Protection circuit and charging device

Abstract

The present disclosure ensures safety against leakage current to a human body with a simple structure. A protection circuit connects a contact positive electrode terminal, a first contact negative electrode terminal, and a second contact negative electrode terminal to a positive electrode terminal and a ground terminal, the contact positive electrode terminal, the first contact negative electrode terminal, and the second contact negative electrode terminal being exposed to the outside in a connector part to be connected to a device provided with a secondary battery. The present invention relates to a protection circuit for a secondary battery having a positive terminal and a ground terminal provided in a power output unit that outputs power supplied to the secondary battery via a contact positive terminal, a first contact negative terminal, and a second contact negative terminal, the protection circuit being characterized by being provided with: a P-type MOSFET connected between the contact positive terminal and the positive terminal; a first circuit connecting the contact positive terminal with a drain terminal of the P-type MOSFET; a second circuit having a positive terminal connected to a source terminal of the P-type MOSFET; a third circuit connecting the second circuit and the first contact negative terminal via a resistor; a fourth circuit connecting a gate terminal of the P-type MOSFET between the first contact negative terminal of the third circuit and the resistor; and a fifth circuit connecting the second contact negative terminal and the ground terminal.

Description

Technical Field

[0001] The invention relates to a protection circuit and a charging device comprising the protection circuit. Background Art

[0002] Conventionally, when charging an electronic device having a built-in secondary battery, a configuration is adopted in which the state of the secondary battery is confirmed using three terminals and then charging is started.

[0003] In a charger for charging such a secondary battery, safety is ensured against leakage current from the exposed terminal portion to the human body as a result (see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 11-178220 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, in such a configuration, components and circuits are required on the charger side for receiving information such as the voltage value and temperature of the secondary battery, resulting in a complicated configuration.

[0009] In view of the above-mentioned prior art, an object of the present invention is to provide a technology capable of ensuring safety against leakage current to the human body with a simple structure.

[0010] Solutions to the problem

[0011] In order to solve the above problems, the protection circuit of the present invention connects the contact positive terminal, the first contact negative terminal and the second contact negative terminal to the positive terminal and the ground terminal, wherein the contact positive terminal, the first contact negative terminal and the second contact negative terminal are exposed to the outside in a connector portion for connecting to a device having a secondary battery, the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs the power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal and the second contact negative terminal, and the protection circuit is characterized in that it has:

[0012] A P-type MOSFET connected between the contact positive terminal and the positive terminal;

[0013] A first circuit connects the contact positive terminal to the drain terminal of the P-type MOSFET;

[0014] a second circuit, connecting the positive terminal to the source terminal of the P-type MOSFET;

[0015] a third circuit, connecting the second circuit to the first contact negative terminal via a resistor;

[0016] a fourth circuit, connecting the gate terminal of the P-type MOSFET between the first contact negative terminal of the third circuit and the resistor; and

[0017] A fifth circuit connects the second contact negative terminal to the ground terminal.

[0018] According to this, even if a person contacts any two of the contact positive terminal, the first contact negative terminal, and the second contact negative terminal exposed to the outside, and any two terminals in contact are electrically connected via the human body, the P-type MOSFET will not be turned on, so that leakage current will not flow through the human body, or will be limited to only a weak leakage current. Therefore, safety can be ensured by using a simple structure of a P-type MOSFET and passive components that does not require a complex structure such as a control unit.

[0019] In addition, the protection circuit of the present invention connects the contact positive terminal, the first contact negative terminal, and the second contact negative terminal to the positive terminal and the ground terminal, wherein the contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connection to a device having a secondary battery, and the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it has:

[0020] A PNP transistor connected between the contact positive terminal and the positive terminal;

[0021] A first circuit connects the contact positive terminal to the collector terminal of the PNP transistor;

[0022] a second circuit, connecting the positive terminal to the emitter terminal of the PNP transistor;

[0023] a third circuit, connecting the second circuit to the first contact negative terminal via a resistor;

[0024] a fourth circuit, connecting the base terminal of the PNP transistor between the first contact negative terminal of the third circuit and the resistor;

[0025] and a fifth circuit connecting the second contact negative terminal to the ground terminal.

[0026] According to this, even if a person contacts any two of the contact positive terminal, the first contact negative terminal, and the second contact negative terminal exposed to the outside, and any two terminals in contact are electrically connected via the human body, the PNP transistor will not be turned on, so that leakage current will not flow through the human body, or will be limited to only a weak leakage current. Therefore, safety can be ensured by using a simple structure that does not require a complex structure such as a control unit and a PNP transistor and passive components.

