AC-DC conversion circuit and device

Abstract

The utility model 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 technical field of power supply, in particular to an AC-DC conversion current and device. BACKGROUND

[0002] With the increasing demand for power quality of electronic devices, power factor correction (PFC) circuits play an important role in alternating current (AC) to direct current (DC) power supplies. Traditional bridge rectifier circuits have been widely used in AC-DC conversion, but they have certain efficiency loss, especially under high load and high frequency operating conditions. In order to improve the efficiency of power conversion and reduce harmonic pollution, the existing AC-DC conversion circuit generally uses a bridgeless PFC circuit, in which a totem pole circuit is combined with a digital signal processor (DSP) control method to achieve higher efficiency power factor correction.

[0003] The totem pole circuit uses its unique structure to significantly reduce output ripple while improving power factor, enhancing the stability of the power supply. However, this solution is complex, and the control system needs to rely on advanced DSP control technology, and usually needs to use gallium nitride (GaN) or silicon carbide (SiC) power MOSFET to meet the requirements of high frequency and high voltage operation. Although these technologies have certain advantages in improving power supply efficiency, they have low conversion efficiency, high hardware cost, long design cycle, complex products and are difficult to mass produce, 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, increasing the design complexity of the control system, making the system debugging and maintenance more difficult.

[0004] Therefore, how to simplify the control method of AC-DC circuit, reduce production cost and improve power conversion efficiency has become a key problem to be solved in the current technical field. Practical new type content

[0005] In order to solve the technical defects proposed in the background art, the present application provides an AC-DC conversion current and device which can simplify the control method of the circuit, avoid the design of traditional totem pole circuit and complex DSP control, reduce the overall hardware cost, improve the conversion efficiency of AC-DC power supply, and have better economic efficiency and market competitiveness.

[0006] The utility model adopts the following technical scheme:

[0007] In the first aspect, the utility model provides an AC-DC conversion circuit, comprising:

[0008] a power module configured to receive alternating current (AC) power delivered by an external power source;

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

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

[0011] a sampling module configured to sample the first DC power or the second DC power and generate a feedback signal;

[0012] a control module electrically connected to the first power conversion module, the second power conversion module, and the sampling module, the control module being configured to output a control signal and adjust the frequency of the control signal in real time to the first control terminal and the second control terminal based on the feedback signal, so that the first power conversion module and the second power conversion module operate.

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

[0014] a first switching unit, a control terminal of the first switching unit being electrically connected to the control module, an input terminal of the first switching unit being electrically connected to the power module, the first switching unit being configured to be turned on / off based on the control signal delivered by the control module;

[0015] a first rectifying unit, an input terminal of the first rectifying unit being electrically connected to an output terminal of the first switching unit, the first rectifying unit being configured to rectify the AC power delivered by the first switching unit into DC power;

[0016] a first energy storage isolation unit, a first terminal of the first energy storage isolation unit being electrically connected to an output terminal of the first rectifying unit, a second terminal of the first energy storage isolation unit being electrically connected to an external load terminal, the first energy storage isolation unit being configured to store the DC power delivered by the first rectifying unit, and when the second power conversion module is converting the AC power delivered by the power module, the first energy storage isolation unit is at a center potential of the AC power, so as to isolate the AC power delivered by the first switching unit to the second power conversion module.

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

[0018] a second switch unit, a control end of the second switch unit being electrically connected with the control module, an input end of the second switch unit being electrically connected with the power module, the second switch unit being used for conducting / turning off based on the control signal delivered by the control module;

[0019] a second rectifier unit, an input end of the second rectifier unit being electrically connected with an output end of the second switch unit, the second rectifier unit being used for rectifying the alternating current delivered by the second switch unit into direct current;

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

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

[0022] a first inductor, a first end of the first inductor being electrically connected with an output end of the first rectifier unit, a second end of the first inductor being electrically connected with an external load terminal;

[0023] a first diode, an anode of the first diode being electrically connected with the second end of the first inductor, a cathode of the first diode being electrically connected with the external load terminal.

