Power conversion circuit and power strip

Abstract

The embodiment of the utility model provides a power conversion circuit and a power strip. The power conversion circuit comprises an input circuit; the input end of the rectifying circuit is coupled with the input circuit; the first end of the primary coil is coupled with the output end of the rectifying circuit; a first power supply input end of the power supply chip is coupled with the first end, a sixth end is coupled with the first power supply input end, and a first grounding end is grounded; the sixth end is connected with the feedback end; the output circuit comprises a power supply output end and a second grounding end; the energy storage filtering unit is coupled between the power supply output end and the second grounding end; the second power input end is coupled to the fifth end; the second power supply input end is coupled to the power supply output end; the self-control switch unit connects and disconnects the second power supply input end and the second grounding end based on the voltage difference. According to the utility model, accurate regulation and control of the output voltage are realized by utilizing multiple transformation of the transformer and cooperating with a feedback control mechanism of the power supply chip. The on-off state of the self-control switch unit is automatically adjusted, and it is ensured that when the load changes or the power supply fluctuates, the output voltage can still be kept stable.

Description

Technical Field

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

[0002] With the rapid development of power electronics technology, the performance of power conversion circuits, as core components of power systems, electronic equipment, and even various industrial automation, household appliances, etc., directly affects the stable operation, energy efficiency, and electromagnetic compatibility of the entire system.

[0003] Existing power conversion circuits usually include input circuits, rectifier circuits, transformers, power control chips, output circuits, and related protection and filtering elements to convert AC power into DC power that meets the requirements of specific equipment.

[0004] However, traditional power conversion circuits still face some technical challenges in practical applications. First, with the continuous improvement of power efficiency requirements, how to achieve high conversion efficiency within a wide input voltage range and reduce energy waste has become an important consideration in power design. Secondly, with the trend of miniaturization of equipment, power conversion circuits need to have high power density, that is, to achieve high power conversion in a smaller volume, which puts higher requirements on the integration and heat dissipation design of the circuit. Furthermore, in order to ensure the normal operation of the equipment and extend its service life, the power output must have good stability and be able to maintain voltage stability under conditions such as load changes and grid fluctuations. This requires the circuit to have excellent voltage regulation performance and dynamic response speed.

[0005] In addition, as electromagnetic compatibility (EMC) standards become increasingly stringent, how to effectively suppress electromagnetic interference (EMI) during the power conversion process and reduce interference to surrounding electronic equipment and communication systems is also an issue that cannot be ignored in current power supply design. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the related art, the purpose of the present disclosure is to provide a power conversion circuit and a power strip to solve the problems in the related art.

[0007] A first aspect of the present disclosure provides a power conversion circuit, comprising:

[0008] Input circuit for connecting AC power;

[0009] A rectifier circuit, an input end of which is coupled to the input circuit;

[0010] A transformer, the transformer comprising a primary coil, a secondary coil and an auxiliary coil;

[0011] The primary coil includes a first end and a second end; the first end is coupled to the output end of the rectifier circuit;

[0012] The secondary coil includes a third end and a fourth end;

[0013] The auxiliary coil includes a fifth end and a sixth end;

[0014] Wherein, the first end, the third end and the fifth end are ends of the same name;

[0015] A power chip, comprising: a first power input terminal, a first power supply input terminal, a feedback terminal and a first ground terminal;

[0016] The first power input terminal is coupled to the first terminal, the sixth terminal is coupled to the first power input terminal via a power supply circuit, and the first ground terminal is grounded;

[0017] The sixth terminal is connected to the feedback terminal of the power chip via a sampling circuit;

[0018] The output circuit comprises: a power supply output terminal and a second ground terminal;

[0019] An energy storage filter unit, coupled between the power supply output terminal and the second ground terminal;

[0020] The self-controlled switch unit comprises: a second power input terminal, a second power supply input terminal and a third ground terminal;

[0021] The second power input terminal is coupled to the fourth terminal; the second power supply input terminal is coupled to the power supply output terminal; the self-controlled switch unit is configured to switch the second power input terminal and the second ground terminal on and off based on the voltage difference between the second power input terminal and the second ground terminal within a variable voltage range.

[0022] In an embodiment of the first aspect, the input side of the input circuit includes a live wire and a neutral wire;

[0023] One end of the live wire is connected to an external power source, and the other end of the live wire is connected to an input end of the rectifier circuit through an overcurrent protection fuse; and / or,

[0024] One end of the neutral line is grounded, and the other end of the neutral line is connected to the input end of the rectifier circuit through a ring fuse.

[0025] In an embodiment of the first aspect, the rectifier circuit includes:

[0026] a first inductor, one end of which is connected to the output end of the input circuit through a current converter;

[0027] a first resistor, the first resistor being connected in parallel with the first inductor;

[0028] a second inductor, one end of the second inductor being connected to the output end of the current converter, and the other end of the second inductor being grounded;

[0029] A first filter capacitor, a second filter capacitor and a third filter capacitor are connected in parallel between the first inductor and the second inductor;

[0030] The other end of the first inductor is grounded through the third filter capacitor.

