A wide voltage charging circuit and charger
By switching the relay state, the secondary side of the transformer can be connected in series or in parallel, solving the problem that traditional chargers cannot adapt to different voltages. This enables flexible adaptation of wide-voltage charging circuits, reducing equipment redundancy and costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ROYPOW TECH CO LTD
- Filing Date
- 2025-07-31
- Publication Date
- 2026-05-22
AI Technical Summary
Traditional chargers have a fixed output voltage range, which cannot flexibly adapt to battery packs with different voltages, resulting in high equipment redundancy and increased costs.
By employing a first LLC resonant module and a second LLC resonant module, a first transformer and a second transformer, and switching the state of the relays, the secondary side of the transformer can be connected in series or in parallel to achieve current and voltage adaptation under different voltage scenarios.
It effectively meets the charging needs of different voltages, adapts to multi-voltage battery packs, reduces equipment redundancy, and reduces costs.
Smart Images
Figure CN224267075U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging circuit technology, specifically to a wide voltage charging circuit and charger. Background Technology
[0002] With the widespread application of multi-voltage battery packs, traditional chargers face significant limitations due to their fixed output voltage range. Current mainstream LLC resonant converter topologies typically employ a single operating mode (such as series or parallel connection), and their output voltage range is limited by the inherent characteristics of the topology, making them unable to flexibly adapt to battery packs with different voltages. Therefore, to meet multi-voltage charging needs, users must purchase chargers with different output ranges, resulting in high equipment redundancy and a significant increase in cost. Utility Model Content
[0003] To address the shortcomings of existing technologies, a wide-voltage charging circuit and charger are proposed.
[0004] To achieve the above objectives, this utility model provides a wide-voltage charging circuit, including a first LLC resonant module, a second LLC resonant module, a first transformer, a second transformer, a first relay, a second relay, and a synchronous rectification module. The output terminal of the first LLC resonant module is connected to the primary side of the first transformer, and the output terminal of the second LLC resonant module is connected to the primary side of the second transformer. The first relay and the second relay each have a first terminal, a second terminal, a third terminal, and a fourth terminal. The synchronous rectification module has a first input terminal and a second input terminal. One end of the secondary side of the first transformer is connected to the third terminal of the first relay and the first input terminal of the synchronous rectification module, and the other end of the secondary side of the first transformer is connected to the first terminal of the second relay. The first terminal of the first relay is connected to one end of the secondary side of the second transformer, and the fourth terminal of the first relay is connected to the second input terminal of the synchronous rectification module. The other end of the secondary side of the second transformer is connected to the first terminal of the second relay, and the third terminal of the second relay is connected to the second input terminal of the synchronous rectification module. When the first relay is open and the second relay is closed, the secondary sides of the first transformer and the second transformer are connected in parallel. When the first relay is closed and the second relay is open, the secondary sides of the first transformer and the second transformer are connected in series.
[0005] According to one embodiment of the present invention, the first LLC resonant module includes a first switching network and a first resonant unit. The input terminal of the first resonant unit is connected to the intersection of two bidirectional switching transistors in the bridge arm of the first switching network, and the output terminal of the first resonant unit is connected to the primary side of the first transformer.
[0006] According to one embodiment of the present invention, the second LLC resonant module includes a second switching network and a second resonant unit. The input terminal of the second resonant unit is connected to the intersection of two bidirectional switching transistors of the bridge arm of the second switching network, and the output terminal of the second resonant unit is connected to the primary side of the second transformer.
[0007] According to one embodiment of the present invention, the first switching network includes a first bridge arm and a second bridge arm, and the first resonant unit includes a capacitor C1 and an inductor L1. The first bridge arm and the second bridge arm are connected in parallel. One end of the capacitor C1 is connected to the intersection of two bidirectional switching transistors of the second bridge arm, and the other end of the capacitor C1 is connected to the inductor L1. The other end of the inductor L1 is connected to one end of the primary side of the first transformer, and the other end of the primary side of the first transformer is connected to the intersection of two bidirectional switching transistors of the first bridge arm.