[0027] In addition, the protection circuit of the present invention connects the contact positive terminal, the first contact negative terminal, and the second contact negative terminal to the positive terminal and the ground terminal, wherein the contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connection to a device having a secondary battery, and the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it has:

[0028] An N-type MOSFET connected between the first contact negative terminal and the ground terminal;

[0029] a sixth circuit, connecting the first contact negative terminal to the drain terminal of the N-type MOSFET;

[0030] A seventh circuit, connecting the ground terminal to the source terminal of the N-type MOSFET;

[0031] an eighth circuit, connecting the seventh circuit and the second contact negative terminal via a resistor;

[0032] a ninth circuit, connecting the gate terminal of the N-type MOSFET between the first contact negative terminal of the eighth circuit and the resistor; and

[0033] A tenth circuit connects the contact positive terminal to the positive terminal.

[0034] According to this, even if a person contacts any two of the contact positive terminal, the first contact negative terminal, and the second contact negative terminal exposed to the outside, and any two terminals in contact are electrically connected via the human body, the N-type MOSFET will not be turned on, so that leakage current will not flow through the human body, or will be limited to only a weak leakage current. Therefore, safety can be ensured by using a simple structure that does not require a complex structure such as a control unit and N-type MOSFET and passive components.

[0035] In addition, the protection circuit of the present invention connects the contact positive terminal, the first contact negative terminal, and the second contact negative terminal to the positive terminal and the ground terminal, wherein the contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connection to a device having a secondary battery, and the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it has:

[0036] An NPN transistor connected between the first contact negative terminal and the ground terminal;

[0037] a sixth circuit, connecting the first contact negative terminal to the collector terminal of the NPN transistor;

[0038] A seventh circuit, connecting the ground terminal to the emitter terminal of the NPN transistor;

[0039] an eighth circuit, connecting the seventh circuit and the second contact negative terminal via a resistor;

[0040] a ninth circuit, connecting the base terminal of the NPN transistor between the first contact negative terminal of the eighth circuit and the resistor; and

[0041] A tenth circuit connects the contact positive terminal to the positive terminal.

[0042] According to this, even if a person contacts any two of the contact positive terminal, the first contact negative terminal, and the second contact negative terminal exposed to the outside, and any two terminals in contact are electrically connected via the human body, the NPN transistor will not be turned on, so that leakage current will not flow through the human body, or will be limited to only a weak leakage current. Therefore, safety can be ensured by using a simple structure that does not require a complex structure such as a control unit and a passive component.

[0043] The charging device of the present invention includes the above-mentioned protection circuit, and is characterized in that:

[0044] In the connector portion, the contact positive electrode terminal, the first contact negative electrode terminal, and the second contact negative electrode terminal are arranged asymmetrically.

[0045] According to this, the contact positive terminal, the first contact negative terminal, and the second contact negative terminal are arranged asymmetrically, so that it is possible to prevent an electronic device having a corresponding terminal arrangement from being connected in an incorrect direction.

[0046] The charging device of the present invention includes the above-mentioned protection circuit, and is characterized in that:

[0047] In the connector portion, the first negative contact terminal and the second negative contact terminal are arranged symmetrically with respect to the positive contact terminal.

[0048] Accordingly, the first negative contact terminal and the second negative contact terminal are symmetrically arranged relative to the positive contact terminal. Therefore, for an electronic device having a terminal configuration corresponding thereto, even if the first negative contact terminal and the second negative contact terminal are connected in the opposite manner relative to the positive contact terminal, the charger and the electronic device can be properly electrically connected to charge the secondary battery.

[0049] The charging device of the present invention includes the above-mentioned protection circuit, and is characterized in that:

[0050] In the connector portion, the contact positive electrode terminal and the second contact negative electrode terminal are arranged symmetrically with respect to the first contact negative electrode terminal.

[0051] Accordingly, the positive terminal and the second contact negative terminal are symmetrically arranged relative to the first contact negative terminal. Therefore, for an electronic device having a terminal configuration corresponding thereto, even if the contact positive terminal and the second contact negative terminal are connected in a manner opposite to the first contact negative terminal, the charger and the electronic device can be electrically connected appropriately to charge the secondary battery.