[0031] In an embodiment of the first aspect, an RCD absorption circuit is further provided between the rectifier circuit and the primary coil, and the RCD absorption circuit includes:

[0032] a second resistor, one end of which is connected to the second end;

[0033] a first capacitor, one end of the first capacitor being connected to one end of the second resistor, and the other end of the first capacitor being connected to the other end of the second resistor;

[0034] a third resistor, one end of the third resistor being connected to the other end of the second resistor;

[0035] A first diode, wherein an anode of the first diode is connected to the first end, and a cathode of the first diode is connected to the other end of the third resistor.

[0036] In an embodiment of the first aspect, the power supply circuit includes:

[0037] a second diode, wherein an anode of the second diode is connected to the fifth end, and a cathode of the second diode is connected to the first power input end of the power chip through a fourth resistor;

[0038] The sixth terminal is connected to the first power supply input terminal through a first energy storage filter capacitor.

[0039] In an embodiment of the first aspect, the sampling circuit includes:

[0040] a fifth resistor, one end of which is connected to the fifth terminal, and the other end of which is connected to the feedback terminal;

[0041] a sixth resistor, the sixth resistor being connected in parallel with the fifth resistor;

[0042] a seventh resistor, one end of the seventh resistor being connected to the other end of the fifth resistor, and the other end of the seventh resistor being grounded;

[0043] A second capacitor is connected in parallel with the seventh resistor.

[0044] In an embodiment of the first aspect, the power chip further includes an overcurrent detection terminal;

[0045] The overcurrent detection terminal is grounded through a current point sampling circuit, and the overcurrent detection terminal forms a sampling voltage corresponding to the current flowing into the first power input terminal through the overcurrent point sampling circuit;

[0046] The overcurrent point sampling circuit comprises:

[0047] an eighth resistor, one end of the eighth resistor being connected to the overcurrent detection end, and the other end of the eighth resistor being connected to the output end of the rectifier circuit;

[0048] A ninth resistor is connected in parallel with the eighth resistor.

[0049] In an embodiment of the first aspect, further comprising:

[0050] a tenth resistor, one end of the tenth resistor being connected to the fourth end, and the other end of the tenth resistor being connected to the third ground end via a third capacitor;

[0051] a fourth capacitor, one end of the fourth capacitor being connected to the third ground terminal, and the other end of the fourth capacitor being connected to the second power supply input terminal;

[0052] A fifth capacitor is connected in series between the second ground terminal and the fifth terminal.

[0053] In an embodiment of the first aspect, the energy storage filter unit includes:

[0054] a second energy storage filter capacitor, wherein a positive electrode of the second energy storage filter capacitor is connected to the third end, and a negative electrode of the second energy storage filter capacitor is connected to the third ground end;

[0055] A third energy storage filter capacitor, the third energy storage filter capacitor is connected in parallel with the second energy storage filter capacitor;

[0056] An eleventh resistor, the eleventh resistor is connected in parallel with the third energy storage filter capacitor, one end of the eleventh resistor is grounded, and the other end of the eleventh resistor is connected to the power supply output end.

[0057] A second aspect of the present disclosure provides a power strip, comprising any one of the power conversion circuits described above.

[0058] Beneficial effects of the utility model: The utility model utilizes multiple transformations of the primary coil, the secondary coil and the auxiliary coil of the transformer, and cooperates with the feedback control mechanism of the power chip to achieve accurate regulation of the output voltage. At the same time, the self-controlled switch unit can automatically adjust its on-off state within the variable voltage range according to the voltage difference between the second power input terminal and the second ground terminal, further enhancing the dynamic response speed and voltage stabilization performance of the circuit, ensuring that the output voltage can remain stable when the load changes or the power supply fluctuates. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A schematic diagram showing the circuit principle of a power conversion circuit in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] like Figure 1, which shows a schematic diagram of the circuit principle of a power conversion circuit in an embodiment of the present disclosure.

[0070] exist Figure 1 In the embodiment, the power conversion circuit includes: an input circuit 1, a rectifier circuit 2, a transformer 3, a power chip 4, a sampling circuit 5, an output circuit 6, an energy storage filter unit 7 and an automatic switch unit 8.

[0071] The input circuit 1 is for connecting to an AC power source.

[0072] The input end of the rectifier circuit 2 is coupled to the input circuit 1 .

[0073] The transformer 3 includes a primary coil 31 , a secondary coil 32 and an auxiliary coil 33 .

[0074] The primary coil 31 includes a first end 311 and a second end 312 .

[0075] The first terminal 311 is coupled to the output terminal of the rectifier circuit 2 .

[0076] The secondary coil 32 includes a third end 321 and a fourth end 322 .

[0077] The auxiliary coil 33 includes a fifth end 331 and a sixth end 332 .

[0078] The first end 311 , the third end 321 and the fifth end 331 are ends with the same name.

[0079] The power chip 4 includes a first power input terminal 41 , a first power supply input terminal 42 , a feedback terminal 43 and a first ground terminal 44 .

[0080] The first power input terminal 41 is coupled to the first terminal 311 , the sixth terminal 332 is coupled to the first power input terminal 42 via the power supply circuit, and the first ground terminal 44 is grounded.

[0081] The sixth terminal 332 is connected to the feedback terminal 43 of the power chip 4 via a sampling circuit 5 .

[0082] The output circuit 6 includes a power supply output terminal 61 and a second ground terminal 62 .

