Power management circuit and power supply

Abstract

The present invention proposes a power management circuit and a power supply, which detect the backflow phenomenon by setting a current direction detection module, and adjust the connection state of the line switching module based on the detection result. When the dynamic connection end is connected to the first static connection end, the first switch tube is turned on, and when the dynamic connection end is connected to the second static connection end, the first switch tube is turned off. Thus, the control of the state of the first switch tube based on the current direction is realized. When the backflow phenomenon occurs, the current can be prevented from flowing back to the power supply module by controlling the state of the first switch tube.

Description

Technical Field

[0001] The present invention relates to the field of power supply safety, and in particular to a power supply management circuit and a power supply. Background Art

[0002] When a power supply is supplying power to a load, if load current backflow occurs, it will affect the normal operation of the power supply and even cause damage to the power supply; therefore, how to avoid current backflow has become an issue that needs to be paid attention to in power supply applications. Summary of the invention

[0003] The main purpose of the present invention is to provide a power management circuit and a power supply, aiming to solve the problem of how to avoid current backflow in the prior art.

[0004] To achieve the above-mentioned object, the present invention provides a power management circuit, which is connected to a power supply module and a load, and includes a first switch tube, a current direction detection module and a line switching module; the drain of the first switch tube is connected to the power supply module as the positive electrode of the power management circuit, and the source of the first switch tube is connected to the load; the detection end of the current direction detection module is arranged on the line where the output end of the first switch tube is connected to the load; the output end of the current direction detection module is connected to the control end of the line switching module, the dynamic connection end of the line switching module is connected to the gate of the first switch tube, the first static connection end of the line switching module is grounded, and the second static connection end of the line switching module is connected to the source of the first switch tube; wherein:

[0005] The current direction detection module is used to detect the current direction on the line to obtain a detection result, and send a control signal corresponding to the detection result to the line switching module;

[0006] The line switching module is used to receive the control signal sent by the current direction detection module, and connect the dynamic connection end with the first static connection end or the second static connection end according to the control signal.

[0007] Optionally, the current direction detection module includes a first resistor, a second resistor and a comparator; wherein:

[0008] The first resistor is connected in series on the line connecting the output end of the first switching tube and the load, the non-inverting input end of the comparator is connected to the end of the first resistor close to the load, and the inverting input end of the comparator is connected to the end of the first resistor close to the first switching tube; the output end of the comparator is connected to the control end of the circuit switching module, and the output end of the comparator is also connected to the power supply through the second resistor.

[0009] Optionally, the line switching module includes a signal determination unit and a switching unit; the control end of the signal determination unit is connected to the output end of the current direction detection module, the output end of the signal determination unit is connected to the control end of the switching unit, the dynamic connection end of the switching unit is connected to the gate of the first switch tube, the first static connection end of the switching unit is grounded, and the second static connection end of the switching unit is connected to the source of the first switch tube; wherein:

[0010] The signal determination unit is used to receive the control signal sent by the current direction detection module, and output a switching signal corresponding to the control signal to the switching unit;

[0011] The switching unit is used to connect the dynamic connection end with the first static connection end or the second static connection end according to the switching signal.

[0012] Optionally, the signal determination unit includes a second switch tube, wherein:

[0013] The gate of the second switch tube is connected to the output end of the current direction detection module, the source of the second switch tube is grounded, and the drain of the second switch tube is connected to the control end of the switching unit.

[0014] Optionally, the second switch tube is an NMOS tube.

[0015] Optionally, the switching unit includes a relay and a first voltage regulator tube; wherein:

[0016] The first end of the coil of the relay is connected to the power supply, the first end of the coil of the relay is also connected to the negative electrode of the first voltage regulator tube, the positive electrode of the first voltage regulator tube is connected to the second end of the coil of the relay, and the second end of the coil of the relay is also connected to the output end of the signal determination unit;

[0017] The first contact of the relay is connected to the gate of the first switch tube, the second contact of the relay is grounded, and the third contact of the relay is connected to the source of the first switch tube; wherein the first contact and the second contact constitute a normally closed contact, and the first contact and the third contact constitute a normally open contact.

