Prompt circuit of switching power supply and switching power supply

Abstract

A switching power supply prompt circuit and a switching power supply relate to the technical field of switching power supplies. The circuit comprises an AC input module, an input capacitor energy storage module, an AC detection module, a control module, a conversion module, a prompt execution module and an output module. The AC input module is used for acquiring an input AC signal when being connected with an input power supply; the input capacitor energy storage module is used for storing energy for an input alternating current signal to provide a first alternating current signal; the alternating current detection module is used for detecting whether the connection between the alternating current input module and the input power supply is disconnected, and outputting a first signal when detecting that the connection is disconnected; the control module enters a protection state in response to a first signal output by the alternating current detection module; the conversion module is used for stopping conversion processing on the first alternating current signal when the control module is in the protection state so as to stop outputting the first direct current signal; and the prompt execution module stops executing the prompt action when the output module stops outputting the direct current.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, in particular to a prompt circuit of a switching power supply and the switching power supply. Background Art

[0002] A switching power supply is an electronic device that efficiently converts and regulates electrical energy to provide a stable output voltage or current. Unlike traditional linear power supplies, switching power supplies use high-frequency switching to efficiently convert electrical energy to a target voltage or current. Switching power supplies are suitable for applications such as computers, mobile phone chargers, LED drivers, and industrial equipment.

[0003] When operating normally, existing switching power supplies have an indicator light connected to the output circuit to display the operating status of the input power supply. However, when the switching power supply is in a no-load state, the output circuit consumes almost no energy. The energy storage capacitor in the switching power supply will continue to supply power to the output circuit after the input power is disconnected. As a result, the indicator light will not turn off, but will remain on until the charge in the energy storage capacitor is completely depleted.

[0004] Because the indicator light doesn't turn off quickly, users might mistakenly believe the power is still working, delaying the next step, such as disassembly, maintenance, or replacement of device components. In some cases, a delayed indicator light may lead to incorrect operation, increasing the risk of equipment damage or personal injury. Utility Model Content

[0005] The main technical problem solved by the utility model is to provide a prompt circuit of a switching power supply and a corresponding switching power supply, wherein the indicator light can be quickly turned off when the switching power supply input is powered off.

[0006] According to the first aspect, an embodiment provides a prompt circuit of a switching power supply, comprising: an AC input module, an input capacitor energy storage module, an AC detection module, a control module, a conversion module, a prompt execution module, and an output module;

[0007] The AC input module is used to obtain an input AC power signal when it is connected to an input power source;

[0008] The input capacitor energy storage module is connected to the AC input module and is used to store energy of the input AC signal to provide a first AC signal;

[0009] The AC detection module is connected to the AC input module and is used to detect whether the connection between the AC input module and the input power supply is disconnected, and output a first signal when disconnection is detected, otherwise output a second signal;

[0010] The control module includes a feedback terminal connected to the AC detection module. The control module has a working state and a protection state. The control module enters the working state in response to the second signal output by the AC detection module, and enters the protection state in response to the first signal output by the AC detection module.

[0011] The conversion module includes a driving end and an input end, the driving end is connected to the control module, and the input end is connected to the input capacitor energy storage module. The conversion module is used to convert the first AC signal to obtain a first DC signal when the control module is in an operating state; the conversion module is also used to stop converting the first AC signal to stop outputting the first DC signal when the control module is in a protection state.

[0012] The output module is connected to the conversion module and is configured to output a DC current when the conversion module outputs a first DC signal, so as to operate a load connected to the switching power supply; or to stop outputting the DC current when the conversion module stops outputting the first DC signal.

[0013] The prompt execution module is connected to the output module and is used to execute a prompt action to prompt the user under the drive of the direct current when the output module outputs direct current, or to stop executing the prompt action when the output module stops outputting direct current.

[0014] In one embodiment, the AC detection module also includes an enable end. When the AC detection module detects that the AC input module is disconnected from the input power supply, the input capacitor energy storage module converts the remaining stored energy charge in the input capacitor energy storage module into a second AC signal, and outputs the second AC signal to the enable end of the AC detection module until there is no remaining stored energy charge in the input capacitor energy storage module.

