Power supply circuit

Abstract

The utility model provides a power supply circuit. The circuit comprises a strong current conversion module and a weak current switching module. The strong current conversion module receives a strong current power supply and is used for converting the strong current power supply into a first weak current power supply; the first input end of the weak current switching module is connected with the strong current conversion module, the second input end of the weak current switching module receives a second weak current power supply, and the output end of the weak current switching module is connected with electric equipment where the power supply circuit is located and external equipment; the weak current switching module is used for using the first weak current power supply or using the first weak current power supply and the second weak current power supply to supply power to electric equipment and external equipment where the power supply circuit is located when the first weak current power supply is received; and when only the second weak-current power supply is received, the second weak-current power supply is used for supplying power to electric equipment where the power supply circuit is located. According to the circuit, the power supply flexibility is improved.

Description

Technical Field

[0001] This application relates to power supply technology, and more particularly to a power supply circuit. Background Technology

[0002] With the continuous development of electronic technology, the number of electrical products is increasing, covering multiple fields such as daily life and industrial production. The normal operation of these devices cannot be separated from the support of electricity, so providing a reliable power supply for electrical equipment is crucial.

[0003] In existing technologies, electronic devices often only support power supply from high-voltage or low-voltage power sources. The power supply solutions are relatively simple and can only be applied to a single scenario, resulting in poor power supply flexibility. Utility Model Content

[0004] This application provides a power supply circuit to improve the flexibility of power supply.

[0005] On the one hand, this application provides a power supply circuit, including: a high-voltage conversion module and a low-voltage switching module;

[0006] The high-voltage conversion module receives high-voltage power and converts the high-voltage power into a first low-voltage power.

[0007] The first input terminal of the low-voltage switching module is connected to the high-voltage conversion module, the second input terminal of the low-voltage switching module receives a second low-voltage power supply, and the output terminal of the low-voltage switching module is connected to the electrical device where the power supply circuit is located and external devices. The low-voltage switching module is used to supply power to the electrical device where the power supply circuit is located and external devices when it receives the first low-voltage power supply, or to supply power to the electrical device where the power supply circuit is located and external devices using both the first and second low-voltage power supplies; and to supply power to the electrical device where the power supply circuit is located when it receives only the second low-voltage power supply.

[0008] Optionally, the low-voltage switching module includes: a first diode, a second diode, a first overvoltage protection diode, and a second overvoltage protection diode;

[0009] The positive terminal of the first diode is connected to the first input terminal of the low-voltage switching module, and the negative terminal of the first diode is connected to the output terminal of the low-voltage switching module; the first input terminal of the low-voltage switching module is connected to the external device, and the output terminal of the low-voltage switching module is connected to the electrical device.

[0010] The positive terminal of the second diode is connected to the second input terminal of the low-voltage switching module, and the negative terminal of the second diode is connected to the output terminal of the low-voltage switching module.

[0011] One end of the first overvoltage protection diode is connected to the first input terminal of the low-voltage switching module, one end of the second overvoltage protection diode is connected to the second input terminal of the low-voltage switching module, and the other ends of the first and second overvoltage protection diodes are grounded.

[0012] Optionally, the high-voltage conversion module includes a surge protection module, a first filtering module, a conversion module, and a second filtering module;

[0013] The input terminal of the surge protection module receives the high-voltage power supply and is used to provide surge protection for the high-voltage power supply.

[0014] The input terminal of the first filtering module is connected to the output terminal of the surge protection module, and is used to filter the high-voltage power supply.

[0015] The input terminal of the conversion module is connected to the output terminal of the first filtering module, and is used to convert the high-voltage power supply that has undergone surge protection and filtering into the first low-voltage power supply.

[0016] The input terminal of the second filtering module is connected to the output terminal of the conversion module, and the output terminal of the second filtering module is connected to the first input terminal of the low-voltage switching module, for isolating the first low-voltage power supply.

[0017] Optionally, the surge protection module includes: a fuse, a first varistor, a second varistor, a third varistor, and a gas discharge tube;

[0018] One end of the fuse is connected to the live wire of the high-voltage power supply, and the other end of the fuse is connected to one end of the first varistor and one end of the third varistor; the other end of the first varistor and one end of the second varistor are connected to the neutral wire of the high-voltage power supply, and the other end of the second varistor and the other end of the third varistor are connected to one end of the gas discharge tube, and the other end of the gas discharge tube is grounded.

