Charging circuit, power supply circuit, electronic device, and power supply system

Abstract

The present application relates to a charging circuit, a power supply circuit, an electronic device, and a power supply system. The charging circuit (10) comprises a resonant circuit (110) and a transformer circuit (120); the transformer circuit (120) comprises a primary coil, and a plurality of secondary coils having dotted terminals connected to each other; and an external power supply device can be isolated from first loads (20) by means of the coupling between the primary coil and each secondary coil. The charging circuit (10) can be connected to a plurality of first loads (20) by means of the plurality of secondary coils, and non-dotted terminals of two adjacent secondary coils can independently output two first power supply voltages so as to provide electric energy to different first loads (20).

Description

Charging circuit, power supply circuit, electronic device and power supply system

[0001] Cross Reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 2024105988694, filed on May 14, 2024, and entitled "Charging circuit, power supply circuit, electronic device and power supply system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of power management, and in particular to a charging circuit, a power supply circuit, an electronic device and a power supply system. BACKGROUND

[0004] The statements herein are merely provided to give a background of the present application and are not necessarily constituting the exemplary technology.

[0005] With the continuous strengthening of the functions of electronic devices, users have increasingly high requirements for the charging speed of electronic devices. However, the charging circuit in the related art is difficult to achieve a balance between greater power charging and reliable performance, and there is a risk of causing battery failure. SUMMARY

[0006] According to various embodiments of the present application, a charging circuit, a power supply circuit, an electronic device and a power supply system can support large power charging while ensuring the reliability of performance.

[0007] The first aspect of the present application provides a charging circuit, comprising:

[0008] a resonance circuit, configured to convert a received direct current signal into an alternating current signal;

[0009] a transformer circuit, comprising a primary coil and a plurality of secondary coils, the primary coil being connected with an output end of the resonance circuit, same-name ends of two adjacent secondary coils being connected, the primary coil being coupled with the plurality of secondary coils respectively, the transformer circuit being configured to perform a voltage transformation on the alternating current signal to output a first supply voltage through each of the secondary coils respectively; the two first supply voltages output by the two adjacent secondary coils being configured to provide power to different first loads respectively.

[0010] The second aspect of the present application provides a power supply circuit, comprising:

[0011] a first load; and

[0012] The charging circuit as described above.

[0013] The third aspect of the present application provides an electronic device, comprising:

[0014] a first load; and

[0015] a charging circuit as described above; or a power supply circuit as described above.

[0016] The fourth aspect of the present application provides a power supply system, comprising:

[0017] a power supply configured to provide a direct current signal; and

[0018] an electronic device as described above.

[0019] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings required to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0021] FIG. 1 is a structural block diagram of a charging circuit according to an embodiment;

[0022] FIG. 2 is a structural block diagram of a charging circuit according to an embodiment;

[0023] FIG. 3 is a circuit schematic diagram of a CP circuit according to the related art;

[0024] FIG. 4 is a circuit schematic diagram of a CP circuit according to the related art;

[0025] FIG. 5 is a structural block diagram of a charging circuit according to an embodiment;

[0026] FIG. 6 is a structural block diagram of a charging circuit according to an embodiment;

[0027] FIG. 7 is a structural block diagram of a charging circuit according to an embodiment;

[0028] FIG. 8 is a structural block diagram of a charging circuit according to an embodiment;

[0029] FIG. 9 is a structural block diagram of a charging circuit according to an embodiment;

[0030] FIG. 10 is a structural block diagram of a charging circuit according to an embodiment;

[0031] FIG. 11 is a circuit schematic diagram of a charging circuit according to an embodiment;

[0032] FIG. 12 is a second circuit diagram of the charging circuit according to an embodiment;

[0033] FIG. 13 is a third circuit diagram of the charging circuit according to an embodiment;

[0034] FIG. 14 is a fourth circuit diagram of the charging circuit according to an embodiment;

[0035] FIG. 15 is a circuit diagram of a charging circuit according to the related art;

[0036] FIG. 16 is a waveform diagram of signals of the charging circuit according to the related art;

[0037] FIG. 17 is a first waveform diagram of signals of the charging circuit according to an embodiment;

[0038] FIG. 18 is a second waveform diagram of signals of the charging circuit according to an embodiment;

[0039] FIG. 19 is a third waveform diagram of signals of the charging circuit according to an embodiment;

[0040] FIG. 20 is a fourth waveform diagram of signals of the charging circuit according to an embodiment;

[0041] FIG. 21 is a structural block diagram of a power supply circuit according to an embodiment. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0043] It can be understood that the terms "first", "second", and the like used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the other element, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0044] It should be noted that when an element is referred to as "provided on" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element.

[0045] FIG. 1 is a structural block diagram of a charging circuit according to an embodiment. Referring to FIG. 1, in the present embodiment, the charging circuit 10 includes a resonance circuit 110 and a transformer circuit 120.

[0046] The resonant circuit 110 is configured to convert the received direct current signal into an alternating current signal; the transformer circuit 120 includes a primary coil and a plurality of secondary coils, the primary coil is connected to the output end of the resonant circuit 110, the same name ends of two adjacent secondary coils are connected, the primary coil is coupled with the plurality of secondary coils respectively, the transformer circuit 120 is configured to perform voltage transformation on the alternating current signal to output a first power supply voltage through each secondary coil respectively; the two first power supply voltages output by the two adjacent secondary coils are respectively used to provide power to different first loads 20.

[0047] The input end of the resonant circuit 110 can be connected to the power supply in a conductive manner to access the direct current signal provided by the power supply, the output end of the resonant circuit 110 is connected to the primary coil, the resonant circuit 110 converts the received direct current signal to obtain an alternating current signal, and the alternating current signal can drive the transformer circuit 120 to perform voltage transformation. Optionally, the power supply can be a charger, an adapter or other external power supply device.

[0048] The primary coil of the transformer circuit 120 can be coupled with a plurality of secondary coils, the same name ends of each two adjacent secondary coils are connected to form a same name end tap, each secondary coil can be connected to a first load 20 respectively, for example, taking two secondary coils as an example, as shown in FIG. 2, the first end of the secondary coil S1 and the first end of the secondary coil S2 are same name ends, the second end of the secondary coil S1 and the second end of the secondary coil S2 are same name ends, and the second end of the secondary coil S1 and the second end of the secondary coil S2 are connected to form a same name end tap. It can be understood that the number of secondary coils can be 2 or more than 2, when the number is more than 2, the first power supply voltages of the two adjacent secondary coils output by the opposite name ends can be the same or different, and the first power supply voltages of the two adjacent secondary coils output by the same name ends can be the same. The two adjacent secondary coils output by the opposite name ends can be understood as two adjacent secondary coils, one of which is a first end output, for example, the secondary coil S1 is a first end output, and the other is a second end output, for example, the secondary coil S2 is a second end output.