[0018] Optionally, the power management circuit further includes an anti-reverse connection module, and the anti-reverse connection module is connected between the gate and the source of the first switch tube, wherein:

[0019] The anti-reverse connection module is used to turn off the first switch tube when the power supply module is reversely connected.

[0020] Optionally, the anti-reverse connection module includes a second voltage regulator tube, a first capacitor and a third resistor; wherein:

[0021] The cathode of the second voltage regulator tube is connected to the source of the first switch tube, the anode of the second voltage regulator tube is grounded through the third resistor, and the first capacitor is connected in parallel with the second voltage regulator tube;

[0022] The first static connection end of the circuit switching module is grounded through the third resistor.

[0023] Optionally, the first switch tube is a PMOS tube.

[0024] In addition, to achieve the above-mentioned purpose, the present invention further provides a power supply, which includes a power supply module and a power management circuit, and the power management circuit is configured as the power management circuit described above.

[0025] The present invention provides a power management circuit and a power supply, wherein the power management circuit is connected to a power supply module and a load, and the power management circuit includes a first switch tube, a current direction detection module and a line switching module; the drain of the first switch tube is connected to the power supply module as the positive electrode of the power management circuit, and the source of the first switch tube is connected to the load; the detection end of the current direction detection module is arranged on the line where the output end of the first switch tube is connected to the load; the output end of the current direction detection module is connected to the control end of the line switching module, the dynamic connection end of the line switching module is connected to the gate of the first switch tube, the first static connection end of the line switching module is grounded, and the second static connection end of the line switching module is connected to the source of the first switch tube; wherein: the current direction detection module is used to detect the current direction on the line to obtain a detection result, and send a control signal corresponding to the detection result to the line switching module; the line switching module is used to receive the control signal sent by the current direction detection module, and connect the dynamic connection end to the first static connection end or the second static connection end according to the control signal. A current direction detection module is set up to detect the backflow phenomenon, and the connection state of the line switching module is adjusted based on the detection result. When the dynamic connection end is connected to the first static connection end, the first switch tube is turned on, and when the dynamic connection end is connected to the second static connection end, the first switch tube is turned off. Thus, the control of the state of the first switch tube based on the current direction is realized. When the backflow phenomenon occurs, the current can be prevented from flowing back to the power supply module by controlling the state of the first switch tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 A functional module diagram of an embodiment of a power management circuit of the present invention;

[0028] Figure 2 The power management circuit of the present invention is applied in Figure 1 Circuit structure diagram in the embodiment.

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

[0030] Description of Figure Numbers:

[0031] Label name Label name 100 Current direction detection module R1~R3 First resistor to third resistor 200 Line switching module Q1~Q2 The first switch tube ~ the second switch tube 210 Signal determination unit Z1~Z2 The first voltage regulator tube ~ the second voltage regulator tube 220 Switching unit K1 Relay 300 Power supply module C1 First capacitor 400 load S1 Comparator 500 Anti-reverse connection module DETAILED DESCRIPTION

[0032] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The present invention provides a power management circuit, which is applied to power supply, see Figure 1 , Figure 1 This is a functional module diagram of an embodiment of the power management circuit of the present invention. In this embodiment, the power management circuit is connected to the power supply module 300 and the load 400, and the power management circuit includes a first switch tube Q1, a current direction detection module 100 and a line switching module 200; the drain of the first switch tube Q1 is connected to the power supply module 300 as the positive electrode of the power management circuit, and the source of the first switch tube Q1 is connected to the load 400; the detection end of the current direction detection module 100 is set on the line where the output end of the first switch tube Q1 is connected to the load 400; the output end of the current direction detection module 100 is connected to the control end of the line switching module 200, the dynamic connection end of the line switching module 200 is connected to the gate of the first switch tube Q1, the first static connection end of the line switching module 200 is grounded, and the second static connection end of the line switching module 200 is connected to the source of the first switch tube Q1; wherein:

[0037] The current direction detection module 100 is used to detect the current direction on the line to obtain a detection result, and send a control signal corresponding to the detection result to the line switching module 200;

[0038] The line switching module 200 is used to receive the control signal sent by the current direction detection module 100, and connect the dynamic connection end with the first static connection end or the second static connection end according to the control signal.