[0019] Optionally, the first filtering module includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a first common-mode inductor;

[0020] One end of the first capacitor is connected to the first output terminal of the surge protection module, and the other end of the first capacitor is connected to the second output terminal of the surge protection module;

[0021] The first input terminal of the first common-mode inductor is connected to one end of the first capacitor, and the second input terminal of the first common-mode inductor is connected to the other end of the first capacitor.

[0022] One end of the second capacitor is connected to the first output terminal of the first common-mode inductor, and the other end of the second capacitor is connected to the second output terminal of the first common-mode inductor.

[0023] One end of the third capacitor is connected to one end of the second capacitor, one end of the fourth capacitor is connected to the other end of the second capacitor, and the other ends of the third capacitor and the fourth capacitor are grounded.

[0024] Optionally, the conversion module includes: a switching power supply module.

[0025] The first input terminal of the switching power supply module is connected to one end of the second capacitor, the second input terminal of the switching power supply module is connected to the other end of the second capacitor, and the first output terminal and the second output terminal of the switching power supply module output the first low-voltage power supply.

[0026] Optionally, the second filtering module includes: a first filtering capacitor, a second filtering capacitor, a third filtering capacitor, a fourth filtering capacitor, and a third overvoltage protection diode;

[0027] One end of the first filter capacitor, one end of the second filter capacitor, one end of the third filter capacitor, one end of the fourth filter capacitor, one end of the third overvoltage protection diode, the first output terminal of the switching power supply module, and the first input terminal of the low-voltage switching module are connected.

[0028] The other end of the first filter capacitor, the other end of the second filter capacitor, the other end of the third filter capacitor, the other end of the fourth filter capacitor, the other end of the third overvoltage protection diode, and the second output terminal of the switching power supply module are connected and grounded.

[0029] Optionally, the circuit further includes: a low-voltage protection module;

[0030] The input terminal of the low-voltage protection module is connected to the output terminal of the low-voltage switching module, and the output terminal of the low-voltage protection module is connected to the electrical equipment, for surge protection and filtering of the power supply of the electrical equipment.

[0031] Optionally, the low-voltage protection module includes: a second common-mode inductor, a fourth overvoltage protection diode, and an energy storage filter capacitor;

[0032] One end of the second common-mode inductor is connected to the output terminal of the low-voltage switching module, and the other end of the second common-mode inductor is connected to the electrical equipment.

[0033] One end of the energy storage filter capacitor is connected to one end of the second common-mode inductor, one end of the fourth overvoltage protection diode is connected to the other end of the second common-mode inductor, and the other end of the energy storage filter capacitor and the other end of the fourth overvoltage protection diode are grounded.

[0034] Optionally, the circuit further includes: a step-down module;

[0035] The input terminal of the step-down module is connected to the output terminal of the low-voltage switching module, and the output terminal of the step-down module is connected to the electrical equipment, for stepping down the power supply of the electrical equipment.

[0036] Optionally, the step-down module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth capacitor, a sixth capacitor, a first inductor, a third diode, and a power chip; the power chip includes an input pin, an enable pin, a BOOT pin, a PH pin, and a VSENSE pin.

[0037] One end of the first resistor is connected to the output terminal of the low-voltage switching module and the input pin of the power chip, and the other end of the first resistor is connected to the enable pin of the power chip.

[0038] One end of the fifth capacitor and one end of the second resistor are connected to the enable pin of the power chip, and the other end of the fifth capacitor and the other end of the second resistor are grounded.

[0039] One end of the sixth capacitor is connected to the BOOT pin of the power chip and the electrical device, and the other end of the sixth capacitor is connected to the PH pin of the power chip.

[0040] One end of the first inductor is connected to the other end of the sixth capacitor, the other end of the first inductor is connected to one end of the third resistor, and the other end of the third resistor is connected to the VSENSE pin of the power chip.

[0041] The negative terminal of the third diode is connected to the PH pin of the power chip, and the positive terminal of the third diode is grounded.

[0042] One end of the fourth resistor is connected to the VSENSE pin of the power chip, and the other end of the fourth resistor is grounded.

