Power supply circuit based on AC-DC conversion

Abstract

The embodiment of the utility model provides a power supply circuit based on AC-DC conversion. The power supply circuit comprises an AC rectification input circuit; the output clamping circuit comprises a switch unit and a clamping unit. The switch unit comprises a first end and a second end which are respectively connected with the output end of the AC rectification input circuit and the output end of the output clamping circuit, and a control end which controls the on-off of the first end and the second end. The clamping unit is connected with the control end and the output end of the output clamping circuit and is configured to clamp the voltage of the control end and the voltage peak value of the voltage between the control end and the output end of the output clamping circuit. The output end of the output clamping circuit is coupled with the first end; and the at least one output circuit is coupled with the at least one secondary coil and forms at least one working voltage output. The output voltage can be monitored and controlled in real time through the output clamping circuit, the peak value of the output voltage after rectification is effectively restrained, damage to components caused by voltage overshoot is avoided, and high-voltage input of the power supply circuit is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power supply circuits, and in particular to a power supply circuit based on AC / DC conversion. Background Art

[0002] In the prior art, power circuits based on AC-DC conversion are widely used in industrial equipment, communication facilities and other types of electrical systems. Although the existing three-phase power circuit design has made significant progress, there are still some problems that need to be solved when facing high-voltage input environments.

[0003] First of all, in the process of high-voltage AC being rectified and converted into DC, due to the nonlinear characteristics of the rectification process, there may be obvious voltage spikes and transient overvoltage phenomena in the output voltage. These overvoltage phenomena may not only damage the components inside the power circuit and reduce the life of the equipment, but may also cause system instability and safety hazards.

[0004] Secondly, existing power supply circuits often lack effective clamping measures for output voltage peaks during voltage conversion and voltage regulation control. In a high-voltage input environment, once an abnormally high voltage or overvoltage event occurs, if there is no immediate clamping protection mechanism, it will directly endanger the safety of the power chip and downstream loads. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present disclosure is to provide a power supply circuit based on AC-DC conversion to solve the problems in the related art.

[0006] A first aspect of the present disclosure provides a power supply circuit based on AC / DC conversion, comprising:

[0007] An AC rectifier input circuit, wherein an input terminal of the AC rectifier input circuit is coupled to AC power;

[0008] The output clamp circuit comprises: a switch unit and a clamp unit;

[0009] The switch unit comprises: a first end and a second end respectively connected to the output end of the AC rectifier input circuit and the output end of the output clamp circuit, and a control end for controlling the switching of the first end and the second end;

[0010] The clamping unit is connected to the control terminal and the output terminal of the output clamping circuit, and is configured to clamp the voltage peaks of the voltage on the control terminal and the voltage between the control terminal and the output terminal of the output clamping circuit, so as to clamp the voltage peak of the output terminal of the output clamping circuit;

[0011] A transformer, the transformer comprising a primary coil, at least one secondary coil and an auxiliary coil;

[0012] The primary coil includes a first end and a second end; the auxiliary coil includes a third end and a fourth end;

[0013] The output end of the output clamp circuit is coupled to the first end;

[0014] A power chip, the power chip comprising a power input terminal, a power supply terminal, a feedback terminal and a chip ground terminal;

[0015] The power input terminal is coupled to the second terminal; the power supply terminal is coupled to the third terminal through a power supply circuit; the feedback terminal is coupled to the fourth terminal through a feedback circuit; and the chip ground terminal is grounded;

[0016] At least one output circuit is coupled to the at least one secondary coil and forms at least one operating voltage output.

[0017] In an embodiment of the first aspect, the switch unit includes:

[0018] A MOS tube, wherein the drain of the MOS tube is connected to the output end of the AC rectifier input circuit, and the source of the MOS tube is coupled to the output end of the output clamp circuit;

[0019] A first resistor, one end of the first resistor is connected to the drain, and the other end of the first resistor is coupled to the gate of the MOS tube through a second resistor.

[0020] In an embodiment of the first aspect, the clamping unit includes:

[0021] a first voltage stabilizing diode, wherein the anode of the first voltage stabilizing diode is connected to the source of the MOS tube, and the cathode of the first voltage stabilizing diode is connected to the gate, so as to clamp the voltage between the gate and the source when reverse breakdown occurs;

[0022] a second voltage stabilizing diode, wherein the anode of the second voltage stabilizing diode is grounded, and the cathode of the second voltage stabilizing diode is connected to the gate, so as to clamp the voltage of the gate when reverse breakdown occurs;

[0023] A first energy storage filter capacitor, wherein a positive electrode of the first energy storage filter capacitor is coupled to the first end, and a negative electrode of the first energy storage filter capacitor is grounded.

[0024] In an embodiment of the first aspect, the AC rectifier input circuit includes:

[0025] At least one live wire input terminal, one end of the live wire input terminal is connected to an external power supply, and the other end of the live wire input terminal is coupled to the input end of the output clamp circuit through a three-phase rectifier bridge and a first capacitor wire in sequence;

[0026] A neutral line input end, one end of which is grounded, and the other end of which is coupled to the input end of the output clamp circuit through the three-phase rectifier bridge and the second capacitor in sequence.

