AC-DC conversion circuit and device

Abstract

The invention discloses an AC-DC conversion circuit, which comprises a power supply module, a first power supply conversion module, a second power supply conversion module, a sampling module and a control module, and is characterized in that when alternating current transmitted by the power supply module is in a first half cycle, the first power supply conversion module is used for converting the alternating current transmitted by the power supply module into first direct current; when the alternating current transmitted by the power supply module is in a second half cycle, the second power supply conversion module is used for converting the alternating current input by the power supply module into a second direct current; the sampling module is used for collecting the first direct current or the second direct current and generating a feedback signal; the control module is configured to be used for outputting a control signal and adjusting the frequency of the control signal to the first control end and the second control end in real time based on the feedback signal, so that the first power conversion module and the second power conversion module work. According to the design, the control mode of the circuit can be simplified, the overall hardware cost is reduced, the mass production is further improved, and meanwhile the conversion efficiency of electric energy is improved.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to an AC-DC conversion current and device. Background Art

[0002] As electronic equipment's requirements for power quality continue to increase, power factor correction (PFC) circuits play an important role in AC to DC power supplies. Traditional bridge rectifier circuits have been widely used in AC-DC conversion, but they suffer from certain efficiency losses, especially under high load and high frequency working conditions. In order to improve power conversion efficiency and reduce harmonic pollution, the prior art AC-DC conversion circuits generally use bridgeless PFC circuits, in which totem pole circuits are used in combination with digital signal processor (DSP) control methods to achieve more efficient power factor correction.

[0003] The totem pole circuit uses its unique structure to significantly reduce output ripple and enhance the stability of the power supply while improving the power factor. However, the complexity of this solution is high, and the control system needs to rely on advanced DSP control technology, and usually needs to use gallium carbide (GaN) or silicon carbide (SiC) power MOSFET to meet the high-frequency and high-voltage working requirements. Although these technologies have certain advantages in improving power efficiency, the conversion efficiency is low, but due to the high hardware cost, long design cycle, complex products and difficulty in mass production, and, therefore, the existing bridgeless PFC circuit has certain challenges in mass production; in addition, the design method combined with DSP control requires fine adjustment and complex algorithm processing, which increases the design complexity of the control system and makes the system debugging and maintenance more difficult.

[0004] Therefore, how to simplify the control method of AC-DC circuits, reduce production costs and improve the conversion efficiency of power supplies has become a key issue that needs to be solved urgently in the current technical field. Summary of the invention

[0005] In order to solve the technical defects raised in the above-mentioned background technology, the embodiments of the present application provide an AC-DC conversion current and device, which can simplify the control method of the circuit, avoid the traditional totem pole circuit and complex DSP control design, reduce the overall hardware cost, and at the same time improve the conversion efficiency of the AC-DC power supply, and have better economy and market competitiveness.

[0006] The present invention adopts the following technical solution:

[0007] In a first aspect, an embodiment of the present invention provides an AC-DC conversion circuit, comprising:

[0008] A power module, the power module is used to receive alternating current transmitted by an external power source;

[0009] A first power conversion module, having a first AC input terminal, a first control terminal and a first DC output terminal, wherein the first AC input terminal is electrically connected to the output terminal of the power module; when the AC power delivered by the power module is in the first half cycle, the first power conversion module is used to convert the AC power delivered by the power module into a first DC power;

[0010] A second power conversion module, having a second AC input terminal, a second control terminal and a second DC output terminal, wherein the second AC input terminal is electrically connected to the output terminal of the power module, and when the AC power delivered by the power module is in the second half cycle, the second power conversion module is used to convert the AC power input by the power module into a second DC power;

[0011] A sampling module, the sampling module is used to collect the first direct current or the second direct current and generate a feedback signal;

[0012] A control module, wherein the control module is electrically connected to the first power conversion module, the second power conversion module and the sampling module respectively, and the control module is configured to output a control signal and adjust the frequency of the control signal to the first control end and the second control end in real time based on the feedback signal, so that the first power conversion module and the second power conversion module can work.

[0013] Optionally, the first power conversion module includes:

[0014] A first switch unit, wherein a control end of the first switch unit is electrically connected to the control module, an input end of the switch unit is electrically connected to the power module, and the first switch unit is used to be turned on / off based on a control signal transmitted by the control module;

[0015] a first rectifying unit, wherein an input end of the first rectifying unit is electrically connected to an output end of the first switching unit, and the first rectifying unit is used to rectify the alternating current transmitted by the first switching unit into direct current;

[0016] A first energy storage isolation unit, wherein a first end of the first energy storage isolation unit is electrically connected to an output end of the first rectifier unit, a second end of the first energy storage isolation unit is electrically connected to an external load terminal, and the first energy storage isolation unit is used to store direct current transmitted by the first rectifier unit; and when the second power conversion module converts the alternating current transmitted by the power module, the first energy storage isolation unit is at a center potential of the alternating current to isolate the alternating current transmitted by the first switch unit to the second power conversion module.