[0043] The power supply circuit provided in this application supports three power connection schemes, allowing high-voltage and low-voltage power supplies to be supplied separately or simultaneously, which can effectively improve the flexibility of the power supply circuit. When there is a high-voltage power input, the power supply circuit can also output low-voltage power to external devices. When only low-voltage power is input, it automatically stops supplying power to external devices, so that it can supply power to external devices when there is no low-voltage power supply. This can meet the needs of various application scenarios and improve the reliability of the power supply circuit. Attached Figure Description

[0044] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0045] Figure 1 The diagram below exemplarily illustrates the structure of a power supply circuit provided in an embodiment of this application;

[0046] Figure 2 The diagram above exemplarily illustrates the structure of the low-voltage switching module provided in an embodiment of this application;

[0047] Figure 3 The diagram above exemplarily illustrates the structure of a high-voltage conversion module provided in an embodiment of this application;

[0048] Figure 4 The diagram above exemplarily illustrates the structure of the low-voltage protection module provided in an embodiment of this application;

[0049] Figure 5 The diagram above illustrates a schematic of the buck module provided in an embodiment of this application.

[0050] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0051] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0052] With the continuous development of electronic technology, the number of electrical products is increasing, covering multiple fields such as daily life and industrial production. The normal operation of these devices cannot be separated from the support of electricity, so providing a reliable power supply for electrical equipment is crucial.

[0053] In existing technologies, electronic devices often only support power supply from high-voltage or low-voltage power sources. The power supply solutions are relatively simple and can only be applied to a single scenario, resulting in poor power supply flexibility.

[0054] In this application, a module refers to a functional module or a logical module. It can be in software form, where its function is implemented by a processor executing program code; or it can be in hardware form. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "OR" relationship.

[0055] The technical solutions of this application are illustrated below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0056] Figure 1 This is a schematic diagram of the power supply circuit provided in an embodiment of this application. Figure 1 As shown, the power supply circuit 100 provided in this application embodiment may include a high-voltage conversion module 10 and a low-voltage switching module 20;

[0057] The high-voltage conversion module 10 receives high-voltage power and converts it into a first low-voltage power supply.

[0058] The first input terminal of the low-voltage switching module 20 is connected to the high-voltage conversion module 10, and the second input terminal of the low-voltage switching module 20 receives the second low-voltage power supply. The low-voltage switching module 20 is used to supply power to the electrical equipment and external equipment by using the first low-voltage power supply or by using the first low-voltage power supply and the second low-voltage power supply when it receives the first low-voltage power supply. When it only receives the second low-voltage power supply, it uses the second low-voltage power supply to supply power to the electrical equipment where the power supply circuit is located.

[0059] In its implementation, the high-voltage conversion module 10 receives high-voltage power and converts it into a first low-voltage power supply. The first input terminal of the low-voltage switching module 20 receives the first low-voltage power supply, and the second input terminal receives a second low-voltage power supply. The output terminal of the low-voltage switching module 20 is connected to the power-consuming equipment and external devices. For example, the high-voltage power supply can be +85~305V AC, the first low-voltage power supply can be +24V DC, and the second low-voltage power supply can be +9~24V DC. It is understood that "external devices" refers to other external devices not belonging to the power-consuming equipment.

[0060] The power supply circuit 100 supports three power connection schemes: In the first power connection scheme, the high-voltage conversion module 10 receives high-voltage power, and the second input terminal of the low-voltage switching module 20 does not receive the second low-voltage power. Therefore, the low-voltage switching module 20 only receives the first low-voltage power, and uses the first low-voltage power to power the electrical equipment and external devices. In the second power connection scheme, the high-voltage conversion module 10 does not receive high-voltage power, and the second input terminal of the low-voltage switching module 20 receives the second low-voltage power. Therefore, the low-voltage switching module 20 only receives the second low-voltage power. In this power connection scheme, external devices can be directly connected to the second low-voltage power, and the low-voltage switching module 20 uses the second low-voltage power to power the electrical equipment. In the third power connection scheme, the high-voltage conversion module 10 receives high-voltage power, and the second input terminal of the low-voltage switching module 20 receives the second low-voltage power. Therefore, the low-voltage switching module 20 receives both the first and second low-voltage power, and uses both the first and second low-voltage power to power the electrical equipment and external devices.

[0061] In this embodiment, the power supply circuit supports three power connection schemes, allowing high-voltage and low-voltage power supplies to be supplied separately or simultaneously, which can effectively improve the flexibility of the power supply circuit. When there is a high-voltage power input, the power supply circuit can also output low-voltage power to external devices. When only low-voltage power is input, it automatically stops supplying power to external devices, so that it can supply power to external devices when there is no low-voltage power supply. This can meet the needs of various application scenarios and improve the reliability of the power supply circuit.