[0027] In an embodiment of the first aspect, the three-phase rectifier bridge includes: a pair of diodes adjacent to each of the live input terminals and the neutral input terminals, including:

[0028] a first diode, wherein an anode of the first diode is coupled to at least one of the live wire input terminals, and a cathode of the first diode is coupled to an input terminal of the output clamp circuit;

[0029] A second diode, wherein an anode of the second diode is grounded, and a cathode of the second diode is coupled to at least one of the live line input terminal and / or the neutral line input terminal.

[0030] In an embodiment of the first aspect, an RCD absorption circuit is further provided between the output end of the output clamp circuit and the first end, and the RCD absorption circuit includes:

[0031] a third resistor, one end of the third resistor being connected to the first end;

[0032] a fourth resistor, the fourth resistor being connected in parallel with the third resistor;

[0033] A first capacitor, wherein the first capacitor is connected in parallel with the fourth resistor;

[0034] A third diode, wherein an anode of the third diode is connected to the power input terminal, and a cathode of the third diode is connected to the other end of the third resistor.

[0035] In an embodiment of the first aspect, the power supply circuit includes:

[0036] a fourth diode, wherein an anode of the fourth diode is coupled to the third end, and a cathode of the fourth diode is coupled to the power supply end via a fifth resistor;

[0037] a second energy storage filter capacitor, wherein a negative electrode of the second energy storage filter capacitor is coupled to the fourth end, and a positive electrode of the second energy storage filter capacitor is coupled to the power supply end;

[0038] A second capacitor is connected in parallel with the second energy storage filter capacitor.

[0039] In an embodiment of the first aspect, the feedback circuit comprises:

[0040] a third voltage stabilizing diode, wherein an anode of the third voltage stabilizing diode is connected to the feedback end, and a cathode of the third voltage stabilizing diode is coupled to an output end of the power supply circuit;

[0041] A third capacitor, one end of the third capacitor is connected to the anode of the third voltage stabilizing diode, and the other end of the third capacitor is grounded.

[0042] In an embodiment of the first aspect, the secondary coil includes a first secondary coil, and the first secondary coil includes a fifth end and a sixth end;

[0043] The fifth end and the second end are ends of the same name;

[0044] The output circuit includes a first output circuit with an output voltage of 5 volts, and the first output circuit includes:

[0045] a fifth diode, wherein an anode of the fifth diode is coupled to the fifth end;

[0046] a third energy storage filter capacitor, wherein the positive electrode of the third energy storage filter capacitor is connected to the negative electrode of the fifth diode, and the negative electrode of the third energy storage filter capacitor is coupled to the sixth end;

[0047] A first voltage regulator tube, wherein an input end of the first voltage regulator tube is coupled to the cathode of the fifth diode, an output end of the first voltage regulator tube is connected to an external load, and a ground end of the first voltage regulator tube is grounded;

[0048] A fourth capacitor, one end of the fourth capacitor is coupled to the output end of the first voltage regulator tube, and the other end of the fourth capacitor is grounded.

[0049] In an embodiment of the first aspect, the secondary coil further includes a second secondary coil, and the second secondary coil includes a seventh end and an eighth end;

[0050] The seventh end and the second end are ends of the same name;

[0051] The output circuit further includes a second output circuit with an output voltage of 12 volts, the second output circuit including:

[0052] a sixth diode, wherein an anode of the sixth diode is coupled to the seventh end;

[0053] a fourth energy storage filter capacitor, wherein the positive electrode of the fourth energy storage filter capacitor is connected to the negative electrode of the sixth diode, and the negative electrode of the fourth energy storage filter capacitor is coupled to the eighth end;

[0054] A second voltage regulator tube, wherein an input end of the second voltage regulator tube is coupled to the cathode of the sixth diode, an output end of the second voltage regulator tube is connected to an external load, and a ground end of the second voltage regulator tube is grounded;

[0055] A fifth capacitor, one end of the fifth capacitor is coupled to the output end of the second voltage regulator tube, and the other end of the fifth capacitor is grounded.

[0056] Beneficial effects of the present disclosure: The present disclosure can monitor and control the output voltage in real time through the output clamping circuit, thereby clamping the DC voltage value output by the AC rectifier input circuit to effectively suppress the peak value of the output voltage after rectification, avoid damage to components caused by voltage overshoot, and realize high-voltage input of the power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic diagram showing the circuit principle of a power supply circuit based on AC-DC conversion in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0058] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0059] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0060] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0061] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of the present disclosure, "a group" means two or more, unless otherwise clearly and specifically defined.

[0062] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0063] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0064] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, modules, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0065] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0066] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0067] like Figure 1 As shown, a power supply circuit based on AC-DC conversion includes: an AC rectifier input circuit, an output clamping circuit, a transformer T, a power supply chip, an output power supply, a power supply circuit and a feedback circuit;

[0068] The input end of the AC rectifier input circuit is coupled to AC power;

[0069] The output clamp circuit comprises: a switch unit and a clamp unit;

[0070] The switch unit comprises: a first end 1 and a second end 2 respectively connected to the output end of the AC rectifier input circuit and the output end of the output clamp circuit, and a control end for controlling the switching of the first end 1 and the second end 2;

[0071] The clamping unit is connected to the control terminal and the output terminal of the output clamping circuit, and is configured to clamp the voltage peaks of the voltage on the control terminal and the voltage between the control terminal and the output terminal of the output clamping circuit, so as to clamp the voltage peak of the output terminal of the output clamping circuit;

