An internal and external battery power supply switching circuit and method

Abstract

The present invention provides a circuit and method for switching power between internal and external batteries. The circuit includes: an external battery power supply circuit electrically connected to an external battery; an internal battery power supply circuit electrically connected to an internal battery; and a first switching circuit electrically connected to the external battery power supply circuit and the internal battery power supply circuit. The first switching circuit receives an on-state electrical signal from the external battery, the first switching circuit is in an on-state, and the first switching circuit controls the internal battery power supply circuit to be in an off-state based on the on-state electrical signal. The first switching circuit receives an off-state electrical signal from the external battery, the first switching circuit is in an off-state, and the first switching circuit controls the internal battery power supply circuit to be in an on-state based on the off-state electrical signal. The solution of the present invention uses the first switching circuit to control the switching between the off-state and on-state of the internal battery power supply circuit based on the on / off status of the external battery, thereby implementing power switching between the external and internal batteries using a hardware circuit, resulting in fast switching response and high stability.

Description

[0001] Internal and external battery power supply switching circuit and method Technical Field

[0002] The present invention relates to the technical field of power supply switching, and in particular to an internal and external battery power supply switching circuit and method. Background Art

[0003] When using an external battery for power supply, if the external battery fails to provide power properly due to an abnormality, the normal operation of the device will be directly affected. To ensure the normal operation of the device, a method of switching between external and internal batteries is used to power the device. However, current external and internal battery switching circuits often rely on microprocessors to process information from the external and internal batteries, and then implement the power supply circuit switching through software programs. This switching of power supply circuits is affected by the stability of the software programs, resulting in untimely power switching or even failure to switch properly, resulting in unsatisfactory switching stability and reliability. Summary of the Invention

[0004] The present invention provides an internal and external battery power supply switching circuit and method. A first switching circuit controls the cutoff and on / off state switching of an internal battery power supply circuit according to the on / off status of an external battery. The power supply switching between the external battery and the internal battery is realized by a hardware circuit without the involvement of software programs and microprocessors. The switching response is fast, the stability is high, and the reliability is high.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] An internal and external battery power supply switching circuit, comprising:

[0007] An external battery power supply circuit electrically connected to an external battery, wherein the external battery power supply circuit is electrically connected to an electrical device;

[0008] an internal battery power supply circuit electrically connected to the internal battery, wherein the internal battery power supply circuit is electrically connected to the power-consuming device;

[0009] a first switching circuit electrically connected to the external battery power supply circuit and the internal battery power supply circuit;

[0010] Wherein, the first switching circuit receives a path electrical signal from the external battery, the first switching circuit is in a path state, and the first switching circuit controls the internal battery power supply circuit to be in a cut-off state according to the path electrical signal;

[0011] The first switching circuit receives a cut-off electrical signal from an external battery, and the first switching circuit is in a cut-off state. The first switching circuit controls the internal battery power supply circuit to be in a conductive state according to the cut-off electrical signal.

[0012] Optionally, the external battery power supply circuit includes:

[0013] a first terminal electrically connected to an external battery, wherein a first pin of the first terminal is electrically connected to the external battery, and a second pin of the first terminal is grounded;

[0014] a first MOS transistor electrically connected to the first wiring terminal, a source pin of the first MOS transistor electrically connected to a first pin of the first wiring terminal, a gate pin of the first MOS transistor grounded, a first capacitor electrically connected between the source pin and the gate pin of the first MOS transistor, and a source pin of the first MOS transistor grounded via a first resistor;

[0015] a first diode electrically connected to the first MOS transistor, wherein an anode pin of the first diode is electrically connected to a drain pin of the first MOS transistor;

[0016] A second terminal electrically connected to the electrical device, wherein the first pin of the second terminal is electrically connected to the cathode pin of the first diode, the first pin of the second terminal is electrically connected to the electrical device, and the second pin of the second terminal is grounded.

[0017] Optionally, the internal battery power supply circuit includes:

[0018] a third terminal electrically connected to the internal battery, wherein a first pin of the third terminal is electrically connected to the internal battery and a second pin of the third terminal is grounded;

[0019] a fifth MOS transistor electrically connected to the third wiring terminal, a source pin of the fifth MOS transistor electrically connected to the first pin of the third wiring terminal, and a fourth capacitor electrically connected between the source pin and the gate pin of the fifth MOS transistor;

[0020] A second diode electrically connected to the fifth MOS transistor, wherein the anode pin of the second diode is electrically connected to the drain pin of the fifth MOS transistor; and the cathode pin of the second diode is electrically connected to the first pin of the second terminal.