[0049] Optionally, the ratio between the number of turns of the primary coil and the number of turns of each secondary coil is N:1, N is a number greater than or equal to 1, the N values corresponding to different secondary coils can be the same or different, and the N value can be adjusted according to the first supply voltage corresponding to each secondary coil. Optionally, the resonant circuit 110 can be an LLC resonant circuit 110, the transformer circuit 120 can be a direct current transformer DCX, and the resonant circuit 110 and the transformer circuit 120 form an LLC(LLC resonant converter)-DCX(Direct Current Transformer) circuit, wherein in the "LLC resonant converter", "L" represents inductance, and "C" represents resonant capacitance. The charging circuit 10 has the advantages of the traditional LLC-DCX circuit, and can achieve high efficiency in a wide range.

[0050] The first load 20 can be a device that needs to use electric energy, such as a battery module, a processor, a display screen, etc. The embodiments are not limited in this regard. The electric energy required by different first loads 20 can be the same or different. For example, taking the first load 20 as a battery as an example, different batteries can be connected in series, and when the capacity and battery voltage of different battery modules are the same, the electric energy required by different batteries is the same. When the capacity and / or battery voltage of different battery modules are different, in order to achieve balanced charging, the electric energy required by different batteries is different.

[0051] When the transformer circuit 120 receives the alternating current signal output by the resonant circuit 110, the primary coil in the transformer circuit 120 is coupled with the plurality of secondary coils to generate electromagnetic induction, thereby achieving voltage conversion. Each secondary coil corresponds to obtain a first supply voltage to provide electric energy to the first load 20 connected to each secondary coil.

[0052] It can be understood that the output state of the secondary coil corresponds to the resonant frequency of the resonant circuit 110. Since the primary coil and the secondary coil are isolated, even if the system is damaged, the primary coil and the secondary coil will not be broken down, and the direct current signal will not be directly transmitted to the first load 20 on the secondary coil. The safety of the system under extreme conditions is ensured. Since the same name ends of any two adjacent secondary coils are connected, the two adjacent secondary coils can relatively independently output the first supply voltage, which can be the same or different. Therefore, when the electric energy required by the two adjacent first loads 20 is the same, the two adjacent secondary coils can provide the same first supply voltage. When the electric energy required by the two adjacent first loads 20 is different, the two adjacent secondary coils can provide different first supply voltages.

[0053] In related embodiments, on the one hand, as the charging power increases, the increase of the adapter output current, the impedance of the output cable line also needs to be smaller, the output cable line becomes thicker, resulting in the increase of the charging cost and the deterioration of the user experience. On the other hand, in order to realize safe charging, a CP (Charge Pump) circuit is usually used for step-down charging. The principle of the CP circuit is to continuously open the switch to charge the capacitor, and close the switch to redistribute the charge of the capacitor, thereby realizing half voltage. As shown in FIG. 3, in one working cycle of the half voltage IC, the first half cycle opens QCH and QCL, and charges the Cfly capacitor and the Cout capacitor in series, and the voltage of the two capacitors in series is VDD; as shown in FIG. 4, in the second half cycle, the Cfly capacitor and the Cout capacitor are connected in parallel by opening the QDH and QDL switches, and the voltage of the intermediate node is close to 1 / 2VDD due to the redistribution of the charge on the capacitors. After multiple cycles, the output voltage stabilizes at 1 / 2VDD, thereby realizing the half voltage function. However, when the power switch tube inside the CP circuit fails, such as short circuit or open circuit caused by aging over time, the higher voltage on the charging line can cause the load to directly flow into other circuits of the electronic device, which can cause device damage, battery fire, and other dangers. In other aspects, other charging circuits can also improve the charging environment, but other charging circuits can also usually only output the same supply voltage, and cannot meet the different power supply needs of different loads.

[0054] The charging circuit 10 provided by the embodiment includes a resonant circuit 110 and a transformer circuit 120. The transformer circuit 120 includes a primary coil and a plurality of secondary coils connected to each other at the same name end. On the one hand, through the coupling between the primary coil and each secondary coil, the external power supply device and the first load 20 can be isolated, and the withstand voltage is very high. Even if the external power supply device provides a higher voltage direct current signal, it will not affect the first load 20 on the secondary coil side, thereby avoiding the risk of failure of the first load 20. Therefore, the charging circuit 10 can be applied to a high-power charging scene, and can ensure the stability and safety of the first load 20 in the high-power charging scene, thereby improving the reliability of the charging circuit 10. In particular, in low-voltage consumer electronic products such as mobile phones and notebooks, the problem of natural breakdown does not occur, and isolation transmission of the charging power is safe and controllable. On the other hand, the charging circuit 10 can be connected to a plurality of first loads 20 through a plurality of secondary coils. The opposite ends of the adjacent two secondary coils can independently output two first supply voltages to provide power to different first loads 20, thereby meeting the different power supply needs of the plurality of first loads 20 and reducing the cost.

[0055] In one of the embodiments, as shown in FIG. 5, the charging circuit 10 further includes a first switch circuit 130.

[0056] The first switch circuit 130 has a first end connected to the first end of the resonance circuit 110 and a second end connected to the second end of the primary coil; and the second end of the resonance circuit 110 is connected to the first end of the primary coil.

[0057] The first switch circuit 130 includes a first group of switch units and a second group of switch units, and the first group of switch units and the second group of switch units are alternately turned on, so that the resonance circuit 110 converts the direct current signal into an alternating current signal, and the first power supply voltage output by each secondary coil is in a corresponding target preset range; when the first group of switch units is in a conductive state, the first end of the resonance circuit 110 is conductively connected to the positive power supply end; and when the second group of switch units is in a conductive state, the first end of the resonance circuit 110 is conductively connected to the negative power supply end.

[0058] It can be understood that the first group of switch units and the second group of switch units are alternately turned on according to a switching frequency in each switching period, the switching frequency is determined based on the resonance frequency of the resonance circuit 110, and each group of switch units is controlled in an on-off state by a received driving signal with a preset duty cycle. Based on the alternate conduction of the first group of switch units and the second group of switch units, the resonance circuit 110 converts the direct current signal into an alternating current signal in the process of alternate conduction of the two groups of switch units. Specifically, the first group of switch units is connected to the positive power supply end and can receive a positive power supply signal; the second group of switch units is connected to the negative power supply end and can receive a negative power supply signal, which can be understood as being equivalent to the end.