[0072] The transformer T comprises a primary coil, at least one secondary coil and an auxiliary coil;

[0073] The primary coil includes a first end 1 and a second end 2; the auxiliary coil includes a third end 3 and a fourth end 4;

[0074] The output end of the output clamp circuit is coupled to the first end 1;

[0075] The power chip includes a power input terminal SW, a power supply terminal VDD, a feedback terminal COMP and a chip ground terminal GND;

[0076] The power input terminal SW is coupled to the second terminal 2; the power supply terminal VDD is coupled to the third terminal 3 through a power supply circuit; the feedback terminal COMP is coupled to the fourth terminal 4 through a feedback circuit; the chip ground terminal GND is grounded;

[0077] At least one of the output circuits is coupled to the at least one secondary coil and forms at least one operating voltage output.

[0078] Specifically, in the prior art, the existing power supply circuits often lack effective clamping measures for the output voltage peak when performing voltage conversion and voltage regulation control. In a high-voltage input environment, once an abnormally high voltage or overvoltage event occurs, if there is no immediate clamping protection mechanism, it will directly endanger the safety of the power chip and downstream loads.

[0079] exist Figure 1 In the embodiment, a power supply circuit is shown including an AC rectifier input circuit, an output clamping circuit, a transformer T, a power supply chip, an output circuit, a power supply circuit and a feedback circuit.

[0080] The AC rectifier input circuit example is four terminals corresponding to three-phase four-wire, for coupling three live wires and one neutral wire respectively. The AC rectifier input circuit includes a rectifier bridge adapted to three-phase four-wire, and the rectifier bridge includes diodes D1-D8, which are used to convert AC power into DC power and output it to the first terminal 1 and the second terminal 2 of the output clamp circuit.

[0081] The output clamp circuit includes a switch unit and a clamp unit. The switch unit is connected between the output end of the AC rectifier input circuit and the output end of the output clamp circuit, and controls the on and off of the first end 1 and the second end 2 through the control end.

[0082] The transformer T includes a primary coil, at least one secondary coil and an auxiliary coil. The first end 1 of the primary coil is coupled to the output end of the output clamp circuit, and the second end 2 is connected to the power input end SW of the power chip. The third end 3 of the auxiliary coil is connected to the power supply end VDD of the power chip through the power supply circuit, and the fourth end 4 is connected to the feedback end COMP of the power chip through the feedback circuit to achieve closed-loop control of the power output voltage.

[0083] The power chip has a power input terminal SW, a power supply terminal VDD, a feedback terminal COMP and a chip ground terminal GND. The input terminal receives the voltage input from the second terminal 2 of the primary coil, the power supply terminal VDD obtains a stable voltage supply from the third terminal 3 of the auxiliary coil, and the feedback terminal COMP is precisely controlled according to the voltage information transmitted by the feedback circuit to ensure the stability of the output voltage. Specifically, the power chip is internally integrated with a comparator circuit connected to the feedback terminal, which can compare the voltage fed back by the feedback circuit with the preset voltage threshold, and control the on and off of SW and GND according to the comparison result.

[0084] Optionally, in some embodiments, the power chip is implemented by AP8012Q and chips of related series with similar functions, or power chips of other manufacturers with similar principles.

[0085] Optionally, the power supply circuit includes at least one output circuit, and the transformer may include at least one secondary coil, each output circuit is coupled to a secondary coil, so as to generate at least one operating voltage output to meet the needs of different loads. In a high-voltage input environment, due to the use of output clamping technology and closed-loop voltage regulation control strategy, even if abnormal high voltage or overvoltage events occur, the clamping protection mechanism can be activated in time, effectively avoiding damage to the power chip and downstream loads due to overvoltage, greatly improving the stability and safety of the entire power supply system, and reducing costs. For power chips, a type with a lower voltage resistance can be selected that is also safe and stable for DC high voltage input, reducing the cost of the power chip.

[0086] Optional, such as Figure 1As shown, the switch unit includes:

[0087] A MOS tube M1, wherein a drain electrode D of the MOS tube M1 is connected to an output end of the AC rectifying input circuit, and a source electrode S of the MOS tube M1 is coupled to an output end of the output clamping circuit;

[0088] A first resistor R1 , one end of the first resistor R1 is connected to the drain D, and the other end of the first resistor R1 is coupled to the gate G of the MOS transistor M1 through a second resistor R2 .

[0089] Specifically, in the above embodiment, the MOS transistor M1 is configured as an enhancement type or a depletion type, and the specific type can be selected according to the actual application requirements, for example, it can be an N-type MOSFET. The drain D of the MOS transistor M1 is connected to the output end of the AC rectifier input circuit to facilitate the transmission of rectified DC power.

[0090] The source S of the MOS transistor M1 is coupled to the output terminal of the output clamp circuit. When the MOS transistor M1 is turned on, current is allowed to flow from the drain D to the source S, so that a voltage is formed at the source S and output to the transformer T.

