit is cut off.

The switching element of the protection circuit 100 may also include a switching transistor or a protection circuit module including the switching transistor.

The switching element of the above protection circuit 100 may also include a FET or a protection circuit module including the FET.

The protection circuit 100 is applicable to a battery pack. That is, a battery pack of a secondary battery such as a lithium ion battery includes: a battery pack, which is formed by connecting cells of one or more secondary batteries in series; Output control signal; protection element, which contains a fuse assembly and a thermistor, the fuse assembly is connected in series with the charging and discharging circuit, and the action of the thermistor is controlled by a switch element connected to the signal control part; and a delay circuit, which includes a resistance element connected to the above-mentioned battery pack and a capacitor element connected to the above-mentioned resistance element and connected to the above-mentioned battery pack; the protection circuit uses the delay circuit to delay the applied voltage and buffer the inrush current when switching , and when the value of the current flowing through the above-mentioned charge-discharge circuit exceeds the predetermined fusing current value, the above-mentioned fuse assembly is blown to cut off the above-mentioned charge-discharge circuit, and through the above-mentioned signal control part, the above-mentioned monomer or the above-mentioned battery pack When the predetermined voltage value is exceeded, the above-mentioned thermistor is heated to blow the above-mentioned fuse assembly, thereby cutting off the above-mentioned charging and discharging circuit.

With regard to the structure of the present invention, the protection device can be simplified with particular attention to the overcharge protection, and it can contribute to the cost reduction of the battery pack and the protection circuit. (industrial availability)

The present invention can be used in the protection circuit of electric and electronic equipment using the protection elements of thermistor and fuse assembly, especially in the protection device of secondary battery such as battery pack.

10,20,30,40,50,60,70,80,100: protection circuit 11,21,31,41,51,61,71,81,101: Monomer 12,22,32,42,52,62,72,82,102: battery pack 13,23,33,43,53,63,73,83,103: Signal Control Department 14,24,34,44,54,64,74,84,104: External terminals 15-1, 25-1, 35-1, 55-1, 65-1, 85-1: 1st switching element 15-2, 25-2, 35-2, 55-2, 65-2, 85-2: 2nd switching element 15-3, 25-3, 35-3, 55-3, 65-3, 85-3: 3rd switching element 16,26,36,46,56,66,76,86,106: protection elements 16-1,26-1,36-1,46-1,56-1,66-1,76-1,86-1,106-1: fuse assembly 16-2, 26-2, 36-2, 46-2, 56-2, 66-2, 76-2, 86-2, 106-2: Thermistor 27,37,67: Inverter components 45,75: switch control element 48,78,105: switching elements 89,109: delay circuit 89-1, 109-1: resistance element 89-2, 109-2: capacitor components

FIG. 1 is a diagram showing a protection circuit 10 of the present invention. FIG. 2 is a diagram showing a protection circuit 20 of the present invention. FIG. 3 is a diagram showing a protection circuit 30 of the present invention. FIG. 4 is a diagram showing a protection circuit 40 of the present invention. FIG. 5 is a diagram showing a protection circuit 50 according to Embodiment 1 of the present invention. FIG. 6 is a diagram showing a protection circuit 60 according to Embodiment 2 of the present invention. FIG. 7 is a diagram showing a protection circuit 70 according to Embodiment 3 of the present invention. FIG. 8 is a diagram showing a protection circuit 80 according to Embodiment 4 of the present invention. Fig. 9 is a graph showing the buffer effect obtained by using the delay circuit of the present invention. Fig. 10 is a diagram showing a protection circuit 100 obtained by modifying the fourth embodiment of the present invention.

10: Protection circuit

11: Monomer

12: Battery pack

13: Signal Control Department

14: External terminal

15-1: 1st switching element

15-2: Second switching element

15-3: 3rd switching element

16: Protection element

16-1: Fuse assembly

16-2: Thermistor

Claims (36)