[0021] Optionally, the first switching circuit includes:

[0022] a third MOS transistor electrically connected to the first wiring terminal, a gate pin of the third MOS transistor electrically connected to the first pin of the first wiring terminal, a gate pin of the third MOS transistor electrically connected to the first pin of the first wiring terminal, a gate pin of the third MOS transistor grounded through a sixth resistor, a source pin of the third MOS transistor grounded through a seventh resistor, a source pin of the third MOS transistor electrically connected to the gate pin of the fifth MOS transistor, and a drain pin of the third MOS transistor electrically connected to the source pin of the fifth MOS transistor.

[0023] Optionally, the internal and external battery power supply switching circuit further includes:

[0024] a second switching circuit electrically connected to the external battery power supply circuit and the internal battery power supply circuit;

[0025] Wherein, the second switching circuit receives a path electrical signal from the external battery, the second switching circuit is in a path state, and the second switching circuit controls the internal battery power supply circuit to be in a cut-off state according to the path electrical signal;

[0026] The second switching circuit receives a cut-off electrical signal from the external battery, and the second switching circuit is in a cut-off state. The second switching circuit controls the internal battery power supply circuit to be in a conductive state according to the cut-off electrical signal.

[0027] Optionally, the second switching circuit includes:

[0028] A photocoupler electrically connected to the first wiring terminal, wherein the anode pin of the photocoupler is electrically connected to the first pin of the first wiring terminal via an eighth resistor, a fifth capacitor is electrically connected between the anode pin and cathode pin of the photocoupler, the cathode pin of the photocoupler is grounded, the collector pin of the photocoupler is electrically connected to the source pin of the fifth MOS transistor, the emitter pin of the photocoupler is grounded via a ninth resistor, and the emitter pin of the photocoupler is electrically connected to the gate pin of the fifth MOS transistor.

[0029] Optionally, the internal and external battery power supply switching circuit further includes:

[0030] A charging circuit electrically connected to the external battery power supply circuit and the internal battery power supply circuit, when the external battery supplies power, charges the internal battery through the external battery power supply circuit and the charging circuit.

[0031] Optionally, the charging circuit includes:

[0032] a fourth MOS transistor electrically connected to the first diode, a source pin of the fourth MOS transistor electrically connected to the cathode pin of the first diode, a second capacitor electrically connected between the source pin and the gate pin of the fourth MOS transistor, and a drain pin of the fourth MOS transistor electrically connected to the first pin of the third terminal;

[0033] a second MOS transistor electrically connected to the fourth MOS transistor, wherein a drain pin of the second MOS transistor is electrically connected to the source pin of the fourth MOS transistor through a second resistor, a drain pin of the second MOS transistor is electrically connected to the gate pin of the fourth MOS transistor through a third resistor, a source pin of the second MOS transistor is grounded, a gate pin of the second MOS transistor is grounded through a fifth resistor, a third capacitor is electrically connected between the gate pin and the source pin of the second MOS transistor, and the gate pin of the second MOS transistor is electrically connected to the first pin of the third wiring terminal through a fourth resistor.

[0034] The present invention further provides a method for switching between internal and external battery power supplies, which is applied to the internal and external battery power supply switching circuit described above. The method comprises:

[0035] The first switching circuit receives a path electrical signal from an external battery;

[0036] The first switching circuit controls the internal battery power supply circuit to be in a cut-off state according to the path electrical signal;

[0037] The first switching circuit receives a cut-off electrical signal from an external battery;

[0038] The first switching circuit controls the internal battery power supply circuit to be in a conducting state according to the cut-off electrical signal.

[0039] Optionally, the method further includes:

[0040] The second switching circuit receives a path electrical signal from an external battery;

[0041] The second switching circuit controls the internal battery power supply circuit to be in a cut-off state according to the path electrical signal;

[0042] The second switching circuit receives a cut-off electrical signal from an external battery;

[0043] The second switching circuit controls the internal battery power supply circuit to be in a conducting state according to the cut-off electrical signal.

