AC-DC CONVERTER CIRCUITS AND AC-DC CONVERTER DEVICES

Abstract

An AC-DC converter circuit is disclosed in the current application. The AC-DC converter circuit comprises a power module, a first power converter module, a second power converter module, a sampling module, and a control module. When the AC current supplied by the power module is in the first half-cycle, the first power converter module is configured to convert the AC current supplied by the power module into the first DC current; when the AC current supplied by the power module is in the second half-cycle, the second power converter module is configured to convert the AC current supplied by the power module into the second DC current. The sampling module is configured to sample either the first DC current or the second DC current and generate a feedback signal.The control module is configured to output a control signal and adjust the frequency of the control signal in real time to the first and second control units based on the feedback signal, in order to make the first and second power conversion modules operate. The design simplifies the circuit's control method, reduces overall hardware costs to enhance mass production capabilities, and improves power conversion efficiency.

Description

AC-DC conversion circuit and device Technical Field

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

[0002] With the increasing demands for power quality from electronic devices, power factor correction (PFC) circuits play a crucial role in AC-to-DC power supplies. Traditional bridge rectifier circuits are widely used in AC-DC conversion, but they suffer from efficiency losses, especially under high load and high frequency operating conditions. To improve power conversion efficiency and reduce harmonic pollution, existing AC-DC conversion circuits generally employ bridgeless PFC circuits, where totem-pole circuits are combined with digital signal processor (DSP) control methods to achieve more efficient power factor correction.

[0003] Totem-pole circuits, with their unique structure, can significantly reduce output ripple and enhance power supply stability while improving power factor. However, this approach is highly complex, requiring advanced DSP control technology and typically employing gallium carbide (GaN) or silicon carbide (SiC) power MOSFETs to meet high-frequency and high-voltage operating requirements. While these technologies offer advantages in improving power efficiency, their low conversion efficiency presents challenges due to high hardware costs, long design cycles, product complexity, and difficulties in mass production. Furthermore, the design methodology incorporating DSP control requires fine-tuning and complex algorithm processing, increasing the design complexity of the control system and making system debugging and maintenance more difficult.

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

[0005] To address the technical deficiencies mentioned in the background section, this application provides an AC-DC conversion current and device that simplifies circuit control, avoids the design of traditional totem-pole circuits and complex DSP control, reduces overall hardware costs, and improves the conversion efficiency of AC-DC power supplies, thus possessing better economic efficiency and market competitiveness.

[0006] The present invention adopts the following technical solution: In a first aspect, embodiments of the present invention provide an AC-DC conversion circuit, comprising: a power module for receiving AC power supplied 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 supplied by the power module is in a first half-cycle, the first power conversion module is used to convert the AC power supplied 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; when the AC power supplied by the power module is in a 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; and a sampling module for acquiring the first DC power or the second DC power and generating a feedback signal. The control module is electrically connected to the first power conversion module, the second power conversion module, and the sampling module, respectively. The control module 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 and the second power conversion module can work.

[0007] Optionally, the first power conversion module includes: a first switching unit, the control terminal of which is electrically connected to the control module, and the input terminal of which is electrically connected to the power module, wherein the first switching unit is used to turn on / off based on a control signal transmitted by the control module; a first rectifier unit, the input terminal of which is electrically connected to the output terminal of which is used to rectify the AC power transmitted by the first switching unit into DC power; a first energy storage isolation unit, the first terminal of which is electrically connected to the output terminal of which is electrically connected, and the second terminal of which is electrically connected to an external load terminal, wherein the first energy storage isolation unit is used to store the DC power transmitted by the first rectifier unit; and when the second power conversion module converts the AC power transmitted by the power module, the first energy storage isolation unit is at the center potential of the AC power to isolate the AC power transmitted by the first switching unit to the second power conversion module.

[0008] Optionally, the second power conversion module includes: a second switching unit, the control terminal of which is electrically connected to the control module, and the input terminal of which is electrically connected to the power module, the second switching unit being used to turn on / off based on a control signal transmitted by the control module; a second rectifier unit, the input terminal of which is electrically connected to the output terminal of which is used to rectify the AC power transmitted by which the second switching unit is used to convert it into DC power; a second energy storage isolation unit, the first terminal of which is electrically connected to the output terminal of which is electrically connected, and the second terminal of which is electrically connected to an external load terminal, the second energy storage isolation unit being used to store the DC power transmitted by which the second rectifier unit is used; and when the first power conversion module is converting the AC power transmitted by the power module, the second energy storage isolation unit is at the center potential of the AC power to isolate the AC power transmitted by the second switching unit to the first power conversion module.