[0017] Optionally, the second power conversion module includes:

[0018] A second switch unit, wherein a control end of the second switch unit is electrically connected to the control module, an input end of the second switch unit is electrically connected to the power module, and the second switch unit is used to be turned on / off based on a control signal transmitted by the control module;

[0019] a second rectifying unit, wherein an input end of the second rectifying unit is electrically connected to an output end of the second switching unit, and the second rectifying unit is used to rectify the alternating current transmitted by the second switching unit into direct current;

[0020] a second energy storage isolation unit, wherein the first end of the second energy storage isolation unit is electrically connected to the output end of the first rectifier unit, the second end of the second energy storage isolation unit is electrically connected to an external load terminal, and the second energy storage isolation unit is used to store the direct current transmitted by the second rectifier unit; and when the first power conversion module is converting the alternating current transmitted by the power module, the second energy storage isolation unit is at the center potential of the alternating current to isolate the alternating current transmitted by the second switch unit to the first power conversion module.

[0021] Optionally, the first energy storage isolation unit includes:

[0022] a first inductor, wherein a first end of the first inductor is electrically connected to an output end of the first rectifying unit, and a second end of the first inductor is electrically connected to an external load terminal;

[0023] A first diode, wherein an anode of the first diode is electrically connected to the second end of the first inductor, and a cathode of the first diode is electrically connected to the external load terminal.

[0024] Optionally, the second energy storage isolation unit includes:

[0025] a second inductor, wherein a first end of the second inductor is electrically connected to an output end of the second rectifying unit, and a second end of the second inductor is electrically connected to an external load terminal;

[0026] A second diode, an anode of the second diode is electrically connected to the second end of the second inductor, and a cathode of the second diode is electrically connected to the external load terminal.

[0027] Optionally, the first switch unit includes:

[0028] A first transistor, wherein a base of the first transistor is electrically connected to the control module, and a collector of the first transistor is electrically connected to an external power supply;

[0029] a second triode, wherein the base of the second triode is electrically connected to the control module, and the emitter of the second triode is electrically connected to the emitter of the first triode;

[0030] A first switching element, wherein the gate of the first switching element is electrically connected to the collector of the second transistor, the drain is electrically connected to the second end of the first inductor, and the source is electrically connected to the input end of the first rectifier unit, and the first switching element is used to receive the control signal and turn on / off the alternating current transmitted from the first inductor to the first rectifier unit based on the control signal.

[0031] Optionally, the second switch unit includes:

[0032] a third triode, wherein the base of the second triode is electrically connected to the control module, and the emitter of the second triode is electrically connected to the emitter of the fourth triode;

[0033] a fourth triode, wherein a base of the fourth triode is electrically connected to the control module, and a collector of the fourth triode is electrically connected to the external power supply;

[0034] A second switching element, wherein the gate of the second switching element is electrically connected to the emitter of the second transistor, the drain is electrically connected to the first end of the second inductor, the source is electrically connected to the input end of the second rectifier unit, and the second switching element is used to receive the control signal and turn on / off the alternating current transmitted from the second inductor to the first rectifier unit based on the control signal.

[0035] Optionally, the sampling module includes a sampling resistor R1, a first end of the sampling resistor is electrically connected to the source of the first switching element and the second switching element respectively, and a second end of the sampling resistor is electrically connected to the control module, for collecting the first direct current or the second direct current and generating a feedback signal.

[0036] Optionally, the control module includes a control chip U1 having a signal output end and a signal receiving end, the signal output end being electrically connected to the gates of the first switching element and the second switching element respectively, and the signal receiving end being electrically connected to the second end of the sampling resistor, the control chip being used to output a control signal and to adjust the pulse width frequency of the control signal to the gates of the first switching element and the second switching element respectively in real time based on the feedback signal received by the signal receiving end, so as to control the on / off of the first switching element and the second switching element.

[0037] In a second aspect, an embodiment of the present invention provides an AC-DC conversion device, including the AC-DC conversion circuit as described in the first aspect;

[0038] A circuit board, the AC-DC conversion circuit is engraved on the circuit board.