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

[0025] a second inductor, a first end of the second inductor being electrically connected with an output end of the second rectifier unit, a second end of the second inductor being electrically connected with an external load terminal;

[0026] a second diode, an anode of the second diode being electrically connected with the second end of the second inductor, a cathode of the second diode being electrically connected with the external load terminal.

[0027] Optionally, the first switch unit comprises:

[0028] a first triode, a base of the first triode being electrically connected with the control module, a collector of the first triode being electrically connected with an external power supply;

[0029] A second triode, a base of the second triode being electrically connected with the control module, an emitter of the second triode being electrically connected with an emitter of the first triode;

[0030] A first switch element, a gate of the first switch element being electrically connected with a collector of the second triode, a drain being electrically connected with a second end of the first inductor, a source being electrically connected with an input end of the first rectifying unit, the first switch element being used for receiving the control signal and turning on / off the alternating current of the first inductor delivered to the first rectifying unit based on the control signal.

[0031] Optionally, the second switch unit comprises:

[0032] A third triode, a base of the second triode being electrically connected with the control module, an emitter of the second triode being electrically connected with an emitter of the fourth triode;

[0033] A fourth triode, a base of the fourth triode being electrically connected with the control module, a collector being electrically connected with the external power supply;

[0034] A second switch element, a gate of the second switch element being electrically connected with the emitter of the second triode, a drain being electrically connected with a first end of the second inductor, a source being electrically connected with an input end of the second rectifying unit, the second switch element being used for receiving the control signal and turning on / off the alternating current of the second inductor delivered to the first rectifying unit based on the control signal.

[0035] Optionally, the sampling module comprises a sampling resistor, a first end of the sampling resistor being electrically connected with the source of the first switch element and the source of the second switch element respectively, a second end of the sampling resistor being electrically connected with the control module, the sampling resistor being used for collecting the first direct current or the second direct current and generating a feedback signal.

[0036] Optionally, the control module comprises a control chip, the control chip having a signal output end and a signal receiving end, the signal output end being electrically connected with the gate of the first switch element and the gate of the second switch element respectively, the signal receiving end being electrically connected with the second end of the sampling resistor, the control chip being used for outputting the control signal and adjusting the pulse width frequency of the control signal to the gate of the first switch element and the gate of the second switch element in real time based on the feedback signal received by the signal receiving end, so as to control the turning on / off of the first switch element and the second switch element.

[0037] In the second aspect, the utility model embodiment provides AC-DC conversion device, including as the AC-DC conversion circuit of first aspect;

[0038] Circuit board, the AC-DC conversion circuit is engraved in the circuit board.

[0039] In summary, the utility model discloses the beneficial effect is:

[0040] Through first power conversion module and second power conversion module handle positive half cycle and negative half cycle's alternating current signal respectively, improved conversion efficiency, avoided the waste of electric energy, improved the stability and electric power quality of power conversion. Meanwhile, the cooperation of sampling module and control module, real-time acquisition direct current output signal and automatic adjustment control frequency according to feedback signal, optimized the efficiency of power conversion, reduced the dependence on complex digital signal processor (DSP) technology, so that the design of the utility model is more simple. Control module can dynamically adjust the working state of each power conversion module, not only improve the operation efficiency of the embodiment, but also simplify the design and debugging process, reduce the development cycle, and reduce the demand for high-cost components (such as gallium carbide and silicon carbide MOSFET), reduce the overall hardware cost, and improve the mass productivity of the utility model, have better economy and market competitiveness. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating labor.

[0042] Figure 1 It is the AC-DC conversion circuit architecture diagram of the utility model embodiment;

[0043] Figure 2 It is the principle diagram of the first power conversion module of the utility model embodiment;

[0044] Figure 3 It is the principle diagram of the second power conversion module of the utility model embodiment;

[0045] Figure 4 It is the schematic diagram of the first power conversion module of the utility model embodiment when working;

[0046] Figure 5 It is the schematic diagram of the second power conversion module of the utility model embodiment when working;

[0047] Figure 6 It is the specific structure principle diagram of the first power conversion module and the second power conversion module of the utility model embodiment;