[0044] The above solution of the present invention includes at least the following beneficial effects:

[0045] The above solution of the present invention controls the cut-off and on-state switching of the internal battery power supply circuit according to the on-off status of the external battery through the first switching circuit, and realizes the power supply switching between the external battery and the internal battery by hardware circuit without the participation of software programs and microprocessors. The switching response is fast, the stability is high, and the reliability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a module diagram of an internal and external battery power supply switching circuit provided by an embodiment of the present invention;

[0047] Figure 2 4 is a circuit diagram of an internal and external battery power supply switching circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0049] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an internal and external battery power supply switching circuit, comprising:

[0050] An external battery power supply circuit 10 electrically connected to an external battery 20 , wherein the external battery power supply circuit 10 is electrically connected to an electric device 30 ;

[0051] an internal battery power supply circuit 40 electrically connected to the internal battery 50 , wherein the internal battery power supply circuit 40 is electrically connected to the power-consuming device 30 ;

[0052] a first switching circuit 60 electrically connected to the external battery power supply circuit 10 and the internal battery power supply circuit 40;

[0053] The first switching circuit 60 receives a path electrical signal from the external battery 20, and the first switching circuit 60 is in a path state. The first switching circuit 60 controls the internal battery power supply circuit 40 to be in a cut-off state according to the path electrical signal.

[0054] The first switching circuit 60 receives a cut-off electrical signal from the external battery 20 , and the first switching circuit 60 is in a cut-off state. The first switching circuit 60 controls the internal battery power supply circuit 40 to be in a conductive state according to the cut-off electrical signal.

[0055] In this embodiment, when the external battery 20 is supplying power normally, the external battery power supply circuit 10 is in a conducting state, the first switching circuit 60 receives a conducting electrical signal from the external battery 20, the first switching circuit 60 is in a conducting state, and the first switching circuit 60 controls the internal battery power supply circuit 40 to be in a cut-off state according to the conducting electrical signal, and the external battery 20 and the external battery power supply circuit 10 supply power to the power-consuming device 30;

[0056] When the external battery 20 cannot supply power normally, the external battery power supply circuit 10 is in the cut-off state, and the first switching circuit 60 receives the cut-off electrical signal from the external battery 20. The first switching circuit 60 is in the cut-off state. The first switching circuit 60 controls the internal battery power supply circuit 40 to be in the on state according to the cut-off electrical signal, and the power-consuming device 30 is powered by the internal battery 50 and the internal battery power supply circuit 40.

[0057] Through the above method, the power supply switching between the external battery 20 and the internal battery 50 can be realized by hardware circuit without the participation of software programs and microprocessors, and the switching response is fast, the stability is high, and the reliability is high.

[0058] like Figure 2 As shown, in an optional embodiment of the present invention, the external battery power supply circuit 10 includes:

[0059] a first terminal P1 electrically connected to the external battery 20 , wherein a first pin of the first terminal P1 is electrically connected to the external battery 20 , and a second pin of the first terminal P1 is grounded;

[0060] a first MOS transistor Q1 electrically connected to the first wiring terminal P1, a source pin of the first MOS transistor Q1 electrically connected to the first pin of the first wiring terminal P1, a gate pin of the first MOS transistor Q1 grounded, a first capacitor C1 electrically connected between the source pin and the gate pin of the first MOS transistor Q1, and the source pin of the first MOS transistor Q1 grounded via a first resistor R12;

[0061] a first diode D1 electrically connected to the first MOS transistor Q1, wherein an anode pin of the first diode D1 is electrically connected to a drain pin of the first MOS transistor Q1;

[0062] The second terminal P2 is electrically connected to the electrical device 30, the first pin of the second terminal P2 is electrically connected to the cathode pin of the first diode D1, the first pin of the second terminal P2 is electrically connected to the electrical device 30, and the second pin of the second terminal P2 is grounded.

[0063] In this embodiment, when the external battery 20 is supplying power normally, the first MOS transistor Q1 is turned on, the external battery power supply circuit 10 is in a conduction state, and the first diode D1 limits the single direction of current flow, thereby supplying power to the power-consuming device 30;

[0064] When the external battery 20 is abnormally unable to supply power, the first MOS transistor Q1 is turned off, and the external battery power supply circuit 10 is in a cut-off state, thereby being unable to power the powered device 30. The cut-off of the first MOS transistor Q1 serves to isolate the external battery 20 and the powered device 30, thereby preventing abnormal conditions such as a short circuit of the external battery 20 from causing damage to the powered device 30.

[0065] like Figure 2 As shown, in an optional embodiment of the present invention, the internal battery power supply circuit 40 includes:

[0066] a third terminal P3 electrically connected to the internal battery 50 , wherein a first pin of the third terminal P3 is electrically connected to the internal battery 50 , and a second pin of the third terminal P3 is grounded;

[0067] a fifth MOS transistor Q5 electrically connected to the third wiring terminal P3, a source pin of the fifth MOS transistor Q5 electrically connected to the first pin of the third wiring terminal P3, and a fourth capacitor C4 electrically connected between the source pin and the gate pin of the fifth MOS transistor Q5;

[0068] A second diode D2 is electrically connected to the fifth MOS transistor Q5 , wherein the anode pin of the second diode D2 is electrically connected to the drain pin of the fifth MOS transistor Q5 ; and the cathode pin of the second diode D2 is electrically connected to the first pin of the second terminal P2 .