[0039] In summary, the beneficial effects of the present invention are:

[0040] The first power conversion module and the second power conversion module process the AC signals of the positive half cycle and the negative half cycle respectively, thereby improving the conversion efficiency, avoiding the waste of electric energy, and improving the stability and power quality of the power conversion. At the same time, the sampling module and the control module are used in coordination to collect the DC output signal in real time and automatically adjust the control frequency according to the feedback signal, thereby optimizing the efficiency of the power conversion, reducing the dependence on the complex digital signal processor (DSP) technology, and making the design of the present invention more concise. The control module can dynamically adjust the working state of each power conversion module, which not only improves the operating efficiency of the present embodiment, but also simplifies the design and debugging process, shortens the development cycle, and reduces the demand for high-cost components (such as gallium carbide and silicon carbide MOSFET), reduces the overall hardware cost, and improves the mass production of the present invention, with better economy and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 is an AC-DC conversion circuit architecture diagram of an embodiment of the present invention;

[0043] Figure 2 is a schematic diagram of a first power conversion module according to an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of a second power conversion module according to an embodiment of the present invention;

[0045] Figure 4 is a schematic diagram of the first power conversion module of the embodiment of the present invention when it is working;

[0046] Figure 5 is a schematic diagram of the second power conversion module of the embodiment of the present invention when it is working;

[0047] Figure 6 is a specific structural principle diagram of the first power conversion module and the second power conversion module of an embodiment of the present invention;

[0048] Figure 7 Schematic diagram of a power module according to an embodiment of the present invention. Description of the drawings:

[0050] 100, power module; 110, first filter unit; 120, second filter unit; 130, protection unit; LF1, first common mode inductor; LF2, second common mode inductor;

[0051] 200, first power conversion module; 210, first switch unit; Q1, first transistor; Q2, second transistor; Q5, first switch element; 220, first rectifier unit; D1, first rectifier diode; 230, first energy storage isolation unit; L1, first inductor; D5, first diode;

[0052] 300, second power conversion module; 310, second switch unit; Q3, third transistor; Q4, fourth transistor; Q6, second switch element; 320, second rectifier unit; D2, second rectifier diode; 330, second energy storage isolation unit; L2, second inductor; D6, second diode;

[0053] 400, sampling module; R1, sampling resistor;

[0054] 500, control module; U1, control chip;

[0055] V+, load terminal. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0057] like Figure 1As shown, an embodiment of the present application provides an AC-DC conversion circuit, including a power module 100, a first power conversion module 200, a second power conversion module 300, a sampling module 400 and a control module 500, wherein the power module 100 is used to receive the alternating current transmitted by an external power source; the first power conversion module 200 has a first alternating current input terminal, a first control terminal and a first direct current output terminal, wherein the first alternating current input terminal is electrically connected to the output terminal of the power module 100; when the alternating current transmitted by the power module 100 is a first half cycle, the first power conversion module 200 is used to convert the alternating current transmitted by the power module 100 into a first direct current; the second power conversion module 300 has a second alternating current input terminal, a second control terminal and a first direct current output terminal The second DC output terminal and the second AC input terminal are electrically connected to the output terminal of the power module 100. When the AC power transmitted by the power module 100 is the second half cycle, the second power conversion module 300 is used to convert the AC power input by the power module 100 into a second DC power; the adopting module is used to collect the first DC power or the second DC power and generate a feedback signal; the control module 500 is electrically connected to the first power conversion module 200, the second power conversion module 300 and the sampling module 400 respectively, and the control module 500 is configured to output a control signal and adjust the frequency of the control signal to the first control terminal and the second control terminal in real time based on the feedback signal, so that the first power conversion module 200 and the second power conversion module 300 can work.

[0058] In the embodiment of the present application, the power supply circuit is used for external AC power, and the power supply circuit may include a first filter unit 110, a protection unit 130, a first common mode inductor LF1, a second filter unit 120 and a second common mode inductor LF2. Among them, the two ends of the first filter unit 110 are electrically connected to the protection unit 130, and the protection unit 130 may be a varistor, and the two ends of the varistor are connected in parallel with the first filter unit 110, the two ports on the input side of the first common mode inductor LF1 are electrically connected to the two ends of the varistor, the two ends of the second filter unit 120 are electrically connected to the two sides of the output end of the first common mode inductor LF1, and the input end of the second common mode inductor LF2 is electrically connected to the output end of the first common mode inductor LF1. By connecting the first filter unit 110 in parallel with the protection unit 130 (such as a varistor), surge voltage and transient overvoltage from the external AC power supply can be effectively absorbed to protect sensitive components in the circuit from damage. The varistor is connected to the input end of the first common mode inductor LF1, ensuring that the common mode interference on the input side is effectively suppressed, reducing the impact of external noise on the power supply. The second filter unit 120 further filters the high frequency noise at the output end of the power supply to ensure the stability of the output voltage. The second common mode inductor LF2 is connected to the first common mode inductor LF1, and by suppressing differential mode noise and common mode noise, the electromagnetic compatibility (EMC) of the power supply is further improved, ensuring the stable operation of the power supply under different working conditions.

