Charging mode control circuit and charger

Abstract

The utility model relates to the technical field of chargers, in particular to a charging mode control circuit and a charger. In the charging mode control circuit, a voltage detection chip is electrically connected with a power management chip; the voltage detection chip is used for enabling the power management chip to enter a constant-current charging mode when detecting that the charging voltage is lower than the saturation voltage; the voltage detection chip is used for switching the power management chip to a constant-voltage charging mode when the charging voltage is detected to be higher than saturation voltage; the current detection module is electrically connected with the power management chip through the first switch element; the current detection module is used for triggering the first switch element to be switched on when it is detected that the charging current is smaller than a current threshold value, so that the power management chip is switched to a trickle charging mode. The charging mode control circuit and the charger provided by the utility model have the advantages of high charging efficiency and safety, quicker charging and capability of reaching the saturation capacity of the battery.

Description

Technical Field

[0001] This utility model relates to the field of charger technology, and more specifically, to a charging mode control circuit and a charger. Background Technology

[0002] Most current lithium battery chargers for rehabilitation medical products still use constant voltage charging throughout the entire charging process. With constant voltage charging, the battery voltage remains constant while the charging current gradually decreases. The battery is considered fully charged when the charging current reaches a certain value. Constant voltage charging has disadvantages such as slow charging speed and inaccurate full capacity readings, which can shorten battery life. Utility Model Content

[0003] The purpose of this invention is to provide a charging mode control circuit and a charger to alleviate the technical problems of slow charging and inaccurate full capacity in existing chargers.

[0004] The charging mode control circuit provided by this utility model includes a voltage detection chip, a current detection module, and a first switching element.

[0005] The first power port and the second power port of the voltage detection chip are respectively connected to the positive line and the negative line of the charging line to detect the charging voltage; the two input terminals of the current detection module are connected in series to the positive line of the charging line to detect the charging current.

[0006] The first output terminal of the voltage detection chip is electrically connected to the first port of the power management chip; the voltage detection chip is used to send a first voltage signal to the power management chip when it detects that the charging voltage is lower than the saturation voltage, so that the power management chip enters the constant current charging mode.

[0007] The second output terminal of the voltage detection chip is electrically connected to the second port of the power management chip; the voltage detection chip is used to send a second voltage signal to the power management chip when it detects that the charging voltage has reached or exceeded the saturation voltage, so that the power management chip switches to constant voltage charging mode.

[0008] The current detection module is electrically connected to the first port of the power management chip through the first switching element; the current detection module is used to trigger the first switching element to conduct when the charging current is detected to be less than the current threshold, so as to send a third voltage signal to the power management chip, so as to switch the power management chip to trickle charging mode.

[0009] Preferably, as one possible implementation, the current detection module includes an operational amplifier and a detection resistor, the detection resistor is connected in series with the positive line of the charging circuit, and the two input terminals of the operational amplifier are respectively connected to the two ends of the detection resistor, and the output terminal of the operational amplifier is electrically connected to the control terminal of the first switching element.

[0010] The first terminal of the first switching element is electrically connected to the first port of the power management chip and the external power supply, and the second terminal of the first switching element is grounded.

[0011] The output of the operational amplifier is used to output a high level when the charging current is detected to be less than the current threshold, so as to trigger the first switching element to turn on.

[0012] Preferably, as one possible implementation, the charging mode control circuit further includes: a second switching element, a first diode, and a choke resistor.

[0013] The first output terminal of the voltage detection chip is electrically connected to one end of the choke resistor, the other end of the choke resistor is electrically connected to the control terminal of the second switching element, the first terminal of the second switching element is electrically connected to an external power supply, and the second terminal of the second switching element is grounded.

[0014] The positive terminal of the first diode is electrically connected to the first output terminal of the voltage detection chip, and the negative terminal of the first diode is electrically connected to the first terminal of the first switching element.

[0015] The voltage detection chip is used to output a high level through the first output terminal when it detects that the charging voltage is lower than the saturation voltage, so as to turn on the second switching element and send the first voltage signal to the power management chip.

[0016] Preferably, as one possible implementation, the charging mode control circuit further includes: a first voltage divider resistor, a second voltage divider resistor, and a third voltage divider resistor.