[0069] In this embodiment, when the external battery 20 is supplying power normally, the first switching circuit 60 turns off the fifth MOS transistor Q5, thereby turning off the internal battery power supply circuit 40, so that the internal battery 50 and the internal battery power supply circuit 40 cannot supply power to the power-consuming device 30.

[0070] When the external battery 20 fails to supply power normally, the first switching circuit 60 turns on the fifth MOS transistor Q5, and the internal battery power supply circuit 40 is in a conducting state. The second diode D2 limits the single direction of current flow, thereby supplying power to the power-consuming device 30.

[0071] When the internal battery 50 supplies power to the electrical device, if an abnormal state such as a short circuit occurs in the internal battery 50, the fifth MOS transistor Q5 is turned off. The turning off of the fifth MOS transistor Q5 serves to isolate the internal battery 50 and the electrical device 30, thereby preventing the abnormal state such as the short circuit of the internal battery 50 from causing damage to the electrical device 30.

[0072] like Figure 2 As shown, in an optional embodiment of the present invention, the first switching circuit 60 includes:

[0073] a third MOS transistor Q3 electrically connected to the first wiring terminal P1, a gate pin of the third MOS transistor Q3 electrically connected to the first pin of the first wiring terminal P1, a gate pin of the third MOS transistor Q3 grounded via a sixth resistor R6, a source pin of the third MOS transistor Q3 grounded via a seventh resistor R7, a source pin of the third MOS transistor Q3 electrically connected to the gate pin of the fifth MOS transistor Q5, and a drain pin of the third MOS transistor Q3 electrically connected to the source pin of the fifth MOS transistor Q5.

[0074] In this embodiment, when the external battery 20 is supplying power normally, the third MOS transistor Q3 is turned on, causing the fifth MOS transistor Q5 to be turned off, and the internal battery power supply circuit 40 to be in a cut-off state, thereby powering the power-consuming device 30 through the external battery 20 and the external battery power supply circuit 10;

[0075] When the external battery 20 is abnormal and cannot supply power normally, the third MOS transistor Q3 is turned off, so that the fifth MOS transistor Q5 is turned on, and the internal battery power supply circuit 40 is in a conductive state, so that the internal battery 50 and the internal battery power supply circuit 40 are used to power the power-consuming device 30, thereby realizing power supply switching; the power supply switching between the external battery 20 and the internal battery 50 is realized by hardware circuit without the participation of software programs and microprocessors, and the switching response is fast, the stability is high, and the reliability is high.

[0076] like Figure 1 As shown, in an optional embodiment of the present invention, the internal and external battery power supply switching circuit further includes:

[0077] a second switching circuit 70 electrically connected to the external battery power supply circuit 10 and the internal battery power supply circuit 40;

[0078] The second switching circuit 70 receives a path electrical signal from the external battery 20, and the second switching circuit 70 is in a path state. The second switching circuit 70 controls the internal battery power supply circuit 40 to be in a cut-off state according to the path electrical signal.

[0079] The second switching circuit 70 receives a cut-off electrical signal from the external battery 20 , and is in a cut-off state. The second switching circuit 70 controls the internal battery power supply circuit 40 to be in a conductive state according to the cut-off electrical signal.

[0080] In this embodiment, when the external battery 20 is supplying power normally, the external battery power supply circuit 10 is in a conducting state, the second switching circuit 70 receives a conducting electrical signal from the external battery 20, and the second switching circuit 70 is in a conducting state. The second switching circuit 70 controls the internal battery power supply circuit 40 to be in a cut-off state according to the conducting electrical signal, and the external battery 20 and the external battery power supply circuit 10 supply power to the power-consuming device 30.

[0081] When the external battery 20 cannot supply power normally, the external battery power supply circuit 10 is in the cut-off state, and the second switching circuit 70 receives the cut-off electrical signal from the external battery 20. The second switching circuit 70 is in the cut-off state. The second switching circuit 70 controls the internal battery power supply circuit 40 to be in the on state according to the cut-off electrical signal, and the power-consuming device 30 is powered by the internal battery 50 and the internal battery power supply circuit 40.