[0059] It should be understood that the first half cycle is a positive half cycle, and the second half cycle is a negative half cycle. It is understandable that the alternating current has a positive half cycle and a negative half cycle. When the alternating current delivered by the power module 100 is a positive half cycle, the first power conversion module 200 converts the alternating current into a first direct current; and when the alternating current enters a negative half cycle, the second power conversion module 300 converts the alternating current into a second direct current. The power module 100 transmits the alternating current signal to the input end of the first power conversion module 200 and the second power conversion module 300 through its output end, respectively, and can perform power conversion in the positive half cycle and the negative half cycle respectively. It should be noted that the first power conversion module 200 and the second power conversion module 300 cannot work at the same time, only one of them can work. The sampling module 400 collects the output first direct current or second direct current in real time, and generates feedback signals, which reflect the current working state of the first power conversion module 200 or the second power conversion module 300 and the output voltage characteristics. The control module 500 is connected to the power module 100, the first power conversion module 200, the second power conversion module 300 and the sampling module 400. Based on the feedback signal provided by the sampling module 400, the control module 500 dynamically adjusts the frequency of the control signal and outputs it to the first control terminal and the second control terminal, thereby accurately adjusting the start and stop states of the first power conversion module 200 and the second power conversion module 300. The first power conversion module 200 and the second power conversion module 300 process the AC signals of the positive half cycle and the negative half cycle respectively, thereby avoiding the waste of electric energy and improving the stability and power quality. At the same time, the sampling module 400 and the control module 500 are used in coordination to collect the DC output signal in real time and automatically adjust the control frequency according to the feedback signal, thereby optimizing the efficiency of power conversion and reducing the dependence on complex digital signal processor (DSP) technology, making the design of this embodiment more concise. The control module 500 can dynamically adjust the working state of each power conversion module, which not only improves the operating efficiency, but also simplifies the design and debugging process, shortens the development cycle, reduces the demand for high-cost components (such as gallium carbide and silicon carbide MOSFET), reduces the overall hardware cost, and improves the mass production of this embodiment, so that it has better economy and market competitiveness.

[0060] Further, such as Figure 2 and Figure 6As shown, the first power conversion module 200 includes a first switch unit 210, a first rectifier unit 220 and a first energy storage isolation unit 230. The control end of the first switch unit 210 is electrically connected to the control module 500, and the input end of the switch unit is electrically connected to the power module 100. The first switch unit 210 is used to turn on / off based on the control signal transmitted by the control module 500; the input end of the first rectifier unit 220 is electrically connected to the output end of the first switch unit 210, and the first rectifier unit is used to rectify the AC power transmitted by the first switch unit. The first end of the first energy storage isolation unit 230 is electrically connected to the output end of the first rectifier unit 220, and the second end of the first energy storage isolation unit 230 is electrically connected to the external load terminal V+. The first energy storage isolation unit 230 is used to store the direct current transmitted by the first rectifier unit 220; and when the second power conversion module 300 converts the alternating current transmitted by the power module 100, the first energy storage isolation unit 230 is at the center potential of the alternating current to isolate the alternating current transmitted from the first switch unit 210 to the second power conversion module 300.

[0061] In an embodiment of the present application, the first switch unit 210 has a control end, which is electrically connected to the main control module. The main control module sends a control signal to the first switch unit 210. The control signal can be a PWM signal (pulse width modulation mode signal), which can continuously drive the first switch unit 210 to be turned on and off, thereby controlling the current at the input end and the current at the output end of the first switch unit 210. The first rectifier unit 220 can be a first rectifier diode D1. The first switch control unit controls the current to flow into the first rectifier diode D1, thereby converting alternating current into a first direct current; then, through the presence of the second energy storage unit, the first energy storage isolation unit 230 stores the first direct current from the first rectifier unit 220 to ensure that the output current is stable and efficient.

[0062] Optional, such as Figure 3 and Figure 6As shown, the second power conversion module 300 includes a second switch unit 310, a second rectifier unit 320, and a second energy storage isolation unit 330. The control end of the second switch unit 310 is electrically connected to the control module 500, and the input end of the first switch unit 210 is electrically connected to the power module 100. The second switch unit 310 is used to turn on / off based on the control signal transmitted by the control module 500; the input end of the second rectifier unit 320 is electrically connected to the output end of the second switch unit 310, and the second rectifier unit 320 is used to transmit the second switch unit 310. The alternating current is rectified into direct current; the first end of the second energy storage isolation unit 330 is electrically connected to the output end of the first rectifying unit 220, the second end of the second energy storage isolation unit 330 is electrically connected to the external load terminal V+, and the second energy storage isolation unit 330 is used to store the direct current delivered by the second rectifying unit 320; and when the first power conversion module 200 converts the alternating current delivered by the power module 100, the second energy storage isolation unit 330 is at the center potential of the alternating current to isolate the alternating current delivered by the second switch unit 310 to the first power conversion module 200.