[0062] Figure 2 This is a schematic diagram of the structure of the low-voltage switching module provided in an embodiment of this application. Figure 2 As shown, in one possible implementation, the low-voltage switching module 20 includes: a first diode D3, a second diode D5, a first overvoltage protection diode D8, and a second overvoltage protection diode D7;

[0063] The positive terminal of the first diode D3 is connected to the first input terminal of the low-voltage switching module 20, and the negative terminal of the first diode D3 is connected to the output terminal of the low-voltage switching module 20; the first input terminal of the low-voltage switching module 20 is connected to an external device, and the output terminal of the low-voltage switching module 20 is connected to the electrical equipment.

[0064] The positive terminal of the second diode D5 is connected to the second input terminal of the low-voltage switching module 20, and the negative terminal of the second diode D5 is connected to the output terminal of the low-voltage switching module 20.

[0065] One end of the first overvoltage protection diode D8 is connected to the first input terminal of the low-voltage switching module 20, one end of the second overvoltage protection diode D7 is connected to the second input terminal of the low-voltage switching module 20, and the other ends of the first overvoltage protection diode D8 and the second overvoltage protection diode D7 are grounded.

[0066] Taking a first low-voltage power supply of +24V and a second low-voltage power supply of +9~24V as an example, in a specific implementation, the first input terminal of the low-voltage switching module 20 receives the first low-voltage power supply and is connected to an external device; the second input terminal of the low-voltage switching module 20 receives the second low-voltage power supply, and the output terminal of the low-voltage switching module 20 is connected to the power-consuming device. The first diode D3 and the second diode D5 prevent current from flowing arbitrarily. In the first power connection scheme, the low-voltage switching module 20 only receives the first low-voltage power supply, the first diode D3 is conducting, and the second diode D5 is not conducting. The low-voltage switching module 20 uses the first low-voltage power supply to power the electrical equipment and external devices. In the second power connection scheme, the low-voltage switching module 20 only receives the second low-voltage power supply, the first diode D3 is not conducting, and the second diode D5 is conducting. The low-voltage switching module 20 uses the second low-voltage power supply to power the electrical equipment. In the third power connection scheme, the high-voltage conversion module 10 receives the high-voltage power supply, and the second input terminal of the low-voltage switching module 20 receives the second low-voltage power supply. Therefore, the low-voltage switching module 20 receives both the first and second low-voltage power supplies and uses both to power the electrical equipment and external devices. In the third power connection scheme, when either the high-voltage power supply or the second low-voltage power supply fails, the output terminal of the low-voltage switching module will never lose power, thus providing a stable power supply to the electrical equipment. The first and second input terminals of the low-voltage switching module 20 are respectively equipped with a grounded first overvoltage protection diode D8 and a second overvoltage protection diode D7, which can break down when a surge pulse voltage occurs at the first or second input terminal of the low-voltage switching module 20, thereby achieving surge protection.

[0067] For example, the first overvoltage protection diode D8 and the second overvoltage protection diode D7 can be transient voltage suppressor (TVS) diodes. The first diode D3 and the second diode D5 can be unidirectional diodes, or other reverse protection circuits can be used, such as P-channel MOSFETs, etc., without limitation.

[0068] Figure 3 This is a schematic diagram of the high-voltage conversion module provided in an embodiment of this application. Figure 3 As shown, in one possible implementation, the high-voltage conversion module 10 includes a surge protection module 11, a first filtering module 12, a conversion module 13, and a second filtering module 14.

[0069] The input terminal of the surge protection module 11 receives high-voltage power and is used to provide surge protection for the high-voltage power.

[0070] The input terminal of the first filtering module 12 is connected to the output terminal of the surge protection module 11, and is used to filter the high-voltage power supply.

[0071] The input terminal of the conversion module 13 is connected to the output terminal of the first filter module 12, and is used to convert the high-voltage power supply that has been surge protected and filtered into the first low-voltage power supply.

[0072] The input terminal of the second filtering module 14 is connected to the output terminal of the conversion module 13, and the output terminal of the second filtering module 14 is connected to the first input terminal of the low-voltage switching module 20, which is used to isolate the first low-voltage power supply.