[0082] The second switching circuit 70 can realize the power supply switching between the external battery 20 and the internal battery 50 by hardware circuit without the participation of software programs and microprocessors, and has fast switching response, high stability and high reliability.

[0083] The first switching circuit 60 and the second switching circuit 70 cooperate with each other to switch the power supply between the external battery 20 and the internal battery 50, which can further ensure the normal power supply switching between the external battery 20 and the internal battery 50 and ensure the stability and reliability of the power supply switching.

[0084] like Figure 2 As shown, in an optional embodiment of the present invention, the second switching circuit 70 includes:

[0085] A photocoupler U1 is electrically connected to the first wiring terminal P1, an anode pin of the photocoupler U1 is electrically connected to the first pin of the first wiring terminal P1 via an eighth resistor R8, a fifth capacitor C5 is electrically connected between the anode pin and cathode pin of the photocoupler U1, the cathode pin of the photocoupler U1 is grounded, a collector pin of the photocoupler U1 is electrically connected to the source pin of the fifth MOS transistor Q5, an emitter pin of the photocoupler U1 is grounded via a ninth resistor R9, and the emitter pin of the photocoupler U1 is electrically connected to the gate pin of the fifth MOS transistor Q5.

[0086] In this embodiment, when the external battery 20 is normally supplying power, the photocoupler U1 is turned on, causing the fifth MOS transistor Q5 to be turned off, and the internal battery power supply circuit 40 to be in an off state, thereby powering the power-consuming device 30 through the external battery 20 and the external battery power supply circuit 10;

[0087] When the external battery 20 is abnormal and cannot supply power normally, the photocoupler U1 is turned off, so that the fifth MOS tube Q5 is turned on, and the internal battery power supply circuit 40 is in a conductive state, so that the internal battery 50 and the internal battery power supply circuit 40 are used to power the power-consuming device 30, thereby realizing power supply switching; the power supply switching between the external battery 20 and the internal battery 50 is realized by hardware circuit without the participation of software programs and microprocessors, and the switching response is fast, the stability is high, and the reliability is high.

[0088] like Figure 1 As shown, in an optional embodiment of the present invention, the internal and external battery power supply switching circuit further includes:

[0089] The charging circuit 80 is electrically connected to the external battery power supply circuit 10 and the internal battery power supply circuit 40 . When the external battery 20 supplies power, the internal battery 50 is charged through the external battery power supply circuit 10 and the charging circuit 80 .

[0090] In this embodiment, when the external battery 20 is supplying power normally and the internal battery 50 is normal, the charging circuit 80 is in a conducting state, and the internal battery 50 is charged through the external battery 20, the external battery power supply circuit 10 and the charging circuit 80;

[0091] During the charging process, if the internal battery 50 is short-circuited to the ground, the charging circuit 80 is in a cut-off state, and charging of the internal battery 50 is stopped, thereby ensuring the safety of the entire circuit.

[0092] like Figure 2 As shown, in an optional embodiment of the present invention, the charging circuit 80 includes:

[0093] a fourth MOS transistor Q4 electrically connected to the first diode D1, a source pin of the fourth MOS transistor Q4 electrically connected to the cathode pin of the first diode D1, a second capacitor C2 electrically connected between the source pin and the gate pin of the fourth MOS transistor Q4, and a drain pin of the fourth MOS transistor Q4 electrically connected to the first pin of the third wiring terminal P3;

[0094] A second MOS transistor Q2 electrically connected to the fourth MOS transistor Q4, a drain pin of the second MOS transistor Q2 electrically connected to the source pin of the fourth MOS transistor Q4 via a second resistor R2, a drain pin of the second MOS transistor Q2 electrically connected to the gate pin of the fourth MOS transistor Q4 via a third resistor R3, a source pin of the second MOS transistor Q2 grounded, a gate pin of the second MOS transistor Q2 grounded via a fifth resistor R5, a third capacitor C3 electrically connected between the gate pin and source pin of the second MOS transistor Q2, and a gate pin of the second MOS transistor Q2 electrically connected to the first pin of the third wiring terminal P3 via a fourth resistor R4.

[0095] In this embodiment, when the external battery 20 is supplying power normally and the internal battery 50 is normal, the second MOS transistor Q2 is turned on, causing the fourth MOS transistor Q4 to be turned on, and the external battery 20 charges the internal battery 50 through the external battery power supply circuit 10 and the fourth MOS transistor Q4;

[0096] During the charging process, if the internal battery 50 is short-circuited to the ground, the second MOS transistor Q2 is turned off, causing the fourth MOS transistor Q4 to be turned off, stopping the charging of the internal battery 50, ensuring the safety of the entire circuit. The charging of the internal battery 50 and the charging stop protection are implemented by the hardware circuit, with high stability and reliability.