[0039] The current direction detection module 100 is used to detect the current direction on the line; under normal circumstances, the voltage output by the power supply module 300 supplies power to the load 400 through the first switch tube Q1, and the current direction is from the power supply module 300 to the first switch tube Q1, and then to the load 400; when backflow occurs, the current direction is from the load 400 to the first switch tube Q1, and then to the power supply module 300; therefore, the detection end of the current direction detection module 100 is set on the line where the output end of the first switch tube Q1 is connected to the load 400, so as to accurately detect whether backflow occurs; the current direction detection module 100 obtains the detection result based on the detection, and sends the detection result to the line switching module 200.

[0040] The circuit switching module 200 includes a dynamic connection end and two static connection ends, and the dynamic connection end is not connected to the two static connection ends at the same time; in this embodiment, the first switch tube Q1 is a PMOS tube; when the dynamic connection end is connected to the first static connection end, the gate of the first switch tube Q1 is grounded through the circuit switching module 200. At this time, the gate-source voltage of the first switch tube Q1 meets the threshold voltage, the first switch tube Q1 is turned on, and the power supply module 300 can supply power to the load 400; when the dynamic connection end is connected to the second static connection end, the gate of the first switch tube Q1 is connected to the source of the first switch tube Q1 through the circuit switching module 200. At this time, the gate-source voltage of the first switch tube Q1 does not meet the threshold voltage, the first switch tube Q1 is turned off, the power supply module 300 cannot supply power to the load 400, and at the same time, the current cannot be backflowed to the power supply module 300.

[0041] From the above principle, it can be seen that when the current direction detection module 100 detects that the current direction flows from the power supply module 300 to the load 400, the dynamic connection end of the line switching module 200 will be connected to the first static connection end to turn on the first switch tube Q1; and when the current direction detection module 100 detects that the current direction flows from the load 400 to the power supply module 300, the dynamic connection end of the line switching module 200 will be connected to the second static connection end to turn off the first switch tube Q1 to achieve backflow prevention.

[0042] In this embodiment, a current direction detection module 100 is set to detect the backflow phenomenon, and the connection state of the line switching module 200 is adjusted based on the detection result. When the dynamic connection end is connected to the first static connection end, the first switch tube Q1 is turned on, and when the dynamic connection end is connected to the second static connection end, the first switch tube Q1 is turned off. Thus, the state of the first switch tube Q1 is controlled based on the current direction. When the backflow phenomenon occurs, the current can be prevented from flowing back to the power supply module 300 by controlling the state of the first switch tube Q1.

[0043] Furthermore, the current direction detection module 100 includes a first resistor R1, a second resistor R2 and a comparator S1; wherein:

[0044] The first resistor R1 is connected in series on the line connecting the output end of the first switch tube Q1 and the load 400, the non-inverting input end of the comparator S1 is connected to the end of the first resistor R1 close to the load 400, and the inverting input end of the comparator S1 is connected to the end of the first resistor R1 close to the first switch tube Q1; the output end of the comparator S1 is connected to the control end of the line switching module 200, and the output end of the comparator S1 is also connected to the power supply through the second resistor R2.

[0045] The first resistor R1 is connected in series to the circuit connecting the output end of the first switch tube Q1 and the load 400; therefore, the voltage on the circuit will produce a voltage drop when passing through the first resistor R1, and at the same time, the voltage across the first resistor R1 also changes based on the current direction on the circuit; specifically, when the current direction flows from the power supply module 300 to the load 400, the current flows from the end (first end) of the first resistor R1 close to the first switch tube Q1 to the end (second end) of the first resistor R1 close to the load 400. At this time, the voltage at the first end of the first resistor R1 is greater than the voltage at the second end; when the current flows from the power supply module 300 to the load 400, the current flows from the end (first end) of the first resistor R1 close to the first switch tube Q1 to the end (second end) of the first resistor R1 close to the load 400. When the current flows from the load 400 to the power supply module 300, the current flows from the second end of the first resistor R1 to the first end. At this time, the voltage at the second end of the first resistor R1 is greater than the voltage at the first end. It should be noted that since the first resistor R1 is connected in series with the output end of the first switch tube Q1 and a voltage drop is generated on the line connected to the load 400, in order to avoid the influence on the power supply as much as possible, the resistance value of the first resistor R1 can be set to be smaller, thereby reducing the voltage drop of the first resistor R1. The resistance value of the first resistor R1 can be set based on the actual circuit, such as 0.1Ohm.