[0008] According to one embodiment of the present invention, the second switching network includes a third bridge arm and a fourth bridge arm, and the second resonant unit includes a capacitor C2 and an inductor L1; the third bridge arm and the fourth bridge arm are connected in parallel, one end of the capacitor C2 is connected to the intersection of the two bidirectional switching transistors of the fourth bridge arm, the other end of the capacitor C2 is connected to the inductor L2, the other end of the inductor L2 is connected to one end of the primary side of the second transformer, and the other end of the primary side of the second transformer is connected to the intersection of the two bidirectional switching transistors of the third bridge arm.
[0009] According to one embodiment of the present invention, the first bridge arm includes bidirectional switching transistors Q7 and Q21, and the second bridge arm includes bidirectional switching transistors Q3 and Q1. The drain of bidirectional switching transistor Q7 is connected to the drain of bidirectional switching transistor Q3, the source of bidirectional switching transistor Q7 is connected to the drain of bidirectional switching transistor Q21, the source of bidirectional switching transistor Q21 and the source of bidirectional switching transistor Q1 share a common ground terminal, and the drain of bidirectional switching transistor Q1 is connected to the source of bidirectional switching transistor Q3. One end of capacitor C1 is connected to the source of bidirectional switching transistor Q3 and the drain of bidirectional switching transistor Q1 respectively. One end of the primary side of the first transformer is connected to the source of bidirectional switching transistor Q7 and the drain of bidirectional switching transistor Q21 respectively.
[0010] According to one embodiment of the present invention, the third bridge arm includes bidirectional switching transistors Q28 and Q29, and the fourth bridge arm includes bidirectional switching transistors Q27 and Q26; the drain of bidirectional switching transistor Q28 is connected to the drain of bidirectional switching transistor Q27, the source of bidirectional switching transistor Q28 is connected to the drain of bidirectional switching transistor Q29, the source of bidirectional switching transistor Q29 and the source of switching transistor Q26 are grounded together, and the drain of bidirectional switching transistor Q26 is connected to the source of bidirectional switching transistor Q27; one end of capacitor C2 is connected to the source of bidirectional switching transistor Q27 and the drain of bidirectional switching transistor Q26 respectively, and one end of the primary side of the second transformer is connected to the source of bidirectional switching transistor Q28 and the drain of bidirectional switching transistor Q29 respectively.
[0011] According to one embodiment of the present invention, the synchronous rectification module includes bidirectional switching transistors Q34, Q35, Q33, and Q30; the drain of bidirectional switching transistor Q34 is connected to the drain of bidirectional switching transistor Q33, the source of bidirectional switching transistor Q34 is connected to the drain of bidirectional switching transistor Q35, the source of bidirectional switching transistor Q35 is connected to the source of bidirectional switching transistor Q30, and the drain of bidirectional switching transistor Q30 is connected to the source of bidirectional switching transistor Q33; one end of the secondary side of the first transformer and the third end of the first relay are connected together to the intersection of bidirectional switching transistors Q33 and Q30, and the fourth end of the first relay and the third end of the second relay are connected together to the intersection of bidirectional switching transistors Q34 and Q35.
[0012] The utility model also provides a charger, including the wide voltage charging circuit described above.
[0013] The beneficial effects of this invention lie in that, by switching the engaging and disengaging states of the first and second relays in different application scenarios, and switching the series and parallel connection states of the secondary windings of the first and second transformers, in low-voltage, high-current charging scenarios, the first LLC resonant network and the second LLC resonant network operate in phase and at the same frequency, with the first relay disengaged and the second relay engaged, resulting in parallel output from the secondary windings of the first and second transformers, thus increasing the charging current. In high-voltage charging scenarios, the first LLC resonant network and the second LLC resonant network operate out of phase, with the first relay engaged and the second relay disengaged, resulting in series voltage boosting from the secondary windings of the first and second transformers. This effectively meets different charging needs and is adaptable to battery packs with different voltages. Attached Figure Description
[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0015] Figure 1 This is a circuit diagram of the wide voltage charging circuit in the embodiment;
[0016] Figure 2 This is a schematic diagram of the current during the positive half-cycle when the wide voltage charging circuit in the embodiment is applied to a low-voltage, high-current scenario.
[0017] Figure 3 This is a schematic diagram of the current during the negative half-cycle when the wide voltage charging circuit in the embodiment is applied to a low-voltage, high-current scenario.
[0018] Figure 4 This is a schematic diagram of the current during the positive half-cycle when the wide voltage charging circuit in the embodiment is applied to a high voltage charging scenario.