[0083] The energy storage filter unit 7 is coupled between the power supply output terminal 61 and the second ground terminal 62 to perform energy storage / discharge and filtering functions.

[0084] The self-controlled switch unit 8 includes a second power input terminal 81 , a second power supply input terminal 82 and a third ground terminal 83 .

[0085] The second power input terminal 81 is coupled to the fourth terminal 322;

[0086] The second power supply input terminal 82 is coupled to the power supply output terminal 61;

[0087] The self-controlled switch unit 8 is configured to switch the second power input terminal 81 and the second ground terminal 62 on the basis of a voltage difference between the second power input terminal 81 and the second ground terminal 62 being within a variable voltage range.

[0088] Specifically, in the above embodiment, the input circuit 1 of the power conversion circuit is connected to an external AC power source, such as a mains power source, to provide power for the entire power circuit, ensuring that the AC power source can be safely and stably input to subsequent circuits for processing.

[0089] The input circuit 1 inputs AC power. Based on the requirement of rectifying the AC power into DC power for output to the load, the input circuit 1 is coupled to the rectifier circuit 2 at the rear stage to convert the input AC power into DC power for output.

[0090] The transformer 3 comprises a primary coil 31 , a secondary coil 32 and an auxiliary coil 33 , wherein the primary coil 31 is connected to the output end of the rectifier circuit 2 to receive rectified direct current.

[0091] As an example, the first end 311 of the primary coil 31 is connected to the output end of the rectifier circuit 2 .

[0092] There is a certain proportional relationship between the number of turns of the secondary coil 32 and the number of turns of the auxiliary coil 33 , so that the auxiliary coil 33 can obtain a voltage proportional to the secondary coil 32 .

[0093] Specifically, the number of turns of the secondary coil 32 (denoted as N_{secondary}) and the number of turns of the auxiliary coil 33 (denoted as N_{auxiliary}) follow the following proportional relationship: N_{secondary}: N_{auxiliary} = K: 1, where K is a positive integer proportional coefficient determined according to actual application requirements and system design parameters.

[0094] In the transformer 3, the voltage ratio between different coils is proportional to the turns ratio. By setting the turns ratio between the secondary coil 32 and the auxiliary coil 33, the ratio of the output voltages between the two coils can be accurately controlled to ensure that the voltage output by the secondary coil 32 meets the load requirements, while the voltage output by the auxiliary coil 33 is suitable as the working power supply of the power chip 4.

[0095] Furthermore, since the turns ratio determines the voltage ratio, the voltage change on the auxiliary coil 33 can also reflect the voltage change on the secondary coil 32, that is, the change in the output voltage of the power supply circuit. Therefore, the output voltage feedback can be obtained based on the voltage sampling on the auxiliary coil 33.

[0096] The first end 311 of the primary coil 31, the third end 321 of the secondary coil 32 and the fifth end 331 of the auxiliary coil 33 are all the same end. When the first power input end 41 and the first ground end 44 are connected, current flows through the primary coil 31, so the primary coil 31 is in an energy storage state.

[0097] When the feedback terminal 43 of the power chip 4 outputs a feedback signal to control the first power input terminal 41 and the first ground terminal 44 to be non-conductive, no current flows through the primary coil 31, and the corresponding secondary coil and the auxiliary coil 33 begin to discharge energy.

[0098] The auxiliary coil 33 can also supply power to the power chip 4. As an example, the first power supply input terminal 42 obtains the electric energy stored in the auxiliary coil 33 through the power supply circuit to supply power to the internal circuit of the power chip 4.

[0099] The first power input terminal 41 of the power chip 4 is coupled to the first terminal 311 of the primary coil 31. The feedback terminal 43 of the power chip 4 is connected to the fifth terminal 331 of the auxiliary coil 33 via the sampling circuit 5 to receive the feedback signal related to the output voltage collected by the sampling circuit 5.

[0100] The power chip 4 is configured to control the on / off between the first power input terminal 41 and the first ground terminal 44 according to the feedback signal of the feedback terminal, such as the on / off frequency and duration within a cycle, so as to perform closed-loop control of the output voltage to stabilize the voltage. That is, in this embodiment, the output voltage is sampled by the sampling circuit 5, and the sampled feedback signal is transmitted to the power chip 4, so that the chip adjusts the output voltage according to the feedback signal to achieve the voltage stabilization function.

[0101] In some embodiments, the power control unit may be implemented by a power control chip, such as a chip of model PN8386J and a related series with similar functions, or a power control chip of other manufacturers with similar principles.

[0102] The output circuit 6 includes a power supply output terminal 61 and a second ground terminal 62. The power supply output terminal 61 provides stabilized DC power to an external load, and the second ground terminal 62 ensures that a stable potential reference is formed between the output circuit 6 and the ground.

[0103] The output circuit 6 may also include filtering, protection and other components to further improve the power quality.

[0104] The energy storage filter unit 7 is connected between the power supply output terminal 61 and the second ground terminal 62, and is mainly composed of energy storage elements such as capacitors and inductors. It is used to filter out ripples in the output voltage and provide a more stable power supply. At the same time, it plays the role of energy storage and transient response, further improving the stability of the power supply.