[0009] Optionally, the first energy storage isolation unit includes: a first inductor, the first end of which is electrically connected to the output terminal of the first rectifier unit, and the second end of which is electrically connected to an external load terminal; and a first diode, the anode of which is electrically connected to the second end of the first inductor, and the cathode of which is electrically connected to the external load terminal.

[0010] Optionally, the second energy storage isolation unit includes: a second inductor, the first end of which is electrically connected to the output terminal of the second rectifier unit, and the second end of which is electrically connected to an external load terminal; and a second diode, the anode of which is electrically connected to the second end of the second inductor, and the cathode of which is electrically connected to the external load terminal.

[0011] Optionally, the first switching unit includes: a first transistor, the base of which is electrically connected to the control module, and the collector of which is electrically connected to an external power supply; a second transistor, the base of which is electrically connected to the control module, and the emitter of which is electrically connected to the emitter of the first transistor; and a first switching element, the gate of which is electrically connected to the collector of the second transistor, the drain of which is electrically connected to the second terminal of the first inductor, and the source of which is electrically connected to the input terminal of the first rectifier unit. The first switching element is used to receive the control signal and, based on the control signal, turn on / off the AC power supplied by the first inductor to the first rectifier unit.

[0012] Optionally, the second switching unit includes: a third transistor, the base of which is electrically connected to the control module, and the emitter of which is electrically connected to the emitter of a fourth transistor; a fourth transistor, the base of which is electrically connected to the control module, and the collector of which is electrically connected to the external power supply; and a second switching element, the gate of which is electrically connected to the emitter of the second transistor, the drain of which is electrically connected to the first terminal of the second inductor, and the source of which is electrically connected to the input terminal of the second rectifier unit. The second switching element is used to receive the control signal and, based on the control signal, turn on / off the AC power supplied by the second inductor to the first rectifier unit.

[0013] Optionally, the sampling module includes a sampling resistor, the first end of which is electrically connected to the source of the first switching element and the second switching element respectively, and the second end of which is electrically connected to the control module, for acquiring the first DC current or the second DC current and generating a feedback signal.

[0014] Optionally, the control module includes a control chip with a signal output terminal and a signal receiving terminal. The signal output terminal is electrically connected to the gates of the first switching element and the second switching element, respectively. The signal receiving terminal is electrically connected to the second terminal 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 terminal, so as to control the on / off state of the first switching element and the second switching element.

[0015] In a second aspect, embodiments of the present invention provide an AC-DC conversion device, including the AC-DC conversion circuit as described in the first aspect; and a circuit board, wherein the AC-DC conversion circuit is etched onto the circuit board.

[0016] In summary, the beneficial effects of this invention are as follows: By processing the positive and negative half-cycle AC signals respectively through the first and second power conversion modules, the conversion efficiency is improved, energy waste is avoided, and the stability and power quality of the power conversion are enhanced. Simultaneously, the coordinated use of the sampling and control modules to acquire DC output signals in real time and automatically adjust the control frequency based on feedback signals optimizes power conversion efficiency, reduces reliance on complex digital signal processor (DSP) technology, and simplifies the design of this invention. The control module can dynamically adjust the operating state of each power conversion module, which not only improves the operating efficiency of this embodiment but also simplifies the design and debugging process, reduces the development cycle, and reduces the need for high-cost components (such as gallium carbide and silicon carbide MOSFETs), lowering the overall hardware cost and improving the mass production feasibility of this invention, resulting in better economic efficiency and market competitiveness. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is an AC-DC conversion circuit architecture diagram according to an embodiment of the present invention; Figure 2 is a schematic diagram of the first power conversion module according to an embodiment of the present invention; Figure 3 is a schematic diagram of the second power conversion module according to an embodiment of the present invention; Figure 4 is a schematic diagram of the first power conversion module in operation according to an embodiment of the present invention; Figure 5 is a schematic diagram of the second power conversion module in operation according to an embodiment of the present invention; Figure 6 is a schematic diagram of the specific structure of the first power conversion module and the second power conversion module according to an embodiment of the present invention; Figure 7 is a schematic diagram of the power module according to an embodiment of the present invention.