[0019] Figure 5 This is a schematic diagram of the current during the negative half-cycle when the wide-voltage charging circuit in the embodiment is applied to a high-voltage charging scenario.
[0020] Explanation of reference numerals in the attached figures
[0021] 1. First LLC resonant module; 11. First switching network; 111. First bridge arm; 112. Second bridge arm; 12. First resonant unit; 2. Second LLC resonant module; 21. Second switching network; 211. Third bridge arm; 212. Fourth bridge arm; 22. Second resonant unit; 3. First transformer; 4. Second transformer; 5. First relay; 6. Second relay; 7. Synchronous rectification module. Detailed Implementation
[0022] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.
[0023] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0024] Please refer to Figure 1 , Figure 1This is a circuit diagram of a wide-voltage charging circuit. This embodiment provides a wide-voltage charging circuit, which includes a first LLC resonant module 1, a second LLC resonant module 2, a first transformer 3, a second transformer 4, a first relay 5, a second relay 6, and a synchronous rectification module 7. The output terminal of the first LLC resonant module 1 is connected to the primary winding of the first transformer 3, and the output terminal of the second LLC resonant module 2 is connected to the primary winding of the second transformer 4. The first relay 5 and the second relay 6 each have a first terminal, a second terminal, a third terminal, and a fourth terminal. The synchronous rectification module 7 has a first input terminal and a second input terminal. During connection, one end of the secondary winding of the first transformer 3 is connected to the third terminal of the first relay 5 and the first input terminal of the synchronous rectification module 7, and the other end of the secondary winding of the first transformer 3 is connected to the first terminal of the second relay 6. One end of the secondary winding of the second transformer 4 is connected to the first terminal of the first relay 5, and the other end of the secondary winding of the second transformer 4 is connected to the first terminal of the second relay 6. The third terminal of the second relay 6 and the fourth terminal of the first relay 5 are both connected to the second input terminal of the synchronous rectification module 7. When the first relay 5 is open and the second relay 6 is closed, the secondary windings of the first transformer 3 and the second transformer 4 are connected in parallel; when the first relay 5 is closed and the second relay 6 is open, the secondary windings of the first transformer 3 and the second transformer 4 are connected in series. Thus, by switching the open or closed states of the first relay 5 and the second relay 6, the series or parallel connection of the secondary windings of the first transformer 3 and the second transformer 4 can be changed, thereby altering the range of the circuit's output voltage and effectively expanding the application scenarios of the wide-voltage charging circuit.
[0025] In practical applications, the input terminals of the first LLC resonant module 1 and the second LLC resonant module 2 are connected to the supply voltage HV+, respectively. The supply voltage HV+ is input to the first LLC resonant module 1 and the second LLC resonant module 2. When the wide-voltage charging circuit is applied to a low-voltage, high-current output scenario, the host computer sends a PMW signal to control the first LLC resonant module 1 and the second LLC resonant module 2 to operate in phase. At the same time, it controls the first relay 5 to open and the second relay 6 to close, so that the secondary sides of the first transformer 3 and the second transformer 4 are connected in parallel. After parallel connection, the voltage phases of the output voltages of the first transformer 3 and the second transformer 4 are the same, and the total output current of the first transformer 3 and the second transformer 4 can be doubled, which is beneficial for the wide-voltage charging circuit to output a large current. When the wide-voltage charging circuit is applied to a high-voltage output scenario, the host computer sends a PMW signal to the first LLC resonant module 1 and the second LLC resonant module 2, causing them to operate in out-of-phase mode. Simultaneously, it controls the first relay 5 to close and the second relay 6 to open, connecting the secondary windings of the first transformer 3 and the second transformer 4 in series. At this point, the total output current capability of the first transformer 3 and the second transformer 4 remains unchanged, but the output voltage capability is increased. The output terminal of the synchronous rectification module is connected to the battery. The synchronous rectification module receives and rectifies the current output from the secondary windings of the first transformer 3 and the second transformer 4, outputting the rectified DC power to the battery to achieve the charging purpose.
[0026] The first LLC resonant module 1 includes a first switching network 11 and a first resonant unit 12. The input terminal of the first resonant unit 12 is connected to the intersection of two bidirectional switching transistors in the bridge arm of the first switching network 11, and the output terminal of the first resonant unit 12 is connected to the primary side of the first transformer 3.