[0017] One end of the first voltage divider resistor is electrically connected to the first port of the power management chip, and the other end is electrically connected to an external power supply; one end of the second voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is grounded; one end of the third voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is electrically connected to the first terminal of the first switching element.

[0018] Preferably, as one possible implementation, the charging mode control circuit further includes a fourth voltage divider resistor; one end of the fourth voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is electrically connected to the first end of the second switching element.

[0019] Preferably, as one possible implementation, the charging mode control circuit further includes an indicator element; one end of the indicator element is electrically connected to the first end of the first switching element, and the other end is electrically connected to an external power supply.

[0020] Preferably, as one possible implementation, the charging mode control circuit further includes a cooling fan; one end of the cooling fan is electrically connected to the first end of the second switching element, and the other end is electrically connected to an external power supply.

[0021] Preferably, as one possible implementation, the charging mode control circuit further includes a second diode and a third diode.

[0022] The positive terminal of the second diode is electrically connected to the first voltage divider resistor, and the negative terminal of the second diode is electrically connected to the third voltage divider resistor; the positive terminal of the third diode is electrically connected to the first voltage divider resistor, and the negative terminal of the third diode is electrically connected to the fourth voltage divider resistor.

[0023] Preferably, as one possible implementation, the first switching element includes a transistor or a field-effect transistor; and / or, the second switching element includes a transistor or a field-effect transistor.

[0024] The charger provided by this utility model includes the above-mentioned charging mode control circuit.

[0025] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0026] During charging, the voltage detection chip monitors the charging voltage in real time, and the current detection module monitors the charging current in real time. Based on the values ​​of the charging voltage and charging current, the module controls the first switching element and the power management chip to make corresponding state adjustments, as follows:

[0027] When the charger is plugged into the battery interface, the battery power is low and the charging voltage is correspondingly low. At this time, the voltage detection chip will send a first voltage signal to the first port of the power management chip through the first output terminal based on the signal that the detected charging voltage is lower than the saturation voltage, so that the power management chip enters the constant current charging mode and charges the battery with constant current.

[0028] During constant current charging, the charging current remains constant, the battery charge gradually increases, and the charging voltage gradually increases accordingly. When the charging voltage rises above the saturation voltage, it indicates that the battery charge is already high. At this time, the voltage detection chip will send a second voltage signal to the second port of the power management chip through the second output terminal based on the signal that the detected charging voltage has reached above the saturation voltage, so that the power management chip enters the constant voltage charging mode to charge the battery at a constant voltage.

[0029] During constant voltage charging, the charging voltage remains constant, the battery capacity continues to increase, and the charging current gradually decreases. When the charging current is less than the current threshold, it indicates that the battery is close to full charge. At this time, the current detection module will trigger the first switching element to conduct based on the signal that the detected charging current is less than the current threshold, so as to send a third voltage signal to the first port of the power management chip, so that the power management chip switches to trickle charging mode to trickle charge the battery. In trickle charging mode, both the charging voltage and the charging current are relatively small.

[0030] Therefore, the charging mode control circuit provided by this utility model can realize three-stage charging of the battery: constant current, constant voltage, and trickle charging. Changes in battery charge can trigger the circuit to switch to different states, thereby achieving adaptive automatic switching of the three charging modes. It has a fast response, high charging efficiency, and high safety. Moreover, the circuit uses fewer components, has high wiring efficiency, and low cost. As a result, it not only charges faster but also reaches the battery's saturation capacity, thus better protecting the battery's performance.

[0031] The charger provided by this utility model includes the above-mentioned charging mode control circuit, and therefore has all the advantages of the above-mentioned charging mode control circuit, which will not be repeated here. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the charging mode control circuit provided in an embodiment of the present invention;

[0034] Figure 2 The voltage and current change curves of the charging mode control circuit provided in this embodiment of the utility model during the charging process.

[0035] Explanation of reference numerals in the attached figures:

[0036] 100 - Current detection module; 200 - First switching element; 300 - Second switching element; 400 - Indicating element. Detailed Implementation

[0037] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0038] The present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0039] See Figure 1 and Figure 2 This embodiment provides a charging mode control circuit, which includes a voltage detection chip U2, a current detection module 100, and a first switching element 200. The first power port VDD and the second power port VSS of the voltage detection chip U2 are respectively connected to the positive line BAT+ and the negative line BAT- of the charging line to detect the charging voltage. The two input terminals of the current detection module 100 are connected in series to the positive line BAT+ of the charging line to detect the charging current.