[0091] In addition, a first resistor R1 and a second resistor R2 are connected between the drain D and the source S of the MOS tube M1 to form a gate G driving circuit. One end of the first resistor R1 is connected to the drain D of the MOS tube M1, and the other end is connected to the gate G of the MOS tube M1 through the second resistor R2. The output voltage of the AC rectifier input circuit is led to the gate G end after the voltage drop through R1 and R2 to control the on and off state of the MOS tube M1.

[0092] Optional, such as Figure 1 As shown, the clamping unit includes:

[0093] A first voltage stabilizing diode DW1, wherein the anode of the first voltage stabilizing diode DW1 is connected to the source S of the MOS tube M1, and the cathode of the first voltage stabilizing diode DW1 is connected to the gate G, so as to clamp the voltage V between the gate G and the source S when the gate is reversely broken down. GS .

[0094] a second voltage stabilizing diode DW2, wherein the anode of the second voltage stabilizing diode DW2 is grounded, and the cathode of the second voltage stabilizing diode DW2 is connected to the gate G to clamp the voltage V of the gate G when the gate G is reversely broken down; G ;

[0095] Specifically, in the above embodiment, the clamping unit uses two voltage regulator diodes connected in series in opposite directions to achieve effective clamping of the output voltage peak to protect the power chip, thereby ensuring that the power circuit can operate safely and stably even in a high-voltage input environment.

[0096] The first voltage stabilizing diode DW1 in the clamping unit has a positive terminal connected to the source S of the MOS tube M1, and a negative terminal connected to the gate G of the MOS tube M1. When the voltage from the source S to the gate G increases abnormally and exceeds the voltage stabilizing threshold of the first voltage stabilizing diode DW1, the first voltage stabilizing diode DW1 will reversely break down and conduct, and through its own voltage stabilizing characteristics, the voltage from the gate G to the source S is clamped within a safe range, thereby preventing excessive voltage from damaging the MOS tube M1 and protecting the power chip.

[0097] At the same time, the second voltage stabilizing diode DW2 is also designed into the clamping unit, with its positive electrode grounded and its negative electrode also connected to the gate G of the MOS tube M1. When the gate G is directly subjected to an excessively high voltage, the second voltage stabilizing diode DW2 will also function at its reverse breakdown voltage point, clamping the gate G voltage at a preset lower value, thereby further enhancing the protection of the gate G voltage.

[0098] It can be seen that the clamping unit is connected to the control end and the output end of the output clamping circuit, and has a dual clamping function. It can not only clamp the voltage of the control end, but also clamp the voltage peak between the control end and the output end of the output clamping circuit, effectively preventing abnormal high voltage or overvoltage from damaging the power supply system.

[0099] In order to improve the anti-interference performance and voltage stability of the circuit, a first energy storage filter capacitor C1 is provided. The positive electrode of the capacitor is coupled to the first terminal 1 of the output clamp circuit (ie, the drain D or source S of the MOS tube M1), and the negative electrode is grounded.

[0100] As an example, when the input voltage is less than the reverse breakdown voltage (voltage regulation threshold) of the second voltage stabilizing diode DW2, the current passes through the first resistor R1 and the second resistor R2, generating a voltage drop. At this time, the voltage V between the source S and the gate G is GS is greater than the preset voltage value of the MOS tube M1, the MOS tube M1 is turned on, and at this time, the voltage V OUT is the gate voltage V G - The voltage V between the source S and the gate G GS .

[0101] When the output voltage VDC at the output end of the AC rectifier input circuit is greater than the reverse breakdown voltage (voltage regulation threshold) of the second diode (D5, D6, D7, D8), the second diode (D5, D6, D7, D8) is broken down, and the gate G voltage V G is equal to the preset clamping voltage. At this time, the voltage V OUT is the voltage V of the second diode (D5, D6, D7, D8) D2- The voltage V between the source S and the gate G GS .

[0102] Optional, such as Figure 1 As shown, the AC rectifier input circuit includes:

[0103] At least one live wire input terminal (L1, L2, L3), one end of the live wire input terminal (L1, L2, L3) is connected to an external power supply, and the other end of the live wire input terminal (L1, L2, L3) is coupled to the input end of the output clamping circuit through a three-phase rectifier bridge and a first capacitor C2 wire L1 in sequence.

[0104] A neutral line input terminal N, one end of which is grounded, and the other end of which is coupled to the input end of the output clamp circuit through the three-phase rectification and the second capacitor C4 and L2 in sequence.

[0105] Optionally, the AC rectifier input circuit includes at least one live wire input terminal (L1-L3), one end of which is directly connected to an external three-phase AC power supply to receive the live wire voltage in the three-phase power supply. The other end of the live wire input terminal (L1-L3) is rectified by a three-phase rectifier bridge to convert the AC voltage into a DC voltage.

[0106] In order to further optimize the rectification effect and protect the circuit, a first capacitor C2 wire L1 is connected in series after the three-phase rectifier bridge. The capacitor wire is used to absorb and release transient voltage, reduce the impact of voltage mutation on the subsequent circuit, and couple the rectified and filtered voltage to the input end of the output clamping circuit.

[0107] In addition, the circuit also includes a neutral line input terminal N (N), one end of which is directly grounded to ensure the electrical safety of the circuit. The other end of the neutral line input terminal N is also rectified by the same three-phase rectifier bridge, and a second capacitor C4 is connected in series after the rectifier bridge. The capacitor also plays a filtering and protection role. In this way, the rectified and filtered neutral line voltage is also coupled to the input end of the output clamp circuit.