[0046] Therefore, the magnitude of the voltage across the first resistor R1 can reflect the current direction in the circuit; and further, a comparator S1 is further provided in this embodiment; the two input terminals of the comparator S1 are respectively connected to the two terminals of the first resistor R1, and therefore, the output of the comparator S1 can indicate the magnitude of the voltage across the first resistor R1, that is, it can indicate the current direction in the circuit. Specifically, when the current direction flows from the power supply module 300 to the load 400, the voltage at the first terminal of the first resistor R1 is greater than the voltage at the second terminal, the voltage at the inverting input terminal of the comparator S1 is greater than the voltage at the same phase input terminal, and the comparator S1 outputs a low level; when the current direction flows from the load 400 to the power supply module 300, the voltage at the first terminal of the first resistor R1 is less than the voltage at the second terminal, the voltage at the inverting input terminal of the comparator S1 is less than the voltage at the same phase input terminal, and the comparator S1 outputs a high level; that is, when the comparator S1 outputs a low level, it indicates that the current direction is normal, and when the comparator S1 outputs a high level, it indicates that the current is reversed.

[0047] The second resistor R2 is a pull-up resistor, which is used to clamp the output of the comparator S1 at a high level when the comparator S1 does not output a low level.

[0048] Further, the line switching module 200 includes a signal determination unit 210 and a switching unit 220; the control end of the signal determination unit 210 is connected to the output end of the current direction detection module 100, the output end of the signal determination unit 210 is connected to the control end of the switching unit 220, the dynamic connection end of the switching unit 220 is connected to the gate of the first switch tube Q1, the first static connection end of the switching unit 220 is grounded, and the second static connection end of the switching unit 220 is connected to the source of the first switch tube Q1; wherein:

[0049] The signal determination unit 210 is used to receive the control signal sent by the current direction detection module 100, and output a switching signal corresponding to the control signal to the switching unit 220;

[0050] The switching unit 220 is used to connect the dynamic connection end with the first static connection end or the second static connection end according to the switching signal.

[0051] The signal determination unit 210 determines the state that the switching unit 220 needs to be set to according to the control signal sent by the current direction detection module 100; when the current direction detection module 100 detects that the current direction flows from the power supply module 300 to the load 400, the dynamic connection end of the switching unit 220 will be connected to the first static connection end to turn on the first switch tube Q1; and when the current direction detection module 100 detects that the current direction flows from the load 400 to the power supply module 300, the dynamic connection end of the switching unit 220 will be connected to the second static connection end to turn off the first switch tube Q1 to achieve backflow prevention.

[0052] Further, the signal determination unit 210 includes a second switch tube Q2, wherein:

[0053] The gate of the second switch tube Q2 is connected to the output end of the current direction detection module 100 , the source of the second switch tube Q2 is grounded, and the drain of the second switch tube Q2 is connected to the control end of the switching unit 220 .

[0054] In this embodiment, the second switch tube Q2 is an NMOS tube for example.

[0055] When the current direction detection module 100 outputs a high level, the gate of the second switch tube Q2 is at a high level, and the source of the second switch tube Q2 is grounded. Therefore, the gate-source voltage of the second switch tube Q2 meets the threshold voltage of the second switch tube Q2, and the second switch tube Q2 is turned on.

[0056] When the current direction detection module 100 outputs a low level, the gate of the second switch tube Q2 is at a low level and the source of the second switch tube Q2 is grounded. Therefore, the gate-source voltage of the second switch tube Q2 does not meet the threshold voltage of the second switch tube Q2 and the second switch tube Q2 is turned off.