[0048] Figure 7 The principle diagram of the power module of the utility model embodiment. BRIEF DESCRIPTION OF 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 triode; Q2, second triode; 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 triode; Q4, fourth triode; 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 scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0057] As Figure 1As shown, the embodiment of the present application provides an AC-DC conversion circuit, which comprises 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 alternating current delivered by an external power supply. The first power conversion module 200 has a first alternating current input end, a first control end and a first direct current output end. The first alternating current input end is electrically connected with the output end of the power module 100. When the alternating current delivered by the power module 100 is in a first half cycle, the first power conversion module 200 is used to convert the alternating current delivered by the power module 100 into first direct current. The second power conversion module 300 has a second alternating current input end, a second control end and a second direct current output end. The second alternating current input end is electrically connected with the output end of the power module 100. When the alternating current delivered by the power module 100 is in a second half cycle, the second power conversion module 300 is used to convert the alternating current input by the power module 100 into second direct current. The sampling module is used to collect the first direct current or the second direct current and generate a feedback signal. The control module 500 is electrically connected with 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 end and the second control end in real time based on the feedback signal, so that the first power conversion module 200 and the second power conversion module 300 work.

[0058] In the embodiment of the present application, the power supply circuit is used for external alternating current. The power supply circuit can 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 with the protection unit 130. The protection unit 130 can be a pressure sensitive resistor. The two ends of the pressure sensitive resistor are connected in parallel with the first filter unit 110. The two ports of the input side of the first common mode inductor LF1 are electrically connected with the two ends of the pressure sensitive resistor. The two ends of the second filter unit 120 are electrically connected with the two sides of the output end of the first common mode inductor LF1. The input end of the second common mode inductor LF2 is electrically connected with the output end of the first common mode inductor LF1. The first filter unit 110 and the protection unit 130 (such as a pressure sensitive resistor) are connected in parallel to effectively absorb the surge voltage and transient overvoltage from the external alternating current power supply, thereby protecting the sensitive elements in the circuit from damage. The pressure sensitive resistor is connected with the input end of the first common mode inductor LF1, which ensures that the common mode interference on the input side is effectively suppressed, thereby reducing the influence of external noise on the power supply. The second filter unit 120 further filters the high frequency noise of the power supply output end, thereby ensuring the stability of the output voltage. The second common mode inductor LF2 is connected with the first common mode inductor LF1. By suppressing differential mode noise and common mode noise, the electromagnetic compatibility (EMC) of the power supply is further improved, thereby 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 can be understood 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 in the positive half cycle, the first power conversion module 200 converts the alternating current into the first direct current; and when the alternating current enters the negative half cycle, the second power conversion module 300 converts the alternating current into the second direct current. The power module 100 delivers the alternating current signal to the input terminals of the first power conversion module 200 and the second power conversion module 300 through the output terminal, 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, and only one of them can work. The sampling module 400 collects the output first direct current or second direct current in real time to generate feedback signals, which reflect the working state and output voltage characteristics of the first power conversion module 200 or the second power conversion module 300. The control module 500 is connected with the power module 100, the first power conversion module 200, the second power conversion module 300 and the sampling module 400, and based on the feedback signals provided by the sampling module 400, the control module 500 dynamically adjusts the frequency of the control signal and outputs to the first control terminal and the second control terminal, so as to accurately adjust the start-stop state of the first power conversion module 200 and the second power conversion module 300. By processing the alternating current signals of the positive half cycle and the negative half cycle by the first power conversion module 200 and the second power conversion module 300 respectively, the waste of electric energy is avoided, and the stability and power quality are improved. At the same time, the sampling module 400 and the control module 500 are used in cooperation, the direct current output signal is collected in real time, and the control frequency is automatically adjusted according to the feedback signal, the efficiency of power conversion is optimized, the dependence on complex digital signal processor (DSP) technology is reduced, and the design of the embodiment is more simple. The control module 500 can dynamically adjust the working state of each power conversion module, not only improves the running 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 MOSFET), reduces the overall hardware cost, improves the mass production of the embodiment, and has better economy and market competitiveness.

[0060] Further, as Figure 2 and Figure 6As shown, 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 rectify the AC power sent by the first switching unit. The first energy storage isolation unit 230 is electrically connected to the output terminal 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 DC power supplied by the first rectifier unit 220. When the second power conversion module 300 converts the AC power supplied by the power module 100, the first energy storage isolation unit 230 is at the center potential of the AC power to isolate the AC power supplied by the first switch unit 210 to the second power conversion module 300.