[0105] The second power input terminal 81 of the self-controlled switch unit 8 is connected to the fifth terminal 331 of the auxiliary coil 33, the second power input terminal 82 is connected to the power output terminal 61 of the output circuit 6, and the third ground terminal 83 is grounded. The unit automatically controls its on-off state within a preset variable voltage range according to the voltage difference between the second power input terminal 81 and the second ground terminal 62 to adjust the output voltage or realize overvoltage, undervoltage protection and other functions.

[0106] The self-controlled switch unit 8 has a power MOSFET with extremely low on-resistance inside to replace the rectifier diode to reduce losses. There is no dead zone voltage caused by the Schottky barrier voltage, thereby reducing losses and improving energy efficiency.

[0107] Two preset voltage values ​​are pre-set in the self-controlled switch unit 8, a first preset voltage value and a second preset voltage value. The first preset voltage value is less than the second preset voltage value. Since they correspond to the ground terminal, the first preset voltage value and the second preset voltage value can be negative values. The second preset voltage value is closer to the ground voltage 0. For example, the first voltage value is -400mV, the second voltage value is -32mV, etc.

[0108] The first preset voltage value actually represents the standard threshold value for releasing the stored energy on the secondary coil 32, and its voltage value can be set in accordance with the on / off state between the first power input terminal 41 and the first ground terminal 44 (it can be set according to the time when the fourth terminal 322 reaches the first preset voltage value).

[0109] The second preset voltage value actually represents the standard threshold value for the secondary coil 32 to store energy, and its voltage value can be set in accordance with the on-off state between the first power input terminal 41 and the first ground terminal 44. When the self-controlled switch unit 8 detects that the voltage value of the second power input terminal 81 is less than the first preset voltage value, for example, below -400mV, such as -450mV, that is, the voltage to ground increases, the self-controlled switch unit 8 drives the MOS tube in the self-controlled switch unit 8 to turn on, and the self-controlled switch unit 8 is turned on.

[0110] When the self-controlled switch unit 8 detects that the voltage value is greater than the second voltage value, the self-controlled switch unit 8 drives the MOS tube to close, and the self-controlled switch unit 8 is disconnected at this time;

[0111] Optionally, the self-controlled switch unit 8 has a clamping function. When the operating frequency of the self-controlled switch unit 8 is lower than 7.5kHz, the chip determines that the self-controlled switch unit 8 is in a light-load state. If at this time, the input voltage of the second power supply input terminal 82 is higher than a preset voltage value, for example, the preset voltage value is 5.7V, the clamping function is activated at this time, thereby achieving the purpose of protecting the circuit;

[0112] Optionally, when the operating frequency of the self-controlled switch unit 8 is higher than 9kHz, the chip determines that the self-controlled switch unit 8 is in overload mode at this time. If the input voltage of the second power supply input terminal 82 is greater than the preset voltage value, such as 6V, the clamping function is activated at this time, thereby achieving the purpose of protecting the circuit.

[0113] Optional, such as Figure 1 As shown, the input side of the input circuit 1 includes a live wire 11 and a neutral wire 12;

[0114] One end of the live wire 11 is connected to an external power source, and the other end of the live wire 11 is connected to the input end of the rectifier circuit 2 through an overcurrent protection fuse 111; and / or,

[0115] One end of the neutral line 12 is grounded, and the other end of the neutral line 12 is connected to the input end of the rectifier circuit 2 through a ring fuse 121 .

[0116] Specifically, in the above embodiment, the input side of the input circuit 1 is configured with a live wire 11 and a neutral wire 12 , and these two wires respectively assume different functions and provide overcurrent protection and / or electromagnetic interference suppression through specific fuses.

[0117] One end of the live wire 11 is directly connected to the external AC power supply as the main power input path of the input circuit 1. The other end of the live wire 11 is connected to the input end of the rectifier circuit 2 through an overcurrent protection fuse 111.

[0118] The overcurrent protection fuse 111 has a certain capacitance value and rated current. When the current in the input circuit 1 increases abnormally due to some reason (such as short circuit, overload, etc.), the overcurrent protection fuse 111 can limit the rising speed of the current through its own impedance, thereby buying time for the subsequent protection devices (such as circuit breakers, fuses, etc.) to act, thereby avoiding serious damage to the circuit caused by the instantaneous excessive current.

[0119] One end of the neutral line 12 is grounded to ensure that the circuit has a good reference potential and is also a part of the current loop. The other end of the neutral line 12 is connected to the input end of the rectifier circuit 2 through a surge protection ring fuse 121.

[0120] Optional, such as Figure 1 As shown, it includes: a rectifier circuit 2, including:

[0121] A first inductor L1, one end of which is connected to the output end of the input circuit 1 through a current converter 21;

[0122] A first resistor R1, wherein the first resistor R1 is connected in parallel with the first inductor L1;

[0123] A second inductor L2, one end of the second inductor L2 is connected to the output end of the current converter 21, and the other end of the second inductor L2 is grounded;

[0124] A first filter capacitor C1, a second filter capacitor C2 and a third filter capacitor C3 are connected in parallel between the first inductor L1 and the second inductor L2;

[0125] The other end of the first inductor L1 is grounded via the third filter capacitor C3.