[0052] Effects of the Invention

[0053] According to the present invention, safety against leakage current to a human body can be ensured with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a circuit diagram of the charger of Example 1.

[0055] Figure 2 1 is a circuit diagram showing a normal connection state between the charger and the electronic device of the first embodiment.

[0056] Figure 3 1 is a diagram showing the electrical connection between the charger and a person according to the first embodiment.

[0057] Figure 4 1 is a diagram showing other electrical connections between the charger of Example 1 and a person.

[0058] Figure 5 1 is a diagram showing other electrical connections between the charger of Example 1 and a person.

[0059] Figure 6 This is a circuit diagram of a charger according to a variation of the first embodiment.

[0060] Figure 7 This is a circuit diagram of the charger of Example 2.

[0061] Figure 8 This is a circuit diagram of a charger according to a variation of the second embodiment.

[0062] Fig. 9 It is a diagram showing the arrangement of terminals in the charger according to the embodiment.

[0063] Fig.10 It is a diagram showing another arrangement of terminals in the charger according to the embodiment. DETAILED DESCRIPTION

[0064] Hereinafter, specific embodiments of the present invention will be described based on the drawings.

[0065] <Example 1>

[0066] Hereinafter, an example of an embodiment of the present invention will be described. However, unless otherwise specified, the size, material, shape, relative arrangement, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to these.

[0067] (Charger structure)

[0068] Figure 1 1 is a circuit diagram of the charger 100 including the protection circuit 200 according to the first embodiment.

[0069] The charger 100 is connected to an electronic device 400 having a secondary battery, and supplies power to the secondary battery. The charger 100 has a connector portion 110 connected to the electronic device 400. Terminals T1, T2, and T3 are provided in the connector portion 110, which are exposed to the outside and are electrically connected to the terminals T21, T22, and T23 on the electronic device 400 side, respectively. Here, the charger 100, the connector portion 110, and the protection circuit 200 are respectively equivalent to the charging device, the connector portion, and the protection circuit of the present invention. In addition, the electronic device 400 is equivalent to the device of the present invention. In addition, the terminals T1, T2, and T3 are respectively equivalent to the contact positive terminal, the second contact negative terminal, and the first contact negative terminal of the present invention.

[0070] The protection circuit 200 is provided between the terminal T1, the terminal T2, and the terminal T3 and the positive terminal T4 and the ground terminal T5 of the output unit 300. The output unit 300 is electrically connected via the protection circuit 200 and the terminal T1, the terminal T2, and the terminal T3, and outputs power to the secondary battery of the electronic device 400. The output unit 300 can be any component or circuit that can output power to the protection circuit 200 via the positive terminal T4, for example, it can be a power conversion device such as a converter connected to a commercial power system, or a connector connected thereto. The communication unit 300 is equivalent to the power output unit of the present invention.

[0071] The terminal T1 is connected to the drain terminal of a p-channel enhancement type metal oxide film field effect transistor (p-MOSFET) Tr1 through a circuit Ln1. In the circuit Ln1, a resistor R1 is connected in series between the terminal T1 and the drain terminal of the p-MOSFETTr1. In addition, the source terminal of the p-MOSFETTr1 is connected to the positive terminal T4 of the output unit 300 through a circuit Ln2. In the circuit Ln2, a fuse F is connected between the positive terminal T4 and the source terminal of the p-MOSFETTr1. Here, the p-MOSFETTr1 is equivalent to the P-type MOSFET of the present invention, and the circuit Ln1 and the circuit Ln2 are respectively equivalent to the first circuit and the second circuit of the present invention.

[0072] The terminal T2 is connected to the ground terminal T5 of the output unit 300 through the circuit Ln3. In the circuit Ln3, a resistor R2 is connected in series between the terminal T2 and the ground terminal T5. In addition, the circuit Ln3 is grounded through the ground line GND. Here, the circuit Ln3 corresponds to the fifth circuit of the present invention.

[0073] A capacitor C1 is connected in series in the circuit Ln4 that connects the connection point P1 between the resistor R1 of the circuit Ln1 and the drain terminal of the p-MOSFETTr1 and the connection point P2 between the resistor R2 of the circuit Ln3 and the ground terminal T5. In addition, the connection point P3 between the source terminal of the p-MOSFETTr1 of the circuit Ln2 and the fuse F and the connection point P4 between the connection point P2 of the circuit Ln3 and the ground line GND are connected via the circuit Ln5. In the circuit Ln5, a capacitor C3 is connected in series between the connection point P3 and the connection point P4.