[0015] In one embodiment, the AC detection module includes a switch module, a control end of the switch module is connected to the AC input module to obtain the first signal or the second signal, and an output end of the switch module is an enable end of the AC detection module.

[0016] In one embodiment, the switch module includes a switch tube M1 and a switch tube M2. The control end of the switch tube M1 is the control end of the switch module, the first end of the switch tube M1 is connected to the control end of the switch tube M2, and the second end of the switch tube M1 is grounded; the first end of the switch tube M2 is connected to the feedback end of the control module, and the second end of the switch tube M2 is grounded.

[0017] In one embodiment, the AC detection module further includes a resistor R1, a resistor R2, a resistor R3, a resistor R7, a resistor R8, a diode D1, a diode D2, a Zener diode ZD1 and a capacitor C1; the input end of the diode D1 is connected to the AC input module, the input end of the diode D2 is connected to the AC input module, the output end of the diode D1 is connected to the output end of the diode D2, the output end of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2, and the second end of the resistor R2 is connected to the first end of the Zener diode ZD2. The output end and the input end of the voltage-stabilizing diode ZD2 are grounded; the second end of the resistor R2 is connected to the first end of the resistor R3, and the second end of the resistor R3 is grounded; the second end of the resistor R2 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is grounded; the second end of the resistor R2 is connected to the control end of the switch tube M1, one end of the switch tube M1 is connected to the first end of the resistor R7, the second end of the resistor R7 is the enable end of the AC detection module, and is connected to the control module; the first end of the resistor R7 is also connected to the first end of the resistor R8, and the second end of the resistor R8 is grounded.

[0018] In one embodiment, the control module includes a control chip, which includes a power supply port, a feedback port and a high-voltage port. The power supply port is used to connect to the input end of the conversion module, the feedback port is the feedback end of the control module, and the high-voltage port is used to connect to the driving end of the conversion module.

[0019] In one embodiment, the control module also includes a resistor R9, a resistor R10, a resistor R11, a capacitor EC3, a diode D3, an optocoupler OC and an auxiliary winding of a transformer; the control chip also includes a function port, a ground port and a current sampling port; the power supply port is also connected to the first end of the capacitor EC3, the second end of the capacitor EC3 is grounded, and the second end of the capacitor EC3 is also connected to the ground port; the power supply port is connected to the output end of the diode D3, the input end of the diode D3 is connected to the first end of the resistor R9, the second end of the resistor R9 is connected to the first end of the resistor R10, the second end of the resistor R10 is grounded, and the second end of the resistor R9 is connected to the function port; the first end of the resistor R9 is also connected to the first end of the auxiliary winding of the transformer, and the second end of the auxiliary winding of the transformer is grounded; the feedback port is connected to the first end of the optocoupler OC, and the second end of the optocoupler OC is grounded; the current sampling port is connected to the first end of the resistor R11, and the second end of the resistor R11 is grounded; the power supply port is also connected to the second end of the resistor R7.

[0020] In one embodiment, the prompt execution module includes an indicator light component or an audio prompt component, wherein the indicator light component can emit light to instruct the user, and the audio prompt component can play sound to prompt the user.

[0021] In one embodiment, the prompt execution module includes a resistor R17 and an indicator light LED1, the first end of the resistor R17 is used to connect to the output module, the second end of the resistor R17 is connected to the input end of the indicator light LED1, and the output end of the indicator light LED1 is grounded.

[0022] According to the second aspect, an embodiment provides a switching power supply, comprising: a prompt circuit of the switching power supply described in any one of the above embodiments, for prompting a user when the switching power supply is connected to an input power supply; or for stopping prompting the user when the switching power supply is disconnected from the input power supply.