[0059] When the first group of switch units is in a conductive state, the connection between the positive power supply end and the first end of the resonance circuit 110 is turned on, the resonance circuit 110 receives a positive direct current signal, excites the coupling between the primary coil and each secondary coil, the output end of the resonance circuit 110 is connected to the first end of the primary coil, thereby exciting the corresponding secondary coil with the same name output end of the first end to generate a positive alternating current signal, and the voltage of the positive alternating current signal can be in a target preset range, at this time the secondary coil output by the adjacent other opposite end can be stored by the auxiliary device; when the second group of switch units is in a conductive state, the connection between the negative power supply end and the first end of the resonance circuit 110 is turned on, the resonance circuit 110 receives a negative direct current signal, excites the coupling between the primary coil and each secondary coil, the output end of the resonance circuit 110 is connected to the first end of the primary coil, thereby exciting the corresponding secondary coil with the opposite output end of the first end to generate a negative alternating current signal, and the voltage of the negative alternating current signal can be in a target preset range, at this time the secondary coil output by the adjacent other opposite end can be stored by the auxiliary device.

[0060] The first switch circuit 130 can be used to adjust the output voltage of each secondary coil, so that each output voltage is in a target preset range, and the power supply demand of different first loads 20 is adapted.

[0061] In one of the embodiments, the different first loads 20 include a plurality of battery modules connected in series; the first group of switch units and the second group of switch units are alternately turned on according to the received driving signals with preset duty cycles, so that the voltage difference of the plurality of battery modules is in a preset range; wherein the duty cycle of the driving signal is determined based on the state information of the plurality of battery modules in the charging and / or discharging process.

[0062] The preset duty cycle of each driving signal has a mapping relationship with the size of the first power supply voltage output by each secondary coil. When the duty cycles of the driving signals received by each group of switch units are the same, the first power supply voltages output by the adjacent two secondary coils with opposite terminals are the same. When the duty cycles of the driving signals received by each group of switch units are different, when the duty cycle of the driving signal of the first group of switch units is greater than that of the second group of switch units, the power supply current output by the secondary coil with the same terminal as the first end of the primary coil is smaller than that of the secondary coil with the opposite terminal as the first end of the primary coil. The size of the power supply current has a mapping relationship with the size of the power supply voltage. By adjusting the duty cycle, the first power supply voltage output by each secondary coil can be correspondingly adjusted, so that the voltage of different battery modules can be adjusted, and the voltage difference of the plurality of battery modules is in a preset range. The preset range can be understood as a relatively balanced range, such as close to zero or equal to zero, so as to realize balanced charging. It can be understood that the preset range can be adjusted and set according to the safety, stability, charging performance, discharging performance and the like of the battery module in practice, and the present embodiment does not limit this.

[0063] The state information of the battery module in the charging or discharging process can include the voltage, current, charging power, charging and discharging temperature, capacitance and the like of the battery module, and the present embodiment does not limit this. The duty cycle is determined based on the state information of the battery module in the charging or discharging process, so that the first power supply voltage finally output by the charging circuit 10 can match the power supply demand of each battery module.

[0064] It can be understood that the first group of switch units and the second group of switch units are alternately turned on, so that the two secondary coils with opposite terminals in each secondary coil can alternately be in the energy storage and discharge state. The charging circuit 10 can provide electric energy in any duty cycle window time within one cycle.

[0065] The first group of switch units and the second group of switch units are controlled, so that the first power supply voltage corresponding to each first load 20 can be effectively controlled and adjusted, and no additional voltage supplement circuit is needed, thereby improving the charging effectiveness and reliability of the charging circuit 10 and effectively reducing the cost.

[0066] In one of the embodiments, as shown in FIG. 6, the plurality of secondary coils includes a first secondary coil (S1 in the figure) and a second secondary coil (S2 in the figure), a first end of the first secondary coil is connected to the first end of the primary coil, a second end of the first secondary coil is connected to a first end of the second secondary coil to form an identical end tap, which can also be understood as a middle tap of the first secondary coil and the second secondary coil, and a second end of the second secondary coil is connected to the second end of the primary coil.

[0067] The plurality of battery modules includes a first battery module and a second battery module, a positive electrode of the first battery module is connected to the first end of the first secondary coil, a negative electrode of the first battery module is connected to the second end of the first secondary coil, and a negative electrode of the second battery module is connected to the second end of the second secondary coil.

[0068] When the first end of the primary coil is connected to the positive power supply end through the resonant circuit 110 and the first group of switch units, the two secondary coils are coupled to the primary coil, and the first secondary coil outputs the first power supply voltage to the first battery module, and the second secondary coil can store energy through the auxiliary device; when the first end of the primary coil is connected to the negative power supply end through the resonant circuit 110 and the first group of switch units, the two secondary coils are coupled to the primary coil, and the second secondary coil outputs the first power supply voltage to the second battery module, and the second secondary coil can store energy through the auxiliary device. It can be understood that the period of alternating conduction is relatively short, and it can be understood that the two secondary coils can always continuously provide the first power supply voltage corresponding to the power supply demand of each secondary coil.

[0069] In one of the embodiments, please continue to refer to FIG. 6, the capacity of the first battery module is less than the capacity of the second battery module; during the charging process, the duty cycle of the driving signal received by the first group of switch units is greater than the duty cycle of the driving signal received by the second group of switch units.

[0070] In the above-mentioned embodiments, when the first group of switch units is turned on, the secondary coil corresponding to the first battery module supplies power to the first battery module; when the second group of switch units is turned on, the secondary coil corresponding to the second battery module supplies power to the first battery module, so that the duty cycle of the first group of switch units and the second group of switch units affects the power supply state of each battery module.

[0071] The first battery module with small capacity has a fast battery voltage rise during charging, and the second battery module with large capacity has a slow battery voltage rise during charging, which easily leads to unbalanced charging, so that the voltage of the first battery module is greater than the voltage of the second battery module. In order to balance the charging, the duty cycle of the driving signal received by the first group of switch units is set to be greater than the duty cycle of the driving signal received by the second group of switch units, so that the charging current Iol corresponding to the first battery module with small capacity is controlled to be less than the charging current Io2 of the second battery module with large capacity, that is, the output current Io2>Iol, the first supply voltage provided to the first battery module is less than the first supply voltage provided to the second battery module, so that the charging is balanced.

[0072] It can be understood that, in other embodiments, if the capacity of the first battery module is greater than the capacity of the second battery module, during the charging process, the duty cycle of the driving signal received by the first group of switch units is less than the duty cycle of the driving signal received by the second group of switch units, which will not be further explained in the embodiment.

[0073] In one of the embodiments, please continue to refer to FIG. 6, the capacity of the first battery module is less than the capacity of the second battery module; during the charging and discharging process, the duty cycle of the driving signal received by the first group of switch units is less than the duty cycle of the driving signal received by the second group of switch units.

[0074] In the above-mentioned embodiments, when the first group of switch units is turned on, the secondary coil corresponding to the first battery module supplies power to the first battery module; when the second group of switch units is turned on, the secondary coil corresponding to the second battery module supplies power to the first battery module, so that the duty cycle of the first group of switch units and the second group of switch units affects the power supply state of each battery module.