[0063] In the embodiment of the present application, the control end of the above-mentioned second switch unit 310 is also electrically connected to the control module 500, the second switch unit 310 and the first switch unit 210 are symmetrically arranged, the input end of the second switch unit 310 is electrically connected to the output end of the power module 100, and the output end is used to output and connect an external load. The second switch unit 310 mainly processes the alternating current of the negative half cycle in this embodiment, and then transmits the conducted current to the second rectifier unit 320. The second rectifier unit 320 can be a second rectifier diode D2. The alternating current transmitted by the second switch unit 310 is converted by the second rectifier diode D2, so that the second direct current can be output, and then the second energy storage isolation unit 330 continues to store the second direct current to ensure the stability and quality of the output current.

[0064] At the same time, it should be noted that the first energy storage isolation unit 230 is arranged in the first power conversion module 200, and the second energy storage isolation unit 330 is arranged in the second power conversion module 300. When the first power conversion module 200 is working (when processing the positive half cycle of the alternating current), that is, when the voltage delivered by the power module 100 is connected, the second energy storage isolation unit 330 will be at the center potential (zero potential) of the alternating current. In other words, there is no voltage at both ends of the second energy storage isolation unit 330. At the same time, since the first switch unit 210 and the second switch unit 310 are turned on at the same time, the second energy storage isolation unit 330 will block the first switch. The current of the switch unit 210 flows to the second switch unit 310, and the input end of the second switch unit 310 is electrically connected to the second end of the second energy storage isolation unit 330, so that when the first power conversion module 200 is working, the second power conversion module 300 will not work at this time; similarly, when the second power conversion is working (when processing the negative half cycle of the alternating current), the first energy storage isolation unit 230 will be at the center potential (zero potential) of the alternating current, and the input end of the first switch unit 210 is electrically connected to the second end of the first energy storage isolation unit 230, so that when the second power conversion module 300 is working, the first power conversion module 200 will not work at this time. In this way, the present embodiment converts electric energy independently in the positive half cycle and the negative half cycle, improves the efficiency of electric energy conversion, and reduces the loss that may be generated by the simultaneous operation of the two power modules 100. In addition, the design simplifies the power control method, avoids complex digital signal processing and high-frequency switch control, reduces the complexity of system design, improves the stability of the system, reduces hardware costs, and enhances the mass production and market competitiveness of the product.

[0065] Optional, such as Figure 6 As shown, the first energy storage isolation unit 230 includes a first inductor L1 and a first diode D5. The first end of the first inductor L1 is electrically connected to the output end of the first rectifier unit, and the second end of the first inductor L1 is electrically connected to the external load terminal V+; the anode of the first diode D5 is electrically connected to the second end of the first inductor L1, and the cathode of the first diode D5 is electrically connected to the external load terminal V+.

[0066] In the embodiment of the present application, the first end of the first inductor L1 is electrically connected to the first rectifier diode D1 and the second common mode inductor LF2. The first inductor L1 is mainly used to store energy for the first direct current transmitted by the first rectifier diode D1, and then transmit the stored first direct current to the anode of the first diode D5. The first diode D5 is mainly used as an energy release path for the first inductor L1, and performs high-frequency rectification and transmits it to the load terminal V+. In addition, it should be noted that the first inductor L1 has not only the function of energy storage, but also the function of isolation. The first inductor L1 has a resistance effect on current changes. As mentioned above, in the positive half cycle of the alternating current, when the current tries to flow from the second switch element Q6 to the first switch element Q5, the first inductor L1 is in the positive half cycle of the alternating current at this time, so the voltage across the first inductor L1 will be close to zero, thereby being able to block the current of the second switch element Q6 from flowing to the first switch element Q5, and thereby in the positive half cycle of the alternating current, enabling the first power conversion module 200 to work, while the second power conversion module 300 does not work.

[0067] Optional, such as Figure 6 As shown, the second energy storage isolation unit 330 includes a second inductor L2 and a second diode. The first end of the second inductor L2 is electrically connected to the output end of the second rectifier unit 320, and the second end of the second inductor L2 is electrically connected to the external load terminal V+; the anode of the second diode D6 is electrically connected to the second end of the second inductor L2, and the cathode of the second diode D6 is electrically connected to the external load terminal V+.