[0040] The first output terminal OUT1 of the voltage detection chip U2 is electrically connected to the first port of the power management chip (Power IC). The voltage detection chip U2 is used to send a first voltage signal to the power management chip when it detects that the charging voltage is lower than the saturation voltage, so that the power management chip enters the constant current charging mode.

[0041] The second output terminal OUT2 of the voltage detection chip U2 is electrically connected to the second port of the power management chip. The voltage detection chip U2 is used to send a second voltage signal to the power management chip when it detects that the charging voltage has reached or exceeded the saturation voltage, so that the power management chip switches to constant voltage charging mode.

[0042] The current detection module 100 is electrically connected to the second port of the power management chip through the first switching element 200. The current detection module 100 is used to trigger the first switching element 200 to conduct when the detected charging current is less than the current threshold, so as to send a third voltage signal to the power management chip to switch the power management chip to trickle charging mode.

[0043] During charging, the voltage detection chip U2 monitors the charging voltage in real time, and the current detection module 100 monitors the charging current in real time. Based on the values ​​of the charging voltage and charging current, the module controls the first switching element 200 and the power management chip to make corresponding state adjustments, as follows:

[0044] When the charger is plugged into the battery interface, the battery power is low and the charging voltage is correspondingly low. At this time, the voltage detection chip U2 will send a first voltage signal to the first port of the power management chip through the first output terminal OUT1 based on the detected signal that the charging voltage is lower than the saturation voltage, so that the power management chip enters the constant current charging mode and charges the battery with constant current.

[0045] During constant current charging, the charging current remains constant, the battery charge gradually increases, and the charging voltage gradually increases accordingly. When the charging voltage rises above the saturation voltage, it indicates that the battery charge is already high. At this time, the voltage detection chip U2 will send a second voltage signal to the second port of the power management chip through the second output terminal OUT2 based on the signal that the detected charging voltage has reached above the saturation voltage, so that the power management chip enters the constant voltage charging mode and performs constant voltage charging on the battery.

[0046] During constant voltage charging, the charging voltage remains constant, the battery capacity continues to increase, and the charging current gradually decreases. When the charging current is less than the current threshold, it indicates that the battery is close to full charge. At this time, the current detection module will trigger the first switching element 200 to conduct based on the signal that the detected charging current is less than the current threshold, so as to send a third voltage signal to the first port of the power management chip, so that the power management chip switches to trickle charging mode to trickle charge the battery. In trickle charging mode, both the charging voltage and the charging current are relatively small.

[0047] Therefore, the charging mode control circuit provided in this embodiment can realize three-stage charging of the battery: constant current, constant voltage, and trickle charging. Changes in battery charge can trigger the circuit to switch to different states, thereby achieving adaptive automatic switching of the three charging modes. It has a fast response, high charging efficiency, and high safety. Moreover, the circuit uses fewer components, has high wiring efficiency, and low cost. As a result, it not only charges faster but also reaches the battery's saturation capacity, thus better protecting the battery's performance.

[0048] In fact, when the voltage detection chip U2 detects that the charging voltage has reached or exceeded the saturation voltage, it sends a high level signal to the second port of the power management chip. This high level signal can be used as the second voltage signal. When the second port of the power management chip receives this second voltage signal, it can switch to constant voltage charging mode.

[0049] In the specific structure of the current detection module 100 described above, an operational amplifier U1 and a detection resistor R5 can be configured. The detection resistor R5 is connected in series to the positive line BAT+ of the charging circuit. The two input terminals of the operational amplifier U1 are respectively connected to the two ends of the detection resistor R5, and the output terminal 1 of the operational amplifier U1 is electrically connected to the control terminal of the first switching element 200, so as to control the on / off state of the first switching element 200 using the operational amplifier U1. The first terminal of the first switching element 200 is electrically connected to the second port of the power management chip and the external power supply, and the second terminal of the first switching element 200 is grounded, so that the first switching element 200 can be smoothly turned on or off. In constant voltage charging mode, as the battery charge increases, the charging current gradually decreases. When the charging current flowing through the detection resistor R5 is less than the current threshold, the voltage difference between the two input terminals 2 and 3 of the operational amplifier U1 will reach the threshold. At this time, the output terminal 1 of the operational amplifier U1 will output a high level, and the first switching element 200 will turn on when it receives the high-level signal, thus realizing the control of the first switching element 200.