[0073] In practical implementation, external power supplies may encounter various problems such as lightning coupling, interference from high-power equipment startup, and electrostatic discharge. Therefore, surge protection module 11 can provide surge protection for the external power supply, improving the safety and reliability of the product. The first filter module 12 can filter the high-voltage power supply, removing noise and improving power quality, thus effectively protecting downstream devices. The surge protection module 11, the first filter module 12, and the second filter module 14 isolate the conversion module 13, effectively preventing electric shock and improving product safety. The conversion module 13 converts the high-voltage power supply to a first low-voltage power supply, providing DC power output. The second filter module 14 filters the first low-voltage power supply, effectively improving its quality and enhancing the reliability and stability of the circuit power supply.

[0074] For example, surge protection module 11 includes: fuse F1, first varistor R1, second varistor R2, third varistor R3, and gas discharge tube D2;

[0075] One end of fuse F1 is connected to the live wire of the high-voltage power supply, and the other end of fuse F1 is connected to one end of the first varistor R1 and one end of the third varistor R3. The other end of the first varistor R1 and one end of the second varistor R2 are connected to the neutral wire of the high-voltage power supply. The other ends of the second varistor R2 and the third varistor R3 are connected to one end of the gas discharge tube D2, and the other end of the gas discharge tube D2 is grounded.

[0076] Among them, the fuse F1 melts when a large current flows through it, thus playing a surge protection role; the first varistor R1, the second varistor R2, and the third varistor R3 are sensitive to voltage changes, and their resistance decreases sharply when they encounter lightning surges. The gas discharge tube D2 breaks down when it encounters lightning surges, thus effectively realizing surge protection and improving the reliability and safety of the circuit.

[0077] For example, the first filtering module 12 includes: a first capacitor C1, a second capacitor C2, a third capacitor C7, a fourth capacitor C8, and a first common-mode inductor L1;

[0078] One end of the first capacitor C1 is connected to the first output terminal of the surge protection module 11, and the other end of the first capacitor C1 is connected to the second output terminal of the surge protection module 11.

[0079] The first input terminal of the first common-mode inductor L1 is connected to one end of the first capacitor C1, and the second input terminal of the first common-mode inductor L1 is connected to the other end of the first capacitor C1.

[0080] One end of the second capacitor C2 is connected to the first output terminal of the first common-mode inductor L1, and the other end of the second capacitor C2 is connected to the second output terminal of the first common-mode inductor L1.

[0081] One end of the third capacitor C7 is connected to one end of the second capacitor C2, one end of the fourth capacitor C8 is connected to the other end of the second capacitor C2, and the other ends of the third capacitor C7 and the fourth capacitor C8 are grounded.

[0082] In the specific implementation, the first capacitor C1 and the second capacitor C2 are used as differential mode capacitors, which can effectively reduce differential mode interference in the power supply; the third capacitor C7 and the fourth capacitor C8 are used as common mode capacitors, which, together with the first common mode inductor L1, can reduce common mode interference, thereby effectively filtering the power supply and removing noise.

[0083] For example, the conversion module 13 includes: a switching power supply module U1:

[0084] The first input terminal AC (L) of the switching power supply module U1 is connected to one end of the second capacitor C2, the second input terminal AC (N) of the switching power supply module U1 is connected to the other end of the second capacitor C2, and the first output terminal +Vo and the second output terminal -Vo of the switching power supply module U1 output the first weak current power supply.

[0085] For example, the second filtering module 14 includes: a first filtering capacitor C3, a second filtering capacitor C4, a third filtering capacitor C5, a fourth filtering capacitor C6, and a third overvoltage protection diode D7;

[0086] One end of the first filter capacitor C3, one end of the second filter capacitor C4, one end of the third filter capacitor C5, one end of the fourth filter capacitor C6, one end of the third overvoltage protection diode D7, and the first output terminal of the switching power supply module and the first input terminal of the low-voltage switching module 20 are connected.

[0087] The other end of the first filter capacitor C3, the other end of the second filter capacitor C4, the other end of the third filter capacitor C5, the other end of the fourth filter capacitor C6, the other end of the third overvoltage protection diode D7, and the second output terminal of the switching power supply module U1 are connected and grounded.