[0074] The terminal T3 is connected to the connection point P5 of the circuit Ln2 through the circuit Ln6. The connection point P5 is provided on the source terminal side of the p-MOSFETTr1 relative to the connection point P3. A resistor R3 is connected in series between the terminal T3 of the circuit Ln6 and the connection point P5. Here, the circuit Ln6 is equivalent to the third circuit of the present invention, and the resistor R3 is equivalent to the resistor of the present invention.

[0075] Between the terminal T3 of the circuit Ln6 and the resistor R3, a circuit Ln7 connected to the gate terminal of the p-MOSFETTr1 is connected at the connection point P6. Furthermore, a connection point P7 provided between the source terminal of the p-MOSFETTr1 and the connection point P5 of the circuit Ln2 and a connection point P8 provided between the resistor R3 and the connection point P6 of the circuit Ln6 are connected via a circuit Ln8. In addition, a capacitor C3 is connected in series to the circuit Ln5. Here, the circuit Ln7 corresponds to the fourth circuit of the present invention.

[0076] A diode D1 is connected in parallel between the source terminal and the drain terminal of the p-MOSFET Tr1 so as to be forward from the drain terminal to the source terminal. A bidirectional TVS (transient voltage suppression) diode D2 is connected in parallel between the gate terminal and the source terminal of the p-MOSFET Tr1.

[0077] like Figure 1 As shown, when the electronic device 400 and the charger 100 are not connected, the terminal T2 and the terminal T3 are not connected, the gate terminal and the source terminal of the p-MOSFETTr1 are connected through the resistor R3 and the capacitor C2 connected in parallel between the circuit Ln2 and the circuit Ln7, and the p-MOSFETTr1 is in a disconnected state, so the charging voltage is not applied to the terminal T1, the terminal T2 and the terminal T3.

[0078] like Figure 2 As shown, when the electronic device 400 is connected to the charger 100, the terminal T1, the terminal T2, and the terminal T3 of the charger 100 are respectively connected to the terminal T21, the terminal T22, and the terminal T23 of the electronic device 400. Therefore, the p-MOSFET Tr1 is turned on, and as shown by the thick arrow, the secondary battery of the electronic device 400 can be charged from the output unit 300 via the protection circuit 200.

[0079] Figure 3 , a state in which a person 500 touches the terminal T1 and the terminal T2 exposed to the outside of the charger 100 is shown. At this time, although the terminal T1 and the terminal T2 are connected via the person 500, the terminal T2 and the terminal T3 are not connected, and the p-MOSFET Tr1 is in an off state, so that a leakage current dangerous to the person 500 does not flow.

[0080] Figure 4 , a state in which a person 500 touches the terminal T1 and the terminal T3 exposed to the outside of the charger 100 is shown. At this time, although the terminal T1 and the terminal T3 are connected via the person 500, the terminal T2 and the terminal T3 are not connected, and the p-MOSFET Tr1 is in an off state, so that a leakage current dangerous to the person 500 does not flow.

[0081] Figure 5, a state in which a person 500 contacts the terminal T2 and the terminal T3 exposed to the outside of the charger 100 is shown. At this time, although the terminal T2 and the terminal T3 are connected via the person 500, the p-MOSFETTr1 is in an off state. Therefore, as shown by the thick arrow, in the positive terminal T4 of the output unit 300 and the person 500, the current output from the positive terminal T4 of the output unit 300 flows to the person 500 via the terminal T3 through the circuit formed by connecting the circuit Ln2 and the circuit Ln6 via the connection point P5. However, by setting the resistance value of the resistor R3 to a larger value such as 4070 kΩ, the leakage current can be suppressed to a level less than 100 μA, which is a standard in medical equipment, so that a leakage current dangerous to the human body does not flow.

[0082] As described above, according to the first embodiment, the protection circuit 200 having a simple structure composed of passive components and transistors can ensure safety against leakage current to the human body.

[0083] <Modification>

[0084] Figure 6 2 is a circuit diagram of a charger 101 including a protection circuit 201 according to a modification of Embodiment 1. The same reference numerals are used for the same configurations as those of the protection circuit 200 according to Embodiment 1, and detailed descriptions thereof are omitted.