[0126] Specifically, in the above embodiment, a first inductor L1 is provided in the rectifier circuit 2 , one end of which is connected to the output end of the input circuit 1 through a current converter 21 (such as a bridge rectifier, a switching power converter, etc.).

[0127] The current converter 21 is responsible for converting the input AC power into the required DC power or pulsating DC power. The first inductor L1 plays the role of energy storage, filtering and anti-interference in this process. Its inductance can limit the rate of change of current, smooth the current waveform, and absorb some high-frequency harmonics.

[0128] The first resistor R1 and the first inductor L1 are connected in parallel in the circuit. The main function of the resistor is to provide a certain damping to the current, which helps to stabilize the working state of the current converter 21 and suppress possible oscillation. In addition, the resistor can also form an RL filter network with the inductor to further improve the current waveform.

[0129] One end of the second inductor L2 is directly connected to the output end of the current converter 21 to receive the converted current. The other end is grounded to form a current loop. The second inductor L2 also has energy storage and filtering functions, and together with the first inductor L1, it forms a dual inductor structure, which can more effectively suppress current fluctuations and electromagnetic interference, and improve the stability of the rectifier circuit 2.

[0130] Three filter capacitors are connected in parallel between the first inductor L1 and the second inductor L2: the first filter capacitor C1, the second filter capacitor C2 and the third filter capacitor C3. These three capacitors form a multi-stage filter network, which deeply filters the rectified current, eliminates the residual AC component and high-frequency noise, and provides a purer DC output.

[0131] In particular, the other end of the first inductor L1 is directly grounded through the third filter capacitor C3. This design further enhances the ability to suppress low-frequency AC components, ensuring that the output current has small ripple and high stability.

[0132] Optional, such as Figure 1 As shown, an RCD absorption circuit 9 is also provided between the rectifier circuit 2 and the primary coil 31, and the RCD absorption circuit 9 includes:

[0133] A second resistor R2, one end of the second resistor R2 is connected to the second end 312;

[0134] A first capacitor C4, one end of the first capacitor C4 is connected to one end of the second resistor R2, and the other end of the first capacitor C4 is connected to the other end of the second resistor R2;

[0135] A third resistor R3, one end of the third resistor R3 is connected to the other end of the second resistor R2;

[0136] A first diode V1 , wherein an anode of the first diode V1 is connected to the first end 311 , and a cathode of the first diode V1 is connected to the other end of the third resistor R3 .

[0137] Specifically, in the above embodiment, an RCD absorption circuit 9 is further provided between the rectifier circuit 2 and the primary coil 31 to further improve the voltage and current waveforms during the rectification process, reduce electromagnetic interference, and protect the rectifier circuit 2 and subsequent equipment from surge shocks.

[0138] As the first component of the RCD absorption circuit 9, one end of the second resistor R2 is connected to the second end 312 of the rectifier circuit 2. The second resistor R2 plays the role of voltage division and current limiting. When overvoltage or overcurrent occurs in the rectifier circuit 2, the second resistor R2 can limit the amplitude of the voltage and current through its own resistance to avoid excessive impact on subsequent circuits.

[0139] One end of the first capacitor C4 is connected to one end of the second resistor R2, and the other end is connected to the other end of the second resistor R2, forming a series relationship. The main functions of the first capacitor C4 are energy storage and filtering. It can absorb the voltage spikes and current pulses generated during the rectification process, smooth the voltage waveform, and reduce electromagnetic interference. At the same time, the charging and discharging characteristics of the capacitor help maintain the continuity of the current and avoid voltage fluctuations caused by current mutations.

[0140] One end of the third resistor R3 is connected to the other end of the second resistor R2, forming a part of the RCD absorption circuit 9. The third resistor R3 also plays a role of current limiting and voltage dividing, and together with the second resistor R2 forms an impedance network to further stabilize and protect the output of the rectifier circuit 2.

[0141] The anode of the first diode V1 is connected to the first terminal 311 of the rectifier circuit 2 , and the cathode of the first diode V1 is connected to the other end of the third resistor R3 .

[0142] The first diode V1 here plays a unidirectional conductive role, only allowing current to flow from the first end 311 to the third resistor R3, and preventing reverse current from passing. This design can prevent voltage spikes and current shocks caused by parasitic inductance effects during the shutdown or reverse recovery of the rectifier circuit 2, protecting the rectifier circuit 2 and subsequent devices from damage.

[0143] Optional, such as Figure 1 As shown, the power supply circuit includes:

[0144] A second diode V2, wherein the anode of the second diode V2 is connected to the fifth terminal 331, and the cathode of the second diode V2 is connected to the first power input terminal 41 of the power chip 4 through a fourth resistor R4;

[0145] The sixth terminal 332 is connected to the first power supply input terminal 42 via a first energy storage filter capacitor C5.

[0146] Specifically, in the above embodiment, the power supply circuit supplies power to the power chip 4, and the positive electrode of the second diode V2 is connected to the fifth end 331 of the auxiliary coil 33. When the auxiliary coil 33 induces a voltage, the second diode V2, with its unidirectional conductive characteristics, only allows 331 to be the positive electrode, and the current flows from the fifth end 331 (positive electrode) to its negative electrode. C5 is used to store energy to supply power to 42 when 33 has no current.