[0108] Through the above design, the AC rectifier input circuit can effectively receive the three-phase AC power supply, and convert the AC power into relatively smooth DC power through the filtering network composed of the three-phase rectifier bridge and the capacitor wire.

[0109] Optional, such as Figure 1 As shown, the three-phase rectifier bridge includes: a pair of diodes adjacent to each of the live input terminals (L1-L3) and the neutral input terminal N, including:

[0110] a first diode (D1, D2, D3, D4), wherein an anode of the first diode (D1, D2, D3, D4) is coupled to at least one of the live wire input terminals (L1-L3), and a cathode of the first diode (D1, D2, D3, D4) is coupled to an input terminal of the output clamp circuit;

[0111] A second diode (D5, D6, D7, D8), wherein the anode of the second diode (D5, D6, D7, D8) is grounded, and the cathode of the second diode (D5, D6, D7, D8) is coupled to at least one of the live line input terminals (L1-L3) and / or the neutral line input terminal N.

[0112] Optionally, in the above embodiment, the diode (D1, D2, D3, D4) is a first diode (D1, D2, D3, D4), and the diode (D5, D6, D7, D8) is a second diode (D5, D6, D7, D8).

[0113] In each phase of AC input, a pair of diodes are included for rectification. As an example, for the live input terminals (L1-L3) (such as phase A, phase B and phase C), each live input terminal (L1-L3) is connected to a first diode (D1, D2, D3, D4). The positive electrode of the first diode (D1, D2, D3, D4) is coupled to the corresponding live input terminal (L1-L3). When the corresponding AC voltage is in the positive half cycle, the diode is turned on to convert the positive half of the AC voltage into DC; its negative electrode is coupled to the input terminal of the output clamp circuit as the rectified DC output.

[0114] In addition, the second diode (D5, D6, D7, D8) in each pair of diodes is mainly used to rectify the negative half cycle of the alternating current. The anode of the second diode (D5, D6, D7, D8) is grounded, and when the alternating voltage is in the negative half cycle, the diode is turned on, and the negative half of the alternating voltage is also converted into direct current.

[0115] It is worth noting that the second diode (D5, D6, D7, D8) here can be coupled to the live wire input terminal (L1~L3) or to the neutral wire input terminal N, depending on the actual wiring method of the rectifier bridge to ensure full-wave rectification, that is, converting all positive and negative half-cycles of the alternating current into direct current in a single direction.

[0116] Optional, such as Figure 1 As shown, an RCD absorption circuit is further provided between the output end of the output clamp circuit and the first end 1, and the RCD absorption circuit comprises:

[0117] A third resistor R3, one end of the third resistor R3 is connected to the first end 1;

[0118] a fourth resistor R4, wherein the fourth resistor R4 is connected in parallel with the third resistor R3;

[0119] A first capacitor C2, wherein the first capacitor C2 is connected in parallel with the fourth resistor R4;

[0120] A third diode D9, wherein an anode of the third diode D9 is connected to the power input terminal SW, and a cathode of the third diode D9 is connected to the other end of the third resistor R3.

[0121] Optionally, in the power supply circuit based on AC / DC conversion, in order to further optimize the stability of the output voltage and protect circuit elements from voltage transients, an RCD absorption circuit is added between the output end of the output clamp circuit and the first end 1 (i.e., the first end 1 of the primary coil).

[0122] like Figure 1 As shown, the RCD absorption circuit is composed of a third resistor R3, a fourth resistor R4, a first capacitor C2 and a third diode D9.

[0123] One end of the third resistor R3 is directly connected to the output end of the output clamp circuit, and the other end serves as a common connection point of the RCD absorption circuit.

[0124] The fourth resistor R4 is connected in parallel with the third resistor R3 between the output end of the output clamp circuit and the common connection point to form a resistor voltage divider network. In the circuit, resistor voltage divider can effectively suppress voltage spikes and reduce the impact of voltage transients on subsequent circuits.

[0125] The first capacitor C2 is also connected in parallel to the fourth resistor R4, and together with the fourth resistor R4, forms an RC filter circuit. The capacitor can absorb and release energy when the voltage suddenly changes, smooth the voltage change, and reduce the impact of voltage overshoot on sensitive components such as the MOS tube M1.

[0126] The anode of the third diode D9 is connected to the power input terminal SW (i.e., the DC high voltage terminal after rectification), and the cathode is connected to the other end of the third resistor R3. When a reverse voltage appears in the circuit (such as the back electromotive force at the moment when the MOS tube M1 is turned off), the third diode D9 is immediately turned on to form a low impedance channel, which quickly discharges the reverse voltage to the ground, thereby playing the role of clamping and absorbing the reverse voltage and protecting the circuit from damage.

[0127] Optional, such as Figure 1 As shown, the power supply circuit includes:

[0128] a fourth diode D10, wherein an anode of the fourth diode D10 is coupled to the third terminal 3, and a cathode of the fourth diode D10 is coupled to the power supply terminal VDD via a fifth resistor R5;

[0129] a second energy storage filter capacitor C3, wherein a negative electrode of the second energy storage filter capacitor C3 is coupled to the fourth terminal 4, and a positive electrode of the second energy storage filter capacitor C3 is coupled to the power supply terminal VDD;

[0130] A second capacitor C4, wherein the second capacitor C4 is connected in parallel with the second energy storage filter capacitor C3.