[0023] According to the above-described embodiment, a prompt circuit for a switching power supply and a switching power supply include an AC input module, an input capacitor energy storage module, an AC detection module, a control module, a conversion module, a prompt execution module, and an output module. When connected to an input power source, the AC input module acquires an input AC signal, and the input capacitor energy storage module stores energy in the input AC signal, thereby providing a first AC signal. The AC detection module outputs a first signal when it detects a disconnection between the AC input module and the input power source, and outputs a second signal when it detects an intact connection between the AC input module and the input power source. In response to the first signal output by the AC detection module, the control module enters a protection state, stopping conversion and processing of the first AC signal and thereby outputting the first DC signal. The prompt execution module then immediately stops executing the prompt action. This application utilizes the prompt circuit of the switching power supply to quickly stop the prompt action of the prompt execution module when the switching power supply is unloaded, allowing the user to more clearly recognize that the input power source has been disconnected. This prevents the user from mistaking the switching power supply for power or a fault due to the long wait for the prompt execution module to stop executing the prompt action. Furthermore, if the prompt execution module does not stop executing the prompt action for a long time after power failure, the user may believe that the input power is still on and continue to operate the switching power supply, which may lead to misoperation or even damage to the switching power supply. The prompt circuit of the switching power supply in this application can intuitively indicate that the switching power supply is in the power-off state, avoiding these potential problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a first structure of a switching power supply in an embodiment;

[0025] Figure 2 Schematic diagram of the structure of a prompt circuit of a switching power supply in one embodiment;

[0026] Figure 3 A schematic structural diagram of an AC detection module in an embodiment;

[0027] Figure 4 This is a schematic structural diagram of a control module in an embodiment;

[0028] Figure 5 A circuit connection diagram of a prompt circuit of a switching power supply in one embodiment;

[0029] Figure 6 FIG. 1 is a second structural diagram of a switching power supply in another embodiment.

[0030] Reference numerals: AC input module 110 , input capacitor energy storage module 120 , AC detection module 130 , switch module 131 , conversion module 140 , control module 150 , control chip 151 , output module 160 , prompt execution module 170 . DETAILED DESCRIPTION

[0031] The present invention is further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted under different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0032] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0033] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0034] Please refer to Figure 1The figure is a schematic diagram of the structure of a switching power supply in one embodiment, which includes an AC input circuit, an input capacitor energy storage circuit, a conversion circuit, an output capacitor energy storage circuit, an output circuit, and an indicator light circuit. When the AC input circuit is disconnected from the input power supply, that is, when the switching power supply is operating at no load, the output circuit consumes almost no energy. At this time, even if the input power supply is disconnected, the input capacitor energy storage circuit still stores a certain amount of charge. This charge can continue to power the entire switching power supply circuit, maintaining normal operation for a period of time.

[0035] When the input power is disconnected, the conversion circuit does not immediately cease operation. Instead, it continues to convert the charge stored in the input capacitor tank circuit into DC power and transmits it to the output circuit. In this case, the indicator circuit and the load connected to the output circuit can still receive power from the output circuit, so the indicator light does not immediately go out.

[0036] This process may last for a long time, usually more than 30 seconds, until the charge in the input capacitor energy storage circuit is completely depleted. Only when the charge stored in the input capacitor energy storage circuit is completely consumed, the conversion circuit stops working, and the output circuit loses power supply, the indicator light will go out.

[0037] While this process does not affect the normal function of the switching power supply, users may mistakenly believe that the device has not been completely powered off, as the indicator light remains on after power is removed, leading to safety concerns. In reality, this is simply a normal phenomenon where the input capacitor energy storage circuit continues to power the circuit and does not represent a safety issue. However, this phenomenon can lead to misunderstandings among users, especially those unfamiliar with the product's performance.

[0038] The present application provides a prompt circuit of a switching power supply and a switching power supply. Figure 1 An AC detection module 130 and a control module 150 are added to the structural diagram of the switching power supply in FIG. 1 . The AC detection module 130 detects whether the AC input module 110 is connected to the input power supply. When it is detected that the AC input module 110 is not connected to the input power supply, the AC detection module 130 sends a short-circuit signal to the control module 150. After receiving the short-circuit signal, the control module 150 enters a protection state, thereby stopping driving the conversion module 140. At this time, the conversion module 140 stops converting energy, thereby turning off the indicator light in the prompt execution module 170. This will be explained in detail below.