[0027] The second LLC resonant module 2 includes a second switching network 21 and a second resonant unit 22. The input terminal of the second resonant unit 22 is connected to the intersection of two bidirectional switching transistors of the bridge arm of the first switching network 11, and the output terminal of the second resonant unit 22 is connected to the primary side of the second transformer 4.
[0028] In use, the first switching network 11 and the second switching network 21 respectively receive DC power output from the power supply, and the first switching network 11 and the second switching network 21 are used to invert the input power supply into AC power. The first resonant unit 12 and the second resonant unit 22 are used to form resonance, so that the circuit achieves maximum efficiency. The primary side of the first transformer 3 is used to receive the AC power output from the first switching network 11, and the primary side of the second transformer 4 is used to receive the AC power output from the second switching network 21.
[0029] Furthermore, the first resonant unit 12 includes a first bridge arm 111 and a second bridge arm 112, and the first resonant unit 12 includes a capacitor C1 and an inductor L1. One end of the capacitor C1 is connected to the intersection of the two bidirectional switching transistors of the second bridge arm 112, and the other end is connected to the inductor L1. The other end of the inductor L1 is connected to one end of the primary winding of the first transformer 3, and the other end of the primary winding of the first transformer 3 is connected to the intersection of the two bidirectional switching transistors of the first bridge arm 111.
[0030] Specifically, the first bridge arm 111 includes bidirectional switching transistors Q7 and Q21, and the second bridge arm 112 includes bidirectional switching transistors Q3 and Q1. The drain of bidirectional switching transistor Q7 is connected to the drain of bidirectional switching transistor Q3, the source of bidirectional switching transistor Q7 is connected to the drain of bidirectional switching transistor Q21, the source of bidirectional switching transistor Q21 and the source of bidirectional switching transistor Q1 share a common ground terminal, and the drain of bidirectional switching transistor Q1 is connected to the source of bidirectional switching transistor Q3. One end of capacitor C1 is connected to the source of bidirectional switching transistor Q3 and the drain of bidirectional switching transistor Q1. One end of the primary side of the first transformer 3 is connected to the source of bidirectional switching transistor Q7 and the drain of bidirectional switching transistor Q21.
[0031] The second switching network 21 includes a third bridge arm 211 and a fourth bridge arm 212. The second resonant unit 22 includes a capacitor C2 and an inductor L1. The third bridge arm 211 and the fourth bridge arm 212 are connected in parallel. One end of the capacitor C2 is connected to the intersection of the two bidirectional switching transistors of the fourth bridge arm 212. The other end of the capacitor C2 is connected to the inductor L2. The other end of the inductor L2 is connected to one end of the primary side of the second transformer 4. The other end of the primary side of the second transformer 4 is connected to the intersection of the two bidirectional switching transistors of the third bridge arm 211.
[0032] The third bridge arm 211 includes bidirectional switching transistors Q28 and Q29, and the fourth bridge arm 212 includes bidirectional switching transistors Q27 and Q26. The drain of bidirectional switching transistor Q28 is connected to the drain of bidirectional switching transistor Q27, the source of bidirectional switching transistor Q28 is connected to the drain of bidirectional switching transistor Q29, the source of bidirectional switching transistor Q29 and the source of switching transistor Q26 are grounded together, and the drain of bidirectional switching transistor Q26 is connected to the source of bidirectional switching transistor Q27. One end of capacitor C2 is connected to the source of bidirectional switching transistor Q27 and the drain of bidirectional switching transistor Q26, respectively. One end of the primary side of the second transformer 4 is connected to the source of bidirectional switching transistor Q28 and the drain of bidirectional switching transistor Q29, respectively.
