A charging control circuit and an electronic device

Abstract

The present invention discloses a charging control circuit and an electronic device. The charging control circuit includes: a first switch, a second switch, a first load, and a control module. With such a setting, when the control module detects that the remaining power of the battery to be charged is lower than the first threshold, the first control signal output is at a high level, causing the first switch and the second switch to conduct, and the power supply to charge the battery to be charged; when the control module detects that the remaining power of the battery to be charged is higher than the second threshold, the first control signal output is at a low level, causing the first switch and the second switch to cut off, and the power supply to stop charging the battery to be charged.

Description

Technical Field

[0001] The present invention relates to the field of electronic circuits, and particularly to a charging control circuit and an electronic device. Background Art

[0002] With the popularization of electronic products, the demand for their own power by electronic products is relatively high, so that conventional electronic products usually set up charge and discharge batteries. In order to ensure the normal operation of the charge and discharge batteries, it is necessary to additionally manage the charge and discharge batteries. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the problem that in the prior art, in order to ensure the normal operation of the charge and discharge batteries, it is necessary to additionally manage the charge and discharge batteries, so as to provide a charging control circuit and an electronic device.

[0004] To achieve the above object, an embodiment of the present invention provides a charging control circuit, which includes: a first switch, a first end of the first switch is connected to a control end of a second switch, and a second end of the first switch is used to connect to a negative electrode of a battery to be charged; the second switch, a first end of the second switch is used to connect to a first power supply end of a power supply, and a second end of the second switch is used to connect to a positive electrode of the battery to be charged; a first load, a first end of the first load is connected to the first end of the first switch and the control end of the second switch, and a second end of the first load is connected to the first end of the second switch; a control module, configured to turn on the first switch when detecting that the power of the battery to be charged is lower than a first threshold, and turn off the first switch when detecting that the power of the battery to be charged is higher than a second threshold.

[0005] Optionally, the charging control circuit further includes: a third switch, a first end of the third switch is used to connect to the first power supply end of the power supply through a first diode, a second end of the third switch is connected to a power supply end of the control module, and the power supply end of the control module is used to connect to the first power supply end of the power supply; a second load, one end is connected to the first end of the third switch, and the other end is connected to a control end of the third switch; a fourth switch, a first end is connected to the control end of the third switch, and a second end is grounded; the fourth switch is configured to be turned on when closed to supply power to the control module; a fifth switch, a first end of the fifth switch is connected to the control end of the third switch; a second end of the fifth switch is used to connect to the negative electrode of the battery to be charged, and the fifth switch is turned on when the control module is powered on and the control module outputs a driving signal.

[0006] Optionally, a control end of the fifth switch is further used to connect to a second power supply end of the power supply.

[0007] Optionally, the charging control circuit further includes: a second diode, the cathode of the second diode is connected to the first end of the third switch, and the anode of the second diode is used to connect to the anode of the battery to be charged; the second diode is used to supply power to the control module by the battery to be charged when there is no first power supply terminal of the power supply and the fourth switch is closed.

[0008] Optionally, the charging control circuit further includes: a first voltage stabilizing module, one end of which is connected to the control end of the second switch, and the other end is connected to the first end of the second switch.

[0009] Optionally, the charging control circuit further includes: a second voltage stabilizing module, one end of which is connected to the control end of the third switch, and the other end is connected to the first end of the third switch.

[0010] Optionally, the charging control circuit further includes: a third diode, the anode of the third diode is connected to the second end of the second switch, and the cathode of the third diode is connected to the positive electrode of the battery to be charged.

[0011] Optionally, it further includes: a sampling module, the input end of the sampling module is adapted to be connected to the first power supply terminal of the power supply, and the output end of the sampling module is adapted to be connected to the control module.

[0012] Optionally, it further includes: a voltage dividing module, one end of the voltage dividing module is connected to the control module, and the other end of the voltage dividing module is connected to the battery to be charged.

[0013] An embodiment of the present invention further provides an electronic device, which includes: the charging control circuit as described in any one of the above embodiments.