A protection circuit, which protects a battery pack of a secondary battery such as a lithium ion battery from overcharging and overheating, and includes: a battery pack formed by connecting more than one secondary battery unit; a signal control unit, It outputs control signals according to the voltage of the above-mentioned single cell or the above-mentioned battery pack; the first switching element and the second switching element are connected in parallel in the current circuit between the above-mentioned battery pack and the external terminal, and receive signals from the above-mentioned control unit The signal is thus on/off controlled; and the protection element has a built-in fuse assembly and a thermistor, the above fuse assembly is connected in parallel with the discharge circuit, and the action of the above-mentioned thermistor is connected to the above-mentioned signal control part The third switching element control. The protection circuit according to claim 1, wherein the first and second switching elements include switching transistors or a protection circuit module including the switching transistors. The protection circuit according to claim 1 or 2, wherein the first and second switching elements include FETs or protection circuit modules including the FETs. The protection circuit according to claim 1 or 2, wherein the first switching element includes a switching transistor, and the switching transistor is connected to the discharge circuit in such a way that the bias direction of the internal diode becomes forward with respect to the discharge direction above, and the above-mentioned second switching element includes a switching transistor, and the switching transistor is connected to the charging circuit in such a manner that the bias direction of the internal diode becomes positive with respect to the charging direction. The protection circuit according to claim 1 or 2, wherein the signal control unit branches its signal circuit and installs an inverter element in any one of the signal circuits, and connects the first switching element to one side of the branched signal circuit. The gate is connected to the gate of the above-mentioned second switching element on the other side. The protection circuit according to claim 1 or 2, wherein the protection circuit is further provided with a delay circuit including a resistance element and a capacitor element. A charging and discharging device, which is a charging and discharging device for a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack, which is formed by connecting more than one secondary battery monomer; a signal control unit, which is based on The voltage output control signal of the above-mentioned single cell or the above-mentioned battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the above-mentioned battery pack and the external terminal, and receive the signal from the above-mentioned signal control part to thereby On/off control; and a protection element with a built-in fuse assembly and a thermistor, the fuse assembly and the discharge circuit are connected in parallel, and the action of the thermistor is controlled by the third connected to the signal control part Switching element control: the signal control unit turns off the first switching element and turns on the second switching element during charging, and turns on the first switching element and turns off the second switching element during discharging. , and the above-mentioned charging circuit and the above-mentioned discharging circuit are on/off controlled, the above-mentioned protection element has the above-mentioned fuse assembly, and the value of the current of the above-mentioned charging circuit flowing through the above-mentioned second switching element in the above-mentioned fuse assembly exceeds a predetermined fusing current or, when the voltage of the above-mentioned single cell or the above-mentioned battery pack exceeds a predetermined voltage value, the above-mentioned thermistor will be fused by the heat generated by energization. The charging and discharging device according to claim 7, wherein the first and second switching elements include switching transistors or a protection circuit module including the switching transistors. The charging and discharging device according to claim 7 or 8, wherein, the above-mentioned 1st and the above-mentioned 2nd The switching element includes a FET or a protection circuit module including the FET. The charging and discharging device according to claim 7 or 8, wherein the first switching element includes a switching transistor, and the switching transistor is connected to the discharging device in such a way that the bias direction of the internal diode is positive relative to the discharging direction. On the circuit, and the above-mentioned second switching element includes a switching transistor, and the switching transistor is connected to the charging circuit in such a manner that the bias direction of the internal diode becomes positive with respect to the charging direction. The charging and discharging device according to claim 7 or 8, wherein the signal control unit branches its signal circuit and installs an inverter element in any one of the signal circuits, and connects the first switching element to one side of the branched signal circuit The other side of the gate is connected to the gate of the second switching element. The charging and discharging device according to claim 7 or 8, wherein the charging and discharging device is further provided with a delay circuit including a resistance element and a capacitor element. A battery pack, which is a battery pack of secondary batteries such as lithium-ion batteries, and includes: a battery pack formed by connecting more than one secondary battery unit; a signal control unit based on the above-mentioned unit or the above-mentioned The voltage output control signal of the battery pack; the first switching element and the second switching element are connected in parallel to the current circuit between the battery pack and the external terminal, and are turned on/off by receiving the signal from the above signal control unit On control; and a protection element, which contains a fuse assembly and a thermistor, the fuse assembly is connected in parallel with the discharge circuit, and the action of the thermistor is controlled by the third switch element connected to the signal control part; the above The signal control unit turns off the first switching element and turns on the second switching element during charging, When discharging, the above-mentioned first switching element is turned on and the above-mentioned second switching element is turned off to perform on/off control of the charging circuit and the above-mentioned discharging circuit, and the above-mentioned protection element is