[0075] In the above-mentioned embodiments, the charging and discharging can be understood as that the battery module supplies power to other loads while charging. The first battery module with small capacity has a fast battery voltage drop during discharging, and the second battery module with large capacity has a slow battery voltage drop during charging, which easily leads to unbalanced charging, so that the voltage of the first battery module is less than the voltage of the second battery module. In order to maintain balanced discharging, the first supply voltage provided to the first battery module is set to be greater than the first supply voltage provided to the second battery module, specifically, the duty cycle of the driving signal received by the first group of switch units is set to be less than the duty cycle of the driving signal received by the second group of switch units, so that the charging current Iol corresponding to the first battery module with small capacity is controlled to be greater than the charging current Io2 of the second battery module with large capacity, that is, the output current Io2<Iol, the first supply voltage provided to the first battery module is greater than the first supply voltage provided to the second battery module, so that the battery module can maintain balanced charging and discharging.

[0076] It can be understood that in other embodiments, if the capacity of the first battery module is greater than the capacity of the second battery module, the duty cycle of the driving signal received by the first group of switch units is greater than the duty cycle of the driving signal received by the second group of switch units during the charging and discharging process, and the present embodiment will not be further explained.

[0077] It should be noted that in other embodiments, the equalization charging of the battery module can be realized by the charging circuit 10, and at the same time, a discharging equalization circuit is introduced to realize the equalization discharging of the battery module. The related embodiments of introducing the discharging equalization circuit will be introduced in the following, and will not be further explained here.

[0078] In one of the embodiments, as shown in FIG. 7, the first group of switch units includes a first switch unit 131, and the second group of switch units includes a second switch unit 132.

[0079] Among them, the first end of the first switch unit 131 is connected with the positive power supply end, the second end of the first switch unit 131 is connected with the first end of the second switch unit 132 as the first end of the first switch circuit 130, and the second end of the second switch unit 132 is connected with the negative power supply end as the second end of the first switch circuit 130.

[0080] The first switch circuit 130 can be understood as a half-bridge topology circuit of the first switch unit 131 and the second switch unit 132, and the first switch unit 131 and the second switch unit 132 are alternately turned on according to the switching frequency, the duty cycle, etc. in a charging time period. The switching frequency is determined based on the resonance frequency, the target preset range of the first supply voltage, etc., and the duty cycle is determined based on the state information of the charging and / or discharging process of the first load 20. It can be understood that the input voltage of the resonance circuit 110 can be understood as the midpoint voltage of the first switch circuit 130, that is, the voltage at the connection of the first switch unit 131 and the second switch unit 132.

[0081] When the first switch unit 131 is turned on, the first end of the resonant circuit 110 is connected to the positive power supply end, each secondary coil is coupled with the primary coil, and the secondary coil at the same end as the resonant circuit 110 connected to the primary coil outputs the first power supply voltage in the target preset range to the load, and the secondary coil at the adjacent different end outputs through the auxiliary device can store energy; when the second switch unit 132 is turned on, the first end of the resonant circuit 110 is connected to the negative power supply end, for example, the ground, each secondary coil is coupled with the primary coil, and the secondary coil at the same end as the resonant circuit 110 connected to the primary coil can store energy through the auxiliary device, and the secondary coil at the adjacent different end outputs the first power supply voltage in the target preset range to the load. The first switch unit 131 and the second switch unit 132 are alternately turned on, so that the resonant circuit 110 converts the direct current signal into an alternating current signal, and the first power supply voltage output by each secondary coil is in the corresponding target preset range. Thus, by controlling the on-off state of the first switch unit 131 and the second switch unit 132, the resonant circuit 110 can work at different frequencies, thereby realizing effective control and adjustment of the first power supply voltage corresponding to each first load 20. Without additional voltage supplement circuit, the charging effectiveness and reliability of the charging circuit 10 can be improved, and the cost can be effectively reduced.

[0082] In one embodiment, as shown in FIG. 8, the first group of switch units includes the first switch unit 131 and the fourth switch unit 134, and the second group of switch units includes the second switch unit 132 and the third switch unit 133.

[0083] In one embodiment, as shown in FIG. 8, the first group of switch units includes the first switch unit 131 and the fourth switch unit 134, and the second group of switch units includes the second switch unit 132 and the third switch unit 133.

[0084] The first switch circuit 130 can be understood as a full-bridge topology circuit of the first switch unit 131, the second switch unit 132, the third switch unit 133, and the fourth switch unit 134. The first switch unit 131 and the fourth switch unit 134 have the same state of the common terminal, the second switch unit 132 and the third switch unit 133 have the same state of the common terminal, the first switch unit 131 and the fourth switch unit 134 form a first group of switch units, and the second switch unit 132 and the third switch unit 133 form a second group of switch units. The first group of switch units and the second group of switch units are alternately turned on according to the switching frequency, the duty cycle, and the like in a charging time period. The switching frequency is determined based on the resonance frequency, the target preset range of the first supply voltage, and the like. The duty cycle is determined based on the state information of the charging and / or discharging process of the first load 20.

[0085] When the first switch unit 131 and the fourth switch unit 134 are turned on, the first end of the resonant circuit 110 is connected to the positive power supply terminal, the first end of the primary coil inputs the positive electrical signal, the second end of the primary coil is connected to the negative power supply terminal, for example, the ground, each secondary coil is coupled with the primary coil, and the secondary coil with the same name end of the primary coil connected to the resonant circuit 110 outputs the first supply voltage in the target preset range to the load, and the secondary coil output by the adjacent different name end can store energy through the auxiliary device. When the second switch unit 132 and the third switch unit 133 are turned on, the first end of the resonant circuit 110 is connected to the negative power supply terminal, for example, the ground, the second end of the primary coil is connected to the positive power supply terminal to input the positive electrical signal, each secondary coil is coupled with the primary coil, and the secondary coil with the same name end of the primary coil connected to the resonant circuit 110 can store energy through the auxiliary device, and the secondary coil output by the adjacent different name end outputs the first supply voltage in the target preset range to the load. The different groups of switch units are alternately turned on, so that the resonant circuit 110 converts the direct current signal into an alternating current signal, and the first supply voltage output by each secondary coil is in the corresponding target preset range. Therefore, by controlling the on-off state of the first switch unit 131, the second switch unit 132, the third switch unit 133, and the fourth switch unit 134, the resonant circuit 110 can work at different frequencies, thereby realizing effective control and adjustment of the first supply voltage corresponding to each first load 20. No additional voltage supplement circuit is needed, which can improve the charging effectiveness and reliability of the charging circuit 10 and effectively reduce the cost.