[0088] In its implementation, the second filtering module 14 can be equipped with multiple filtering capacitors, such as the first filtering capacitor C3, the second filtering capacitor C4, the third filtering capacitor C5, and the fourth filtering capacitor C6. The specific number of filtering capacitors can be set according to actual needs and is not limited here. Different filtering capacitors can have different filtering frequencies, thereby achieving better filtering effects. When the capacitance value of the filtering capacitor is large, it can also play an energy storage role, maintaining the stability of the output voltage of the high-voltage conversion module 10. The third overvoltage protection diode D7 can prevent surge signal interference from downstream equipment, achieving surge protection.

[0089] like Figure 1 As shown, in one possible implementation, the circuit further includes: a low-voltage protection module 30;

[0090] The input terminal of the low-voltage protection module 30 is connected to the output terminal of the low-voltage switching module 20, and the output terminal of the low-voltage protection module 30 is connected to the electrical equipment to perform surge protection and filtering on the power supply of the electrical equipment.

[0091] In a specific implementation, a low-voltage protection module 30 can be set between the output end of the low-voltage switching module 20 and the electrical equipment to perform surge protection and filtering on the power output of the low-voltage switching module 20, which can effectively improve the reliability and safety of the circuit.

[0092] Figure 4 A schematic diagram of the structure of the low-voltage protection module provided in this application embodiment is shown. Figure 4 As shown, for example, the low-voltage protection module 30 includes: a second common-mode inductor L3, a fourth overvoltage protection diode D4; and an energy storage filter capacitor C18.

[0093] One end of the second common mode inductor L3 is connected to the output terminal of the low-voltage switching module 20, and the other end of the second common mode inductor L3 is connected to the electrical equipment.

[0094] One end of the energy storage filter capacitor C18 is connected to one end of the second common mode inductor L3, one end of the fourth overvoltage protection diode D4 is connected to the other end of the second common mode inductor L3, and the other end of the energy storage filter capacitor C18 and the other end of the fourth overvoltage protection diode D4 are grounded.

[0095] The input and output terminals of the low-voltage protection module 30 are connected to the second common-mode inductor L3, which can effectively reduce common-mode interference. The input terminal of the low-voltage protection module 30 is equipped with a grounded energy storage filter capacitor C18, which can effectively maintain the stability of the input voltage and filter out noise signals. The output terminal of the low-voltage protection module 30 is equipped with a grounded fourth overvoltage protection diode D4, which effectively provides surge protection and prevents transient surge voltage from interfering with downstream equipment.

[0096] like Figure 1 As shown, in one possible implementation, the circuit further includes: a step-down module 40;

[0097] The input terminal of the step-down module 40 is connected to the output terminal of the low-voltage switching module 20, and the output terminal of the step-down module 40 is connected to the electrical equipment to perform voltage reduction processing on the power supply of the electrical equipment.

[0098] In a specific implementation, when the power supply circuit 100 is equipped with a low-voltage protection module 30, the input terminal of the step-down module 40 can be connected to the output terminal of the low-voltage protection module 30. The step-down module 40 can step down the power supply of the electrical equipment according to the actual power demand of the electrical equipment, so as to supply the electrical equipment with the power.

[0099] Figure 4 A schematic diagram of the structure of the low-voltage protection module provided in this application embodiment is shown. Figure 4 As shown, for example, the step-down module 40 includes: a first resistor R5, a second resistor R7, a third resistor R4, a fourth resistor R6, a fifth capacitor C19, a sixth capacitor C9, a first inductor L2, a third diode D6, and a power chip U2; the power chip U2 includes an input pin VIN, an enable pin ENA, a BOOT pin, a PH pin, and a VSENSE pin.

[0100] One end of the first resistor R5 is connected to the output terminal of the low-voltage switching module 20 and the input pin VIN of the power chip U2, and the other end of the first resistor R5 is connected to the enable pin ENA of the power chip U2.

[0101] One end of the fifth capacitor C19 and one end of the second resistor R7 are connected to the enable pin ENA of the power chip U2, and the other end of the fifth capacitor C19 and the other end of the second resistor R7 are grounded.

[0102] One end of the sixth capacitor C9 is connected to the BOOT pin of the power chip U2 and the electrical device, and the other end of the sixth capacitor C9 is connected to the PH pin of the power chip U2.

[0103] One end of the first inductor L2 is connected to the other end of the sixth capacitor C9, the other end of the first inductor L2 is connected to one end of the third resistor R4, and the other end of the third resistor R4 is connected to the VSENSE pin of the power chip U2.

[0104] The negative terminal of the third diode D6 is connected to the PH pin of the power chip U2, and the positive terminal of the third diode D6 is grounded.