[0147] The cathode of the second diode V2 is connected to the first power input terminal 41 of the power chip 4 through a fourth resistor R4. The fourth resistor R4 plays the role of current limiting and voltage dividing, which can limit the current flowing into the power chip 4 to prevent overcurrent damage, and appropriately reduce the voltage induced by the auxiliary coil 33 through its resistance value to adapt it to the working voltage range of the power chip 4. In addition, the existence of the resistor can also help absorb voltage spikes and surges and improve the stability of power supply.

[0148] The sixth terminal 332 (the other end of the auxiliary coil 33) is directly connected to the first power supply input terminal 42 of the power chip 4 through a first energy storage filter capacitor C5. The main functions of the capacitor are energy storage and filtering. When the power supply voltage changes, the capacitor can quickly release or absorb charge, smooth voltage fluctuations, reduce ripples, and ensure that the power chip 4 is stably and continuously powered. At the same time, the capacitor can absorb high-frequency interference, improve the electromagnetic compatibility of the power supply, and protect the power chip 4 from high-frequency noise.

[0149] Optional, such as Figure 1 As shown, the sampling circuit 5 includes:

[0150] A fifth resistor R5, one end of the fifth resistor R5 is connected to the fifth end 331, and the other end of the fifth resistor R5 is connected to the feedback end 43;

[0151] a sixth resistor R6, the sixth resistor R6 is connected in parallel with the fifth resistor R5;

[0152] a seventh resistor R7, one end of the seventh resistor R7 is connected to the other end of the fifth resistor R5, and the other end of the seventh resistor R7 is grounded;

[0153] The second capacitor C6 is connected in parallel with the seventh resistor R7.

[0154] Specifically, in the above embodiment, the sampling circuit 5 obtains the voltage signal of the auxiliary coil 33, and transmits it to the feedback terminal 43 of the power chip 4 after voltage division processing. The power chip 4 further adjusts the self-controlled switch unit 8 according to the signal of the feedback terminal 43;

[0155] One end of the fifth resistor R5 is connected to the fifth end 331 of the auxiliary coil 33. When a voltage is generated on the auxiliary coil 33, the voltage is divided by the fifth resistor R5, so that the current flowing through the fifth resistor R5 carries the information of the voltage of the auxiliary coil 33.

[0156] The sixth resistor R6 is connected in parallel with the fifth resistor R5, and the resistance value after parallel connection can be adjusted, thereby adjusting the voltage division ratio. By setting the resistance value, the voltage signal obtained by the sampling circuit 5 can be closer to the working voltage range required by the feedback terminal 43 of the power chip 4.

[0157] One end of the seventh resistor R7 is connected to the other end of the fifth resistor R5, and the other end thereof is grounded. The seventh resistor R7 and the second capacitor C6 together form a low-pass filter for filtering high-frequency noise and interference in the sampled voltage to ensure that the voltage signal fed back to the power chip 4 is pure and stable.

[0158] The second capacitor C6 is connected in parallel with the seventh resistor R7 , one end of the second capacitor C6 is connected to the connection point between the seventh resistor R7 and the fifth resistor R5 , and the other end of the second capacitor C6 is grounded.

[0159] The capacitive reactance of a capacitor decreases as the frequency increases. Therefore, in the low frequency band (such as the fundamental frequency of the power supply voltage), the impedance of the capacitor to the voltage signal is small, allowing the voltage signal to pass; in the high frequency band (such as noise and interference), the impedance of the capacitor to the voltage signal is large, which has a suppressive effect.

[0160] By adjusting the values ​​of the seventh resistor R7 and the second capacitor C6, the cut-off frequency of the low-pass filter can be set to meet the requirements of different power supply systems for noise suppression.

[0161] Optional, such as Figure 1 As shown, the power chip 4 also includes an over-current detection terminal 45;

[0162] The overcurrent detection terminal 45 is grounded through the current point sampling circuit 10, and the overcurrent detection terminal 45 forms a sampling voltage corresponding to the current flowing into the first power input terminal 41 through the overcurrent point sampling circuit 10;

[0163] The overcurrent point sampling circuit 10 comprises:

[0164] an eighth resistor R8, one end of the eighth resistor R8 is connected to the overcurrent detection terminal 45, and the other end of the eighth resistor R8 is connected to the output end of the rectifier circuit 2;

[0165] The ninth resistor R9 is connected in parallel with the eighth resistor R8.

[0166] Optionally, the power chip 4 is provided with an overcurrent detection terminal 45 for real-time monitoring whether the current flowing into the first power input terminal 41 exceeds a preset threshold value, so as to prevent the overcurrent from causing damage to the power chip 4 and subsequent circuits. The overcurrent detection terminal 45 is grounded through the overcurrent point sampling circuit 10, and the sampling circuit 5 can convert the actual current into a sampling voltage, so that the power chip 4 can make an overcurrent judgment.

[0167] One end of the eighth resistor R8 is connected to the overcurrent detection terminal 45 of the power chip 4. When current flows into the first power input terminal 41, the current will generate a voltage drop on the eighth resistor R8, and the voltage drop is proportional to the current, thereby converting the current information into a voltage signal.