[0097] An embodiment of the present invention further provides a method for switching between internal and external battery power supplies, which is applied to the internal and external battery power supply switching circuit described in any of the above embodiments. The method includes:

[0098] The first switching circuit 60 receives a path electrical signal from the external battery 20;

[0099] The first switching circuit 60 controls the internal battery power supply circuit 40 to be in a cut-off state according to the path electrical signal;

[0100] The first switching circuit 60 receives a cut-off electrical signal from the external battery 20;

[0101] The first switching circuit 60 controls the internal battery power supply circuit 40 to be in a conducting state according to the cut-off electrical signal.

[0102] Furthermore, the method further comprises:

[0103] The second switching circuit 70 receives a path electrical signal from the external battery 20;

[0104] The second switching circuit 70 controls the internal battery power supply circuit 40 to be in a cut-off state according to the path electrical signal;

[0105] The second switching circuit 70 receives a cut-off electrical signal from the external battery 20;

[0106] The second switching circuit 70 controls the internal battery power supply circuit 40 to be in a conducting state according to the cut-off electrical signal.

[0107] In this embodiment, when the external battery 20 is supplying power normally, the first MOS transistor Q1 is turned on, the external battery power supply circuit 10 is in a conducting state, the third MOS transistor Q3 and the photocoupler U1 are both turned on, so that the fifth MOS transistor Q5 is turned off, and the internal battery power supply circuit 40 is in a cut-off state, thereby powering the power-consuming device 30 through the external battery 20 and the external battery power supply circuit 10;

[0108] When the external battery 20 is abnormal and cannot supply power normally, the first MOS transistor Q1 is turned off, the external battery power supply circuit 10 is in the cut-off state, the third MOS transistor Q3 and the photocoupler U1 are both turned off, so that the fifth MOS transistor Q5 is turned on, and the internal battery power supply circuit 40 is in the on state, so that the internal battery 50 and the internal battery power supply circuit 40 supply power to the power-consuming device 30;

[0109] During the implementation of the above-mentioned internal and external battery power supply switching method, no software program and microprocessor are required to participate, and the switching response is fast, the stability is high, and the reliability is high.