connected to the current flowing through the above-mentioned second switching element. When the current value of the above-mentioned charging circuit exceeds the predetermined fusing current value, the above-mentioned fuse assembly is blown to cut off the above-mentioned charging circuit, and through the above-mentioned signal control unit, when the above-mentioned single cell or the above-mentioned battery pack exceeds a predetermined voltage value The charging circuit is cut off by causing the thermistor to generate heat to blow the fuse unit. The battery pack according to claim 13, wherein the first and second switching elements include a switching transistor or a protection circuit module including the switching transistor. The battery pack according to claim 13 or 14, wherein the first and second switching elements include FETs or protection circuit modules including the FETs. The battery pack according to claim 13 or 14, wherein the first switching element includes a switching transistor, and the switching transistor is connected to the discharge circuit in such a manner that the bias direction of the internal diode becomes forward with respect to the discharge direction above, and the above-mentioned second switching element includes a switching transistor, and the switching transistor is connected to the charging circuit in such a manner that the bias direction of the internal diode becomes positive with respect to the charging direction. The battery pack according to claim 13 or 14, wherein the signal control part branches its signal circuit and installs an inverter element in any one of the signal circuits, and connects the first switching element to one side of the branched signal circuit. The gate is connected to the gate of the above-mentioned second switching element on the other side. The battery pack according to claim 13 or 14, wherein the battery pack is further provided with a delay circuit including a resistance element and a capacitor element. An electric machine, which uses a battery pack of a secondary battery such as a lithium ion battery, and has: a battery pack formed by connecting one or more secondary battery cells; Discharge protection circuit or charging and discharging device; and the main body of the machine, which is detachably connected to the battery pack for charging the battery pack or receiving power supply from the battery pack for driving; the above battery pack has: a signal control unit , which outputs a control signal according to the voltage of the above-mentioned monomer or the above-mentioned battery pack; the first switching element and the second switching element, which are connected in parallel to the current circuit between the above-mentioned battery pack and the external terminal, and receive signals from the above-mentioned control unit The signal is thus on/off controlled; and the protection element has a built-in fuse assembly and a thermistor, the above fuse assembly is connected in parallel with the discharge circuit, and the action of the above-mentioned thermistor is connected to the above-mentioned signal control part The third switching element control: the signal control unit turns off the first switching element and turns on the second switching element when charging, and turns on the first switching element and turns on the second switching element when discharging. The element is turned off, and the on/off control of the charging circuit and the above-mentioned discharging circuit is performed, and the above-mentioned protection element is fused when the value of the current flowing through the above-mentioned second switching element of the above-mentioned charging circuit exceeds the predetermined fusing current value The fuse assembly cuts off the above-mentioned charging circuit, and by the above-mentioned signal control part, when the above-mentioned single cell or the above-mentioned battery pack exceeds a predetermined voltage value, the above-mentioned thermistor is heated to blow the above-mentioned fuse assembly, thereby turning off the above-mentioned charging circuit. cut off. The electrical machine according to claim 19, wherein the first and second switching elements include switching transistors or a protection circuit module including the switching transistors. The electric device according to claim 19 or 20, wherein the first and second switching elements include FETs or protection circuit modules including the FETs. The electric machine according to claim 19 or 20, wherein the first switching element includes a switching transistor, and the switching transistor is connected to the discharge circuit in such a manner that the bias direction of the internal diode becomes forward with respect to the discharge direction above, and the above-mentioned second switching element includes a switching transistor, and the switching transistor is connected to the charging circuit in such a manner that the bias direction of the internal diode becomes positive with respect to the charging direction. The electrical equipment according to claim 19 or 20, wherein the signal control part branches its signal circuit and installs an inverter element in any one of the signal circuits, and connects the first switch element to one side of the branched signal circuit. The gate is connected to the gate of the above-mentioned second switching element on the other side. The electric machine according to claim 19 or 20, wherein said electric machine is further provided with a delay circuit including a resistance element and a capacitor element. A battery pack, which is a battery pack of secondary batteries such as lithium-ion batteries, and includes: a battery pack formed by connecting more than one secondary battery unit; a signal control unit based on the above-mentioned unit or the above-mentioned The voltage output control signal of the battery pack; the switching control element, which is connected to the discharge circuit and the charging circuit between the battery pack and the external terminal of the battery pack, and receives the signal from the above signal control part to perform on/off control ; and a protection element, which has a built-in fuse assembly and a thermistor, and the above fuse assembly is connected in parallel with the above discharge circuit connected, and the action of the above-mentioned thermistor is controlled by the switch element connected to the above-mentioned signal control part; The circuit is connected and the above-mentioned charging circuit is disconnected, and the above-mentioned charging circuit and the above-mentioned discharging circuit are controlled on/off, and the value of the current of the above-mentioned charging circuit flowing through the above-mentioned switching control element exceeds a predetermined value. When the fusing current value is above the