[0131] Optionally, the power supply circuit mainly includes a fourth diode D10, a fifth resistor R5, a second energy storage filter capacitor C3 and a second capacitor C4. The fourth diode D10 is configured as a forward conducting element, with its positive electrode coupled to the auxiliary coil (third terminal 3) of the transformer T, and its negative electrode connected to the power supply terminal VDD of the power chip through the fifth resistor R5. The fourth diode D10 plays a rectifying role in the circuit, converting the AC signal from the auxiliary coil into DC power, and the fifth resistor R5 plays a current limiting and voltage dividing role here to prevent excessive current from impacting the power chip, and can also affect the time constant of the circuit and adjust the filtering effect.

[0132] The negative electrode of the second energy storage filter capacitor C3 is coupled to the fourth terminal 4 (another terminal of the auxiliary coil) of the transformer T, and the positive electrode thereof is coupled to the power supply terminal VDD of the power chip. The main function of the second energy storage filter capacitor C3 is to store and release energy, filter the rectified pulsating DC power, smooth the voltage fluctuation, and provide a relatively stable DC power supply to the power chip.

[0133] The second capacitor C4 is connected in parallel with the second energy storage filter capacitor C3, and also acts on the filtering link. The total capacitance is increased by parallel capacitors, which further improves the filtering effect, effectively reduces voltage ripple, and ensures that the power chip obtains high-quality, low-noise DC power supply.

[0134] In summary, the power supply circuit in this embodiment uses the fourth diode D10 to achieve rectification, the fifth resistor R5 to limit current and divide voltage, and the second energy storage filter capacitor C3 and the second capacitor C4 are connected in parallel to form a filtering link, which together provide a stable and clean power supply environment for the power chip.

[0135] Optional, such as Figure 1 As shown, the feedback circuit includes:

[0136] a third voltage stabilizing diode DW3, wherein an anode of the third voltage stabilizing diode DW3 is connected to the feedback end, and a cathode of the third voltage stabilizing diode DW3 is coupled to the output end of the power supply circuit;

[0137] A third capacitor C5, one end of the third capacitor C5 is connected to the anode of the third voltage stabilizing diode DW3, and the other end of the third capacitor C5 is grounded.

[0138] Optionally, the feedback circuit includes a third voltage stabilizing diode DW3 and a third capacitor C5. The anode of the third voltage stabilizing diode DW3 is directly connected to the feedback terminal of the power chip, so that it can receive a reference voltage signal from the inside of the power chip or other control circuits. The cathode of the third voltage stabilizing diode DW3 is coupled to the output terminal of the power supply circuit to receive the actual power supply output voltage signal.

[0139] When there is a difference between the output voltage of the power supply circuit and the reference voltage of the feedback terminal, the third voltage stabilizing diode DW3 acts as a voltage reference element to ensure that the voltage of the feedback terminal does not exceed its voltage stabilizing range, thereby ensuring the accuracy and reliability of the comparison result.

[0140] In addition, the third capacitor C5 is configured between the positive electrode of the third voltage stabilizing diode DW3 and the ground to form an RC filter network. The function of the capacitor is to play a filtering effect in the comparison process, eliminate the miscomparison caused by the noise or transient changes in the voltage signal, and ensure that the feedback circuit can stably and accurately perform voltage comparison in a voltage fluctuation environment, so as to better serve the closed-loop control of the power supply circuit and the precise adjustment of the output voltage.

[0141] Optional, such as Figure 1 As shown, the secondary coil includes a first secondary coil, and the first secondary coil includes a fifth end 5 and a sixth end 6;

[0142] The fifth end 5 and the second end 2 are the same end;

[0143] The output circuit includes a first output circuit with an output voltage of 5 volts, such as Figure 1 As shown, the first output circuit includes:

[0144] a fifth diode D11, wherein an anode of the fifth diode D11 is coupled to the fifth end 5;

[0145] a third energy storage filter capacitor C6, wherein the positive electrode of the third energy storage filter capacitor C6 is connected to the negative electrode of the fifth diode D11, and the negative electrode of the third energy storage filter capacitor C6 is coupled to the sixth terminal 6;

[0146] A first voltage regulator tube U1, wherein an input end of the first voltage regulator tube U1 is coupled to the cathode of the fifth diode D11, an output end of the first voltage regulator tube U1 is connected to an external load, and a ground end of the first voltage regulator tube U1 is grounded;

[0147] A fourth capacitor C7, one end of the fourth capacitor C7 is coupled to the output end of the first voltage regulator U1, and the other end of the fourth capacitor C7 is grounded.

[0148] Optionally, the power supply circuit based on AC / DC conversion includes a secondary coil, defined as a first secondary coil, which has two terminals, namely a fifth terminal 5 and a sixth terminal 6. The fifth terminal 5 and the second terminal 2 of the primary coil are the same terminals, which means that they have the same polarity during the electromagnetic induction process of the coil.

[0149] The fifth diode D11 is configured to be forward-conducted, with its anode directly coupled to the fifth end 5 of the first secondary coil. When the first secondary coil induces sufficient voltage, the fifth diode D11 starts to conduct and transmits the voltage on the first secondary coil to the subsequent circuit.