[0086] It can be understood that in other embodiments, the first switch circuit 130 can also include other numbers of switch units, which will not be described one by one in this application. Alternatively, the number of switch units in the first switch circuit 130 can be even, and the first group of switch units and the second group of switch units can include the same number of switch units.

[0087] In one of the embodiments, as shown in FIG. 9, the charging circuit 10 further comprises a plurality of rectifier circuits 140.

[0088] The plurality of rectifier circuits 140 are connected with the plurality of secondary coils respectively, and each rectifier circuit 140 is connected with two ends of the primary secondary coil and the first load 20. Each rectifier circuit 140 is used to rectify the output voltage of the connected secondary coil, so as to output a direct current voltage to the first load 20.

[0089] Each rectifier circuit 140 is connected with two ends of the primary secondary coil and the first load 20. The first supply voltage obtained after the voltage reduction processing of the voltage transformation circuit 120 is an alternating current signal. The rectifier circuit 140 of the embodiment can convert the first supply voltage belonging to the alternating current energy into a direct current signal.

[0090] In the embodiment, the rectification states of the two rectifier circuits 140 connected with the two adjacent secondary coils outputting from the opposite poles are different. Specifically, when the first group of switch units are in the conduction state, the first end of the resonant circuit 110 is connected to the positive power supply end in the conduction state. The first end of the primary coil is connected to the positive power supply signal. The secondary coil outputting from the same pole as the first end of the primary coil outputs a positive alternating current signal (i.e., the first supply voltage). The corresponding rectifier circuit 140 is in the conduction state. The positive alternating current signal is transmitted between the secondary coil and the first load 20 and converted into a direct current voltage. The direct current voltage is loaded to both ends of the first load 20 to supply power to the first load 20. The rectifier circuit 140 corresponding to the secondary coil outputting from the opposite pole as the first end of the primary coil is in the cut-off state, and does not supply power to the corresponding first load 20. When the second group of switch units are in the conduction state, the second end of the primary coil is connected to the negative power supply signal. The secondary coil outputting from the same pole as the second end of the primary coil outputs a negative alternating current signal (i.e., the first supply voltage). The corresponding rectifier circuit 140 is in the conduction state. The negative alternating current signal is transmitted between the secondary coil and the first load 20 and converted into a direct current voltage. The direct current voltage is loaded to both ends of the first load 20 to supply power to the first load 20. The rectifier circuit 140 corresponding to the secondary coil outputting from the opposite pole as the second end of the primary coil is in the cut-off state, and does not supply power to the corresponding first load 20.

[0091] The rectifier circuit 140 of the embodiment, by cooperating with the first switch circuit 130, the voltage transformation circuit 120, and the resonant circuit 110, and the rectification states of the two rectifier circuits 140 connected with the two adjacent secondary coils outputting from the opposite poles being different, can independently obtain the direct current voltage corresponding to the power supply requirement of the different first loads 20, has the adjustability, matches the charging requirement, does not need to additionally set other voltage supplement circuit, and can improve the charging effectiveness and reliability of the charging circuit 10, and effectively reduces the cost.

[0092] In one of the embodiments, the charging circuit 10 further comprises a driving circuit.

[0093] The driving circuit is connected with the controlled end of each switch unit respectively, and is configured to output a corresponding driving signal to each switch unit based on the state information of each first load 20, so as to control the on-off state of each switch unit.

[0094] The state information of each first load 20 can include the voltage, current and charging power between the first load 20, and the temperature and capacity of the first load 20, and the present application does not limit this. For example, the first load 20 is a battery module, and the charging state information obtained by the driving circuit can include the current voltage and capacity of the battery module. The driving circuit generates a corresponding driving signal based on the state information of each first load 20, and the driving signal has parameters such as switching frequency and duty cycle, so that each switch unit can switch the on-off state based on the state information of each first load 20, so as to adjust and control the first power supply voltage, and meet the power supply demand of the first load 20.

[0095] In one of the embodiments, as shown in FIG. 10, the charging circuit 10 further comprises a multi-path current limiting circuit 150.

[0096] Each current limiting circuit 150 has a first end connected with the first end of the secondary coil, and a second end connected with the positive input end of the first load 20, and each current limiting circuit 150 is configured to limit the current of the input power supply signal.

[0097] Each current limiting circuit 150 is connected between the secondary coil and the first load 20, and can limit the current of the power supply signal output by the secondary coil, so as to further adjust the power supply signal output to the first load 20. Through the adjustment of the power supply signal output to the first load 20 by the current limiting processing and the first switch circuit 130, the controllability, reliability and charging efficiency of the power supply signal can be further improved. Taking the first load 20 as a battery module as an example, when the voltage difference between different battery modules is large, the charging balance can be more effectively, efficiently and reliably achieved through the adjustment of the power supply signal output to the first load 20 by the current limiting processing and the first switch circuit 130. It can be understood that in the embodiment in which the charging circuit 10 further comprises a rectifier circuit 140, each current limiting circuit 150 is connected between the rectifier circuit 140 and the first load 20, and can limit the current of the power supply signal output by the rectifier circuit 140. It can be understood that the current limiting parameter of the current limiting processing can be adjusted according to actual needs. When only part of the first load 20 needs to be powered, the path of the first load 20 which does not need to be powered can be disconnected through the current limiting circuit 150.

[0098] In one of the embodiments, as shown in FIG. 11, each rectification circuit 140 includes a rectification switch and a filter capacitor (such as Co1 in the figure), the first end of the rectification switch is connected with the first end of the secondary coil, the second end of the rectification switch is connected with the first end of the filter capacitor and one end of the first load 20 respectively, the second end of the filter capacitor is connected with the second end of the secondary coil and the other end of the first load 20 respectively; wherein the on-off states of the two rectification switches corresponding to the two adjacent secondary coils of the opposite name end output are different.

[0099] When the first group of switch units is in the on state, the secondary coil of the same name end output with the first end of the primary coil outputs a positive alternating current signal, at this time, the corresponding rectification switch is in the on state, the rectification switch of the other rectification circuit 140 adjacent to the opposite name end is in the off state, the positive alternating current signal is converted into a direct current voltage through the filter capacitor of the rectification switch in the on state and is loaded to the two ends of the first load 20 to supply power to the first load 20. When the second group of switch units is in the on state, the secondary coil of the opposite name end output with the first end of the primary coil outputs a negative alternating current signal, at this time, the corresponding rectification switch is in the on state, the rectification switch of the other rectification circuit 140 adjacent to the opposite name end is in the off state, the negative alternating current signal is converted into a direct current voltage through the filter capacitor of the rectification switch in the on state and is loaded to the two ends of the first load 20 to supply power to the first load 20. Thus, through the rectification switch and the filter capacitor, rectification processing can be realized. It can be understood that when the number of secondary coils is greater than 2, the rectification circuit 140 located in the middle can share a rectification switch with one of the adjacent rectification circuits 140. Alternatively, the rectification switch can be a rectification diode D1, D2 (as shown in FIG. 11), can also be a switch tube MOSFET, GaN, SiC, etc., or can be a synchronous rectification tube QSR1, QSR2 (as shown in FIG. 12) synchronized with the corresponding switch unit.