[0057] It can be understood that when the second switch tube Q2 is turned on, the switching unit 220 can be grounded through the second switch tube Q2, and when the second switch tube Q2 is turned off, the switching unit 220 cannot be grounded through the second switch tube Q2. Therefore, the turning on and off of the second switch tube Q2 can output different signals to the switching unit 220 to adjust the connection state of the switching unit 220.

[0058] Furthermore, the switching unit 220 includes a relay K1 and a first voltage regulator tube Z1; wherein:

[0059] The first end of the coil of the relay K1 is connected to the power supply, the first end of the coil of the relay K1 is also connected to the negative electrode of the first voltage regulator tube Z1, the positive electrode of the first voltage regulator tube Z1 is connected to the second end of the coil of the relay K1, and the second end of the coil of the relay K1 is also connected to the output end of the signal determination unit 210;

[0060] The first contact of the relay K1 is connected to the gate of the first switch tube Q1, the second contact of the relay K1 is grounded, and the third contact of the relay K1 is connected to the source of the first switch tube Q1; wherein the first contact and the second contact constitute a normally closed contact, and the first contact and the third contact constitute a normally open contact.

[0061] When the second end of the coil of the relay K1 is grounded, the coil of the relay K1 is energized, the contacts of the relay K1 are actuated, the normally closed contacts are disconnected, and the normally open contacts are closed, that is, the first contacts and the third contacts are closed. At this time, the gate of the first switch tube Q1 is connected to the source of the first switch tube Q1 through the first contacts and the third contacts, and the first switch tube Q1 is turned off.

[0062] When the second end of the coil of relay K1 is not grounded, the coil of relay K1 is not energized, the contacts of relay K1 are restored, the normally closed contacts are closed, and the normally open contacts are disconnected, that is, the first contacts and the second contacts are closed. At this time, the gate of the first switch tube Q1 is grounded through the first contacts and the second contacts, and the first switch tube Q1 is turned on.

[0063] The first voltage regulator tube Z1 is used to protect the coil of the relay K1.

[0064] Furthermore, the power management circuit further includes an anti-reverse connection module 500, and the anti-reverse connection module 500 is connected between the gate and the source of the first switch tube Q1, wherein:

[0065] The anti-reverse connection module 500 is used to turn off the first switch tube Q1 when the power supply module 300 is reversely connected.

[0066] It can be understood that when normally connected, the voltage pin of the power supply module 300 outputs voltage to the load 400, and the ground pin is grounded; when reverse connection occurs, the voltage pin of the power supply module 300 is grounded, and the ground pin outputs voltage; in this case, it is easy to cause damage to the circuit and the load 400; therefore, in this embodiment, an anti-reverse connection module 500 is provided to control the first switch tube Q1 to turn off when the power supply module 300 is reversely connected, thereby avoiding the reverse connection from affecting the subsequent circuit.

[0067] Furthermore, the anti-reverse connection module 500 includes a second voltage regulator tube Z2, a first capacitor C1 and a third resistor R3; wherein:

[0068] The cathode of the second voltage regulator tube Z2 is connected to the source of the first switch tube Q1, the anode of the second voltage regulator tube Z2 is grounded through the third resistor R3, and the first capacitor C1 is connected in parallel with the second voltage regulator tube Z2;

[0069] The first static connection end of the circuit switching module 200 is grounded through the third resistor R3.

[0070] The second voltage regulator tube Z2 is connected in parallel with the first capacitor C1 to prevent breakdown between the gate and the source of the first switch tube Q1.

[0071] When the current direction is normal, the principle of the reverse connection protection module 500 is described as follows:

[0072] When the power supply module 300 is normally connected, the gate of the first switch tube Q1 is grounded through the line switching module 200 and the third resistor R3, and the voltage of the power supply module 300 reaches the source of the first switch tube Q1 through the body diode of the first switch tube Q1. The gate-source voltage of the first switch tube Q1 meets the threshold voltage, and the first switch tube Q1 is turned on;

[0073] When the power supply module 300 is reversely connected, the gate of the first switch tube Q1 is connected to the voltage pin of the power supply module 300 through the line switching module 200 and the third resistor R3. The gate-source voltage of the first switch tube Q1 does not meet the threshold voltage, and the first switch tube Q1 is turned off, realizing the reverse connection protection function.