[0168] Optional, such as Figure 1 As shown, the circuit also includes:

[0169] a tenth resistor R10, one end of the tenth resistor R10 is connected to the fourth end 322, and the other end of the tenth resistor R10 is connected to the third ground end 83 via a third capacitor C7;

[0170] a fourth capacitor C8, where one end of the fourth capacitor C8 is connected to the third ground terminal 83, and the other end of the fourth capacitor C8 is connected to the second power supply input terminal 82;

[0171] A fifth capacitor C9 is connected in series between the second ground terminal 62 and the fifth terminal 331 .

[0172] Specifically, in the above embodiment, one end of the tenth resistor R10 is connected to the fourth end 322 of the secondary coil 32. When the secondary coil 32 generates an output voltage, the tenth resistor R10 provides a discharge path to the ground, which helps to stabilize the voltage of the secondary coil 32 and prevent voltage spikes and transients. At the same time, the tenth resistor R10 and the subsequent capacitor form an RC filter network to smooth the output voltage and reduce ripples.

[0173] The other end of the tenth resistor R10 is connected to the third ground terminal 83 via the third capacitor C7. The third capacitor C7 and the tenth resistor R10 are connected in parallel to form a low-pass filter to filter the output voltage of the secondary coil 32.

[0174] The capacitive reactance of a capacitor decreases as the frequency increases. Therefore, at low frequencies (such as the fundamental frequency of the power supply voltage), the impedance of the capacitor to the voltage signal is small, allowing the voltage signal to pass through.

[0175] In the high frequency band (such as noise and interference), the capacitor has a larger impedance to the voltage signal and plays a suppressive role. By adjusting the value of the tenth resistor R10 and the third capacitor C7, the cutoff frequency of the low-pass filter can be set to meet the requirements of different power supply systems for noise suppression.

[0176] One end of the fourth capacitor C8 is connected to the third ground terminal 83 , and the other end of the fourth capacitor C8 is connected to the second power supply input terminal 82 of the power chip 4 .

[0177] As an energy storage element, the fourth capacitor C8 can absorb instantaneous current changes caused by power supply voltage fluctuations to maintain the stability of the voltage of the second power supply input terminal 82. At the same time, the fourth capacitor C8 can also filter out high-frequency noise in the power supply voltage to improve the power supply quality of the power chip 4.

[0178] A fifth capacitor C9 is also connected in series between the second ground terminal 62 and the fifth terminal 331. The fifth capacitor C9 and the series-connected circuit elements together form a series resonant circuit, which can suppress noise and interference within a specific frequency range.

[0179] Optional, such as Figure 1 As shown, the energy storage filter unit 7 includes:

[0180] A second energy storage filter capacitor C10, wherein the positive electrode of the second energy storage filter capacitor C10 is connected to the third end 321, and the negative electrode of the second energy storage filter capacitor C10 is connected to the third ground end 83;

[0181] A third energy storage filter capacitor C11, the third energy storage filter capacitor C11 is connected in parallel with the second energy storage filter capacitor C10;

[0182] The eleventh resistor R11 is connected in parallel with the third energy storage filter capacitor C11 , one end of the eleventh resistor R11 is grounded, and the other end of the eleventh resistor R11 is connected to the power supply output terminal 61 .

[0183] Specifically, in the above embodiment, when the primary coil 31 and the secondary coil 32 are turned on, the second energy storage capacitor and the third energy storage capacitor in the energy storage filter unit 7 are used to supply power to the power supply output terminal 61;

[0184] The positive electrode of the second energy storage filter capacitor C10 is connected to the third terminal 321 of the secondary coil 32. When the secondary coil 32 generates an output voltage, the second energy storage filter capacitor C10, as an energy storage element, can absorb the instantaneous current change caused by the power supply voltage fluctuation and maintain the voltage stability of the power supply output terminal 61.

[0185] At the same time, the second energy storage filter capacitor C10 can also filter out high-frequency noise in the power supply voltage, thereby improving the quality of power supply output.

[0186] The third energy storage filter capacitor C11 is connected in parallel with the second energy storage filter capacitor C10 to form an energy storage filter network. The presence of parallel capacitors can increase the total energy storage capacity and improve the transient response capability of the power supply system. At the same time, it can also provide a certain parallel capacitor redundancy and improve the reliability of the energy storage filter circuit.

[0187] In addition, by adjusting the values ​​of the second energy storage filter capacitor C10 and the third energy storage filter capacitor C11, the energy storage capacity and filtering characteristics of the energy storage filter network can be set to meet the energy storage and filtering requirements of different power supply systems.

[0188] The eleventh resistor R11 is connected in parallel with the third energy storage filter capacitor C11 , one end of the eleventh resistor R11 is grounded, and the other end is connected to the power supply output terminal 61 .

[0189] The eleventh resistor R11 is used as a discharge resistor. When the power supply system is powered off or fails, the electric energy stored in the energy storage filter capacitor can be quickly released to prevent excessive voltage from being generated during the capacitor discharge process, which may damage the power supply system and the load.

[0190] At the same time, the existence of the eleventh resistor R11 can also provide a certain parallel resistance redundancy, thereby improving the reliability of the energy storage filter circuit.

[0191] A second aspect of the present disclosure provides a power strip, comprising any one of the power conversion circuits described above.