[0033] Please refer to Figure 2 , Figure 2This diagram illustrates the current during the positive half-cycle of a wide-voltage charging circuit applied to a low-voltage, high-current scenario. In practical applications, when the wide-voltage charging circuit is used in a low-voltage, high-current charging scenario, the first relay 5 is open and the second relay 6 is closed, causing the secondary sides of the first transformer 3 and the second transformer 4 to be connected in parallel. Simultaneously, during the positive half-cycle of the current, bidirectional switches Q7 and Q1 of the first switching network 11 are turned on, while bidirectional switches Q3 and Q21 are turned off, driving the primary side of the first transformer 3. At this time, the current of the first LLC resonant module 1 flows sequentially through bidirectional switch Q7, the primary side of the first transformer 3, the first resonant unit 12, and bidirectional switch Q1, finally outputting to ground. The second switching network 21 operates in phase with the first switching network 11. During the positive half-cycle of the current, bidirectional switches Q28 and Q26 are turned on, while bidirectional switches Q27 and Q29 are turned off, driving the primary side of the second transformer 4. At this time, the current of the second LLC resonant module 2 passes sequentially through the bidirectional switch Q28, the primary side of the second transformer 4, the second resonant unit 22, and the bidirectional switch Q26, and is finally output to ground. The primary side of the first transformer 3 drives the secondary side of the first transformer 3 to generate a positive voltage, and the primary side of the second transformer 4 drives the secondary side of the second transformer 4 to generate a positive voltage. Since the secondary sides of the first transformer 3 and the second transformer 4 are connected in parallel, the parallel connection of the first transformer 3 and the second transformer 4 provides a larger charging current.
[0034] Please refer to Figure 3 , Figure 3 This diagram illustrates the current flow during the negative half-cycle of a wide-voltage charging circuit applied to a low-voltage, high-current scenario. During the negative half-cycle, bidirectional switches Q7, Q1, Q28, and Q26 are simultaneously turned off, while bidirectional switches Q3, Q21, Q27, and Q29 are turned on. At this time, the current flow in the first switching network 11 is as follows: bidirectional switch Q3, first resonant unit 12, primary winding of the first transformer 3, bidirectional switch Q21, and finally output to ground. The current flow in the second switching network 21 is the same as that in the first switching network 11, and will not be described in detail here.
[0035] When the current is in the negative half-cycle, the switching of the primary side of the first transformer 3 and the second transformer 4 causes the polarity of the secondary voltage to reverse. Both the secondary sides of the first transformer 3 and the second transformer 4 output negative pulse current. After the secondary sides of the first transformer 3 and the second transformer 4 are connected in parallel, the output negative pulse current is input to the rectifier input module. The synchronous rectifier module 7 rectifies the negative pulse current output by the secondary sides of the first transformer 3 and the second transformer 4.
[0036] Please refer to Figure 4 , Figure 4This diagram illustrates the current during the positive half-cycle of a wide-voltage charging circuit applied to a high-voltage charging scenario. When the circuit is used in a high-voltage charging scenario, the first relay 5 is activated and the second relay 6 is deactivated, connecting the secondary windings of the first transformer 3 and the second transformer 4 in series. During the positive half-cycle, bidirectional switches Q7 and Q1 in the first switching network 11 are activated, while bidirectional switches Q3 and Q21 are deactivated, inducing a positive voltage on the secondary winding of the first transformer 3 and outputting a positive pulse current. In the second switching network 21, bidirectional switches Q29 and Q27 are activated, while bidirectional switches Q28 and Q26 are deactivated, inducing a negative voltage on the secondary winding of the second transformer 4. The negative terminal of the secondary winding of the second transformer 4 is connected in series with the positive terminal of the secondary winding of the first transformer 3 through the activation of the first relay 5, thus boosting the voltage.
[0037] Please refer to Figure 5 , Figure 5 This diagram illustrates the current during the negative half-cycle of a wide-voltage charging circuit applied in a high-voltage charging scenario. During the negative half-cycle, bidirectional switches Q3 and Q21 in the first switching network 11 are turned on, while bidirectional switches Q7 and Q1 are turned off. This induces a negative voltage on the secondary side of the first transformer 3, which outputs a negative current through the series connection of the first relay 5. Meanwhile, bidirectional switches Q28 and Q26 in the second switching network 21 are turned on, while bidirectional switches Q27 and Q29 are turned off, inducing a positive voltage on the secondary side of the second transformer 4. The secondary side of the second transformer 4 is connected in series with the first transformer 3 through the first relay 5, and outputs a negative current. Thus, by connecting the negative voltage on the secondary side of the first transformer 3 with the positive voltage on the secondary side of the second transformer 4 in series, the total voltage is doubled, resulting in a negative pulse current output.