[0100] In one of the embodiments, please continue to refer to FIG. 11 and FIG. 12, the resonant circuit 110 in the above-mentioned embodiment can include a resonant capacitor Cr and a resonant inductor Lr; wherein the first end of the resonant capacitor Cr can be connected with the first switch circuit 130, the second end of the resonant capacitor Cr is connected with the first end of the resonant inductor Lr, and the second end of the resonant inductor Lr is connected with the first end of the primary coil. Through the resonant capacitor Cr and the resonant inductor Lr, the conversion processing of the direct current signal is realized. It can be understood that in other embodiments, other devices can also be included, which are not limited by the present application, as long as the direct current alternating current conversion according to the resonant frequency can be realized.

[0101] In one of the embodiments, please continue to refer to FIG. 11, FIG. 12 and FIG. 13, each of the switch units in the above-mentioned embodiments can include a switch tube, a first diode and a first capacitor; the switch tube, the first diode and the first capacitor are connected in parallel, the source of the switch tube is connected with the anode of the first diode and the first end of the first capacitor, the drain of the switch tube is connected with the cathode of the first diode and the second end of the first capacitor; the drain of the switch tube, the cathode of the first diode and the first end of the first capacitor jointly constitute the first end of the switch unit, and the source of the switch tube, the anode of the first diode and the second end of the first capacitor jointly constitute the second end of the switch unit. The switch tube, the first diode and the first capacitor can realize the alternating conduction function of each of the switch units in the above-mentioned embodiments, and enable the resonant circuit 110 to convert the received direct current signal into an alternating current signal according to the resonant frequency. It should be noted that in the embodiments of the present application, the switch tube and the first diode in each of the switch units can be separately provided, or can be integrated together (FIG. 11-FIG. 13 are examples), and the embodiments of the present application do not limit this.

[0102] In one of the embodiments, please continue to refer to FIG. 14, the current limiting circuit includes rectifier tubes SR1 and SR2. It can be understood that in other embodiments, the charging circuit can also be provided with other devices according to actual needs, for example, as shown in FIG. 11-FIG. 14, a bus capacitor Cin can also be included for energy storage and filtering to ensure the stability of the input direct current signal.

[0103] The related art shown in FIG. 15 and the embodiments of the present application shown in FIG. 11-FIG. 14 are further explained as follows:

[0104] As shown in FIG. 15 (for easy comparison, the first switch circuit, the resonant circuit and the primary coil in the figure are set to be the same as the embodiments of the present application, only for example), in the related art, the LLC-DCX circuit adopts frequency control, adjusts the switching frequency of the switch tube Q1 / Q2 to stabilize the circuit output, the drive signals of the switch tube Q1 / Q2 are symmetrical, that is, the duty cycles are both 50% (including dead time), the output windings S1 / S2 are connected in series to form full-wave rectification and jointly realize the output of the same voltage, that is, only single voltage output can be realized. The drive signal G1 / G2 waveform, the transformer primary side resonant current ILr waveform, the transformer primary side excitation current ILm waveform, the secondary side diode D1, D2 current waveform, the load resistor RL current waveform Io and the like are shown in FIG. 16.

[0105] As shown in FIGS. 11-14, in the present embodiment, the same-named ends of the output windings S1 / S2 in the above-mentioned circuit are connected in parallel, and an intermediate tap is led out, forming a three-terminal output circuit. Two voltages Vo1, Vo2 in series can be obtained through filtering by the filter capacitors Co1, Co2. According to the control mode of the LLC-DCX, symmetric PWM drive signals G1, G2 can be provided to the switch tube Q1, switch tube Q2, and the same output voltages Vo1, Vo2 can be obtained, and the same symmetric currents Io1, Io2 can be output on the same loads RL1, RL2, for example, Io1=Io2=2.32A, and the relevant waveforms are shown in the following FIG. 17. Asymmetric drive signals G1, G2 can also be provided to the switch tube Q1, switch tube Q2, and the control of the output currents Io1, Io2 can be realized by controlling the duty cycles of the drive signals G1, G2.

[0106] For example, in a dual-battery system, due to battery aging, battery characteristics, and the inherent differences between large and small batteries, a battery equalization circuit is needed to control the battery charging voltage, so that the charging voltages of the two batteries are as close as possible, and the phenomenon of overcharging of the battery is prevented. For example, in a large-small battery series system, assuming that the initial voltages of the battery modules are the same (VBAT1=VBAT2) and the capacity of the battery BAT1 is less than that of BAT2, when the same charging current is used (such as the related art charging circuit shown in FIG. 15, battery series charging, same charging current), after a period of time, the voltage of the battery BAT1 will be greater than that of the battery BAT2, i.e., VBAT1>VBAT2. If left unchecked, the phenomenon of battery BAT1 being fully charged while BAT2 not being fully charged will occur. Therefore, in the related art series charging system, a battery equalization circuit needs to be additionally added to synchronize the charge in BAT1 to BAT2, thereby preventing the occurrence of VBAT1>VBAT2. In a battery series system, battery equalization is an important circuit module, and the main function is to balance the voltages of the batteries, thereby ensuring that the multi-cell series system can normally charge and discharge. Therefore, the battery equalization module is the basis for ensuring that the battery can be quickly charged.

[0107] The double-battery series system using the charging circuit 10 of the embodiment can control the output currents Io1 and Io2 by adjusting the duty cycles of the drive signals G1 and G2. Taking the example of the capacity of BAT1 being less than the capacity of BAT2, to ensure that the VBAT1 voltage is consistent with the VBAT2 voltage during charging, the charging current Io2 of BAT2 needs to be greater than the charging current Io1 of BAT1. Therefore, under the condition of keeping the system operating frequency unchanged, the requirement of Io2> Io1 can be met by increasing the duty cycle of the drive signal G1 and decreasing the duty cycle of the drive signal G2. The output currents Io1 and Io2 can be controlled by further adjusting the duty cycles. For example, the output current Io2 = 2.46 A > Io1 = 2.2 A, as shown in FIG. 18. Similarly, if the output current Io1 > Io2 is required, it can be achieved by adjusting the duty cycle of the drive signal G1 to be less than the duty cycle of the drive signal G2, as shown in FIG. 19 (the output current Io1 = 2.45 A > Io2 = 2.198 A) and FIG. 20 (the output current Io1 = 2.58 A > Io2 = 2.06 A).