[0019] Figure Descriptions: 100, Power Module; 110, First Filtering Unit; 120, Second Filtering Unit; 130, Protection Unit; LF1, First Common Mode Inductor; LF2, Second Common Mode Inductor; 200, First Power Conversion Module; 210, First Switching Unit; Q1, First Transistor; Q2, Second Transistor; Q5, First Switching Element; 220, First Rectifier Unit; D1, First Rectifier Diode; 230, First Energy Storage Isolation Unit; L1, First Inductor; D5, First Diode; 300, Second Power Conversion Module; 310, Second Switching Unit; Q3, Third Transistor; Q4, Fourth Transistor; Q6, Second Switching Element; 320, Second Rectifier Unit; D2, Second Rectifier Diode; 330, Second Energy Storage Isolation Unit; L2, Second Inductor; D6, Second Diode; 400, Sampling Module; R1, Sampling Resistor; 500, Control Module; U1, Control Chip; V+, load terminal. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] As shown in Figure 1, this embodiment of the 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. The power module 100 is used to receive AC power supplied by an external power source. The first power conversion module 200 has a first AC input terminal, a first control terminal, and a first DC output terminal, and the first AC input terminal is electrically connected to the output terminal of the power module 100. When the AC power supplied by the power module 100 is in the first half-cycle, the first power conversion module 200 is used to convert the AC power supplied by the power module 100 into a first DC power. The second power conversion module 300 has a second AC input terminal and a second control terminal. The second power conversion module 300 is electrically connected to the output terminal of the power module 100 and the second AC input terminal. When the AC power supplied by the power module 100 is in the second half-cycle, the second power conversion module 300 is used to convert the AC power input by the power module 100 into the second DC power. The sampling 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. 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.

[0022] In this embodiment, the power supply circuit is used to connect to external AC power. This 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. The two ends of the first filter unit 110 are electrically connected to the protection unit 130, which can be a varistor. The two ends of the varistor are connected in parallel with the first filter unit 110. The two input ports 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 both sides of the output terminal of the first common-mode inductor LF1. The input terminal of the second common-mode inductor LF2 is electrically connected to the output terminal of the first common-mode inductor LF1. By connecting the first filter unit 110 and the protection unit 130 (such as a varistor) in parallel, surge voltages and transient overvoltages from the external AC power supply are effectively absorbed, protecting sensitive components in the circuit from damage. A varistor is connected to the input terminal of the first common-mode inductor LF1, ensuring effective suppression of common-mode interference on the input side and reducing the impact of external noise on the power supply. The second filter unit 120 further filters high-frequency noise at the power supply output, ensuring the stability of the output voltage. The second common-mode inductor LF2 is connected to the first common-mode inductor LF1, further improving the electromagnetic compatibility (EMC) of the power supply by suppressing differential-mode and common-mode noise, ensuring stable operation of the power supply under different operating conditions.

[0023] It should be understood that the first half-cycle is the positive half-cycle, and the second half-cycle is the negative half-cycle. Alternating current (AC) has positive and negative half-cycles. When the AC power supplied by power module 100 is in the positive half-cycle, the first power conversion module 200 converts the AC power into the first direct current (DC). When the AC power enters the negative half-cycle, the second power conversion module 300 converts the AC power into the second DC power. Power module 100, through its output terminal, sends the AC signal to the input terminals of the first power conversion module 200 and the second power conversion module 300 respectively, enabling power conversion in both the positive and negative half-cycles. It should be noted that the first power conversion module 200 and the second power conversion module 300 cannot operate simultaneously; only one can operate at a time. The sampling module 400 collects the output first DC power or second DC power in real time and generates feedback signals. These feedback signals reflect the current operating status and output voltage characteristics of the first power conversion module 200 or the second power conversion module 300. The control module 500 is connected to the power supply 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 precisely regulating the start-stop state of the first power conversion module 200 and the second power conversion module 300. By having the first power conversion module 200 and the second power conversion module 300 process the positive and negative half-cycle AC signals respectively, energy waste is avoided, and stability and power quality are improved. At the same time, the cooperative use of the sampling module 400 and the control module 500 allows for real-time acquisition of the DC output signal and automatic adjustment of the control frequency based on the feedback signal, optimizing the power conversion efficiency and reducing reliance on complex digital signal processor (DSP) technology, making the design of this embodiment simpler. The control module 500 can dynamically adjust the working status of each power conversion module, which not only improves operating efficiency, but also simplifies the design and debugging process, reduces the development cycle, reduces the demand for high-cost components (such as gallium carbide and silicon carbide MOSFETs), reduces the overall hardware cost, and improves the mass production capability of this embodiment, thus possessing better economic efficiency and market competitiveness.