[0038] The synchronous rectification module 7 includes bidirectional switching transistors Q34, Q35, Q33, and Q30. The drain of bidirectional switching transistor Q34 is connected to the drain of bidirectional switching transistor Q33, the source of bidirectional switching transistor Q34 is connected to the drain of bidirectional switching transistor Q35, the source of bidirectional switching transistor Q35 is connected to the source of bidirectional switching transistor Q30, and the drain of bidirectional switching transistor Q30 is connected to the source of bidirectional switching transistor Q33. One end of the secondary side of the first transformer 3 and the third end of the first relay 5 are connected to the intersection of bidirectional switching transistors Q33 and Q30. The fourth end of the first relay 5 and the third end of the second relay 6 are connected to the intersection of bidirectional switching transistors Q34 and Q35. In this example, the intersection of bidirectional switching transistors Q34 and Q35 is the first input terminal of the synchronous rectification module 7, and the intersection of bidirectional switching transistors Q33 and Q30 is the second input terminal of the synchronous rectification module.
[0039] During rectification, when the current is in the positive half-cycle, bidirectional switches Q33 and Q35 are turned on, providing a low-impedance path. Bidirectional switches Q34 and Q30 are reverse-biased and cut off to prevent current from flowing in the reverse direction through the secondary sides of the first transformer 3 and the second transformer 4. When the current is in the negative half-cycle, bidirectional switches Q34 and Q30 are turned on, while bidirectional switches Q33 and Q35 are reverse-biased and cut off.
[0040] Thus, in different application scenarios and under different current cycles, efficient energy conversion is achieved by controlling the bidirectional switching transistors Q34, Q33, Q35, and Q30 to complement and interact, thereby ensuring stable output of electrical signals.
[0041] This utility model also provides a charger, which includes the wide voltage charging circuit described above.
[0042] In summary, by switching the engaged and disengaged states of the first relay 5 and the second relay 6 in different application scenarios, and switching the series and parallel connection states of the secondary windings of the first transformer 3 and the second transformer 4, in low-voltage, high-current charging scenarios, the first LLC resonant network and the second LLC resonant network operate in phase and frequency, with the first relay 5 disengaged and the second relay 6 engaged, resulting in parallel output from the secondary windings of the first transformer 3 and the second transformer 4, thus increasing the charging current. In high-voltage charging scenarios, the first LLC resonant network and the second LLC resonant network operate out of phase, with the first relay 5 engaged and the second relay 6 disengaged, resulting in series boost voltage from the secondary windings of the first transformer 3 and the second transformer 4. This effectively meets different charging needs and is adaptable to battery packs with different voltages.
[0043] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.
Claims
1. A wide-voltage charging circuit, characterized in that, include: The system comprises a first LLC resonant module (1), a second LLC resonant module (2), a first transformer (3), a second transformer (4), a first relay (5), a second relay (6), and a synchronous rectification module (7); the output terminal of the first LLC resonant module (1) is connected to the primary side of the first transformer (3), the output terminal of the second LLC resonant module (2) is connected to the primary side of the second transformer (4), the first relay (5) and the second relay (6) have a first terminal, a second terminal, a third terminal, and a fourth terminal, respectively, and the synchronous rectification module (7) has a first input terminal and a second input terminal; one end of the secondary side of the first transformer (3) is connected to the third terminal of the first relay (5) and the first input terminal of the synchronous rectification module (7), and the first transformer (3) is connected to the primary side of the second transformer (4). 3) The other end of the secondary side is connected to the first end of the second relay (6); the first end of the first relay (5) is connected to one end of the secondary side of the second transformer (4), and the fourth end of the first relay (5) is connected to the second input end of the synchronous rectification module (7); the other end of the secondary side of the second transformer (4) is connected to the first end of the second relay (6), and the third end of the second relay (6) is connected to the second input end of the synchronous rectification module (7); when the first relay (5) is open and the second relay (6) is closed, the secondary sides of the first transformer (3) and the second transformer (4) are connected in parallel; when the first relay (5) is closed and the second relay (6) is open, the secondary sides of the first transformer (3) and the second transformer (4) are connected in series.
2. The wide voltage charging circuit according to claim 1, characterized in that, The first LLC resonant module (1) includes a first switching network (11) and a first resonant unit (12). The input terminal of the first resonant unit (12) is connected to the intersection of two bidirectional switching transistors in the bridge arm of the first switching network (11), and the output terminal of the first resonant unit (12) is connected to the primary side of the first transformer (3).