[0039] Please refer to Figure 2In one embodiment, a prompt circuit 100 of a switching power supply is provided, including an AC input module 110, an input capacitor energy storage module 120, an AC detection module 130, a conversion module 140, a control module 150, an output module 160 and a prompt execution module 170.

[0040] Please refer to Figure 5 In one embodiment, the AC input module 110 is used to obtain an input AC power signal when the AC input module 110 is connected to an input power source. The AC input module 110 includes a fuse F1, a thermistor NTC1, and a rectifier bridge BD1. The first end of the fuse F1 serves as the live wire of the AC input module 110 and is used to connect to the input power source. The second end of the fuse F1 is connected to the first input end of the rectifier bridge BD1. The first end of the thermistor NTC1 serves as the neutral wire of the AC input module 110 and is used to connect to the input power source. The second end of the thermistor NTC1 is connected to the second input end of the rectifier bridge BD1. The first and second output ends of the rectifier bridge BD1 are connected to the input capacitor energy storage module 120. The second ends of the fuse F1 and the thermistor NTC1 are also used to connect to the AC detection module 130.

[0041] Please refer to Figure 5 In one embodiment, input capacitor energy storage module 120 is connected to AC input module 110 and is configured to store energy from an input AC signal to provide a first AC signal. Input capacitor energy storage module 120 includes capacitor EC1. A first end of capacitor EC1 is connected to a first output end of rectifier bridge BD1. A second end of capacitor EC1 is connected to a second output end of rectifier bridge BD1. The second end of capacitor EC1 is grounded.

[0042] In one embodiment, the AC detection module 130 is connected to the AC input module 110 and is used to detect whether the connection between the AC input module 110 and the input power supply is disconnected, and outputs a first signal when it is detected that the connection is disconnected; and outputs a second signal when it is detected that the connection is not disconnected.

[0043] Please refer to Figure 3 In one embodiment, the AC detection module 130 includes a switch module 131 , the control end of the switch module 131 is connected to the AC input module 110 to obtain the first signal or the second signal; the output end of the switch module 131 is the enable end of the AC detection module 130 .

[0044] Please refer to Figure 5 In one embodiment, the switch module 131 includes a switch tube M1 and a switch tube M2. The control end of the switch tube M1 is the control end of the switch module 131. The first end of the switch tube M1 is connected to the control end of the switch tube M2, and the second end of the switch tube M1 is grounded. The first end of the switch tube M2 is connected to the feedback end of the control module 150, and the second end of the switch tube M2 is grounded.

[0045] Please refer to Figure 5 In one embodiment, the AC detection module 130 further includes a resistor R1, a resistor R2, a resistor R3, a resistor R7, a resistor R8, a diode D1, a diode D2, a Zener diode ZD1, and a capacitor C1. The input end of the diode D1 is connected to the AC input module 110, that is, the input end of the diode D1 is connected to the second end of the thermistor NTC1. The input end of the diode D2 is connected to the AC input module 110, that is, the input end of the diode D2 is connected to the second end of the fuse F1. The output end of the diode D1 is connected to the output end of the diode D2, the output end of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2, the second end of the resistor R2 is connected to the output end of the Zener diode ZD2, and the input end of the Zener diode ZD2 is grounded. The second end of the resistor R2 is connected to the first end of the resistor R3, and the second end of the resistor R3 is grounded. The second end of the resistor R2 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is grounded. The control terminal of the switch M1 is connected to the AC input module 110. Specifically, the control terminal of the switch M1 is connected to the second terminal of the resistor R2. One terminal of the switch M1 is connected to the first terminal of the resistor R7. The second terminal of the switch M1 is grounded. The second terminal of the resistor R7 is connected to the control module 150. The first terminal of the resistor R7 is also connected to the first terminal of the resistor R8. The second terminal of the resistor R8 is grounded. The first terminal of the switch M1 is also connected to the control terminal of the switch M2. The first terminal of the switch M2 is connected to the feedback terminal of the control module 150. The second terminal of the switch M2 is grounded.