[0024] Further, as shown in Figures 2 and 6, the first power conversion module 200 includes a first switching unit 210, a first rectifier unit 220, and a first energy storage isolation unit 230. The control terminal of the first switching unit 210 is electrically connected to the control module 500, and the input terminal of the switching unit is electrically connected to the power module 100. The first switching unit 210 is used to turn on / off based on the control signal sent by the control module 500. The input terminal of the first rectifier unit 220 is electrically connected to the output terminal of the first switching unit 210. The first rectifier unit is used to convert the power signal sent by the first switching unit into a power supply unit. The alternating current is rectified into direct current; 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 supplied by the first rectifier unit 220; and when the second power conversion module 300 converts the alternating current supplied 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 supplied by the first switching unit 210 to the second power conversion module 300.

[0025] In this embodiment, the first switching unit 210 has a control terminal, which is electrically connected to the main control module. The main control module sends a control signal to the first switching unit 210. This control signal can be a PWM signal (pulse width modulation mode signal), which can continuously drive the first switching unit 210 to turn on and off, thereby controlling the current at the input terminal and the current at the output terminal of the first switching 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 the AC power into the first DC power. Then, through the presence of the second energy storage unit, the first energy storage isolation unit 230 stores the first DC power from the first rectifier unit 220 to ensure that the output current has stability and high efficiency.

[0026] Optionally, as shown in Figures 3 and 6, the second power conversion module 300 includes a second switching unit 310, a second rectifier unit 320, and a second energy storage isolation unit 330. The control terminal of the second switching unit 310 is electrically connected to the control module 500, and the input terminal of the first switching unit 210 is electrically connected to the power module 100. The second switching unit 310 is used to turn on / off based on the control signal transmitted by the control module 500. The input terminal of the second rectifier unit 320 is electrically connected to the output terminal of the second switching unit 310. The second rectifier unit 320 is used to convert the second switching unit 310 into a power supply module 100. The AC power supplied by the second rectifier unit 320 is rectified into DC power. The first end of the second energy storage isolation unit 330 is electrically connected to the output end of the first rectifier unit 220, and the second end of the second energy storage isolation unit 330 is electrically connected to the external load terminal V+. The second energy storage isolation unit 330 is used to store the DC power supplied by the second rectifier unit 320. When the first power conversion module 200 converts the AC power supplied by the power module 100, the second energy storage isolation unit 330 is at the center potential of the AC power to isolate the AC power supplied by the second switch unit 310 to the first power conversion module 200.

[0027] In this embodiment, the control terminal of the second switching unit 310 is also electrically connected to the control module 500. The second switching unit 310 and the first switching unit 210 are symmetrically arranged. The input terminal of the second switching unit 310 is electrically connected to the output terminal of the power module 100. The output terminal is used to output and connect to an external load. The second switching unit 310 mainly processes the AC power of the negative half-cycle in this embodiment, and then sends the current after conduction to the second rectifier unit 320. The second rectifier unit 320 can be the second rectifier diode D2. The AC power sent by the second switching unit 310 is converted by the second rectifier diode D2, so that the second DC power can be output. Then the second energy storage isolation unit 330 continues to store the second DC power to ensure that the output current has stability and quality.

[0028] It should also be noted that the first energy storage isolation unit 230 is located in the first power conversion module 200, and the second energy storage isolation unit 330 is located in the second power conversion module 300. When the first power conversion module 200 is working (processing the positive half-cycle of AC power), that is, when the voltage supplied by the power module 100 is connected, the second energy storage isolation unit 330 will be at the center potential (zero potential) of the AC power. In other words, there is no voltage across the second energy storage isolation unit 330. Furthermore, since the first switching unit 210 and the second switching unit 310 are simultaneously turned on, the second energy storage isolation unit 330 will block the first switching unit 210 from being turned on. The current from the switching unit 210 flows to the second switching unit 310. Furthermore, the input terminal of the second switching unit 310 is electrically connected to the second terminal of the second energy storage isolation unit 330. Therefore, when the first power conversion module 200 is working, the second power conversion module 300 will not be working. Similarly, when the second power conversion module is working (processing the negative half-cycle of AC power), the first energy storage isolation unit 230 will be at the center potential (zero potential) of the AC power, and the input terminal of the first switching unit 210 will be electrically connected to the second terminal of the first energy storage isolation unit 230. Therefore, when the second power conversion module 300 is working, the first power conversion module 200 will not be working. In this way, this embodiment independently converts electrical energy in the positive and negative half-cycles, improving the efficiency of energy conversion and reducing potential losses caused by the simultaneous operation of the two power modules 100. In addition, this design simplifies the power control method, avoids complex digital signal processing and high-frequency switching control, reduces the complexity of the system design, improves system stability, reduces hardware costs, and enhances the product's mass production capability and market competitiveness.