[0050] In this embodiment, a second switching element 300, a first diode D1, and a choke resistor R6 can also be provided. The first output terminal OUT1 of the voltage detection chip U2 is electrically connected to one end of the choke resistor R6, and the other end of the choke resistor R6 is electrically connected to the control terminal of the second switching element 300, so that the voltage detection chip U2 can control the on / off state of the second switching element 300. The first terminal of the second switching element 300 is electrically connected to an external power supply, and the second terminal of the second switching element 300 is grounded, so that the second switching element 300 can be smoothly turned on or off. At the same time, the positive terminal of the first diode D1 is electrically connected to the first output terminal OUT1 of the voltage detection chip U2, and the negative terminal of the first diode D1 is electrically connected to the first switching element 200.

[0051] When the voltage detection chip U2 detects that the charging voltage is lower than the saturation voltage, it can output a high level through the first output terminal OUT1. Under this condition, if the battery power is low, the charging current is above the current threshold. At this time, the first switching element 200 is not turned on. After the first output terminal OUT1 of the voltage detection chip U2 outputs a high level, it can smoothly control the second switching element 300 to turn on, so as to send the first voltage signal to the power management chip and enter the constant current charging mode. If the battery power is close to full charge, the charging current is less than the current threshold, indicating that the reason why the charging voltage is lower than the saturation voltage is not because of insufficient power, but because the charging voltage is low in trickle charging mode. At this time, the first switching element 200 will turn on, and the first output terminal OUT1 of the voltage detection chip U2 will be grounded through the first diode D1 and the first switching element 200. This causes the level of the first output terminal OUT1 of the voltage detection module U2 to be pulled low. Thus, the second switching element 300 will not receive a high level and will not turn on. This avoids the power management chip receiving an incorrect mode switching signal in trickle charging mode, thus maintaining the trickle charging mode.

[0052] In this embodiment, a first voltage divider resistor R1, a second voltage divider resistor R2, and a third voltage divider resistor R3 can be configured. One end of the first voltage divider resistor R1 is electrically connected to the first port of the power management chip, and the other end is grounded. One end of the second voltage divider resistor R2 is electrically connected between the first voltage divider resistor R1 and the power management chip, and the other end is grounded. One end of the third voltage divider resistor R3 is electrically connected between the first voltage divider resistor R1 and the power management chip, and the other end is electrically connected to the first terminal of the first switching element 200. When the battery is close to full charge and the charging current is less than the current threshold, the first switching element 200 is turned on. As a result, the circuit where the third voltage divider resistor R3 is located is turned on. The second voltage divider resistor R2 and the third voltage divider resistor R3 are connected in parallel and divide the voltage with the first voltage divider resistor R1, causing a change in the voltage at the second port of the power management chip. This voltage change is the third voltage signal. When the power management chip recognizes this third voltage signal, it enters the trickle charging mode, realizing the switching from constant voltage charging mode to trickle charging mode.

[0053] In this embodiment, a fourth voltage divider resistor R4 can also be provided. One end of the fourth voltage divider resistor R4 is electrically connected between the first voltage divider resistor R1 and the power management chip, and the other end of the fourth voltage divider resistor R4 is electrically connected to the first terminal of the second switching element 300. When the battery charge is low, the charging voltage is lower than the saturation voltage, and the charging current is higher than the current threshold, the first switching element 200 is turned off, and the second switching element 300 is turned on. As a result, the line where the third voltage divider resistor R3 is located is cut off, and the line where the fourth voltage divider resistor R4 is located is turned on. Thus, the second voltage divider resistor R2 and the fourth voltage divider resistor R4 are connected in parallel, and the voltage is divided with the first voltage divider resistor R1, causing the voltage at the first port of the power management chip to change. This voltage change signal is the first voltage signal. When the power management chip recognizes the first voltage signal, it will enter the constant current charging mode to charge the battery with a constant current.