[0068] In the embodiment of the present application, the first end of the second inductor L2 is electrically connected to the second rectifier diode D2 and the second common mode inductor LF2. The second inductor L2 is mainly used to store the second direct current transmitted by the second rectifier diode D2, and then transmit the first direct current after energy storage to the anode of the second diode D6. The second diode D6 is mainly used as an energy release path for the first inductor L1, and performs high-frequency rectification, and outputs it to the load terminal V+, thereby supplying power to the load device. In addition, it should be noted that the principle and function of the second inductor L2 are consistent with those of the first inductor L1, and can only work during the negative half cycle of the alternating current. The specific principle is consistent with the principle mentioned in the first inductor L1, and is symmetrically designed. Therefore, at this time, the second inductor L2 is in the negative half cycle of the alternating current, so the voltage at both ends of the second inductor L2 will be close to zero, thereby being able to block the current of the first switch element Q5 from flowing to the second switch element Q6, and thereby during the negative half cycle of the alternating current, enabling the second power conversion module 300 to work, while the first power conversion module 200 does not work.

[0069] There may be multiple first inductors L1 and second inductors L2 connected in parallel to form an inductor string.

[0070] Optional, such as Figure 6 As shown, the first switch unit 210 includes a first transistor Q1, a second transistor Q2, and a first switch element Q5. The base of the first transistor Q1 is electrically connected to the control module 500, and the collector of the first transistor Q1 is electrically connected to the external power supply; the base of the second transistor Q2 is electrically connected to the control module 500, and the emitter of the second transistor Q2 is electrically connected to the emitter of the first transistor; the gate of the first switch element Q5 is electrically connected to the collector of the second transistor Q2, the drain is electrically connected to the second end of the first inductor L1, and the source is electrically connected to the input end of the first rectifier unit 220. The first switch element Q5 is used to receive a control signal and turn on / off the alternating current transmitted to the first rectifier unit 220 by the first inductor L1 based on the control signal.

[0071] In the embodiment of the present application, the first transistor Q1 is an NPN transistor, the second transistor Q2 is a PNP transistor, and the first switch element Q5 can be a first MOS transistor. The collector of the first transistor Q1 is electrically connected to an external power supply, and the base is electrically connected to the control module 500. The control module 500 regulates the current flow process through the control signal. The control signal first reaches the first transistor Q1 to control its on and off states. When it is turned on, the current flows to the second transistor Q2. The emitter of the second transistor Q2 also starts to turn on after receiving the signal sent by the emitter of the first transistor. After turning on, the control current flows through the first current limiting resistor R7, and enters the first switch element Q5 after being limited by the first current limiting resistor R7. When the first switch element Q5 is turned on, the current passes through the first inductor L1 and is transmitted to the first rectifier diode D1 for rectification and conversion, completing the conversion of AC to DC. Therefore, under the action of the control signal, the current flow can be efficiently managed, the working state of the switching element can be adjusted, and the conversion of electric energy can be completed, ultimately achieving the purpose of current control and rectification.

[0072] Optional, such as Figure 6 As shown, the second switch unit 310 includes a third transistor Q3, a fourth transistor Q4 and a second switch element Q6, the base of the second transistor Q2 is electrically connected to the control module 500, and the emitter of the second transistor Q2 is electrically connected to the emitter of the fourth transistor Q4; the base of the fourth transistor Q4 is electrically connected to the control module 500, and the collector is electrically connected to the external power supply; the gate of the second switch element Q6 is electrically connected to the emitter of the second transistor Q2, the drain is electrically connected to the first end of the second inductor L2, and the source is electrically connected to the input end of the second rectifier unit 320, and the second switch element Q6 is used to receive a control signal and turn on / off the alternating current transmitted from the second inductor L2 to the first rectifier unit 220 based on the control signal.

[0073] In the embodiment of the present application, the third transistor Q3 is a PNP type, and the fourth transistor Q4 is an NPN type. In this circuit, the fourth transistor Q4 is an NPN type transistor, and its base is connected to the control module 500. The control module 500 controls the switching state of the fourth transistor Q4 according to the input signal. When the control signal increases the base current of the fourth transistor Q4, the fourth transistor Q4 is turned on, and the current flows from its collector to the emitter. At this time, the emitter voltage of the fourth transistor Q4 will affect the working state of the third transistor Q3 (PNP type) connected thereto. Specifically, when the fourth transistor Q4 is turned on, its emitter voltage is close to the ground potential, so that the base-emitter voltage of the third transistor Q3 meets its turn-on condition, and the third transistor Q3 also starts to turn on. The emitter of the third transistor Q3 is connected to the emitter of the fourth transistor Q4, so its collector current will continue to flow to the fourth transistor Q4, keeping the fourth transistor Q4 in a conducting state. The gate of the second switch element Q6 is connected to the emitter of the third transistor Q3. When the third transistor Q3 is turned on, the potential change of its emitter will affect the gate of the second switch element Q6. When the second switch element Q6 is turned on, the current passes through the second inductor L2 and is transmitted to the second rectifier diode D2 for rectification and conversion, completing the conversion of AC to DC.

