Secondary overlapped multi-group series rectification output circuit of switching power supply

Abstract

The utility model discloses a secondary overlapped multi-group series rectification output circuit of a switching power supply. The secondary overlapped multi-group series rectification output circuit comprises a transformer and at least three series rectification circuits electrically connected with the transformer, each rectification circuit comprises a rectification diode, an RC absorption circuit, a capacitor filter circuit and a dummy load circuit; the transformer is provided with at least three secondary windings; the corresponding end of the rectifier diode is electrically connected with the corresponding ends of the secondary winding of the transformer, the RC absorption circuit, the capacitor filter circuit and the dummy load circuit respectively; wherein the rectifier diode is used for converting alternating current on the secondary winding side of the transformer into direct current; the RC absorption circuit is used for absorbing a backward voltage peak of the rectifier diode; the capacitor filter circuit is used for smoothing the output voltage; and the dummy load circuit is used for stabilizing the output voltage under a low load condition. According to the utility model, the problems of high withstand voltage and EMC of the rectifier diode are effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a secondary superimposed multi-group series rectifier output circuit for a switching power supply. Background Technology

[0002] Existing switching power supplies typically use a single rectifier circuit on the secondary side to convert AC to DC. However, this design has some limitations in high-voltage output applications. First, the rectifier diodes in a single rectifier circuit need to withstand high reverse voltages, which limits diode selection and increases cost. Second, single rectifier circuits have poor electromagnetic compatibility (EMC) performance and are prone to electromagnetic interference. Furthermore, when the load is light, the output voltage is prone to fluctuations, affecting the stability of the power supply.

[0003] To address these issues, some technologies attempt to improve EMC performance and stability by adding extra filtering components or using more complex circuit designs. However, these methods often increase circuit complexity and cost, and may not achieve the desired results in practical applications. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a secondary-side overlapping multi-group series rectifier output circuit for a switching power supply.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] This utility model provides a secondary-side overlapped multi-group series rectifier output circuit for a switching power supply, comprising:

[0007] A transformer, and at least three rectifier circuits connected in series to the transformer;

[0008] Each rectifier circuit includes a rectifier diode, an RC snubber circuit, a capacitor filter circuit, and a dummy load circuit.

[0009] The transformer has at least three secondary windings;

[0010] The corresponding terminals of the rectifier diodes are electrically connected to the corresponding terminals of the transformer's secondary winding, RC absorption circuit, capacitor filter circuit, and dummy load circuit, respectively.

[0011] Among them, the rectifier diode is used to convert the AC power on the secondary winding side of the transformer into DC power; the RC snubber circuit is used to absorb the reverse voltage spikes of the rectifier diode; the capacitor filter circuit is used to smooth the output voltage; and the dummy load circuit is used to stabilize the output voltage under low load conditions.

[0012] Preferably, the RC absorption circuit includes a first resistor and a first capacitor;

[0013] The first end of the rectifier diode is electrically connected to the first winding of the transformer and the first end of the first capacitor, respectively. The second end of the rectifier diode is electrically connected to the corresponding ends of the second winding of the transformer, the first resistor, the capacitor filter circuit, and the dummy load circuit, respectively. The second end of the capacitor is electrically connected to the second end of the resistor.

[0014] Preferably, the capacitor filter circuit includes a second capacitor; the second terminal of the rectifier diode is electrically connected to the corresponding terminal of the second capacitor.

[0015] Preferably, the dummy load circuit includes a second resistor and a third resistor connected in series; the second terminal of the rectifier diode is electrically connected to the corresponding terminals of the second and third resistors connected in series.

[0016] Preferably, the secondary superimposed multi-group series rectifier output circuit of the switching power supply further includes a filter load circuit; the corresponding terminal of the filter load circuit is electrically connected to the second terminal of the rectifier diode.

[0017] Preferably, the filter load circuit includes capacitor C30, resistors R58, R59, R60, R61, and conjugate inductor LF4;

[0018] The second terminal of the rectifier diode is electrically connected to the first terminal of capacitor C30, the first terminal of resistor R60, the first terminal of resistor R61, and the first corresponding terminal of conjugate inductor LF4, respectively.

[0019] The second terminal of capacitor C30 is electrically connected to the first terminal of resistor R58, the first terminal of resistor R59, and the second corresponding terminal of inductor LF4, respectively.

[0020] The second end of resistor R58 is electrically connected to the second ends of resistor R60, resistor R61, and resistor R59, respectively.

[0021] The technical solution of this utility model has the following beneficial effects:

[0022] This utility model provides a secondary superimposed multi-group series rectifier output circuit for a switching power supply. This circuit can overcome the limitations of the prior art, provide a more stable and efficient power output, and improve electromagnetic compatibility. It effectively solves the problems of high withstand voltage and EMC of rectifier diodes.

[0023] Enhanced voltage stability: Multiple series rectifier circuits can more effectively distribute the voltage and reduce the voltage stress on individual rectifier diodes, thereby providing a more stable output voltage under different load conditions. This allows the use of lower-cost diodes, reducing the overall cost.