[0150] The third energy storage filter capacitor C6 is connected between the cathode of the fifth diode D11 and the sixth end 6 of the first secondary coil. After the rectified voltage passes through the fifth diode D11, the third energy storage filter capacitor C6 stores and filters the voltage, eliminates the AC component in the voltage, and forms a smoother DC.

[0151] The first voltage regulator U1 is used for precise voltage regulation, and its input end is coupled to the cathode of the fifth diode D11 to receive the voltage that has been preliminarily rectified and filtered. The output end of the voltage regulator is directly connected to the external load to provide a stable first voltage (such as 5V) for the load. The ground end of the voltage regulator is grounded to ensure a good reference ground plane in the circuit.

[0152] The fourth capacitor C7 is connected between the output end of the first voltage regulator U1 and the ground to form a filter network at the output end, further eliminating voltage fluctuations caused by factors such as load changes or internal noise of the power supply, thereby ensuring the stability of the output voltage.

[0153] Optional, such as Figure 1 As shown, the secondary coil further includes a second secondary coil, and the second secondary coil includes a seventh end 7 and an eighth end 8;

[0154] The seventh end 7 and the second end 2 are ends of the same name;

[0155] The output circuit also includes a second output circuit with an output voltage of 12 volts. Figure 1 As shown, the second output circuit includes:

[0156] a sixth diode D12, wherein an anode of the sixth diode D12 is coupled to the seventh terminal 7;

[0157] A fourth energy storage filter capacitor C8, wherein the positive electrode of the fourth energy storage filter capacitor C8 is connected to the negative electrode of the sixth diode D12, and the negative electrode of the fourth energy storage filter capacitor C8 is coupled to the eighth terminal 8;

[0158] A second voltage regulator tube U2, wherein an input end of the second voltage regulator tube U2 is coupled to the cathode of the sixth diode D12, an output end of the second voltage regulator tube U2 is connected to an external load, and a ground end of the second voltage regulator tube U2 is grounded;

[0159] A fifth capacitor C9, one end of the fifth capacitor C9 is coupled to the output end of the second voltage regulator tube U2, and the other end of the fifth capacitor C9 is grounded.

[0160] Optionally, in addition to the first secondary coil, the transformer T may also include a second secondary coil, which has a seventh terminal 7 and an eighth terminal 8, wherein the seventh terminal 7 and the second terminal 2 of the primary coil are the same terminals, indicating that they have the same polarity during the electromagnetic induction process.

[0161] The sixth diode D12 is used as a rectifying element, and its anode is coupled to the seventh terminal 7 of the second secondary coil. When the second secondary coil induces a voltage, the sixth diode D12 is forward-conducted to convert the AC voltage into a DC voltage.

[0162] One end of the fourth energy storage filter capacitor C8 is connected to the cathode of the sixth diode D12, and the other end is coupled to the eighth end 8 of the second secondary coil. The function of the capacitor is to store and release energy, smooth the rectified voltage waveform, filter out the AC component in the voltage, and provide a relatively smooth DC voltage.

[0163] The second voltage regulator U2 is used for precise voltage regulation, and its input end is coupled to the cathode of the sixth diode D12 to receive the rectified and preliminarily filtered voltage. The output end of the voltage regulator is directly connected to the external load to provide a stable 12 volt voltage for the load. The ground end of the voltage regulator is grounded to ensure that the circuit has a good reference ground plane.

[0164] The fifth capacitor C9 is connected in series between the output end of the second voltage regulator U2 and the ground to form an output filter network, which further reduces the voltage fluctuation caused by load changes or internal noise of the power supply and ensures the stability and quality of the output voltage.

[0165] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the protection scope of the present disclosure.

Claims

1. A power supply circuit based on AC / DC conversion, characterized in that: include: An AC rectifier input circuit, wherein an input terminal of the AC rectifier input circuit is coupled to AC power; The output clamping circuit comprises: a switch unit and a clamping unit; The switch unit comprises: a first end and a second end respectively connected to the output end of the AC rectifier input circuit and the output end of the output clamp circuit, and a control end for controlling the switching of the first end and the second end; The clamping unit is connected to the control terminal and the output terminal of the output clamping circuit, and is configured to clamp the voltage peaks of the voltage on the control terminal and the voltage between the control terminal and the output terminal of the output clamping circuit, so as to clamp the voltage peak of the output terminal of the output clamping circuit; A transformer, the transformer comprising a primary coil, at least one secondary coil and an auxiliary coil; The primary coil includes a first end and a second end; the auxiliary coil includes a third end and a fourth end; The output end of the output clamp circuit is coupled to the first end; A power chip, the power chip comprising a power input terminal, a power supply terminal, a feedback terminal and a chip ground terminal; The power input terminal is coupled to the second terminal; the power supply terminal is coupled to the third terminal through a power supply circuit; the feedback terminal is coupled to the fourth terminal through a feedback circuit; and the chip ground terminal is grounded; At least one output circuit is coupled to the at least one secondary coil and forms at least one operating voltage output.