[0061] 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.

[0062] Optional, such as Figure 3 and Figure 6As shown, the second power conversion module 300 includes a second switch unit 310, a second rectification 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 configured to be turned on or turned off based on the control signal transmitted by the control module 500. The input end of the second rectification unit 320 is electrically connected to the output end of the second switch unit 310, and the second rectification unit 320 is configured to rectify the alternating current transmitted by the second switch unit 310 into direct current. The first end of the second energy storage isolation unit 330 is electrically connected to the output end of the first rectification 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 configured to store the direct current transmitted by the second rectification unit 320. When the first power conversion module 200 converts the alternating current transmitted by the power module 100, the second energy storage isolation unit 330 is at the center potential of the alternating current, so as to isolate the alternating current transmitted 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 second switch unit 310 is also electrically connected to the control module 500, and the second switch unit 310 is symmetrically arranged with the first switch unit 210. 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 configured to output and connect to the external load. The second switch unit 310 mainly processes the alternating current in the negative half cycle in the embodiment, and then transmits the turned-on current to the second rectification unit 320. The second rectification unit 320 can be a second rectification diode D2. The second rectification diode D2 converts the alternating current transmitted by the second switch unit 310, so as to output the second direct current. Then, the second energy storage isolation unit 330 continues to store the second direct current, so as to ensure that the output current has stability and quality.

[0064] Meanwhile, 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 works (when the positive half cycle of the alternating current is processed), that is, when the voltage delivered by the power module 100 is connected, the second energy storage isolation unit 330 is at the center potential (zero potential) of the alternating current. In other words, there is no voltage across 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 current flow of the first switch unit 210 to the second switch unit 310. In addition, the input end of the second switch unit 310 is electrically connected to the second end of the second energy storage isolation unit 330. Therefore, when the first power conversion module 200 works, the second power conversion module 300 will not work. Similarly, when the second power conversion works (when the negative half cycle of the alternating current is processed), the first energy storage isolation unit 230 is at the center potential (zero potential) of the alternating current. The input end of the first switch unit 210 is electrically connected to the second end of the first energy storage isolation unit 230. Therefore, when the second power conversion module 300 works, the first power conversion module 200 will not work. In this way, the embodiment independently converts electrical energy in the positive half cycle and the negative half cycle, improves the efficiency of electrical energy conversion, and reduces the loss that may be caused by the simultaneous work of the two power modules 100. In addition, the design simplifies the power control mode, avoids complex digital signal processing and high-frequency switch control, reduces the complexity of system design, improves the stability of the system, reduces the hardware cost, enhances the product's mass production and market competitiveness.

[0065] 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+.

[0066] 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.

[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 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.

[0069] 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.

[0070] Optionally, as shown in Figure 6 The first switch unit 210 includes a first triode Q1, a second triode Q2, and a first switch element Q5. The base of the first triode Q1 is electrically connected to the control module 500, and the collector of the first triode Q1 is electrically connected to an external power supply. The base of the second triode Q2 is electrically connected to the control module 500, and the emitter of the second triode Q2 is electrically connected to the emitter of the first triode. The gate of the first switch element Q5 is electrically connected to the collector of the second triode 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 rectification unit 220. The first switch element Q5 is used to receive a control signal and turn on / off the first inductor L1 based on the control signal to deliver AC power to the first rectification unit 220.

[0071] In the embodiment of the present application, the first triode Q1 is an NPN triode, the second triode Q2 is a PNP triode, and the first switch element Q5 can be a first MOS tube. The collector of the first triode Q1 is electrically connected to an external power supply, and the base is electrically connected to the control module 500. The control module 500 adjusts the current flow process through the control signal. The control signal first reaches the first triode Q1 to control its on / off state. When it is turned on, the current flows to the second triode Q2. After the emitter of the second triode Q2 receives the signal from the emitter of the first triode, it also starts to conduct. After conduction, the control current flows through the first current-limiting resistor R7 and then enters the first switch element Q5 after limiting the current through 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 delivered to the first rectifier diode D1 for rectification conversion, completing the conversion of AC power to DC power. Thus, under the action of the control signal, the current flow can be efficiently managed, the working state of the switch element can be adjusted, the conversion of electric energy can be completed, and the purpose of current control and rectification can be achieved.