[0024] Improved circuit reliability: The combined use of RC snubber circuit and capacitor filter circuit significantly improves circuit reliability by absorbing voltage spikes and reducing voltage ripple, thereby reducing the risk of damage to rectifier diodes and other components.

[0025] Enhanced EMC performance: The combination of RC snubber circuit and capacitor filter circuit effectively reduces voltage spikes and ripples, improves the electromagnetic compatibility of the circuit, and reduces electromagnetic interference.

[0026] Improved efficiency: The design of the filter load circuit helps to reduce energy loss and improve the power conversion efficiency.

[0027] The circuit design of this invention is relatively simple and easy to implement, while providing excellent performance and simplifying the power supply design process. This circuit is suitable for various switching power supply applications requiring high stability and high electromagnetic compatibility, such as communication equipment, computers, servers, medical equipment, and industrial control equipment. The design of the dummy load circuit and the filtered load circuit helps protect the circuit under low load or no-load conditions, preventing damage caused by excessive voltage. Attached Figure Description

[0028] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] Reference Figure 1 This utility model provides a secondary-side overlapped multi-group series rectifier output circuit for a switching power supply, comprising:

[0035] Transformer T2, and at least three rectifier circuits 100 electrically connected to transformer T2 in series;

[0036] Each rectifier circuit 100 includes a rectifier diode 101, an RC snubber circuit 102, a capacitor filter circuit 103, and a dummy load circuit 104; the output rectifier diodes are multiple diodes connected in series, and the voltage rating of each rectifier diode can be a common material available on the market.

[0037] The transformer T2 has at least three secondary windings, and the number of secondary windings can be set to 3-10. The corresponding rectifier circuit 100 can also be set to 3-10 groups.

[0038] The corresponding terminals of the rectifier diode 101 are electrically connected to the corresponding terminals of the secondary winding of the transformer T2, the RC absorption circuit 102, the capacitor filter circuit 103, and the dummy load circuit 104, respectively.

[0039] Among them, rectifier diode 101 is used to convert the AC power on the secondary winding side of transformer T2 into DC power; RC snubber circuit 102 is used to absorb the reverse voltage spike of rectifier diode 101; capacitor filter circuit 103 is used to smooth the output voltage; dummy load circuit 104 is used to stabilize the output voltage under low load conditions.

[0040] Furthermore, the RC absorption circuit 102 includes a first resistor and a first capacitor (C15 and R57, or C14 and R62, or C32 and R64). The first terminal of the rectifier diode 101 is electrically connected to the first winding of the transformer and the first terminal of the first capacitor, respectively. The second terminal of the rectifier diode is electrically connected to the corresponding terminals of the second winding of the transformer, the first resistor, the capacitor filter circuit 103, and the dummy load circuit 104, respectively. The second terminal of the capacitor is electrically connected to the second terminal of the resistor. In this embodiment, the first capacitor absorbs the voltage spike generated by the rectifier diode (101) during reverse recovery. The first resistor is used to limit the current and prevent excessive current from flowing into the rectifier diode, thereby protecting the diode from damage. By absorbing the voltage spike, the RC absorption circuit 102 effectively protects the rectifier diode from high voltage surges and extends the diode's service life. The reduction of voltage spikes means a reduction in electromagnetic interference generated by the circuit, which helps to meet electromagnetic compatibility standards and reduce interference to other electronic devices. The combined effect of current limiting and voltage spike absorption improves the stability and quality of the power supply output and reduces voltage and current fluctuations.

[0041] Furthermore, the capacitor filter circuit 103 includes a second capacitor; the second terminal of the rectifier diode is electrically connected to the corresponding terminal of the second capacitor; the capacitor filter circuit is used to smooth the rectified DC voltage, reduce voltage ripple and fluctuations. By reducing the ripple of the output voltage, the capacitor filter circuit helps to improve the power quality and provide a more stable DC power supply to the load. The smoothed voltage after filtering helps to improve the circuit's response speed to load changes and ensures the stability of the voltage when the load changes.

[0042] Furthermore, the dummy load circuit 104 includes a second resistor and a third resistor connected in series; the second terminal of the rectifier diode is electrically connected to the corresponding terminals of the second and third resistors connected in series. The dummy load circuit 104 protects subsequent circuits and components by stabilizing the output voltage, preventing damage caused by excessive voltage; by maintaining a stable output voltage, the dummy load circuit improves the reliability of the power supply, ensuring that the power supply can operate normally under various load conditions.