[0085] In the protection circuit 201, a PNP transistor Tr2 is used instead of the p-MOSFET Tr1. Here, the emitter terminal of the PNP transistor Tr2 is connected to the positive terminal T4 via the fuse F through the circuit Ln2. In addition, the collector terminal of the PNP transistor Tr2 is connected to the terminal T1 through the circuit Ln1. And, the base terminal of the PNP transistor Tr2 is connected to the circuit Ln6 connecting the terminal T3 and the circuit Ln2 through the circuit Ln11. In the circuit Ln11, a resistor R11 is connected in series between the base terminal of the PNP transistor Tr2 and the connection point P6 with the circuit Ln6. In addition, a resistor R12 is connected in parallel between the emitter terminal and the base terminal of the PNP transistor Tr2. The resistor R12 is connected to the circuit Ln11 at the connection point P11, and is connected in series to the circuit Ln12 connected to the circuit Ln2 at the connection point P12. In addition, at this time, a capacitor C2 is connected in series in the circuit Ln6 connecting the terminal T3 and the circuit Ln2.

[0086] Here, the PNP transistor Tr2 is equivalent to the PNP transistor of the present invention. In addition, the circuit Ln6 from the terminal T3 to the connection point P6, the circuit Ln11 from the connection point P6 to the connection point P11, and the circuit Ln12 from the connection point P11 to the connection point P12 are equivalent to the third circuit of the present invention. In addition, the resistor R12 is equivalent to the resistor of the present invention. In addition, the circuit Ln11 from the connection point P11 to the base terminal of the PNP transistor Tr2 is equivalent to the fourth circuit of the present invention.

[0087] The operation when the charger 101 having the protection circuit 201 is connected to the electronic device 400 is the same as that described for the charger 100. In addition, the operation of the protection circuit 201 when the person 500 touches any two of the terminals T1, T2, and T3 of the charger 101 is also the same as that described for the protection circuit 200, so the description is omitted.

[0088] As described above, according to this modification, the safety against leakage current to the human body can be ensured by the protection circuit 201 having a simple structure composed of passive components and transistors.

[0089] <Example 2>

[0090] Figure 7 2 shows a circuit diagram of the charger 102 according to the second embodiment including the protection circuit 202. The components common to the charger 100 and the protection circuit 200 according to the first embodiment are denoted by the same reference numerals and detailed descriptions thereof are omitted.

[0091] In the protection circuit 202 , the n-MOSFET Tr3 is provided in a circuit connecting the ground terminal T5 and the terminal T2 , instead of in a circuit connecting the positive terminal T4 and the terminal T1 .

[0092] The circuit Ln3 having one end connected to the terminal T2 is connected to the drain terminal of the n-MOSFETTr3 via the resistor R2 at the other end of the circuit Ln3. Furthermore, the source terminal of the n-MOSFETTr3 is connected to the ground terminal T5 via the circuit Ln21. Here, the n-MOSFETTr3 is equivalent to the N-type MOSFET of the present invention. In addition, the circuit Ln3 and the circuit Ln21 are respectively equivalent to the sixth circuit and the seventh circuit of the present invention.

[0093] Here, the terminal T3 is connected to the circuit Ln21 at the connection point P21 via the circuit Ln22. A resistor R21 is connected in series to the circuit Ln22. Furthermore, the gate terminal of the n-MOSFETTr3 is connected to the circuit Ln22 at the connection point P22 via the circuit Ln23. Between the circuit Ln22 and the circuit Ln21, a capacitor C21 is connected via the circuit Ln24. Through the circuit Ln24, one end of the capacitor C21 is connected to the circuit Ln22 at the connection point P23 between the connection point P22 of the circuit Ln22 and the resistor R21, and the other end of the capacitor C21 is connected to the circuit Ln21 at the connection point P24 between the source terminal of the n-MOSFETTr3 and the connection point P21. In addition, the circuit Ln1 connects the terminal T1 to the positive terminal T4, and on the circuit Ln1, a fuse F, a connection point P3, a connection point P1, and a resistor R1 are sequentially arranged from the positive terminal T4 side. Here, the circuit Ln22 corresponds to the eighth circuit of the present invention, and the resistor R21 corresponds to the resistor of the present invention. In addition, the circuit Ln23 corresponds to the ninth circuit of the present invention. In addition, the circuit Ln1 corresponds to the tenth circuit of the present invention.