2. The power supply circuit according to claim 1, characterized in that: The switch unit comprises: A MOS tube, wherein the drain of the MOS tube is connected to the output end of the AC rectifier input circuit, and the source of the MOS tube is coupled to the output end of the output clamp circuit; A first resistor, one end of the first resistor is connected to the drain, and the other end of the first resistor is coupled to the gate of the MOS tube through a second resistor.

3. The power supply circuit according to claim 2, characterized in that: The clamping unit comprises: a first voltage stabilizing diode, wherein the anode of the first voltage stabilizing diode is connected to the source of the MOS tube, and the cathode of the first voltage stabilizing diode is connected to the gate, so as to clamp the voltage between the gate and the source when reverse breakdown occurs; a second voltage stabilizing diode, wherein the anode of the second voltage stabilizing diode is grounded, and the cathode of the second voltage stabilizing diode is connected to the gate, so as to clamp the voltage of the gate when reverse breakdown occurs; A first energy storage filter capacitor, wherein a positive electrode of the first energy storage filter capacitor is coupled to the first end, and a negative electrode of the first energy storage filter capacitor is grounded.

4. The power supply circuit according to claim 1, characterized in that: The AC rectifier input circuit comprises: At least one live wire input terminal, one end of the live wire input terminal is connected to an external power supply, and the other end of the live wire input terminal is coupled to the input end of the output clamp circuit through a three-phase rectifier bridge and a first capacitor wire in sequence; A neutral line input end, one end of which is grounded, and the other end of which is coupled to the input end of the output clamp circuit through the three-phase rectification and a second capacitor in sequence.

5. The power supply circuit according to claim 4, characterized in that: The three-phase rectifier bridge comprises: a pair of diodes adjacent to each of the live input terminals and the neutral input terminals, comprising: a first diode, wherein an anode of the first diode is coupled to at least one of the live wire input terminals, and a cathode of the first diode is coupled to an input terminal of the output clamp circuit; A second diode, wherein an anode of the second diode is grounded, and a cathode of the second diode is coupled to at least one of the live line input terminal and / or the neutral line input terminal.

6. The power supply circuit according to claim 1, characterized in that: An RCD absorption circuit is further provided between the output end of the output clamp circuit and the first end, and the RCD absorption circuit comprises: a third resistor, one end of the third resistor being connected to the first end; a fourth resistor, the fourth resistor being connected in parallel with the third resistor; A first capacitor, wherein the first capacitor is connected in parallel with the fourth resistor; A third diode, wherein an anode of the third diode is connected to the power input terminal, and a cathode of the third diode is connected to the other end of the third resistor.

7. The power supply circuit according to claim 1, characterized in that: The power supply circuit comprises: a fourth diode, wherein an anode of the fourth diode is coupled to the third end, and a cathode of the fourth diode is coupled to the power supply end via a fifth resistor; a second energy storage filter capacitor, wherein a negative electrode of the second energy storage filter capacitor is coupled to the fourth end, and a positive electrode of the second energy storage filter capacitor is coupled to the power supply end; A second capacitor is connected in parallel with the second energy storage filter capacitor.

8. The power supply circuit according to claim 1, characterized in that: The feedback circuit comprises: a third voltage stabilizing diode, wherein an anode of the third voltage stabilizing diode is connected to the feedback end, and a cathode of the third voltage stabilizing diode is coupled to an output end of the power supply circuit; A third capacitor, one end of the third capacitor is connected to the anode of the third voltage stabilizing diode, and the other end of the third capacitor is grounded.

9. The power supply circuit according to claim 1, characterized in that: The secondary coil includes a first secondary coil, and the first secondary coil includes a fifth end and a sixth end; The fifth end and the second end are ends of the same name; The output circuit includes a first output circuit with an output voltage of 5 volts, and the first output circuit includes: a fifth diode, wherein an anode of the fifth diode is coupled to the fifth end; a third energy storage filter capacitor, wherein the positive electrode of the third energy storage filter capacitor is connected to the negative electrode of the fifth diode, and the negative electrode of the third energy storage filter capacitor is coupled to the sixth end; A first voltage regulator tube, wherein an input end of the first voltage regulator tube is coupled to the cathode of the fifth diode, an output end of the first voltage regulator tube is connected to an external load, and a ground end of the first voltage regulator tube is grounded; A fourth capacitor, one end of the fourth capacitor is coupled to the output end of the first voltage regulator tube, and the other end of the fourth capacitor is grounded.

10. The power supply circuit according to claim 1, characterized in that: The secondary coil further includes a second secondary coil, and the second secondary coil includes a seventh end and an eighth end; The seventh end and the second end are ends of the same name; The output circuit further includes a second output circuit with an output voltage of 12 volts, the second output circuit including: a sixth diode, wherein an anode of the sixth diode is coupled to the seventh end; a fourth energy storage filter capacitor, wherein the positive electrode of the fourth energy storage filter capacitor is connected to the negative electrode of the sixth diode, and the negative electrode of the fourth energy storage filter capacitor is coupled to the eighth end; A second voltage regulator tube, wherein an input end of the second voltage regulator tube is coupled to the cathode of the sixth diode, an output end of the second voltage regulator tube is connected to an external load, and a ground end of the second voltage regulator tube is grounded; A fifth capacitor, one end of the fifth capacitor is coupled to the output end of the second voltage regulator tube, and the other end of the fifth capacitor is grounded.

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