[0054] Preferably, in this embodiment, an indicator element 400 may also be provided. One end of the indicator element 400 is electrically connected to the first end of the first switching element 200, and the other end is electrically connected to an external power supply. When the first switching element 200 is turned on, the indicator element 400 will issue a prompt message, thereby allowing the user to determine whether the battery is fully charged based on the prompt from the indicator element 400. Specifically, the indicator element 400 can be an indicator light, such as a light-emitting diode (LED) D4. Using an LED D4 as the indicator element not only reduces the power consumption of the indicator element but also avoids generating excessive heat.

[0055] Furthermore, in this embodiment, a cooling fan B1 can also be provided. One end of the cooling fan B1 is electrically connected to the first end of the second switching element 300, and the other end is electrically connected to an external power supply. Thus, when the second switching element 300 is turned on, the cooling fan B1 starts to work. It should be noted that when the second switching element 300 is turned on, the power management chip is in constant current charging mode. At this time, the charging current is large, and the battery heats up severely. The operation of the cooling fan B1 can cool the battery and improve the battery's heat dissipation effect.

[0056] Specifically, a resistor R7 can be provided between the indicator element 400 and the first switching element 200, and a resistor R8 can be provided between the cooling fan B1 and the second switching element 300.

[0057] In this embodiment, a second diode D2 and a third diode D3 can also be provided. The positive terminal of the second diode D2 is electrically connected to the first voltage divider resistor R1, and the negative terminal of the second diode D2 is electrically connected to the third voltage divider resistor R3. In this way, the current in the line where the third voltage divider resistor R3 is located can be limited to flowing from the first voltage divider resistor R1 to the third voltage divider resistor R3, and no reverse current will occur. The positive terminal of the third diode D3 is electrically connected to the first voltage divider resistor R1, and the negative terminal of the third diode D3 is electrically connected to the fourth voltage divider resistor R4. In this way, the current in the line where the fourth voltage divider resistor R4 is located can be limited to flowing from the first voltage divider resistor R1 to the fourth voltage divider resistor R4, and no reverse current will occur.

[0058] The first switching element 200 can be a transistor Q1 or a field-effect transistor. Preferably, transistor Q1 is used as the first switching element 200, with the base of transistor Q1 being the control terminal of the first switching element 200, the collector of transistor Q1 being the first terminal of the first switching element 200, and the emitter of transistor Q1 being the second terminal of the first switching element 200. When the output terminal 1 of operational amplifier U1 outputs a high level, transistor Q1 can conduct, making the circuit where the third voltage divider resistor R3 is located conduct.

[0059] The second switching element 300 can be a transistor Q2 or a field-effect transistor. Preferably, transistor Q2 is used as the second switching element 300, with the base of transistor Q2 being the control terminal of the second switching element 300, the collector of transistor Q2 being the first terminal of the second switching element 300, and the emitter of transistor Q2 being the second terminal of the second switching element 300. When the first output terminal OUT1 of the voltage detection chip U1 outputs a high level, transistor Q2 can conduct, making the circuit where the fourth voltage divider resistor R4 is located conduct.

[0060] The external power supply mentioned above can be a 5V power supply.

[0061] In addition, the voltage detection chip U2 can also determine the remaining power of the battery when the charger is plugged into the battery interface. Generally, the rated voltage of the battery is lower than the saturation voltage, so the normal remaining power of the battery will be lower than the saturation voltage. Therefore, when the charger is plugged into the high-voltage battery interface, if the voltage detection chip U2 determines that the remaining power of the battery is higher than the saturation voltage, the battery will not be charged.

[0062] This embodiment also provides a charger, which includes the above-described charging mode control circuit.

[0063] The charger provided in this embodiment, because it includes the above-mentioned charging mode control circuit, has all the advantages of the above-mentioned charging mode control circuit. It can realize three-stage charging of the battery: constant current, constant voltage, and trickle charging. Changes in battery power can trigger the circuit to switch to different states, thereby realizing adaptive automatic switching of the three charging modes. It has a fast response, high charging efficiency, and high safety. Moreover, the number of components used in the circuit is small, the wiring efficiency is high, and the cost is low. Therefore, it not only charges faster but also reaches the battery's saturation capacity, which can better protect the battery's performance.