[0094] In such a protection circuit 202, the circuit Ln3 and the circuit Ln21 connecting the terminal T2 and the ground terminal T5 are connected / disconnected by turning on / off the n-MOSFETTr3. In this way, the n-MOSFETTr3 whose threshold is opposite to the positive and negative of the p-MOSFETTr1 of the first embodiment is provided between the circuit Ln3 and the circuit Ln21 connected to the ground terminal T5 side and the circuit Ln22 whose one end is connected to the terminal T3, so that the n-MOSFETTr3 is turned on and off by the same mechanism as the protection circuit 200 of the first embodiment, and the same effect can be obtained. However, in the electronic device 401 connected to the charger 102 of such a structure to charge the secondary battery, the terminal T21 and the terminal T23 are connected inside the electronic device 401. The terminal T1, the terminal T2, and the terminal T3 of the charger 102 are connected to the terminal T21, the terminal T22, and the terminal T23 of the electronic device 401, respectively, and the terminal T1 and the terminal T3 of the charger 102 are short-circuited, so that the secondary battery of the electronic device 401 is charged.

[0095] As described above, according to the second embodiment, the safety against leakage current to the human body can be ensured by the protection circuit 202 having a simple structure composed of passive components and transistors.

[0096] <Modification>

[0097] Figure 82 shows a circuit diagram including a protection circuit 203 of a charger 103 according to a modification of Embodiment 2. The same reference numerals are used for the common configurations of the protection circuit 202 according to Embodiment 2 and the protection circuit 200 according to Embodiment 1, and detailed descriptions thereof are omitted.

[0098] In the protection circuit 203, an NPN transistor Tr4 is used instead of the n-MOSFET Tr3. Here, the collector terminal of the NPN transistor Tr4 is connected to the terminal T2 through the circuit Ln3. In addition, the emitter terminal of the NPN transistor Tr4 is connected to the ground terminal T5 through the circuit Ln21. And, the base terminal of the NPN transistor Tr4 is connected to the circuit Ln22 through the circuit Ln25. A resistor R22 is connected in series in the circuit Ln25, one end of the circuit Ln25 is connected to the base terminal of the NPN transistor Tr4, and the other end is connected to the circuit Ln22 at the connection point P25. In addition, a resistor R23 is connected in parallel between the emitter terminal and the base terminal of the NPN transistor Tr4 through the circuit Ln26. Through the circuit Ln26, one end of the resistor R23 is connected to the circuit Ln25 at the connection point P27 between the base terminal of the NPN transistor Tr4 and the resistor R22, and the other end of the resistor R23 is connected to the circuit Ln21 at the connection point P26 between the emitter terminal of the NPN transistor Tr4 and the connection point P24. Here, the NPN transistor Tr4 is equivalent to the NPN transistor of the present invention. In addition, the circuit Ln22 from the terminal T3 to the connection point P25, the circuit Ln25 from the connection point P25 to the connection point P27, and the circuit Ln26 from the connection point P27 to the connection point P26 are equivalent to the eighth circuit of the present invention, and the circuit Ln25 from the connection point P27 to the base terminal of the NPN transistor Tr4 is equivalent to the ninth circuit of the present invention.

[0099] The operation when the charger 103 having the protection circuit 203 is connected to the electronic device 400 is the same as that of the charger 102. In addition, the operation of the protection circuit 203 when the person 500 touches any two of the terminals T1, T2, and T3 of the charger 103 is also the same as that of the protection circuit 202, so the description is omitted.

[0100] As described above, according to this modification, the safety against leakage current to the human body can be ensured by the protection circuit 203 having a simple structure composed of passive components and transistors.

[0101] <Charger Configuration>

[0102] The following describes the configuration structure of the terminal T1, the terminal T2, and the terminal T3 in the charger 100 having the protection circuit 200. The chargers 101, 102, and 103 each having the protection circuit 201, the protection circuit 202, and the protection circuit 203 can also adopt the following structure, so a separate description is omitted.