[0029] Optionally, as shown in Figure 6, 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+.

[0030] In this embodiment, the first terminal 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 the first DC current supplied by the first rectifier diode D1, and then supply the stored first DC current to the anode of the first diode D5. The first diode D5 mainly serves as a path for releasing the energy of the first inductor L1, and performs high-frequency rectification, and supplies it to the load terminal V+. In addition, it should be noted that the first inductor L1, in addition to its energy storage function, also has an isolation function, and the first inductor L1 has a resistance to current changes. As mentioned above, during the positive half-cycle of the AC current, when the current attempts to flow from the second switching element Q6 to the first switching element Q5, the voltage across the first inductor L1 will be close to zero because it is in the positive half-cycle of the AC current. This can block the current from flowing from the second switching element Q6 to the first switching element Q5, thus enabling the first power conversion module 200 to work during the positive half-cycle of the AC current, while the second power conversion module 300 does not work.

[0031] Optionally, as shown in Figure 6, 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+.

[0032] In this embodiment, the first terminal 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 DC current supplied by the second rectifier diode D2, and then supply the stored first DC current to the anode of the second diode D6. The second diode D6 mainly serves as a path for releasing the energy of 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 the same as those of the first inductor L1. It can only work during the negative half-cycle of the AC current. The specific principle is the same as that of the first inductor L1 mentioned above, and it is symmetrically designed. Therefore, since the second inductor L2 is in the negative half-cycle of the AC current, the voltage across the second inductor L2 will be close to zero, which can block the current from flowing from the first switching element Q5 to the second switching element Q6. Thus, during the negative half-cycle of the AC current, the second power conversion module 300 can work, while the first power conversion module 200 does not work.

[0033] The number of the first inductor L1 and the second inductor L2 can be multiple, and they can be connected in parallel to form an inductor string.

[0034] Optionally, as shown in Figure 6, the first switching unit 210 includes a first transistor Q1, a second transistor Q2, and a first switching 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 an 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 switching element Q5 is electrically connected to the collector of the second transistor Q2, the drain is electrically connected to the second terminal of the first inductor L1, and the source is electrically connected to the input terminal of the first rectifier unit 220. The first switching element Q5 is used to receive control signals and, based on the control signals, turn on / off the AC power supplied to the first rectifier unit 220 via the first inductor L1.

[0035] In this embodiment, the first transistor Q1 is an NPN transistor, the second transistor Q2 is a PNP transistor, and the first switching element Q5 can be a first MOSFET. 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 through a control signal. The control signal first reaches the first transistor Q1, controlling its on / off state. When it is on, the current flows to the second transistor Q2. After receiving the signal from the emitter of the first transistor, the emitter of the second transistor Q2 also begins to conduct. After conduction, the control current flows through the first current-limiting resistor R7. After being limited by the first current-limiting resistor R7, it enters the first switching element Q5. When the first switching element Q5 is on, the current passes through the first inductor L1 and is delivered to the first rectifier diode D1 for rectification and conversion, completing the conversion of AC to DC. Thus, under the action of control signals, it can efficiently manage current flow, adjust the working state of switching elements, and thereby complete the conversion of electrical energy, ultimately achieving the purpose of current control and rectification.

[0036] Optionally, as shown in Figure 6, the second switching unit 310 includes a third transistor Q3, a fourth transistor Q4, and a second switching 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 an external power supply. The gate of the second switching element Q6 is electrically connected to the emitter of the second transistor Q2, the drain is electrically connected to the first terminal of the second inductor L2, and the source is electrically connected to the input terminal of the second rectifier unit 320. The second switching element Q6 is used to receive control signals and, based on the control signals, turn on / off the second inductor L2 to supply AC power to the first rectifier unit 220.