[0014] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0015] 1. An embodiment of the present invention provides a charging control circuit, which includes: a first switch, the first end of the first switch is connected to the control end of the second switch, and the second end of the first switch is used to connect to the negative electrode of the battery to be charged; the second switch, the first end of the second switch is used to connect to the first power supply terminal of the power supply, and the second end of the second switch is used to connect to the positive electrode of the battery to be charged; the first load, the first end of the first load is connected to the first end of the first switch and the control end of the second switch, and the second end of the first load is connected to the first end of the second switch; a control module, the power supply terminal of the control module is used to connect to the first power supply terminal of the power supply; the control module is used to turn on the first switch when detecting that the power of the battery to be charged is lower than the first threshold, and turn off the first switch when detecting that the power of the battery to be charged is higher than the second threshold.

[0016] With such a setting, when the control module detects that the remaining power of the battery to be charged is lower than the first threshold, the first control signal output is at a high level, causing the first switch and the second switch to conduct, and the first power supply terminal of the power supply to charge the battery to be charged; when the control module detects that the remaining power of the battery to be charged is higher than the second threshold, the first control signal output is at a low level, causing the first switch and the second switch to cut off, and the first power supply terminal of the power supply to stop charging the battery to be charged.

[0017] 2. In the embodiment of the present invention, by setting the third switch, the fifth switch, the second load, and the fourth switch, when the first power supply terminal connected to the power supply is connected and the battery to be charged has no power, the fourth switch is closed. After the control module is powered on, the fifth switch is controlled to conduct, so that the third switch conducts, and thus the control module can be powered by the power supply.

[0018] 3. In the embodiment of the present invention, by using the control terminal of the fifth switch to connect to the second power supply terminal of the power supply, if the power of the battery to be charged is relatively low, it may not be able to meet the voltage required for the control module to start, and at this time the control module may not be able to work. When the second power supply terminal of the power supply is connected to the circuit, the second power supply terminal of the power supply can directly supply power to the control module and charge the battery to be charged. In this way, it can be ensured that even if the fourth switch is not closed at this time, the circuit system can still work normally.

[0019] 4. In the embodiment of the present invention, by setting the second diode, when the battery to be charged has power and the first power supply terminal of the power supply is not connected, the fourth switch is closed. After the control module is powered on, the fifth switch is controlled to conduct, so that the third switch conducts, and thus the control module can be powered by the battery to be charged. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a modular circuit diagram of an embodiment of the present invention;

[0022] Figure 2 It is a circuit diagram of all modules of an embodiment of the present invention;

[0023] Figure 3 It is a circuit diagram of the whole of an embodiment of the present invention.

[0024] Reference Numerals:

[0025] The first switch 10; the second switch 20; the third switch 30; the fourth switch 40; the fifth switch 50; the sampling module 60; the voltage dividing module 70; the first voltage stabilizing module 80; the second voltage stabilizing module 90;

[0026] The first resistor R1; the second resistor R2; the third resistor R3; the fourth resistor R4; the first load R5; the sixth resistor R6; the seventh resistor R7; the eighth resistor R8; the ninth resistor R9; the tenth resistor R10; the eleventh resistor R11; the twelfth resistor R12; the second load R13; the fourteenth resistor R14;

[0027] The first capacitor C1; the second capacitor C2; the third capacitor C3; the fourth capacitor C4; the electrolytic capacitor C12;

[0028] The first diode D1; the second diode D2; the third diode D3; the fourth diode D4;

[0029] The first MOS transistor Q2; the first triode Q3; the second MOS transistor Q1; the second triode Q4;

[0030] The first voltage stabilizing diode ZD1; the second voltage stabilizing diode ZD2;

[0031] The first power supply terminal VIN1; the second power supply terminal VIN2; the push-button switch S3; the battery to be charged BT1;

[0032] The BC terminal; the AVL terminal; the BVL terminal; the VCC terminal; the DC terminal. Specific embodiments

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two components. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Embodiment 1

[0038] As Figure 1 shown, the embodiment of the present invention provides a charging control circuit, which includes a first switch 10, a second switch 20, a first load R5, and a control module. The control module includes a BC terminal, an AVL terminal, a BVL terminal, a VCC terminal, and a DC terminal. The BC terminal is used to output a control signal to the first switch 10. The BVL terminal is used to detect the voltage of the battery BT1 to be charged. The DC terminal is used to output a control signal to the fifth switch 50. The power supply terminal VCC is used to connect to the first power supply terminal VIN1 of the power supply to supply power to the control module and the load of the electronic device. The AVL terminal is used to detect the voltage of the first power supply terminal VIN1 of the power supply.