[0192] 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 conversion circuit, characterized in that: include: Input circuit for connecting AC power; A rectifier circuit, an input end of which is coupled to the input circuit; A transformer, the transformer comprising a primary coil, a secondary coil and an auxiliary coil; The primary coil includes a first end and a second end; the first end is coupled to the output end of the rectifier circuit; The secondary coil includes a third end and a fourth end; The auxiliary coil includes a fifth end and a sixth end; Wherein, the first end, the third end and the fifth end are ends of the same name; A power chip, comprising: a first power input terminal, a first power supply input terminal, a feedback terminal and a first ground terminal; The first power input terminal is coupled to the first terminal, the sixth terminal is coupled to the first power input terminal via a power supply circuit, and the first ground terminal is grounded; The sixth terminal is connected to the feedback terminal of the power chip via a sampling circuit; The output circuit comprises: a power supply output terminal and a second ground terminal; An energy storage filter unit, coupled between the power supply output terminal and the second ground terminal; The self-controlled switch unit comprises: a second power input terminal, a second power supply input terminal and a third ground terminal; The second power input terminal is coupled to the fourth terminal; The second power supply input terminal is coupled to the power supply output terminal; The self-controlled switch unit is configured to switch the second power input terminal and the second ground terminal on the basis of a voltage difference between the second power input terminal and the second ground terminal being within a variable voltage range.

2. The power conversion circuit according to claim 1, characterized in that: The input side of the input circuit (1) comprises a live wire and a neutral wire; One end of the live wire is connected to an external power source, and the other end of the live wire is connected to an input end of the rectifier circuit through an overcurrent protection fuse; and / or, One end of the neutral line is grounded, and the other end of the neutral line is connected to the input end of the rectifier circuit through a ring fuse.

3. The power conversion circuit according to claim 1, characterized in that: include: A rectifier circuit, comprising: A first inductor, one end of which is connected to the output end of the input circuit (1) via a current converter; a first resistor, the first resistor being connected in parallel with the first inductor; a second inductor, one end of the second inductor being connected to the output end of the current converter, and the other end of the second inductor being grounded; A first filter capacitor, a second filter capacitor and a third filter capacitor are connected in parallel between the first inductor and the second inductor; The other end of the first inductor is grounded through the third filter capacitor.

4. The power conversion circuit according to claim 1, characterized in that: An RCD absorption circuit is also provided between the rectifier circuit and the primary coil, and the RCD absorption circuit comprises: a second resistor, one end of which is connected to the second end; a first capacitor, one end of the first capacitor being connected to one end of the second resistor, and the other end of the first capacitor being connected to the other end of the second resistor; a third resistor, one end of the third resistor being connected to the other end of the second resistor; A first diode, wherein an anode of the first diode is connected to the first end, and a cathode of the first diode is connected to the other end of the third resistor.

5. The power conversion circuit according to claim 1, characterized in that: The power supply circuit comprises: a second diode, wherein an anode of the second diode is connected to the fifth end, and a cathode of the second diode is connected to the first power input end of the power chip through a fourth resistor; The sixth terminal is connected to the first power supply input terminal through a first energy storage filter capacitor.

6. The power conversion circuit according to claim 1, characterized in that: The sampling circuit comprises: a fifth resistor, one end of which is connected to the fifth terminal, and the other end of which is connected to the feedback terminal; a sixth resistor, the sixth resistor being connected in parallel with the fifth resistor; a seventh resistor, one end of the seventh resistor being connected to the other end of the fifth resistor, and the other end of the seventh resistor being grounded; A second capacitor is connected in parallel with the seventh resistor.

7. The power conversion circuit according to claim 1, characterized in that: The power chip also includes an overcurrent detection terminal; The overcurrent detection terminal is grounded through a current point sampling circuit, and the overcurrent detection terminal forms a sampling voltage corresponding to the current flowing into the first power input terminal through the overcurrent point sampling circuit; The overcurrent point sampling circuit comprises: an eighth resistor, one end of the eighth resistor being connected to the overcurrent detection end, and the other end of the eighth resistor being connected to the output end of the rectifier circuit; A ninth resistor is connected in parallel with the eighth resistor.

8. The power conversion circuit according to claim 1, characterized in that: Also includes: a tenth resistor, one end of the tenth resistor being connected to the fourth end, and the other end of the tenth resistor being connected to the third ground end via a third capacitor; a fourth capacitor, one end of the fourth capacitor being connected to the third ground terminal, and the other end of the fourth capacitor being connected to the second power supply input terminal; A fifth capacitor is connected in series between the second ground terminal and the fifth terminal.

9. The power conversion circuit according to claim 1, characterized in that: The energy storage filter unit comprises: a second energy storage filter capacitor, wherein a positive electrode of the second energy storage filter capacitor is connected to the third end, and a negative electrode of the second energy storage filter capacitor is connected to the third ground end; A third energy storage filter capacitor, the third energy storage filter capacitor is connected in parallel with the second energy storage filter capacitor; An eleventh resistor, the eleventh resistor is connected in parallel with the third energy storage filter capacitor, one end of the eleventh resistor is grounded, and the other end of the eleventh resistor is connected to the power supply output end.

10. A power strip, characterized in that: The invention comprises a power conversion circuit as described in any one of claims 1 to 9 above.

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