[0103] Fig. 9 , an example of the configuration structure of the terminal T1, the terminal T2, and the terminal T3 in the connector part 110 of the charger 100 is shown. The charger 100 includes a flat, substantially rectangular housing 120 and a cable 130. One end of the cable 130 is connected to the housing 120, and the other end is connected to a power source such as an AC adapter. In the planar connector part 110 formed on one side of the housing 120, the terminal T2, the terminal T1, and the terminal T3 are sequentially arranged from the cable 130 side along the axis Ax1 in the long dimension direction of the connector part 110. Furthermore, the terminal T1, the terminal T2, and the terminal T3 are asymmetrically arranged with respect to the axis Ax1 in the long dimension direction of the connector part 110. That is, the terminal T1 is arranged on one side of the axis Ax1, and the terminal T2 and the terminal T3 are arranged on the other side of the axis Ax1. In order to contact the terminals T1, T2 and T3 on the charger 100 side, the terminals T21, T22 and T23 of the electronic device 400 are also arranged asymmetrically with respect to the axis of the arrangement direction. Therefore, even if the connector parts 110 of the electronic device 400 and the charger 100 are connected in the opposite direction relative to the arrangement direction of their respective terminals, they cannot be properly connected, thereby preventing the electronic device 400 and the charger 100 from being connected in the wrong direction.

[0104] Fig.10 2 shows another example of the arrangement of the terminal T1, the terminal T2, and the terminal T3 in the connector 110 of the charger 100 (the same applies to the charger 101). Fig. 9Similarly, it includes a flat, roughly rectangular housing 120 and a cable 130. One end of the cable 130 is connected to the housing 120, and the other end is connected to a power source such as an AC adapter. In the planar connector portion 110 formed on one side of the housing 120, the terminal T2, the terminal T1, and the terminal T3 are arranged in sequence from the cable 130 side along the axis Ax1 in the long dimension direction of the connector portion 110. Moreover, the terminal T1 and the terminal T2 and the terminal T3 are arranged symmetrically with respect to the axis Ax1 in the long dimension direction of the connector portion 110. In addition, at this time, the terminal T1 is set as the positive electrode, and the terminal T2 and the terminal T3 are both set as the negative electrode, so that the terminal T1 as the positive electrode and the terminal T2 and the terminal T3 as the negative electrode are arranged symmetrically with respect to the axis Ax2 in the direction orthogonal to the long dimension direction. Therefore, in order to contact the terminals T1, T2, and T3 on the charger 100 side, the terminals T21, T22, and T23 of the electronic device 400 are also symmetrically arranged with respect to the axis Ax1 of the arrangement direction, and the terminals T21, T22, and T23 are symmetrically arranged with respect to the axis Ax2 in the direction orthogonal to the arrangement direction. With such an arrangement, even if the connectors 110 of the electronic device 400 and the charger 100 are connected in the opposite direction with respect to the arrangement direction of their respective terminals, they can be properly connected, so that the electronic device 400 and the charger 100 can be connected without paying attention to the orientation, and the situation that the connection in the wrong orientation and the inability to properly connect will not occur.

[0105] It should be noted that, in the connector portion 110 , the terminals T2 and T3 may be arranged in reverse.

[0106] Fig.10 2 shows another configuration structure of the terminal T1, the terminal T2, and the terminal T3 in the connector 110 of the charger 102 (the same applies to the charger 103). Fig.10In the figure, the reference numerals in parentheses indicate the configuration structure in the charger 102 and the charger 103 (the configuration of the terminal T3 is the same as that of the charger 100 and the charger 101 described above). At this time, in the planar connector part 110 formed on one side of the housing 120, the terminal T1, the terminal T2, and the terminal T3 are sequentially arranged from the cable 130 side along the axis Ax1 in the long dimension direction of the connector part 110. And the terminal T2 and the terminal T1 and the terminal T3 are symmetrically arranged with respect to the axis Ax1 in the long dimension direction of the connector part 110. In addition, the terminal T2 as the negative electrode, the terminal T1 as the positive electrode, and the terminal T3 as the negative electrode are symmetrically arranged with respect to the axis Ax2 in the direction orthogonal to the long dimension direction. At this time, in order to contact the terminals T1, T2, and T3 on the charger 102 side, the terminals T21, T22, and T23 of the electronic device 401 are also symmetrically arranged with respect to the axis Ax1 of the arrangement direction. With respect to the terminal T22, the terminals T21 and T23 are symmetrically arranged with respect to the axis Ax2 in the direction orthogonal to the arrangement direction. Therefore, the connectors 110 of the electronic device 401 and the charger 102 are symmetrically arranged with respect to the arrangement directions of their respective terminals. With such an arrangement, even if the connectors 110 of the electronic device 401 and the charger 102 are connected in the opposite direction with respect to the arrangement directions of their respective terminals, they can be properly connected. Therefore, the electronic device 401 and the charger 102 can be connected without paying attention to the orientation. Even if they are connected in the wrong orientation, there is no situation where they cannot be properly connected.