[0037] In this embodiment, 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 turns on, and the current flows from its collector to its emitter. At this time, the emitter voltage of the fourth transistor Q4 will affect the operating state of the third transistor Q3 (PNP type) connected to it. Specifically, when the fourth transistor Q4 turns on, its emitter voltage is close to ground potential, so that the base-emitter voltage of the third transistor Q3 meets its conduction condition, and the third transistor Q3 also begins to conduct. The emitter of the third transistor Q3 is connected to the emitter of the fourth transistor Q4. Therefore, its collector current continues to flow to the fourth transistor Q4, keeping the fourth transistor Q4 on. The gate of the second switching element Q6 is connected to the emitter of the third transistor Q3. When the third transistor Q3 is on, the potential change at its emitter affects the gate of the second switching element Q6. When the second switching element Q6 is on, the current flows through the second inductor L2 and is delivered to the second rectifier diode D2 for rectification and conversion, completing the conversion from AC to DC.

[0038] Optionally, as shown in Figures 3 and 4, the sampling module 400 includes a sampling resistor R1. The first end of the sampling resistor R1 is electrically connected to the source of the first switching element Q5 and the second switching element Q6, respectively. The second end of the sampling resistor R1 is electrically connected to the control module 500, and is used to acquire the first DC current or the second DC current and generate a feedback signal.

[0039] In this embodiment, the sampling resistor R1 operates based on Ohm's law. When current flows through the sampling resistor R1, a voltage drop is generated across its terminals, and this voltage drop is proportional to the magnitude of the current. Specifically, when current flows through the sampling resistor R1, a voltage drop is generated across the resistor, the magnitude of which 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 achieving current "voltage sampling". Through this method, the control module 500 can monitor the current changes in the circuit in real time and adjust the circuit's operating state based on the current feedback signal, achieving closed-loop control and ensuring the stability and precise adjustment of the circuit.

[0040] Optionally, as shown in Figure 2, the control module 500 includes a control chip U1, which has a signal output terminal and a signal receiving terminal. The signal output terminal is electrically connected to the gates of the first switching element Q5 and the second switching element Q6, respectively. The signal receiving terminal is electrically connected to the second terminal 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 terminal, so as to control the conduction / cutoff of the first switching element Q5 and the second switching element Q6.

[0041] In this embodiment, the control chip U1 adjusts the operating state (on or off) of two switching elements (first switching element Q5 and second switching element Q6). The signal output terminal of the control chip U1 is connected to the gate of the first and second switching elements Q6 respectively, and is used to output control signals to adjust the switching state of the switching elements. When a control signal is applied to the gate, the switching elements change their on and off states according to the high or low 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 terminal of the control chip U1 is connected to the second terminal of the sampling resistor R1. The function of the sampling resistor R1 is to generate a voltage signal across its terminals when current flows through it. This voltage signal is proportional to the magnitude of the current 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 switching element Q5 and the second switching element Q6. In this way, the control chip U1 can accurately control the operating state of the switching elements, ensure stable current regulation, optimize the operating efficiency of the circuit, and realize closed-loop control.

[0042] It should be noted that power factor correction is also handled by the control chip U1.

[0043] A second aspect of this application discloses an AC-DC conversion device (not shown in the figures), including the AC-DC conversion circuit as described above; it also includes a circuit board on which the AC-DC conversion circuit is etched. This design, incorporating the aforementioned AC-DC conversion device, simplifies its circuit control, thereby reducing costs and improving mass production capabilities.

[0044] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship described in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0045] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An AC-DC conversion circuit, characterized by, include: A power module, wherein the power module is used to receive AC power supplied by an external power source; The first power conversion module has a first AC input terminal, a first control terminal, and a first DC output terminal. The first AC input terminal is electrically connected to the output terminal of the power module. When the AC power supplied by the power module is in the first half-cycle, the first power conversion module is used to convert the AC power supplied by the power module into the first DC power. The second power conversion module has a second AC input terminal, a second control terminal and a second DC output terminal. The second AC input terminal is electrically connected to the output terminal of the power module. When the AC power supplied 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, which is used to acquire a first DC current or a second DC current and generate a feedback signal; The control module is electrically connected to the first power conversion module, the second power conversion module, and the sampling module, respectively. The control module 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 and the second power conversion module can work.