[0074] It should be noted that when the power supply module 300 is reversely connected, the source of the second switch tube Q2 inputs the voltage of the power supply module 300. At this time, the coil of the relay K1 is also not energized and maintains the initial state, that is, the first contact and the second contact are closed.

[0075] It should be noted that the second contact of the relay K1 needs to be grounded. In practical applications, the second contact of the relay K1 can be grounded through the third resistor R3.

[0076] The overall principle of this application is explained below:

[0077] When the power supply module 300 is connected normally and the current flows from the power supply module 300 to the load 400:

[0078] The voltage at the first end of the first resistor R1 is greater than the voltage at the second end, the voltage at the inverting input end of the comparator S1 is greater than the voltage at the non-inverting input end, the comparator S1 outputs a low level, the gate-source voltage of the second switch tube Q2 does not meet the threshold voltage of the second switch tube Q2, and the second switch tube Q2 is turned off; the second end of the coil of the relay K1 is not grounded, the coil of the relay K1 is not energized, the contacts of the relay K1 are restored, the normally closed contacts are closed, and the normally open contacts are disconnected, that is, the first contacts are closed and the second contacts are closed. At this time, the gate of the first switch tube Q1 is grounded through the first contact and the second contact, and the first switch tube Q1 is turned on; the power supply module 300 normally supplies power to the load 400.

[0079] When the power supply module 300 is connected normally and the current flows from the load 400 to the power supply module 300:

[0080] The voltage at the first end of the first resistor R1 is less than the voltage at the second end, the voltage at the inverting input end of the comparator S1 is less than the voltage at the non-inverting input end, the comparator S1 outputs a high level, the gate-source voltage of the second switch tube Q2 meets the threshold voltage of the second switch tube Q2, and the second switch tube Q2 is turned on; the second end of the coil of the relay K1 is grounded, the coil of the relay K1 is energized, the contacts of the relay K1 are actuated, the normally closed contact is disconnected, and the normally open contact is closed, that is, the first contact and the third contact are closed. At this time, the gate of the first switch tube Q1 is connected to the source of the first switch tube Q1 through the first contact and the third contact, and the first switch tube Q1 is turned off, preventing current backflow.

[0081] When the power supply module 300 is reversely connected and the current flows from the power supply module 300 to the load 400:

[0082] The voltage at the first terminal of the first resistor R1 is greater than the voltage at the second terminal, the voltage at the inverting input terminal of the comparator S1 is greater than the voltage at the non-inverting input terminal, the comparator S1 outputs a low level, the second switch tube Q2 is turned off, the first contact and the second contact of the relay K1 are closed, the gate of the first switch tube Q1 is connected to the voltage pin of the power supply module 300 through the first contact, the second contact, and the third resistor R3, the positive voltage of the second voltage regulator tube Z2 is greater than the negative voltage, the gate voltage of the first switch tube Q1 is greater than the source voltage, and the first switch tube Q is turned off; the anti-reverse connection function is realized.

[0083] When the power supply module 300 is reversely connected and the current flows from the load 400 to the power supply module 300:

[0084] The voltage at the first terminal of the first resistor R1 is less than the voltage at the second terminal, the voltage at the inverting input terminal of the comparator S1 is less than the voltage at the non-inverting input terminal, the comparator S1 outputs a high level, the second switch tube Q2 is turned on, the first contact and the third contact of the relay K1 are closed, the gate of the first switch tube Q1 is connected to the source through the first contact and the third contact, the gate voltage of the first switch tube Q1 is equal to the source voltage, and the first switch tube Q1 is turned off; the anti-reverse connection function is realized.

[0085] The present invention also protects a power supply, which includes a power supply module 300 and a power management circuit. The structure of the power management circuit can refer to the above embodiment and will not be described in detail here. As a matter of course, since the power supply of this embodiment adopts the technical solution of the above power management circuit, the power supply has all the beneficial effects of the above power management circuit.