[0110] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An internal and external battery power supply switching circuit, characterized in that: include: an external battery power supply circuit (10) electrically connected to an external battery (20), wherein the external battery power supply circuit (10) is electrically connected to an electric device (30); an internal battery power supply circuit (40) electrically connected to the internal battery (50), wherein the internal battery power supply circuit (40) is electrically connected to the power-consuming device (30); a first switching circuit (60) electrically connected to the external battery power supply circuit (10) and the internal battery power supply circuit (40); The first switching circuit (60) receives a path electrical signal from the external battery (20), the first switching circuit (60) is in a path state, and the first switching circuit (60) controls the internal battery power supply circuit (40) to be in a cut-off state according to the path electrical signal; The first switching circuit (60) receives a cut-off electrical signal from the external battery (20), the first switching circuit (60) is in a cut-off state, and the first switching circuit (60) controls the internal battery power supply circuit (40) to be in a pass state according to the cut-off electrical signal; Wherein, the external battery power supply circuit (10) comprises: a first wiring terminal (P1) electrically connected to an external battery (20), a first pin of the first wiring terminal (P1) electrically connected to the external battery (20), and a second pin of the first wiring terminal (P1) grounded; a first MOS transistor (Q1) electrically connected to the first wiring terminal (P1), a source pin of the first MOS transistor (Q1) electrically connected to a first pin of the first wiring terminal (P1), a gate pin of the first MOS transistor (Q1) grounded, a first capacitor (C1) electrically connected between the source pin and the gate pin of the first MOS transistor (Q1), and the source pin of the first MOS transistor (Q1) grounded via a first resistor (R12); a first diode (D1) electrically connected to the first MOS tube (Q1), wherein the anode pin of the first diode (D1) is electrically connected to the drain pin of the first MOS tube (Q1); a second wiring terminal (P2) electrically connected to the electrical device (30), a first pin of the second wiring terminal (P2) electrically connected to the cathode pin of the first diode (D1), a first pin of the second wiring terminal (P2) electrically connected to the electrical device (30), and a second pin of the second wiring terminal (P2) grounded; When the external battery (20) is abnormal and unable to supply power, the first MOS tube (Q1) is cut off, and the external battery power supply circuit (10) is in a cut-off state; Wherein, the internal battery power supply circuit (40) comprises: a third terminal (P3) electrically connected to the internal battery (50), a first pin of the third terminal (P3) electrically connected to the internal battery (50), and a second pin of the third terminal (P3) grounded; a fifth MOS transistor (Q5) electrically connected to the third wiring terminal (P3), a source pin of the fifth MOS transistor (Q5) electrically connected to a first pin of the third wiring terminal (P3), and a fourth capacitor (C4) electrically connected between the source pin and the gate pin of the fifth MOS transistor (Q5); a second diode (D2) electrically connected to the fifth MOS tube (Q5), the anode pin of the second diode (D2) electrically connected to the drain pin of the fifth MOS tube (Q5); and the cathode pin of the second diode (D2) electrically connected to the first pin of the second wiring terminal (P2); When the internal battery (50) supplies power to the electrical equipment, if the internal battery (50) is in an abnormal state, the fifth MOS tube (Q5) is cut off; a charging circuit (80) electrically connected to the external battery power supply circuit (10) and the internal battery power supply circuit (40), wherein when the external battery (20) supplies power, the internal battery (50) is charged via the external battery power supply circuit (10) and the charging circuit (80); Wherein, the charging circuit (80) comprises: a fourth MOS transistor (Q4) electrically connected to the first diode (D1), a source pin of the fourth MOS transistor (Q4) electrically connected to the cathode pin of the first diode (D1), a second capacitor (C2) electrically connected between the source pin and the gate pin of the fourth MOS transistor (Q4), and a drain pin of the fourth MOS transistor (Q4) electrically connected to the first pin of the third wiring terminal (P3); a second MOS tube (Q2) electrically connected to the fourth MOS tube (Q4), the drain pin of the second MOS tube (Q2) electrically connected to the source pin of the fourth MOS tube (Q4) via a second resistor (R2), the drain pin of the second MOS tube (Q2) electrically connected to the gate pin of the fourth MOS tube (Q4) via a third resistor (R3), the source pin of the second MOS tube (Q2) grounded, the gate pin of the second MOS tube (Q2) grounded via a fifth resistor (R5), a third capacitor (C3) electrically connected between the gate pin and the source pin of the second MOS tube (Q2), and the gate pin of the second MOS tube (Q2) electrically connected to the first pin of the third wiring terminal (P3) via a fourth resistor (R4); During the charging process, the internal battery (50) is short-circuited to the ground, the second MOS transistor (Q2) is turned off, causing the fourth MOS transistor (Q4) to be turned off, thereby stopping the charging of the internal battery (50).

2. The internal and external battery power supply switching circuit according to claim 1, characterized in that: The first switching circuit (60) comprises: A third MOS tube (Q3) electrically connected to the first wiring terminal (P1), a gate pin of the third MOS tube (Q3) electrically connected to the first pin of the first wiring terminal (P1), a gate pin of the third MOS tube (Q3) grounded via a sixth resistor (R6), a source pin of the third MOS tube (Q3) grounded via a seventh resistor (R7), a source pin of the third MOS tube (Q3) electrically connected to the gate pin of the fifth MOS tube (Q5), and a drain pin of the third MOS tube (Q3) electrically connected to the source pin of the fifth MOS tube (Q5).

3. The internal and external battery power supply switching circuit according to claim 1, characterized in that: Also includes: a second switching circuit (70) electrically connected to the external battery power supply circuit (10) and the internal battery power supply circuit (40); The second switching circuit (70) receives a path electrical signal from the external battery (20), the second switching circuit (70) is in a path state, and the second switching circuit (70) controls the internal battery power supply circuit (40) to be in a cut-off state according to the path electrical signal; The second switching circuit (70) receives a cut-off electrical signal from the external battery (20), and the second switching circuit (70) is in a cut-off state. The second switching circuit (70) controls the internal battery power supply circuit (40) to be in a pass state according to the cut-off electrical signal.

4. The internal and external battery power supply switching circuit according to claim 3, characterized in that: The second switching circuit (70) comprises: A photoelectric coupler (U1) electrically connected to the first wiring terminal (P1), an anode pin of the photoelectric coupler (U1) electrically connected to the first pin of the first wiring terminal (P1) via an eighth resistor (R8), a fifth capacitor (C5) electrically connected between the anode pin and the cathode pin of the photoelectric coupler (U1), the cathode pin of the photoelectric coupler (U1) grounded, the collector pin of the photoelectric coupler (U1) electrically connected to the source pin of the fifth MOS tube (Q5), the emitter pin of the photoelectric coupler (U1) grounded via a ninth resistor (R9), and the emitter pin of the photoelectric coupler (U1) electrically connected to the gate pin of the fifth MOS tube (Q5).