[0039] The control end of the first switch 10 is connected to the control module. The first end of the first switch 10 is connected to the control end of the second switch 20. The second end of the first switch 10 is used to connect to the negative electrode of the battery BT1 to be charged. The first end of the second switch 20 is used to connect to the first power supply terminal VIN1 of the power supply. The second end of the second switch 20 is used to connect to the positive electrode of the battery BT1 to be charged. The first end of the first load R5 is connected to the first end of the first switch 10 and the control end of the second switch 20. The second end of the first load R5 is connected to the first end of the second switch 20.

[0040] After connecting the first power supply terminal VIN1 of the power supply and the battery BT1 to be charged, if the BVL terminal of the control module detects that the power of the battery BT1 to be charged is lower than the first threshold, it indicates that the power of the battery BT1 to be charged is low and needs to be charged. Therefore, the BC terminal of the control module outputs a high level, causing the first switch 10 to conduct. The current flows through the first power supply terminal VIN1 of the power supply, the first load R5, and the first switch 10, causing the second switch 20 to conduct. Thus, the first power supply terminal VIN1 of the power supply can supply power to the battery BT1 to be charged. When the BVL terminal of the control module detects that the power of the battery BT1 to be charged is higher than the second threshold, it outputs a low level, the first switch 10 disconnects, and the second switch 20 disconnects. Thus, the first power supply terminal VIN1 of the power supply stops supplying power to the battery BT1 to be charged. It should be noted here that the first threshold is less than the second threshold.

[0041] Of course, for the magnitudes of the first threshold and the second threshold, the first threshold can be 5%, and the second threshold can be 99%. Those skilled in the art can change them according to the actual situation. This technical solution is only an example and is not limited. As long as it can achieve the same technical effect.

[0042] Embodiment 2

[0043] As Figure 1 shown, in the embodiment of the present invention, the charging control circuit further includes a third switch 30, a fifth switch 50, a second load R13, and a fourth switch 40. The power supply terminal VCC of the control module is used to connect to the first power supply terminal VIN1 of the power supply. That is, the control module requires the first power supply terminal VIN1 of the power supply to provide a driving voltage.

[0044] As Figure 1 shown, the first end of the third switch 30 is used to connect to the first power supply terminal VIN1 of the power supply through the first diode D1, and the second end of the third switch 30 is connected to the power supply terminal VCC of the control module. The control end of the fifth switch 50 is connected to the DC end of the control module, and the first end of the fifth switch 50 is connected to the control end of the third switch 30; the second end of the fifth switch 50 is used to connect to the negative electrode of the battery BT1 to be charged. One end of the second load R13 is connected to the first end of the third switch 30, and the other end is connected to the control end of the third switch 30. The first end of the fourth switch 40 is connected to the control end of the third switch 30, and the second end is grounded.

[0045] Specifically, when the rechargeable battery BT1 needs to be charged, first close the fourth switch 40. At this time, since the current flows through the first power supply terminal VIN1 of the power supply, the second load R13, and the fourth switch 40, there is a voltage difference across the second load R13, so that the third switch 30 conducts, and the first power supply terminal VIN1 of the power supply can supply power to the control module. After the control module gets power, the control module detects the power of the rechargeable battery BT1 to be charged. If it is detected that the power of the rechargeable battery BT1 to be charged is lower than the first threshold, it means that the power of the rechargeable battery BT1 to be charged is low and needs to be charged. Thus, the control module outputs a high level, causing the first switch 10 to conduct. The current flows through the first power supply terminal VIN1 of the power supply, the first load R5, and the first switch 10, and the second switch 20 conducts, so that the first power supply terminal VIN1 of the power supply can supply power to the rechargeable battery BT1. When the control module detects that the power of the rechargeable battery BT1 to be charged is higher than the second threshold, it outputs a low level, the first switch 10 is turned off, and the second switch 20 is turned off, so that the first power supply terminal VIN1 of the power supply stops supplying power to the rechargeable battery BT1.