[0107] It should be noted that, in the connector portion 110 , the terminals T1 and T3 may be arranged in reverse.

[0108] Description of Reference Numerals

[0109] 100, 101, 102, 103: charger;

[0110] 110: connector part;

[0111] 200, 201, 202, 203: protection circuit;

[0112] 300: output unit;

[0113] 400: Electronic equipment;

[0114] T1, T2, T3: terminals.

Claims

1. A protection circuit, connecting a contact positive terminal, a first contact negative terminal and a second contact negative terminal to a positive terminal and a ground terminal, wherein: The contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connecting to a device having a secondary battery, the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it comprises: A P-type MOSFET connected between the contact positive terminal and the positive terminal; A first circuit connects the contact positive terminal to the drain terminal of the P-type MOSFET; a second circuit, connecting the positive terminal to the source terminal of the P-type MOSFET; a third circuit, connecting the second circuit to the first contact negative terminal via a resistor; a fourth circuit, connecting the gate terminal of the P-type MOSFET between the first contact negative terminal of the third circuit and the resistor; and A fifth circuit connects the second contact negative terminal to the ground terminal.

2. A protection circuit, connecting a contact positive terminal, a first contact negative terminal and a second contact negative terminal to a positive terminal and a ground terminal, wherein: The contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connecting to a device having a secondary battery, the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it comprises: A PNP transistor connected between the contact positive terminal and the positive terminal; A first circuit connects the contact positive terminal to the collector terminal of the PNP transistor; a second circuit, connecting the positive terminal to the emitter terminal of the PNP transistor; a third circuit, connecting the second circuit to the first contact negative terminal via a resistor; a fourth circuit, connecting the base terminal of the PNP transistor between the first contact negative terminal of the third circuit and the resistor; and A fifth circuit connects the second contact negative terminal to the ground terminal.

3. A protection circuit, connecting a contact positive terminal, a first contact negative terminal and a second contact negative terminal to a positive terminal and a ground terminal, wherein: The contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connecting to a device having a secondary battery, the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it comprises: An N-type MOSFET connected between the first contact negative terminal and the ground terminal; a sixth circuit, connecting the first contact negative terminal to the drain terminal of the N-type MOSFET; A seventh circuit, connecting the ground terminal to the source terminal of the N-type MOSFET; an eighth circuit, connecting the seventh circuit and the second contact negative terminal via a resistor; a ninth circuit, connecting the gate terminal of the N-type MOSFET between the first contact negative terminal of the eighth circuit and the resistor; and A tenth circuit connects the contact positive terminal to the positive terminal.

4. A protection circuit, connecting a contact positive terminal, a first contact negative terminal and a second contact negative terminal to a positive terminal and a ground terminal, wherein: The contact positive terminal, the first contact negative terminal, and the second contact negative terminal are exposed to the outside in a connector portion for connecting to a device having a secondary battery, the positive terminal and the ground terminal are provided in a power output portion, and the power output portion outputs power supplied to the secondary battery via the contact positive terminal, the first contact negative terminal, and the second contact negative terminal, and the protection circuit is characterized in that it comprises: An NPN transistor connected between the first contact negative terminal and the ground terminal; a sixth circuit, connecting the first contact negative terminal to the collector terminal of the NPN transistor; A seventh circuit, connecting the ground terminal to the emitter terminal of the NPN transistor; an eighth circuit, connecting the seventh circuit and the second contact negative terminal via a resistor; a ninth circuit, connecting the base terminal of the NPN transistor between the first contact negative terminal of the eighth circuit and the resistor; and A tenth circuit connects the contact positive terminal to the positive terminal.

5. A charging device, comprising the protection circuit according to any one of claims 1 to 4, characterized in that: In the connector portion, the contact positive electrode terminal, the first contact negative electrode terminal, and the second contact negative electrode terminal are arranged asymmetrically.

6. A charging device, comprising the protection circuit according to claim 1 or 2, characterized in that: In the connector portion, the first negative contact terminal and the second negative contact terminal are arranged symmetrically with respect to the positive contact terminal.

7. A charging device, comprising the protection circuit according to claim 3 or 4, characterized in that: In the connector portion, the contact positive electrode terminal and the second contact negative electrode terminal are arranged symmetrically with respect to the first contact negative electrode terminal.

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