5. A method for switching between internal and external battery power supply, characterized in that: Applied to the internal / external battery power supply switching circuit according to any one of claims 1 to 4, the method comprises: The first switching circuit (60) receives a path electrical signal from an external battery (20); The first switching circuit (60) controls the internal battery power supply circuit (40) to be in a cut-off state according to the path electrical signal; and charges the internal battery (50) through the external battery power supply circuit (10) and the charging circuit (80), wherein the charging circuit (80) is electrically connected to the external battery power supply circuit (10) and the internal battery power supply circuit (40); The first switching circuit (60) receives a cut-off electrical signal from an external battery (20); The first switching circuit (60) controls the internal battery power supply circuit (40) to be in a conductive state according to the cut-off electrical signal; Wherein, the external battery power supply circuit (10) comprises: a first wiring terminal (P1) electrically connected to an external battery (20), a first pin of the first wiring terminal (P1) electrically connected to the external battery (20), and a second pin of the first wiring terminal (P1) grounded; a first MOS transistor (Q1) electrically connected to the first wiring terminal (P1), a source pin of the first MOS transistor (Q1) electrically connected to a first pin of the first wiring terminal (P1), a gate pin of the first MOS transistor (Q1) grounded, a first capacitor (C1) electrically connected between the source pin and the gate pin of the first MOS transistor (Q1), and the source pin of the first MOS transistor (Q1) grounded via a first resistor (R12); a first diode (D1) electrically connected to the first MOS tube (Q1), wherein the anode pin of the first diode (D1) is electrically connected to the drain pin of the first MOS tube (Q1); a second wiring terminal (P2) electrically connected to the electrical device (30), a first pin of the second wiring terminal (P2) electrically connected to the cathode pin of the first diode (D1), a first pin of the second wiring terminal (P2) electrically connected to the electrical device (30), and a second pin of the second wiring terminal (P2) grounded; When the external battery (20) is abnormal and unable to supply power, the first MOS tube (Q1) is cut off, and the external battery power supply circuit (10) is in a cut-off state; Wherein, the internal battery power supply circuit (40) comprises: a third terminal (P3) electrically connected to the internal battery (50), a first pin of the third terminal (P3) electrically connected to the internal battery (50), and a second pin of the third terminal (P3) grounded; a fifth MOS transistor (Q5) electrically connected to the third wiring terminal (P3), a source pin of the fifth MOS transistor (Q5) electrically connected to a first pin of the third wiring terminal (P3), and a fourth capacitor (C4) electrically connected between the source pin and the gate pin of the fifth MOS transistor (Q5); a second diode (D2) electrically connected to the fifth MOS tube (Q5), the anode pin of the second diode (D2) electrically connected to the drain pin of the fifth MOS tube (Q5); and the cathode pin of the second diode (D2) electrically connected to the first pin of the second wiring terminal (P2); When the internal battery (50) supplies power to the electrical equipment, if the internal battery (50) is in an abnormal state, the fifth MOS tube (Q5) is cut off; Wherein, the charging circuit (80) comprises: a fourth MOS transistor (Q4) electrically connected to the first diode (D1), a source pin of the fourth MOS transistor (Q4) electrically connected to the cathode pin of the first diode (D1), a second capacitor (C2) electrically connected between the source pin and the gate pin of the fourth MOS transistor (Q4), and a drain pin of the fourth MOS transistor (Q4) electrically connected to the first pin of the third wiring terminal (P3); a second MOS tube (Q2) electrically connected to the fourth MOS tube (Q4), the drain pin of the second MOS tube (Q2) electrically connected to the source pin of the fourth MOS tube (Q4) via a second resistor (R2), the drain pin of the second MOS tube (Q2) electrically connected to the gate pin of the fourth MOS tube (Q4) via a third resistor (R3), the source pin of the second MOS tube (Q2) grounded, the gate pin of the second MOS tube (Q2) grounded via a fifth resistor (R5), a third capacitor (C3) electrically connected between the gate pin and the source pin of the second MOS tube (Q2), and the gate pin of the second MOS tube (Q2) electrically connected to the first pin of the third wiring terminal (P3) via a fourth resistor (R4); During the charging process, the internal battery (50) is short-circuited to the ground, the second MOS transistor (Q2) is turned off, causing the fourth MOS transistor (Q4) to be turned off, thereby stopping the charging of the internal battery (50).

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