[0105] One end of the fourth resistor R6 is connected to the VSENSE pin of the power chip U2, and the other end of the fourth resistor R6 is grounded.

[0106] In the specific implementation, the first resistor R5, the second resistor R7, the third resistor R4, the fourth resistor R6, the fifth capacitor C19, the sixth capacitor C9, the first inductor L2, the third diode D6, and the power chip U2 constitute a buck converter circuit. The voltage VOUT output by the buck module 40 to the electrical device is V... SENSE ×(R4 / R6+1) can be used to adjust VOUT by adjusting the resistance values ​​of the third resistor R4 and the fourth resistor R6. Where V... SENSE This refers to the voltage of the VSENSE pin of the power chip U2.

[0107] In this design, multiple grounded filter capacitors can be installed at the output terminals of the input and output terminals of the step-down module 40. For example, one end of the fifth filter capacitor C12, the sixth filter capacitor C13, the seventh filter capacitor C10, and the eighth filter capacitor C11 is connected to one end of the first resistor R5, and the other end of the fifth filter capacitor C12, the sixth filter capacitor C13, the seventh filter capacitor C10, and the eighth filter capacitor C11 is grounded. One end of the ninth filter capacitor C16, the tenth filter capacitor C14, the eleventh filter capacitor C17, and the twelfth filter capacitor C15 is connected to one end of the third resistor R4, and the other end of the ninth filter capacitor C16, the tenth filter capacitor C14, the eleventh filter capacitor C17, and the twelfth filter capacitor C15 is connected to the other end of the fourth resistor R6. These filter capacitors effectively filter the power supply to the input and output of the step-down module 40, improving the quality of power supply to the electrical equipment.

[0108] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0109] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A power supply circuit, characterized in that, include: High-voltage conversion module and low-voltage switching module; The high-voltage conversion module receives high-voltage power and converts the high-voltage power into a first low-voltage power. The first input terminal of the low-voltage switching module is connected to the high-voltage conversion module, the second input terminal of the low-voltage switching module receives a second low-voltage power supply, and the output terminal of the low-voltage switching module is connected to the power-consuming equipment where the power supply circuit is located and external devices. The low-voltage switching module is used to supply power to the power-consuming equipment where the power supply circuit is located and external devices when it receives the first low-voltage power supply, or to supply power to the power-consuming equipment where the power supply circuit is located and external devices using both the first and second low-voltage power supplies; and to supply power to the power-consuming equipment where the power supply circuit is located when it receives only the second low-voltage power supply.

2. The circuit according to claim 1, characterized in that, The low-voltage switching module includes: a first diode, a second diode, a first overvoltage protection diode, and a second overvoltage protection diode; The positive terminal of the first diode is connected to the first input terminal of the low-voltage switching module, and the negative terminal of the first diode is connected to the output terminal of the low-voltage switching module; the first input terminal of the low-voltage switching module is connected to the external device, and the output terminal of the low-voltage switching module is connected to the electrical device. The positive terminal of the second diode is connected to the second input terminal of the low-voltage switching module, and the negative terminal of the second diode is connected to the output terminal of the low-voltage switching module. One end of the first overvoltage protection diode is connected to the first input terminal of the low-voltage switching module, one end of the second overvoltage protection diode is connected to the second input terminal of the low-voltage switching module, and the other ends of the first and second overvoltage protection diodes are grounded.

3. The circuit according to claim 1, characterized in that, The high-voltage conversion module includes a surge protection module, a first filtering module, a conversion module, and a second filtering module; The input terminal of the surge protection module receives the high-voltage power supply and is used to provide surge protection for the high-voltage power supply. The input terminal of the first filtering module is connected to the output terminal of the surge protection module, and is used to filter the high-voltage power supply. The input terminal of the conversion module is connected to the output terminal of the first filtering module, and is used to convert the high-voltage power supply that has undergone surge protection and filtering into the first low-voltage power supply. The input terminal of the second filtering module is connected to the output terminal of the conversion module, and the output terminal of the second filtering module is connected to the first input terminal of the low-voltage switching module, for filtering the first low-voltage power supply.