[0072] Optionally, as shown in Figure 6 The second switch unit 310 includes a third triode Q3, a fourth triode Q4, and a second switch element Q6. The base of the second triode Q2 is electrically connected to the control module 500, and the emitter of the second triode Q2 is electrically connected to the emitter of the fourth triode Q4. The base of the fourth triode 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 switch element Q6 is electrically connected to the emitter of the second triode 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 rectification unit 320. The second switch element Q6 is used to receive a control signal and turn on / off the second inductor L2 based on the control signal to deliver AC power to the first rectification unit 220.

[0073] In the embodiment of the present application, the third transistor Q3 is PNP type and the fourth transistor Q4 is 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 causes the base current of the fourth transistor Q4 to increase, the fourth transistor Q4 is turned 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 working state of the third transistor Q3 (PNP type) connected thereto. Specifically, when the fourth transistor Q4 is turned on, its emitter voltage approaches ground potential, causing the base-emitter voltage of the third transistor Q3 to meet the turn-on condition, and the third transistor Q3 also begins 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, maintaining the state of the fourth transistor Q4 being turned on. The gate of the second switching element Q6 is connected to the emitter of the third transistor Q3, and when the third transistor Q3 is turned on, the potential variation of its emitter will affect the gate of the second switching element Q6. When the second switching element Q6 is turned on, the current passes through the second inductor L2 and is delivered to the second rectifier diode D2 for rectification conversion, completing the conversion of alternating current to direct current.

[0074] Optionally, as shown in FIG. 4, the sampling module 400 includes a sampling resistor R1, and the first end of the sampling resistor R1 is electrically connected to the source of the first switching element Q5 and the source of the second switching element Q6 respectively, and the 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. Figure 3

[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 across the two ends of the resistor, 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 across the two ends of the resistor, and the size 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 value of the sampling resistor R1. The control module 500 indirectly obtains the size of the current by measuring the voltage drop across the two ends of the sampling resistor R1, thereby realizing the "voltage sampling" of the current. Through this method, the control module 500 can monitor the current change 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 accurate adjustment of the circuit.

[0076] Optionally, as shown in FIG. 4, the sampling module 400 includes a sampling resistor R1, and the first end of the sampling resistor R1 is electrically connected to the source of the first switching element Q5 and the source of the second switching element Q6 respectively, and the 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. Figure 2 ​As 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 gate of the first switch element Q5 and the second switch 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 gate of the first switch element Q5 and the second switch element Q6 in real time based on the feedback signal received by the signal receiving end, so as to control the conduction / cutoff of the first switch element Q5 and the second switch element Q6.

[0077] In the embodiment of the present application, the control chip U1 adjusts the working state (conduction or cutoff) 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, for outputting a control signal to adjust the switching state of the switch elements. When a control signal is applied to the gate, the switch element will change the conduction and cutoff state according to the high or low or pulse width modulation (PWM) change of the control signal, so as to control the flow of current. At the same time, the signal receiving end of the control chip U1 is connected to the second end of the sampling resistor R1. The sampling resistor R1 functions to generate a voltage signal at both ends thereof when current flows through it, and the voltage signal is proportional to the current size, which 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, so as to adjust the conduction / cutoff 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 adjustment of the current, optimize the operation 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; further including a circuit board, and the AC-DC conversion circuit is engraved on the circuit board. In this design, the AC-DC conversion device has the above-mentioned circuit control mode, which can simplify the circuit control mode, and further reduce the cost and improve the mass production.

[0080] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0081] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An AC-DC conversion circuit, characterized in that, 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 as described in claim 1, characterized in that, 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 as described in claim 2, characterized in that, 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 supply 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 as described in claim 3, characterized in that, 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 as described in claim 4, characterized in that, 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 as described in claim 5, characterized in that, 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 as described in claim 6, characterized in that, 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 as described in claim 7, characterized in that... 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 as described in claim 8, characterized in that, 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 converter, characterized in that, 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.

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