[0046] In the embodiment of the present invention, the control end of the fifth switch is also used to connect to the second power supply terminal VIN2 of the power supply. When the first power supply terminal VIN1 and the second power supply terminal VIN2 of the power supply are not connected to the circuit and the power of the rechargeable battery is low, the entire system is powered by the rechargeable battery BT1.

[0047] However, if the power of the rechargeable battery is low, it may not be able to meet the voltage required for the control module to start, and at this time the control module may not work. When the first power supply terminal VIN1 and the second power supply terminal VIN2 of the power supply are connected to the circuit at the same time, the power supply can directly supply power to the control module and charge the rechargeable battery BT1 through the first power supply terminal VIN1 and the second power supply terminal VIN2. In this way, it can be ensured that even if the fourth switch 40 is not closed at this time, the circuit system can still work normally.

[0048] The charging control circuit further includes a second diode D2. The cathode of the second diode D2 is connected to the first end of the third switch 30, and the anode of the second diode D2 is used to connect to the anode of the rechargeable battery BT1.

[0049] Specifically, when the battery BT1 to be charged is fully charged or the battery level is higher than the first threshold, and the first power supply terminal VIN1 and the second power supply terminal VIN2 of the power supply are not connected to the circuit, if it is necessary for the battery BT1 to be charged to supply power to the control module and other loads of the electronic device, the fourth switch 40 needs to be closed. At this time, the battery BT1 to be charged will supply power to the control module and other loads of the electronic device. Similarly, when the fourth switch 40 is the key switch S3, the key switch S3 needs to be pressed, and the key switch S3 is closed. As a result, the third switch 30 is turned on, and the battery BT1 to be charged can supply power to the control module. After the control module gets power, it outputs a high level to the fifth switch 50, making the fifth switch 50 turned on, so as to maintain the conduction of the third switch 30.

[0050] Embodiment 3

[0051] As Figure 2 shown, in the embodiment of the present invention, the charging control circuit further includes a sampling module 60, a voltage dividing module 70, a first voltage stabilizing module 80 and a second voltage stabilizing module 90.

[0052] In the embodiment of the present invention, one end of the first voltage stabilizing module 80 is connected to the control end of the second switch 20, and the other end is connected to the first end of the second switch 20. One end of the second voltage stabilizing module 90 is connected to the control end of the third switch, and the other end is connected to the first end of the third switch.

[0053] The input end of the sampling module 60 is adapted to be connected to the first power supply terminal VIN1 of the power supply, and the output end of the sampling module 60 is adapted to be connected to the AVL end of the control module. One end of the voltage dividing module 70 is connected to the BVL end of the control module, and the other end of the voltage dividing module 70 is connected to the battery BT1 to be charged.

[0054] Embodiment 4

[0055] As Figure 3 shown, in the embodiment of the present invention, the first switch 10 includes an eighth resistor R8, a seventh resistor R7 and a first triode Q3, and the second switch 20 is a first MOS transistor Q2. The third switch 30 can be a second MOS transistor Q1, and the fifth switch 50 can include a second triode Q4, a fifteenth resistor R15, a sixteenth resistor R16 and a seventeenth resistor R17. The sampling module 60 includes a first resistor R1, a second resistor R2, a third resistor R3 and a second capacitor C2. The voltage dividing module 70 includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and a third capacitor C3. The first voltage stabilizing module 80 is a first voltage stabilizing diode ZD1, and the second voltage stabilizing module 90 can be a second voltage stabilizing diode ZD2.

[0056] Specifically, the control terminal of the first triode Q3 is connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is connected to the BC terminal of the control module; the first end of the first triode Q3 is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the control terminal of the first MOS transistor Q2. The second end of the first triode Q3 is used to connect to the negative electrode of the battery BT1 to be charged. In the embodiment of the present invention, the second end of the first triode Q3 and the negative electrode of the battery BT1 to be charged are both grounded.