3. The wide voltage charging circuit according to claim 1, characterized in that, The second LLC resonant module (2) includes a second switching network (21) and a second resonant unit (22). The input terminal of the second resonant unit (22) is connected to the intersection of two bidirectional switching transistors of the bridge arm of the second switching network (21), and the output terminal of the second resonant unit (22) is connected to the primary side of the second transformer (4).
4. The wide voltage charging circuit according to claim 2, characterized in that, The first switching network (11) includes a first bridge arm (111) and a second bridge arm (112). The first resonant unit (12) includes a capacitor C1 and an inductor L1. The first bridge arm (111) and the second bridge arm (112) are connected in parallel. One end of the capacitor C1 is connected to the intersection of the two bidirectional switching transistors of the second bridge arm (112), and the other end is connected to the inductor L1. The other end of the inductor L1 is connected to one end of the primary side of the first transformer (3). The other end of the primary side of the first transformer (3) is connected to the intersection of the two bidirectional switching transistors of the first bridge arm (111).
5. The wide voltage charging circuit according to claim 3, characterized in that, The second switching network (21) includes a third bridge arm (211) and a fourth bridge arm (212). The second resonant unit (22) includes a capacitor C2 and an inductor L1. The third bridge arm (211) and the fourth bridge arm (212) are connected in parallel. One end of the capacitor C2 is connected to the intersection of the two bidirectional switching transistors of the fourth bridge arm (212). The other end of the capacitor C2 is connected to the inductor L2. The other end of the inductor L2 is connected to one end of the primary side of the second transformer (4). The other end of the primary side of the second transformer (4) is connected to the intersection of the two bidirectional switching transistors of the third bridge arm (211).
6. The wide voltage charging circuit according to claim 4, characterized in that, The first bridge arm (111) includes bidirectional switching transistors Q7 and Q21, and the second bridge arm (112) includes bidirectional switching transistors Q3 and Q1. The drain of the bidirectional switching transistor Q7 is connected to the drain of the bidirectional switching transistor Q3, the source of the bidirectional switching transistor Q7 is connected to the drain of the bidirectional switching transistor Q21, the source of the bidirectional switching transistor Q21 and the source of the bidirectional switching transistor Q1 share a common ground terminal, and the drain of the bidirectional switching transistor Q1 is connected to the source of the bidirectional switching transistor Q3. One end of the capacitor C1 is connected to the source of the bidirectional switching transistor Q3 and the drain of the bidirectional switching transistor Q1. One end of the primary side of the first transformer is connected to the source of the bidirectional switching transistor Q7 and the drain of the bidirectional switching transistor Q21.
7. The wide voltage charging circuit according to claim 5, characterized in that, The third bridge arm (211) includes bidirectional switching transistors Q28 and Q29, and the fourth bridge arm (212) includes bidirectional switching transistors Q27 and Q26. The drain of the bidirectional switching transistor Q28 is connected to the drain of the bidirectional switching transistor Q27, the source of the bidirectional switching transistor Q28 is connected to the drain of the bidirectional switching transistor Q29, the source of the bidirectional switching transistor Q29 and the source of the switching transistor Q26 are grounded together, and the drain of the bidirectional switching transistor Q26 is connected to the source of the bidirectional switching transistor Q27. One end of the capacitor C2 is connected to the source of the bidirectional switching transistor Q27 and the drain of the bidirectional switching transistor Q26, and one end of the primary side of the second transformer (4) is connected to the source of the bidirectional switching transistor Q28 and the drain of the bidirectional switching transistor Q29.
8. The wide voltage charging circuit according to claim 1, characterized in that, The synchronous rectification module (7) includes bidirectional switching transistors Q34, Q35, Q33, and Q30; the drain of the bidirectional switching transistor Q34 is connected to the drain of the bidirectional switching transistor Q33, the source of the bidirectional switching transistor Q34 is connected to the drain of the bidirectional switching transistor Q35, the source of the bidirectional switching transistor Q35 is connected to the source of the bidirectional switching transistor Q30, and the drain of the bidirectional switching transistor Q30 is connected to the source of the bidirectional switching transistor Q33; one end of the secondary side of the first transformer and the third end of the first relay (5) are connected together to the intersection of the bidirectional switching transistors Q33 and Q30, and the fourth end of the first relay (5) and the third end of the second relay (6) are connected together to the intersection of the bidirectional switching transistors Q34 and Q35.
9. A charger, characterized in that, Includes the wide voltage charging circuit as described in any one of claims 1-8.