2. The AC-DC conversion circuit of claim 1, wherein, The first power conversion module includes: The first switching unit has its control terminal electrically connected to the control module and its input terminal electrically connected to the power module. The first switching unit is used to turn on / off based on the control signal transmitted by the control module. The first rectifier unit has its input terminal electrically connected to the output terminal of the first switching unit. The first rectifier unit is used to rectify the AC power supplied by the first switching unit into DC power. The first energy storage isolation unit has a first end electrically connected to the output end of the first rectifier unit and a second end electrically connected to an external load terminal. The first energy storage isolation unit is used to store the DC power supplied by the first rectifier unit. When the second power conversion module converts the AC power supplied by the power module, the first energy storage isolation unit is at the center potential of the AC power to isolate the AC power supplied by the first switching unit to the second power conversion module.

3. The AC-DC conversion circuit of claim 2, wherein, The second power conversion module includes: The second switching unit has its control terminal electrically connected to the control module and its input terminal electrically connected to the power module. The second switching unit is used to turn on / off based on the control signal transmitted by the control module. The second rectifier unit has its input terminal electrically connected to the output terminal of the second switching unit. The second rectifier unit is used to rectify the AC power supplied by the second switching unit into DC power. The second energy storage isolation unit has a first end electrically connected to the output end of the first rectifier unit and a second end electrically connected to an external load terminal. The second energy storage isolation unit is used to store the DC power supplied by the second rectifier unit. When the first power conversion module converts the AC power supplied by the power module, the second energy storage isolation unit is at the center potential of the AC power to isolate the AC power supplied by the second switching unit to the first power conversion module.

4. The AC-DC conversion circuit of claim 3, wherein, The first energy storage isolation unit includes: The first inductor has a first end electrically connected to the output terminal of the first rectifier unit and a second end electrically connected to an external load terminal. The first diode has its anode electrically connected to the second terminal of the first inductor, and its cathode electrically connected to the external load terminal.

5. The AC-DC conversion circuit of claim 4, wherein, The second energy storage isolation unit includes: The second inductor has its first end electrically connected to the output terminal of the second rectifier unit and its second end electrically connected to the external load terminal. The second diode has its anode electrically connected to the second terminal of the second inductor, and its cathode electrically connected to the external load terminal.

6. The AC-DC conversion circuit of claim 5, wherein, The first switching unit includes: The first transistor has its base electrically connected to the control module and its collector electrically connected to an external power supply. The base of the second transistor is electrically connected to the control module, and the emitter of the second transistor is electrically connected to the emitter of the first transistor. A first switching element has its gate electrically connected to the collector of the second transistor, its drain electrically connected to the second terminal of the first inductor, and its source electrically connected to the input terminal of the first rectifier unit. The first switching element is used to receive the control signal and, based on the control signal, turn on / off the AC power supplied by the first inductor to the first rectifier unit.

7. The AC-DC conversion circuit of claim 6, wherein, The second switching unit includes: The base of the third transistor and the second transistor are electrically connected to the control module, and the emitter of the second transistor is electrically connected to the emitter of the fourth transistor. The fourth transistor has its base electrically connected to the control module and its collector electrically connected to the external power supply. The second switching element has its gate electrically connected to the emitter of the second transistor, its drain electrically connected to the first terminal of the second inductor, and its source electrically connected to the input terminal of the second rectifier unit. The second switching element is used to receive the control signal and, based on the control signal, turn on / off the AC power supplied by the second inductor to the first rectifier unit.

8. The AC-DC conversion circuit of claim 7, wherein The sampling module includes a sampling resistor. The first end of the sampling resistor is electrically connected to the source of the first switching element and the second switching element, respectively. The second end of the sampling resistor is electrically connected to the control module. It is used to collect the first DC current or the second DC current and generate a feedback signal.

9. The AC-DC conversion circuit of claim 8, wherein, The control module includes a control chip with a signal output terminal and a signal receiving terminal. The signal output terminal is electrically connected to the gates of the first switching element and the second switching element, respectively. The signal receiving terminal is electrically connected to the second terminal 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 terminal, so as to control the conduction / cutoff of the first switching element and the second switching element.

10. An AC-DC conversion device, characterized by comprising: Includes the AC-DC conversion circuit as described in any one of claims 1-9; The circuit board, on which the AC-DC conversion circuit is etched.

Images