[0108] Therefore, the charging circuit 10 provided by the embodiment has at least the following advantages: 1. The natural isolation characteristic of the transformer circuit 120 is used to achieve isolated transmission of charging power, greatly improving the safety and reliability of the charging system; 2. By adjusting the connection mode of the transformer output winding, only one center-tapped winding can be used to achieve separate charging of two battery modules of a double-battery series system, for example, to improve the step-down ratio of the DCX transformer and reduce transformer loss and design difficulty; 3. By adjusting the duty cycles of the drive signals G1 and G2, the output currents of the two output windings can be controlled to meet the requirements of different charging currents, thereby meeting the requirement of balanced charging. In addition, in combination with the discharge circuit described later, the charge-discharge balancing circuit can be omitted from the system, saving system cost.

[0109] The embodiments of the present application also provide a power supply circuit, which comprises: a first load 20; and the charging circuit 10 according to any one of the above embodiments or a combination of multiple embodiments. Based on the charging circuit 10 according to the above embodiments, the power supply circuit can be applied to a high-power charging scenario, and can ensure the stability and safety of operation in the high-power charging scenario, improve the reliability of the power supply circuit, and particularly when applied to a low-voltage consumer electronic product such as a mobile phone or a notebook computer, the problem of natural breakdown does not occur, the safe and controllable isolation transmission of charging power is realized, different power supply requirements are met, and the cost is reduced. In one of the embodiments, as shown in FIG. 21, the different first loads 20 comprise a plurality of battery modules connected in series (two are exemplified in the figure, which are a first battery module and a second battery module, respectively); the power supply circuit further comprises: a second load 30 and a discharging circuit 40. The discharging circuit 40 comprises: a conversion circuit 410 and a plurality of second switch circuits 420.

[0110] The conversion circuit 410 is connected with the positive poles of the plurality of battery modules and the second load 30, respectively, and is configured to adjust the discharging current of the plurality of battery modules when the plurality of battery modules output a second power supply voltage to the second load 30. Each of the plurality of second switch circuits 420 is connected with the positive pole of a battery module other than the battery module connected in series at the first position. Each of the plurality of second switch circuits 420 short-circuits the plurality of battery modules between the battery module connected with the second switch circuit 420 in the on state and the conversion circuit 410 when the second switch circuit 420 is in the on state.

[0111] In the off state of each of the plurality of second switch circuits 420, the plurality of battery modules can simultaneously output the second power supply voltage to the second load 30. At this time, the conversion circuit 410 can adjust the discharging current of the plurality of battery modules to match the power supply requirement of the second load 30. The conversion circuit 410 can be a CP circuit, which can perform step-down processing on the second power supply voltage output by the plurality of battery modules to adjust the discharging current. The CP circuit can adopt an existing CP circuit, and the present embodiment does not make further limitation on this. The second load 30 can be other power-consuming devices in an electronic device other than the battery module.

[0112] Wherein, each second switch circuit 420 is connected with the positive pole of a battery module except the first battery module in series, when any second switch circuit 420 is in the on state to connect the second load 30 and the positive pole of the corresponding battery module, the positive pole of the other battery module connected with the second switch circuit 420 will be short-circuited, thereby, the remaining other battery modules directly supply power to the second load 30, and the discharge balancing between the remaining other battery modules and the short-circuited other battery modules can be realized. Through the first switch circuit 130 and the conversion circuit 410, on the one hand, the balanced discharge can be realized, and on the other hand, the remaining other battery modules directly supply power to the second load 30, so that the discharge efficiency can be effectively improved. Optionally, in the charging and discharging process, the second switch circuit 420 can also cooperate with the charging circuit 10 to realize the voltage balancing among the plurality of battery modules. Optionally, the second switch circuit 420 can include a MOSFET, GaN, SiC or the like.

[0113] The embodiments of the present application also provide an electronic device, comprising: a first load 20; and a charging circuit 10 according to any one of the above embodiments or a combination of multiple embodiments; or a power supply circuit according to any one of the above embodiments or a combination of multiple embodiments. Based on the charging circuit 10 or the power supply circuit according to the above embodiments, the electronic device can be applied to a high-power charging scene, and the stability and safety of the electronic device working in the high-power charging scene can be ensured, the reliability of the electronic device is improved, and when the electronic device is a low-voltage consumer electronic product such as a mobile phone or a notebook computer, the natural breakdown problem does not occur, the safe and controllable isolation transmission of the charging power is realized, different power supply requirements are met, and the cost is reduced.

[0114] The embodiments of the present application also provide a power supply system, comprising: a power supply for providing a direct current signal; and an electronic device according to any one of the above embodiments or a combination of multiple embodiments. Based on the electronic device according to the above embodiments, the power supply system can be applied to a high-power charging scene, and the stability and safety of the power supply system working in the high-power charging scene can be ensured, the system reliability is improved, the safe and controllable isolation transmission of the charging power is realized, different power supply requirements are met, and the cost is reduced.

[0115] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0116] The above embodiments only express several implementation ways of the present application, and the description is specific and detailed, but it should not be understood as a limitation to the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A charging circuit comprising: a resonance circuit configured to convert a received direct current signal into an alternating current signal; a transformer circuit comprising a primary coil and a plurality of secondary coils, opposite ends of adjacent two of the secondary coils being connected, the primary coil being coupled to each of the plurality of secondary coils, the transformer circuit being configured to transform the alternating current signal to output a first supply voltage through each of the plurality of secondary coils, and the first supply voltage output by adjacent two of the secondary coils being configured to provide power to different first loads, respectively.

2. The charging circuit of claim 1, further comprising: a first switching circuit, a first end of the first switching circuit being connected to a first end of the resonance circuit, and a second end of the first switching circuit being connected to a second end of the primary coil, and a second end of the resonance circuit being connected to a first end of the primary coil; wherein the first switching circuit comprises a first group of switching units and a second group of switching units, the first group of switching units and the second group of switching units being configured to be alternatively turned on, such that the resonance circuit converts the direct current signal into the alternating current signal, and the first supply voltage output by each of the plurality of secondary coils is within a corresponding target preset range; when the first group of switching units is in a turned-on state, the first end of the resonance circuit is connected to a positive power supply end; and when the second group of switching units is in a turned-on state, the first end of the resonance circuit is connected to a negative power supply end.

3. The charging circuit of claim 2, wherein the different first loads comprise a plurality of battery modules connected in series, and the first group of switching units and the second group of switching units are configured to be alternatively turned on according to a received driving signal having a preset duty cycle, such that a voltage difference of the plurality of battery modules is within a preset range; wherein the duty cycle of the driving signal is determined based on state information of the plurality of battery modules during charging and / or discharging.