[0057] Then, as Figure 3 shown, the first end of the first MOS transistor Q2 is connected in series with the ninth resistor R9 and the fourth resistor R4 in sequence. The other end of the fourth resistor R4 is used to connect to the first power supply terminal VIN1 of the power supply. The second end of the first MOS transistor Q2 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is used to connect to the positive electrode of the battery BT1 to be charged.

[0058] As Figure 3 shown, specifically, the control terminal of the second MOS transistor Q1 is connected to one end of the fourteenth resistor R14, the other end of the fourteenth resistor R14 is connected to the anode of the fourth diode D4, the cathode of the fourth diode is connected to one end of the fourth switch 40, and the other end of the fourth switch 40 is grounded. The fourth switch 40 can be a push-button switch S3, which is closed when pressed and opened when released. The first end of the second MOS transistor Q1 is used to connect to the first power supply terminal VIN1 of the power supply and the battery BT1 to be charged, and the second end of the second MOS transistor Q1 is connected to the power supply terminal VCC of the control module.

[0059] As Figure 3 shown, the control terminal of the second triode Q4 is connected to the fifteenth resistor R15, the sixteenth resistor R16, and the seventeenth resistor R17 at the same time. The other end of the sixteenth resistor R16 is connected to the control module. The other end of the fifteenth resistor R15 is used to connect to the second power supply terminal VIN2 of the power supply, and the other end of the seventeenth resistor is grounded. The first end of the second triode Q4 is connected to the anode of the fourth diode D4, and the second end of the second triode Q4 is used to connect to the negative electrode of the battery BT1 to be charged. In the embodiment of the present invention, the second end of the second triode Q4 is grounded.

[0060] In the embodiment of the present invention, by connecting the control terminal of the second triode Q4 in series with the fifteenth resistor R15 and the second power supply terminal VIN2 of the power supply in sequence, with the input of the second power supply terminal VIN2 of the power supply, it is possible to supply power to the control module and the load without controlling through the push-button switch S3, which can directly ensure the normal operation of the system.

[0061] In an embodiment of the present invention, the cathode of the first zener diode ZD1 is connected to the first end of the first MOS transistor Q2, and the anode is connected to the control end of the first MOS transistor Q2. The cathode of the second zener diode ZD2 is connected to the first end of the second MOS transistor Q1, and the anode is connected to the control end of the second MOS transistor Q1.

[0062] In the charging control circuit, the jumper J is adapted to connect the source and drain of the second MOS transistor Q1. When the jumper is connected between the source and drain of the second MOS transistor Q1, the first power supply terminal VIN1 of the power supply and the battery BT1 to be charged can be directly connected to the power supply terminal VCC of the control module.

[0063] Moreover, in the charging control circuit, an electrolytic capacitor C12 and a first capacitor C1 are further included. One end of the electrolytic capacitor C12 is used to connect to the first power supply terminal VIN1 of the power supply, and the other end is grounded. One end of the first capacitor C1 is used to connect to the first power supply terminal VIN1 of the power supply, and the other end is grounded.

[0064] As Figure 3 shown, one end of the first resistor R1 is used to connect to the first power supply terminal VIN1 of the power supply, and the other end is connected to the third resistor R3. The other end of the third resistor R3 is grounded. The AVL terminal of the control module is connected with a second resistor R2, and the other end of the second resistor R2 is connected between the first resistor R1 and the third resistor R3. One end of the second capacitor C2 is connected to the AVL terminal of the control module, and the other end of the second capacitor C2 is grounded.

[0065] One end of the eleventh resistor R11 is connected to the positive electrode of the battery BT1 to be charged, and the other end is connected to the twelfth resistor R12. The other end of the twelfth resistor R12 is connected to the negative electrode of the battery BT1 to be charged. The negative electrode of the battery BT1 to be charged is grounded. One end of the tenth resistor R10 is connected to the BVL terminal of the control module, and the other end is connected between the eleventh resistor R11 and the twelfth resistor R12. One end of the third capacitor C3 is connected to the BVL terminal of the control module, and the other end of the third capacitor C3 is grounded.