[0074] Optional, such as Figure 3 and Figure 4 As shown, the sampling module 400 includes a sampling resistor R1, a first end of the sampling resistor R1 is electrically connected to the source of the first switch element Q5 and the second switch element Q6, and a second end of the sampling resistor R1 is electrically connected to the control module 500, for collecting the first direct current or the second direct current and generating a feedback signal.

[0075] In the embodiment of the present application, the principle of the sampling resistor R1 is based on Ohm's law. When the current passes through the sampling resistor R1, a voltage drop will be generated at both ends of the sampling resistor R1, and the voltage drop is proportional to the current. Specifically, when the current flows through the sampling resistor R1, a voltage drop will be generated at both ends of the resistor. The magnitude of the voltage drop is determined by the formula V=I×R, where V is the voltage drop, I is the current, and R is the resistance of the sampling resistor R1. The control module 500 indirectly obtains the magnitude of the current by measuring the voltage drop across the sampling resistor R1, thereby realizing the "voltage sampling" of the current. Through this method, the control module 500 can monitor the current changes in the circuit in real time, and adjust the working state of the circuit according to the feedback signal of the current, realize closed-loop control, and ensure the stability and precise regulation of the circuit.

[0076] Optional, such as Figure 2As shown, the control module 500 includes a control chip U1 having a signal output end and a signal receiving end. The signal output end is electrically connected to the gates of the first switching element Q5 and the second switching element Q6 respectively, and the signal receiving end is electrically connected to the second end of the sampling resistor R1. The control chip U1 is used to output a control signal and adjust the pulse width frequency of the control signal to the gates of the first switching element Q5 and the second switching element Q6 in real time based on the feedback signal received by the signal receiving end to control the on / off of the first switching element Q5 and the second switching element Q6.

[0077] In the embodiment of the present application, the control chip U1 adjusts the working state (on or off) of the two switch elements (the first switch element Q5 and the second switch element Q6). The signal output end of the control chip U1 is connected to the gate of the first and second switch elements Q6 respectively, and is used to output a control signal to adjust the switch state of the switch element. When a control signal is applied to the gate, the switch element will change the on and off state according to the level of the control signal or the change of pulse width modulation (PWM), thereby controlling the flow of current. At the same time, the signal receiving end of the control chip U1U1 is connected to the second end of the sampling resistor R1. The function of the sampling resistor R1 is to generate a voltage signal at both ends when current flows through it. The voltage signal is proportional to the current size and is transmitted to the control chip U1 as a feedback signal. The control chip U1 monitors the current in the circuit in real time by receiving the feedback signal, and then adjusts the pulse width frequency of the control signal according to the received feedback signal, thereby adjusting the on / off time of the first switch element Q5 and the second switch element Q6. In this way, the control chip U1 can accurately control the working state of the switch element, ensure the stable regulation of the current, optimize the operating efficiency of the circuit, and realize closed-loop control.

[0078] It should be noted that the power factor correction is also processed by the control chip U1.

[0079] The second aspect of the present application proposes an AC-DC conversion device (not shown in the figure), including the AC-DC conversion circuit mentioned above; and also including a circuit board, and the AC-DC conversion circuit is recorded on the circuit board. In this design, with the above AC-DC conversion device, its circuit control method can be simplified, thereby reducing costs and improving mass production.

[0080] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0081] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An AC-DC conversion circuit, characterized in that: include: A power module, the power module is used to receive alternating current transmitted by an external power source; A first power conversion module, having a first AC input terminal, a first control terminal and a first DC output terminal, wherein the first AC input terminal is electrically connected to the output terminal of the power module; when the AC power delivered by the power module is in the first half cycle, the first power conversion module is used to convert the AC power delivered by the power module into a first DC power; A second power conversion module, having a second AC input terminal, a second control terminal and a second DC output terminal, wherein the second AC input terminal is electrically connected to the output terminal of the power module, and when the AC power delivered by the power module is in the second half cycle, the second power conversion module is used to convert the AC power input by the power module into a second DC power; A sampling module, the sampling module is used to collect the first direct current or the second direct current and generate a feedback signal; A control module, wherein the control module is electrically connected to the first power conversion module, the second power conversion module and the sampling module respectively, and the control module is configured to output a control signal and adjust the frequency of the control signal to the first control end and the second control end in real time based on the feedback signal, so that the first power conversion module and the second power conversion module can work.