4. The charging circuit of claim 3, wherein when the duty cycle of the driving signal received by the first group of switching units and the second group of switching units is the same, the first supply voltage output by adjacent two of the secondary coils connected at opposite ends is the same; when the duty cycle of the driving signal of the first group of switching units is greater than the duty cycle of the driving signal of the second group of switching units, the supply current output by the secondary coil connected at the same end as the first end of the primary coil is less than the supply current output by the secondary coil connected at the opposite end as the first end of the primary coil, and the supply current and the supply voltage are in a mapping relationship.

5. The charging circuit of claim 3, wherein the plurality of secondary coils comprises a first secondary coil and a second secondary coil, a first end of the first secondary coil being coupled to the first end of the primary coil, a second end of the first secondary coil being connected to a first end of the second secondary coil to form a same-end tap, and a second end of the second secondary coil being coupled to the second end of the primary coil. wherein The plurality of battery modules comprises a first battery module and a second battery module, a positive electrode of the first battery module is connected with a first end of the first secondary coil, a negative electrode of the first battery module is connected with a second end of the first secondary coil, a negative electrode of the second battery module is connected with a second end of the second secondary coil.

6. The charging circuit of claim 5, wherein a capacity of the first battery module is less than a capacity of the second battery module; during charging, a duty cycle of a driving signal received by the first group of switch units is greater than a duty cycle of a driving signal received by the second group of switch units.

7. The charging circuit of claim 5, wherein a capacity of the first battery module is less than a capacity of the second battery module; during charging and discharging, a duty cycle of a driving signal received by the first group of switch units is less than a duty cycle of a driving signal received by the second group of switch units.

8. The charging circuit of claim 2, wherein the first group of switch units comprises a first switch unit, and the second group of switch units comprises a second switch unit; wherein a first end of the first switch unit is connected with the positive power supply end, a second end of the first switch unit is connected with a first end of the second switch unit as a first end of the first switch circuit, and a second end of the second switch unit is connected with the negative power supply end as a second end of the first switch circuit.

9. The charging circuit of claim 8, wherein when the first switch unit is turned on, a first end of the resonant circuit is connected to the positive power supply end, the secondary coils are respectively coupled with the primary coil, and the secondary coils with the same name end as the resonant circuit connected end of the primary coil output a first power supply voltage in the target preset range to a load; when the second switch unit is turned on, the first end of the resonant circuit is connected to the negative power supply end, the secondary coils are respectively coupled with the primary coil, and the adjacent different name end output secondary coils output a first power supply voltage in the target preset range to a load.

10. The charging circuit of claim 2, wherein the first group of switch units comprises a first switch unit and a fourth switch unit, and the second group of switch units comprises a second switch unit and a third switch unit; wherein a first end of the first switch unit is connected with the positive power supply end, a second end of the first switch unit is connected with a first end of the second switch unit as a first end of the first switch circuit, a second end of the second switch unit is connected with the negative power supply end, a first end of the third switch unit is connected with the positive power supply end, a second end of the third switch unit is connected with a first end of the fourth switch unit as a second end of the first switch circuit, and a second end of the fourth switch unit is connected with the negative power supply end.

11. The charging circuit of claim 10, wherein when the first switch unit and the fourth switch unit are turned on, the first end of the resonant circuit is connected to the positive power supply, the first end of the primary coil inputs a positive electrical signal, the second end of the primary coil is connected to the negative power supply, the secondary coils are coupled to the primary coil respectively, and the secondary coils with the same name end as the resonant circuit of the primary coil output a first power supply voltage in a target preset range to the load; when the second switch unit and the third switch unit are turned on, the second end of the resonant circuit is connected to the negative power supply, the second end of the primary coil is connected to the positive power supply to input a positive electrical signal, the secondary coils are coupled to the primary coil respectively, and the adjacent secondary coils with different name ends output a first power supply voltage in a target preset range to the load.

12. The charging circuit of any one of claims 8-11, wherein each switch unit comprises a switch tube, a first diode and a first capacitor; the switch tube, the first diode and the first capacitor are connected in parallel, the source of the switch tube is connected to the anode of the first diode and the first end of the first capacitor, the drain of the switch tube is connected to the cathode of the first diode and the second end of the first capacitor; the drain of the switch tube, the cathode of the first diode and the first end of the first capacitor jointly constitute the first end of the switch unit, and the source of the switch tube, the anode of the first diode and the second end of the first capacitor jointly constitute the second end of the switch unit.

13. The charging circuit of claim 2, wherein the charging circuit further comprises: a plurality of rectifier circuits connected to the plurality of secondary coils respectively, each of the rectifier circuits is connected to two ends of a secondary coil and a first load respectively, and each of the rectifier circuits is used for rectifying the output voltage of the connected secondary coil to output a direct current voltage to the first load; wherein the rectification states of the two rectifier circuits connected to the adjacent two secondary coils with different name ends are different.

14. The charging circuit of claim 13, wherein each of the rectifier circuits comprises a rectifier switch and a filter capacitor, a first end of the rectifier switch is connected to the first end of the secondary coil, a second end of the rectifier switch is connected to a first end of the filter capacitor and a first load, respectively, a second end of the filter capacitor is connected to the second end of the secondary coil and another end of the first load, respectively; wherein, the on-off states of the two rectifier switches connected to the adjacent two secondary coils with different name ends are different.

15. The charging circuit of any one of claims 2-11, 13-14, wherein the charging circuit further comprises: a driving circuit connected to the controlled end of each switch unit respectively, and used for outputting a corresponding driving signal to each switch unit based on the state information of each first load to control the on-off state of each switch unit.

16. The charging circuit of any one of claims 1-11, 13-14, wherein the charging circuit further comprises: a plurality of current limiting circuits, the first end of each current limiting circuit is connected to the first end of a secondary coil, the second end of each current limiting circuit is connected to the positive input end of the first load, and each current limiting circuit is used for current limiting the input power supply signal.

17. A power supply circuit, comprising: a first load; and the charging circuit of any one of claims 1-16. ​ 18. The power supply circuit of claim 17, wherein the different first load comprises a plurality of battery modules in series; the power supply circuit further comprising: a second load and a discharging circuit, the discharging circuit comprising: a conversion circuit connected with the positive poles of the plurality of battery modules and the second load, respectively, for adjusting discharging current of the plurality of battery modules when the plurality of battery modules output a second power supply voltage to the second load; a plurality of second switch circuits, each of the second switch circuits being connected with the positive pole of a battery module except the first battery module, and each of the second switch circuits, in an on state, short-circuiting a plurality of battery modules between the battery module connected with the second switch circuit in the on state and the conversion circuit.

19. An electronic device, comprising: a first load; and a charging circuit as claimed in any one of claims 1-16; or a power supply circuit as claimed in any one of claims 17-18.

20. A power supply system, comprising: a power supply for providing a direct current signal; and an electronic device as claimed in claim 19.

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