[0066] As Figure 3 shown, the charging control circuit further includes a fourth resistor R4 and a ninth resistor R9. One end of the fourth resistor R4 is used to connect to the first power supply terminal VIN1 of the power supply, and the other end is connected with the ninth resistor R9. The other end of the ninth resistor R9 is connected to the first end of the first MOS transistor Q2.

[0067] As Figure 3 shown, the specific working process of the embodiment of the present invention is as follows:

[0068] The first power supply terminal VIN1 of the power supply and the battery BT1 to be charged supply power to the power supply terminal VCC of the control module through the second MOS transistor Q1, and the load also needs to be powered through the power supply terminal VCC.

[0069] 1. When the first power supply terminal VIN1 and the second power supply terminal VIN2 of the power supply are input.

[0070] Since the second power supply terminal VIN2 of the power supply is input, current flows from the first power supply terminal VIN1 of the power supply through the fifteenth resistor R15 and the seventeenth resistor R17 to ground in sequence. Therefore, a high level is input to the base of the second triode Q4, causing the second triode Q4 to conduct. In this way, current flows from the first power supply terminal VIN1 of the power supply through the first diode D1, the second load R13, the fourteenth resistor R14, and the second triode Q4 to ground, so there is a voltage drop between the gate and source of the second MOS transistor Q1, enabling the second MOS transistor Q1 to continuously conduct. The first power supply terminal VIN1 of the power supply can continuously supply power to the control module and the load.

[0071] After the control module is powered on, it detects the power of the battery BT1 to be charged through the BVL terminal. When it detects that the power of the battery BT1 to be charged is lower than the first threshold, it indicates that the power of the battery BT1 to be charged is low and needs to be charged. Thus, the BC terminal of the control module outputs a high level, causing the first triode Q3 to conduct. Current flows from the first power supply terminal VIN1 of the power supply through the fourth resistor R4, the ninth resistor R9, the first load R5, the sixth resistor R6, and the first triode Q3 to ground, resulting in a voltage drop between the gate and source of the first MOS transistor Q2, enabling the first MOS transistor Q2 to conduct. In this way, current flows from the first power supply terminal VIN1 of the power supply through the fourth resistor R4, the ninth resistor R9, the first MOS transistor Q2, the third diode D3, and the battery BT1 to be charged to ground, so that the first power supply terminal VIN1 of the power supply can charge the battery BT1 to be charged. When it is detected through the BVL terminal that the power of the battery BT1 to be charged is higher than the second threshold, the BC terminal of the control module outputs a low level, the first triode Q3 is turned off, and the first MOS transistor Q2 is turned off, so that the first power supply terminal VIN1 of the power supply stops supplying power to the battery BT1 to be charged. Due to the presence of the second diode D2, the electric energy of the battery BT1 to be charged will not flow to the control module and the load, enabling the battery BT1 to be charged to enter the low-power mode, which can greatly extend the usage time.

[0072] 2. When there is no input from the first power supply terminal VIN1 and the second power supply terminal VIN2 of the power supply.

[0073] Since the control module is not powered on, the control terminal of the second triode Q4 does not receive a high-level input, so the second triode Q4 is cut off and the second MOS transistor Q1 is cut off. At this time, if you want to supply power to the load and the control module through the battery BT1 to be charged, just press the key switch S3, and then the current flows through the battery BT1 to be charged to the second diode D2, the second load R13, the fourteenth resistor R14, the fourth diode D4, and the key switch S3 to the ground in sequence. Therefore, there is a voltage across the second load R13, the second MOS transistor Q1 is turned on, and the battery BT1 to be charged is turned on to the power supply terminal VCC of the control module, so that the battery BT1 to be charged can supply power to the control module and the load.