above-mentioned fuse assembly, the above-mentioned charging circuit is cut off, and the above-mentioned signal control unit is used to make the above-mentioned thermistor generate heat when the above-mentioned monomer or the above-mentioned battery pack exceeds a predetermined voltage value, and the above-mentioned The fuse assembly cuts off the above-mentioned charging circuit. The battery pack according to claim 25, wherein the switch control element includes a switch element selected from a group of selectors, switch controllers, CMOS transistors, and FETs, or a protection circuit module including the switch element. The battery pack according to claim 25 or 26, wherein the switching control element includes a switching element with an inverter or a protection circuit module including the switching element with an inverter. The battery pack according to claim 25 or 26, wherein the battery pack is further provided with a delay circuit including a resistance element and a capacitor element. An electric machine, which uses a battery pack of a secondary battery such as a lithium ion battery, and has: a battery pack formed by connecting one or more secondary battery cells; discharge protection circuit or charging and discharging device; and the main body of the machine, which is detachably connected to the battery pack for charging the battery pack or receiving electricity from the battery pack Driven by power supply; the above-mentioned battery pack has: a signal control unit, which outputs a control signal according to the voltage of a single cell or a battery pack; a switching control element, which is connected to the discharge circuit between the above-mentioned battery pack and the external terminal of the above-mentioned battery pack; A charging circuit, which receives a signal from the signal control unit to perform on/off control; and a protection element, which contains a fuse assembly and a thermistor, the fuse assembly is connected in parallel with the discharge circuit, and the thermal sensor The action of the resistor is controlled by a switching element connected to the above-mentioned signal control part; the above-mentioned signal control part disconnects the above-mentioned discharge circuit and connects the above-mentioned charging circuit when charging, and turns on the above-mentioned discharge circuit and turns on the above-mentioned charging circuit when discharging. The charging circuit is disconnected, and the above-mentioned charging circuit and the above-mentioned discharging circuit are controlled on/off, and the above-mentioned protection element is when the current value of the above-mentioned charging circuit flowing through the above-mentioned switching control element exceeds a predetermined fusing current value, The above-mentioned fuse assembly is blown to cut off the above-mentioned charging circuit, and by the above-mentioned signal control part, when the above-mentioned monomer or the above-mentioned battery pack exceeds a predetermined voltage value, the above-mentioned thermistor is heated and the above-mentioned fuse assembly is blown, so that the above-mentioned The charging circuit is cut off. The electrical machine according to claim 29, wherein the switch control element includes a switch element selected from a group of selectors, switch controllers, CMOS transistors, and FETs, or a protection circuit module including the switch element. The electrical machine according to claim 29 or 30, wherein the switching control element includes a switching element with an inverter or a protection circuit module including the switching element with an inverter. Group. The electric machine according to claim 29 or 30, wherein said electric machine is further provided with a delay circuit including a resistance element and a capacitor element. A protection circuit, which protects a battery pack of a secondary battery such as a lithium ion battery from overcharging and overheating, and includes: a battery pack composed of one or more secondary battery cells connected in series; a signal control unit , which outputs a control signal according to the voltage of the above-mentioned monomer or the above-mentioned battery pack; the protection element, which has a built-in fuse assembly and a thermistor, and the above-mentioned fuse assembly is connected in series with the charging and discharging circuit, and the action of the above-mentioned thermistor is controlled by the connection A switch element control in the above-mentioned signal control section; and a delay circuit including a resistor element connected in series to the battery pack and a capacitor element connected to the resistor element and connected in parallel to the battery pack; the switch element includes FET or A protection circuit module including the FET. The protection circuit according to claim 33, wherein the switching element includes a switching transistor or a protection circuit module including the switching transistor. A battery pack, which is a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack, which is composed of one or more secondary battery cells connected in series; a signal control unit, which is based on the above-mentioned single cells or The voltage output control signal of the above-mentioned battery pack; the protection element, which has a built-in fuse assembly and a thermistor, the above-mentioned fuse assembly is connected in series with the charging and discharging circuit, and the action of the above-mentioned thermistor is controlled by 1 connected to the above-mentioned signal control part a switching element control; and a delay circuit comprising a resistor element connected in series to the battery pack and a capacitor element connected to the resistor element and connected in parallel to the battery pack; The above-mentioned switching element includes a FET or a protection circuit module containing the FET; and the protection circuit uses the above-mentioned delay circuit to delay the applied voltage to buffer the inrush current during switching, and when the value of the current flowing through the above-mentioned charging and discharging circuit exceeds At a predetermined fusing current value, the above-mentioned fuse assembly is blown to cut off the above-mentioned charging and discharging circuit, and the above-mentioned thermistor is heated when the above-mentioned single cell or the above-mentioned battery pack exceeds a predetermined voltage value through the above-mentioned signal control part. The above-mentioned fuse assembly is blown to cut off the above-mentioned charging and discharging circuit. The battery pack according to claim 35, wherein the switching element includes a switching transistor or a protection circuit module including the switching transistor.

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