[0043] Furthermore, the secondary superimposed multi-group series rectifier output circuit of the switching power supply also includes a filter load circuit 200; the corresponding terminals of the filter load circuit 200 are electrically connected to the second terminals of the rectifier diode 101; the filter load circuit 200 includes a capacitor C30, resistors R58, R59, R60, R61, and a conjugate inductor LF4; the second terminals of the rectifier diode 101 are electrically connected to the first terminals of capacitor C30, resistors R60 and R61, and the first corresponding terminals of the conjugate inductor LF4; the second terminals of capacitor C30 are electrically connected to the first terminals of resistors R58 and R59, and the second corresponding terminals of inductor LF4; the second terminals of resistors R58 and R58 are electrically connected to the second terminals of resistors R60, R61, and R59. In this embodiment, the filter load circuit, through the combination of inductor LF4 and capacitor C30, is used to further smooth the current, reduce current ripple, and thus improve the stability of the power supply. The design of a filter load circuit helps reduce electromagnetic interference and improve the electromagnetic compatibility of the circuit. By integrating a filter load circuit into the secondary superimposed multi-group series rectifier output circuit of a switching power supply, the current and voltage stability of the power supply can be significantly improved, electromagnetic interference can be reduced, and the adaptability and reliability of the power supply can be enhanced, thereby meeting the stringent requirements of modern electronic equipment for power supply stability and quality.

[0044] This utility model provides a secondary superimposed multi-group series rectifier output circuit for a switching power supply. This circuit can overcome the limitations of the prior art, provide a more stable and efficient power output, and improve electromagnetic compatibility.

[0045] Enhanced voltage stability: Multiple series rectifier circuits can more effectively distribute the voltage and reduce the voltage stress on individual rectifier diodes, thereby providing a more stable output voltage under different load conditions. This allows the use of lower-cost diodes, reducing the overall cost.

[0046] Improved circuit reliability: The combined use of RC snubber circuit and capacitor filter circuit significantly improves circuit reliability by absorbing voltage spikes and reducing voltage ripple, thereby reducing the risk of damage to rectifier diodes and other components.

[0047] Enhanced EMC performance: The combination of RC snubber circuit and capacitor filter circuit effectively reduces voltage spikes and ripples, improves the electromagnetic compatibility of the circuit, and reduces electromagnetic interference.

[0048] Improved efficiency: The design of the filter load circuit helps to reduce energy loss and improve the power conversion efficiency.

[0049] The circuit design of this invention is relatively simple and easy to implement, while providing excellent performance and simplifying the power supply design process. This circuit is suitable for various switching power supply applications requiring high stability and high electromagnetic compatibility, such as communication equipment, computers, servers, medical equipment, and industrial control equipment. The design of the dummy load circuit and the filtered load circuit helps protect the circuit under low load or no-load conditions, preventing damage caused by excessive voltage.

[0050] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A secondary-side overlapped multi-group series rectifier output circuit for a switching power supply, characterized in that, include: A transformer, and at least three rectifier circuits connected in series to the transformer; Each rectifier circuit includes a rectifier diode, an RC snubber circuit, a capacitor filter circuit, and a dummy load circuit. The transformer has at least three secondary windings; The corresponding terminals of the rectifier diodes are electrically connected to the corresponding terminals of the transformer's secondary winding, RC absorption circuit, capacitor filter circuit, and dummy load circuit, respectively. Among them, the rectifier diode is used to convert the alternating current on the secondary winding side of the transformer into direct current; the RC snubber circuit is used to absorb the reverse voltage spikes of the rectifier diode. A capacitor filter circuit is used to smooth the output voltage; a dummy load circuit is used to stabilize the output voltage under low load conditions.

2. The secondary superimposed multi-group series rectifier output circuit of the switching power supply according to claim 1, characterized in that, The RC absorption circuit includes a first resistor and a first capacitor; The first end of the rectifier diode is electrically connected to the first winding of the transformer and the first end of the first capacitor, respectively. The second end of the rectifier diode is electrically connected to the corresponding ends of the second winding of the transformer, the first resistor, the capacitor filter circuit, and the dummy load circuit, respectively. The second end of the capacitor is electrically connected to the second end of the resistor.

3. The secondary superimposed multi-group series rectifier output circuit of the switching power supply according to claim 2, characterized in that, The capacitor filter circuit includes a second capacitor; the second terminal of the rectifier diode is electrically connected to the corresponding terminal of the second capacitor.

4. The secondary superimposed multi-group series rectifier output circuit of the switching power supply according to claim 2, characterized in that, The dummy load circuit includes a second resistor and a third resistor connected in series; the second terminal of the rectifier diode is electrically connected to the corresponding terminals of the second and third resistors connected in series.

5. The secondary superimposed multi-group series rectifier output circuit of the switching power supply according to claim 2, characterized in that, The secondary superimposed multi-group series rectifier output circuit of the switching power supply also includes a filter load circuit; the corresponding terminal of the filter load circuit is electrically connected to the second terminal of the rectifier diode.

6. The secondary superimposed multi-group series rectifier output circuit of the switching power supply according to claim 5, characterized in that, The filter load circuit includes capacitor C30, resistors R58, R59, R60, R61, and conjugate inductor LF4. The second terminal of the rectifier diode is electrically connected to the first terminal of capacitor C30, the first terminal of resistor R60, the first terminal of resistor R61, and the first corresponding terminal of conjugate inductor LF4, respectively. The second terminal of capacitor C30 is electrically connected to the first terminal of resistor R58, the first terminal of resistor R59, and the second corresponding terminal of inductor LF4, respectively. The second end of resistor R58 is electrically connected to the second ends of resistor R60, resistor R61, and resistor R59, respectively.

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