[0074] After the control module is powered on, it outputs a high level through the DC terminal, causing the second triode Q4 to conduct. In this way, the current flows through the battery BT1 to be charged to the second diode D2, the second load R13, the fourteenth resistor R14, and the second triode Q4 to the ground to form a loop. Therefore, the second MOS transistor Q1 can continue to conduct, and the battery BT1 to be charged can continuously supply power to the control module and the load. When the key switch S3 rebounds, the second MOS transistor Q1 will not be cut off.

[0075] Embodiment 5

[0076] The embodiment of the present invention also provides an electronic device, which includes: a charging control circuit as described in any one of the above embodiments.

[0077] The electronic device can be a small-power household appliance such as a fan or a humidifier.

[0078] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A charging control circuit, characterized in that, comprising: A first switch (10), a first end of the first switch (10) is connected to a control end of a second switch (20), and a second end of the first switch (10) is used to connect to a negative electrode of a battery to be charged (BT1); The second switch (20), a first end of the second switch (20) is used to connect to a first power supply terminal (VIN1) of a power supply, and a second end of the second switch (20) is used to connect to a positive electrode of the battery to be charged (BT1); A first load (R5), a first end of the first load (R5) is connected to the first end of the first switch (10) and the control end of the second switch (20), and a second end of the first load (R5) is connected to the first end of the second switch (20); A control module, configured to turn on the first switch (10) when detecting that the power of the battery to be charged (BT1) is lower than a first threshold, and turn off the first switch (10) when detecting that the power of the battery to be charged (BT1) is higher than a second threshold; A third switch (30), a first end of the third switch (30) is used to connect to the first power supply terminal (VIN1) of the power supply through a first diode, a second end of the third switch (30) is connected to a power supply terminal (VCC) of the control module, and the power supply terminal (VCC) of the control module is used to connect to the first power supply terminal (VIN1) of the power supply; A second load (R13), one end is connected to the first end of the third switch (30), and the other end is connected to the control end of the third switch (30); A fourth switch (40), a first end is connected to the control end of the third switch (30), and a second end is grounded; the fourth switch (40) is configured to conduct when closed to supply power to the control module; A fifth switch (50), a first end of the fifth switch (50) is connected to the control end of the third switch (30); a second end of the fifth switch (50) is used to connect to the negative electrode of the battery to be charged (BT1), and the fifth switch (50) conducts when the control module is powered on and the control module outputs a driving signal.

2. The charging control circuit according to claim 1, characterized in that, A control end of the fifth switch (50) is further used to connect to a second power supply terminal (VIN2) of the power supply.

3. The charging control circuit according to claim 1 or 2, characterized in that, further comprising: A second diode (D2), a cathode of the second diode (D2) is connected to the first end of the third switch (30), and an anode of the second diode (D2) is used to connect to an anode of the battery to be charged (BT1); the second diode (D2) is configured to supply power to the control module by the battery to be charged (BT1) when the first power supply terminal (VIN1) of the power supply is not connected and the fourth switch (40) is closed.

4. The charging control circuit according to claim 1 or 2, characterized in that, further comprising: The first voltage stabilizing module (80), one end of which is connected to the control end of the second switch (20), and the other end of which is connected to the first end of the second switch (20).

5. The charging control circuit according to claim 4, characterized in that, further comprising: A second voltage stabilizing module (90), one end of which is connected to the control end of the third switch (30), and the other end of which is connected to the first end of the third switch (30).

6. The charging control circuit according to claim 1 or 2, characterized in that, further comprising: A third diode (D3), the anode of the third diode (D3) is connected to the second end of the second switch (20), and the cathode of the third diode (D3) is connected to the positive electrode of the battery to be charged (BT1).

7. The charging control circuit according to claim 1 or 2, characterized in that, further comprising: A sampling module (60), the input end of the sampling module (60) is adapted to be connected to the first power supply terminal (VIN1) of the power supply, and the output end of the sampling module (60) is adapted to be connected to the control module.

8. The charging control circuit according to claim 1 or 2, characterized in that, further comprising: A voltage dividing module (70), one end of the voltage dividing module (70) is connected to the control module, and the other end of the voltage dividing module (70) is connected to the battery to be charged (BT1).

9. An electronic device, characterized in that, comprising: The charging control circuit according to any one of claims 1-8.

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