[0086] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a..." does not exclude the presence of other identical elements in the process, method, article or system including the element. The serial numbers of the above-mentioned embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments.

[0087] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A power management circuit, characterized in that: The power management circuit is connected to the power supply module and the load, and includes a first switch tube, a current direction detection module and a line switching module; the drain of the first switch tube is connected to the power supply module as the positive electrode of the power management circuit, and the source of the first switch tube is connected to the load; the detection end of the current direction detection module is arranged on the line connected to the output end of the first switch tube and the load; the output end of the current direction detection module is connected to the control end of the line switching module, the dynamic connection end of the line switching module is connected to the gate of the first switch tube, the first static connection end of the line switching module is grounded, and the second static connection end of the line switching module is connected to the source of the first switch tube; wherein: The current direction detection module is used to detect the current direction on the line to obtain a detection result, and send a control signal corresponding to the detection result to the line switching module; The line switching module is used to receive the control signal sent by the current direction detection module, and connect the dynamic connection end with the first static connection end or the second static connection end according to the control signal.

2. The power management circuit according to claim 1, characterized in that: The current direction detection module includes a first resistor, a second resistor and a comparator; wherein: The first resistor is connected in series on the line connecting the output end of the first switching tube and the load, the non-inverting input end of the comparator is connected to the end of the first resistor close to the load, and the inverting input end of the comparator is connected to the end of the first resistor close to the first switching tube; the output end of the comparator is connected to the control end of the circuit switching module, and the output end of the comparator is also connected to the power supply through the second resistor.

3. The power management circuit according to claim 1, wherein: The line switching module includes a signal determination unit and a switching unit; the control end of the signal determination unit is connected to the output end of the current direction detection module, the output end of the signal determination unit is connected to the control end of the switching unit, the dynamic connection end of the switching unit is connected to the gate of the first switch tube, the first static connection end of the switching unit is grounded, and the second static connection end of the switching unit is connected to the source of the first switch tube; wherein: The signal determination unit is used to receive the control signal sent by the current direction detection module, and output a switching signal corresponding to the control signal to the switching unit; The switching unit is used to connect the dynamic connection end with the first static connection end or the second static connection end according to the switching signal.

4. The power management circuit according to claim 3, characterized in that: The signal determination unit includes a second switch tube, wherein: The gate of the second switch tube is connected to the output end of the current direction detection module, the source of the second switch tube is grounded, and the drain of the second switch tube is connected to the control end of the switching unit.

5. The power management circuit according to claim 4, characterized in that: The second switch tube is an NMOS tube.

6. The power management circuit according to claim 3, characterized in that: The switching unit includes a relay and a first voltage regulator tube; wherein: The first end of the coil of the relay is connected to the power supply, the first end of the coil of the relay is also connected to the negative electrode of the first voltage regulator tube, the positive electrode of the first voltage regulator tube is connected to the second end of the coil of the relay, and the second end of the coil of the relay is also connected to the output end of the signal determination unit; The first contact of the relay is connected to the gate of the first switch tube, the second contact of the relay is grounded, and the third contact of the relay is connected to the source of the first switch tube; wherein the first contact and the second contact constitute a normally closed contact, and the first contact and the third contact constitute a normally open contact.

7. The power management circuit according to claim 1, wherein: The power management circuit further includes an anti-reverse connection module, which is connected between the gate and the source of the first switch tube, wherein: The anti-reverse connection module is used to turn off the first switch tube when the power supply module is reversely connected.

8. The power management circuit according to claim 7, characterized in that: The anti-reverse connection module includes a second voltage regulator tube, a first capacitor and a third resistor; wherein: The cathode of the second voltage regulator tube is connected to the source of the first switch tube, the anode of the second voltage regulator tube is grounded through the third resistor, and the first capacitor is connected in parallel with the second voltage regulator tube; The first static connection end of the circuit switching module is grounded through the third resistor.

9. The power management circuit according to any one of claims 1 to 8, characterized in that: The first switch tube is a PMOS tube.

10. A power supply, characterized in that: The power supply comprises a power supply module and a power management circuit according to any one of claims 1 to 9.

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