2. The AC-DC conversion circuit according to claim 1, characterized in that: The first power conversion module comprises: A first switch unit, wherein a control end of the first switch unit is electrically connected to the control module, an input end of the switch unit is electrically connected to the power module, and the first switch unit is used to be turned on / off based on a control signal transmitted by the control module; a first rectifying unit, wherein an input end of the first rectifying unit is electrically connected to an output end of the first switching unit, and the first rectifying unit is used to rectify the alternating current transmitted by the first switching unit into direct current; A first energy storage isolation unit, wherein a first end of the first energy storage isolation unit is electrically connected to an output end of the first rectifier unit, a second end of the first energy storage isolation unit is electrically connected to an external load terminal, and the first energy storage isolation unit is used to store direct current transmitted by the first rectifier unit; and when the second power conversion module converts the alternating current transmitted by the power module, the first energy storage isolation unit is at a center potential of the alternating current to isolate the alternating current transmitted by the first switch unit to the second power conversion module.

3. The AC-DC conversion circuit according to claim 2, characterized in that: The second power conversion module includes: A second switch unit, wherein a control end of the second switch unit is electrically connected to the control module, an input end of the second switch unit is electrically connected to the power module, and the second switch unit is used to be turned on / off based on a control signal transmitted by the control module; a second rectifying unit, wherein an input end of the second rectifying unit is electrically connected to an output end of the second switching unit, and the second rectifying unit is used to rectify the alternating current transmitted by the second switching unit into direct current; a second energy storage isolation unit, wherein the first end of the second energy storage isolation unit is electrically connected to the output end of the first rectifier unit, the second end of the second energy storage isolation unit is electrically connected to an external load terminal, and the second energy storage isolation unit is used to store the direct current transmitted by the second rectifier unit; and when the first power conversion module is converting the alternating current transmitted by the power module, the second energy storage isolation unit is at the center potential of the alternating current to isolate the alternating current transmitted by the second switch unit to the first power conversion module.

4. The AC-DC conversion circuit according to claim 3, characterized in that: The first energy storage isolation unit comprises: a first inductor, wherein a first end of the first inductor is electrically connected to an output end of the first rectifying unit, and a second end of the first inductor is electrically connected to an external load terminal; A first diode, wherein an anode of the first diode is electrically connected to the second end of the first inductor, and a cathode of the first diode is electrically connected to the external load terminal.

5. The AC-DC conversion circuit according to claim 3, characterized in that: The second energy storage isolation unit comprises: a second inductor, wherein a first end of the second inductor is electrically connected to an output end of the second rectifying unit, and a second end of the second inductor is electrically connected to an external load terminal; A second diode, an anode of the second diode is electrically connected to the second end of the second inductor, and a cathode of the second diode is electrically connected to the external load terminal.

6. The AC-DC conversion circuit according to claim 4, characterized in that: The first switch unit comprises: A first transistor, wherein a base of the first transistor is electrically connected to the control module, and a collector of the first transistor is electrically connected to an external power supply; a second triode, wherein the base of the second triode is electrically connected to the control module, and the emitter of the second triode is electrically connected to the emitter of the first triode; A first switching element, wherein the gate of the first switching element is electrically connected to the collector of the second transistor, the drain is electrically connected to the second end of the first inductor, and the source is electrically connected to the input end of the first rectifier unit, and the first switching element is used to receive the control signal and turn on / off the alternating current transmitted from the first inductor to the first rectifier unit based on the control signal.

7. The AC-DC conversion circuit according to claim 6, characterized in that: The second switch unit comprises: a third triode, wherein the base of the second triode is electrically connected to the control module, and the emitter of the second triode is electrically connected to the emitter of the fourth triode; a fourth triode, wherein a base of the fourth triode is electrically connected to the control module, and a collector of the fourth triode is electrically connected to the external power supply; A second switching element, wherein the gate of the second switching element is electrically connected to the emitter of the second transistor, the drain is electrically connected to the first end of the second inductor, the source is electrically connected to the input end of the second rectifier unit, and the second switching element is used to receive the control signal and turn on / off the alternating current transmitted from the second inductor to the first rectifier unit based on the control signal.

8. The AC-DC conversion circuit according to claim 7, characterized in that The sampling module includes a sampling resistor R1, a first end of the sampling resistor is electrically connected to the source of the first switching element and the second switching element respectively, and a second end of the sampling resistor is electrically connected to the control module, for collecting the first direct current or the second direct current and generating a feedback signal.

9. The AC-DC conversion circuit according to claim 8, characterized in that: The control module includes a control chip having a signal output end and a signal receiving end, wherein the signal output end is electrically connected to the gates of the first switching element and the second switching element respectively, and the signal receiving end is electrically connected to the second end of the sampling resistor. The control chip is used to output a control signal and adjust the pulse width frequency of the control signal to the gates of the first switching element and the second switching element in real time based on the feedback signal received by the signal receiving end to control the on / off of the first switching element and the second switching element.

10. An AC-DC conversion device, characterized in that: comprising the AC-DC conversion circuit as claimed in any one of claims 1 to 9; A circuit board, the AC-DC conversion circuit is engraved on the circuit board.

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