4. The circuit according to claim 3, characterized in that, The surge protection module includes: a fuse, a first varistor, a second varistor, a third varistor, and a gas discharge tube; One end of the fuse is connected to the live wire of the high-voltage power supply, and the other end of the fuse is connected to one end of the first varistor and one end of the third varistor; the other end of the first varistor and one end of the second varistor are connected to the neutral wire of the high-voltage power supply, and the other end of the second varistor and the other end of the third varistor are connected to one end of the gas discharge tube, and the other end of the gas discharge tube is grounded.

5. The circuit according to claim 3, characterized in that, The first filtering module includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a first common-mode inductor; One end of the first capacitor is connected to the first output terminal of the surge protection module, and the other end of the first capacitor is connected to the second output terminal of the surge protection module; The first input terminal of the first common-mode inductor is connected to one end of the first capacitor, and the second input terminal of the first common-mode inductor is connected to the other end of the first capacitor. One end of the second capacitor is connected to the first output terminal of the first common-mode inductor, and the other end of the second capacitor is connected to the second output terminal of the first common-mode inductor. One end of the third capacitor is connected to one end of the second capacitor, one end of the fourth capacitor is connected to the other end of the second capacitor, and the other ends of the third capacitor and the fourth capacitor are grounded.

6. The circuit according to claim 5, characterized in that, The conversion module includes: a switching power supply module; The first input terminal of the switching power supply module is connected to one end of the second capacitor, the second input terminal of the switching power supply module is connected to the other end of the second capacitor, and the first output terminal and the second output terminal of the switching power supply module output the first low-voltage power supply.

7. The circuit according to claim 6, characterized in that, The second filtering module includes: a first filtering capacitor, a second filtering capacitor, a third filtering capacitor, a fourth filtering capacitor, and a third overvoltage protection diode; One end of the first filter capacitor, one end of the second filter capacitor, one end of the third filter capacitor, one end of the fourth filter capacitor, one end of the third overvoltage protection diode, the first output terminal of the switching power supply module, and the first input terminal of the low-voltage switching module are connected. The other end of the first filter capacitor, the other end of the second filter capacitor, the other end of the third filter capacitor, the other end of the fourth filter capacitor, the other end of the third overvoltage protection diode, and the second output terminal of the switching power supply module are connected and grounded.

8. The circuit according to claim 1, characterized in that, The circuit also includes: a low-voltage protection module; The input terminal of the low-voltage protection module is connected to the output terminal of the low-voltage switching module, and the output terminal of the low-voltage protection module is connected to the electrical equipment, for surge protection and filtering of the power supply of the electrical equipment.

9. The circuit according to claim 8, characterized in that, The low-voltage protection module includes: a second common-mode inductor, a fourth overvoltage protection diode, and an energy storage filter capacitor; One end of the second common-mode inductor is connected to the output terminal of the low-voltage switching module, and the other end of the second common-mode inductor is connected to the electrical equipment. One end of the energy storage filter capacitor is connected to one end of the second common-mode inductor, one end of the fourth overvoltage protection diode is connected to the other end of the second common-mode inductor, and the other end of the energy storage filter capacitor and the other end of the fourth overvoltage protection diode are grounded.

10. The circuit according to any one of claims 1-9, characterized in that, The circuit also includes: a step-down module; The input terminal of the step-down module is connected to the output terminal of the low-voltage switching module, and the output terminal of the step-down module is connected to the electrical equipment, for stepping down the power supply of the electrical equipment.

11. The circuit according to claim 10, characterized in that, The step-down module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth capacitor, a sixth capacitor, a first inductor, a third diode, and a power chip; the power chip includes an input pin, an enable pin, a BOOT pin, a PH pin, and a VSENSE pin. One end of the first resistor is connected to the output terminal of the low-voltage switching module and the input pin of the power chip, and the other end of the first resistor is connected to the enable pin of the power chip. One end of the fifth capacitor and one end of the second resistor are connected to the enable pin of the power chip, and the other end of the fifth capacitor and the other end of the second resistor are grounded. One end of the sixth capacitor is connected to the BOOT pin of the power chip and the electrical device, and the other end of the sixth capacitor is connected to the PH pin of the power chip. One end of the first inductor is connected to the other end of the sixth capacitor, the other end of the first inductor is connected to one end of the third resistor, and the other end of the third resistor is connected to the VSENSE pin of the power chip. The negative terminal of the third diode is connected to the PH pin of the power chip, and the positive terminal of the third diode is grounded. One end of the fourth resistor is connected to the VSENSE pin of the power chip, and the other end of the fourth resistor is grounded.

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