[0064] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. 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 a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A charge mode control circuit, characterized by, It includes a voltage detection chip, a current detection module, and a first switching element; The first power port and the second power port of the voltage detection chip are respectively connected to the positive line and the negative line of the charging circuit to detect the charging voltage; the two input terminals of the current detection module are connected in series with the positive line of the charging circuit to detect the charging current. The first output terminal of the voltage detection chip is electrically connected to the first port of the power management chip; the voltage detection chip is used to send a first voltage signal to the power management chip when it detects that the charging voltage is lower than the saturation voltage, so that the power management chip enters the constant current charging mode. The second output terminal of the voltage detection chip is electrically connected to the second port of the power management chip; the voltage detection chip is used to send a second voltage signal to the power management chip when it detects that the charging voltage has reached or exceeded the saturation voltage, so that the power management chip switches to constant voltage charging mode; The current detection module is electrically connected to the first port of the power management chip through the first switching element. The current detection module is used to trigger the first switching element to conduct when the charging current is detected to be less than the current threshold, so as to send a third voltage signal to the power management chip, so that the power management chip switches to trickle charging mode.

2. The charge mode control circuit of claim 1, wherein, The current detection module includes an operational amplifier and a detection resistor. The detection resistor is connected in series with the positive line of the charging circuit, and the two input terminals of the operational amplifier are respectively connected to the two ends of the detection resistor. The output terminal of the operational amplifier is electrically connected to the control terminal of the first switching element. The first terminal of the first switching element is electrically connected to the first port of the power management chip and the external power supply, and the second terminal of the first switching element is grounded. The output of the operational amplifier is used to output a high level when the charging current is detected to be less than the current threshold, so as to trigger the first switching element to turn on.

3. The charge mode control circuit of claim 2, wherein, Also includes: The second switching element, the first diode, and the choke resistor; The first output terminal of the voltage detection chip is electrically connected to one end of the choke resistor, the other end of the choke resistor is electrically connected to the control terminal of the second switching element, the first terminal of the second switching element is electrically connected to an external power supply, and the second terminal of the second switching element is grounded. The positive terminal of the first diode is electrically connected to the first output terminal of the voltage detection chip, and the negative terminal of the first diode is electrically connected to the first terminal of the first switching element. The voltage detection chip is used to output a high level through the first output terminal when it detects that the charging voltage is lower than the saturation voltage, so as to turn on the second switching element and send the first voltage signal to the power management chip.

4. The charge mode control circuit of claim 3, wherein, Also includes: First voltage divider resistor, second voltage divider resistor, and third voltage divider resistor; One end of the first voltage divider resistor is electrically connected to the first port of the power management chip, and the other end is electrically connected to an external power supply. One end of the second voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is grounded; One end of the third voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is electrically connected to the first end of the first switching element.

5. The charge mode control circuit of claim 4, wherein, Also includes: Fourth voltage divider resistor; One end of the fourth voltage divider resistor is electrically connected between the first voltage divider resistor and the power management chip, and the other end is electrically connected to the first end of the second switching element.

6. The charge mode control circuit of claim 5, wherein, Also includes: Indicator element; One end of the indicator element is electrically connected to the first end of the first switch element, and the other end is electrically connected to an external power supply.

7. The charge mode control circuit of claim 5, wherein, Also includes: Cooling fan; One end of the cooling fan is electrically connected to the first end of the second switching element, and the other end is electrically connected to an external power supply.

8. The charge mode control circuit of claim 5, wherein, Also includes: Second diode and third diode; The positive terminal of the second diode is electrically connected to the first voltage divider resistor, and the negative terminal of the second diode is electrically connected to the third voltage divider resistor; The positive terminal of the third diode is electrically connected to the first voltage divider resistor, and the negative terminal of the third diode is electrically connected to the fourth voltage divider resistor.

9. A charge mode control circuit according to any one of claims 3 to 8, characterised in that, The first switching element includes a transistor or a field-effect transistor; And / or, the second switching element includes a transistor or a field-effect transistor.

10. A charger characterized by comprising: Includes the charging mode control circuit according to any one of claims 1-9.

Images