[0046] It should be noted that the second end of the resistor R7 of the AC detection module 130 serves as the enable end of the AC detection module 130. When the AC detection module 130 detects that the AC input module 110 is disconnected from the input power supply, the capacitor EC1 in the input capacitor energy storage module 120 converts the remaining energy stored charge in the capacitor EC1 into a second AC signal, and outputs the second AC signal to the enable end of the AC detection module 130. The resistor R7 and the resistor R8 are used to consume the remaining energy stored charge until there is no remaining energy stored charge in the capacitor EC1.

[0047] In one embodiment, conversion module 140 is an AC / DC conversion module. Conversion module 140 includes a drive end and an input end. The drive end is connected to control module 150, and the input end is connected to input capacitor energy storage module 120. Conversion module 140 is configured to convert a first AC signal to generate a first DC signal when control module 150 is in an operating state. Conversion module 140 is also configured to stop converting the first AC signal and outputting the first DC signal when control module 150 is in a protection state.

[0048] Please refer to Figure 5In one embodiment, the conversion module 140 includes a resistor R5, a resistor R6, a resistor R4, a capacitor C2, a diode D4, a transformer, a diode D5, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C3, a capacitor C4, a light-emitting diode D6, and a Zener diode ZD2. The first end of the resistor R5 serves as the input end of the conversion module 140, the second end of the resistor R5 is connected to the first end of the resistor R6, and the second end of the resistor R6 is connected to the power supply port of the control module 150. The first end of the resistor R5 is also connected to the first end of the resistor R4, the first end of the resistor R4 is also connected to the first end of the capacitor C2, the first end of the capacitor C2 is also connected to the first end of the main winding of the transformer, the second end of the resistor R4 is connected to the second end of the capacitor C2, the second end of the capacitor C2 is connected to the output end of the diode D4, the input end of the diode D4 is connected to the second end of the main winding of the transformer, and the second end of the main winding of the transformer serves as the driving end of the conversion module 140. The first end of the transformer's secondary winding is connected to the input end of diode D5. The second end of the transformer's secondary winding is grounded. The output end of diode D5 is connected to the first end of resistor R12. The second end of resistor R12 is connected to the input end of light-emitting diode D6. The output end of light-emitting diode D6 is connected to the output end of Zener diode ZD2. The output end of Zener diode ZD2 is grounded. The second end of resistor R12 is also connected to the first end of resistor R13. The second end of resistor R13 is connected to the output end of light-emitting diode D6. The second end of resistor R13 is connected to the first end of capacitor C3. The second end of capacitor C3 is connected to the first end of resistor R14. The second end of resistor R14 is connected to the first end of the transformer's secondary winding. The first end of capacitor C4 is connected to the output end of light-emitting diode D6. The second end of capacitor C4 is connected to the first end of resistor R15. The second end of resistor R15 is connected to the first end of resistor R16. The second end of resistor R16 is grounded.

[0049] In one embodiment, the control module 150 includes a feedback end connected to the AC detection module 130. The control module 150 has a working state and a protection state. The control module 150 enters the working state in response to the second signal output by the AC detection module 130, and the control module 150 enters the protection state in response to the first signal output by the AC detection module 130.

[0050] Please refer to Figure 4 In one embodiment, the control module 150 includes a control chip 151, which includes a power supply port VDD, a feedback port FB, and a high-voltage port DRAIN. The power supply port is connected to the input of the conversion module 140, the feedback port is the feedback port of the control module 150, and the high-voltage port is connected to the driving end of the conversion module 140.

[0051] Please refer to Figure 5In one embodiment, the control module 150 includes a resistor R9, a resistor R10, a resistor R11, a capacitor EC3, a diode D3, an optocoupler OC, and an auxiliary winding of a transformer. The control chip 151 also includes a ground port GND, a function port DEM, and a current sampling port CS. The power supply port VDD is connected to the first end of the capacitor EC3, the second end of the capacitor EC3 is grounded, and the second end of the capacitor EC3 is also connected to the ground port GND. The power supply port VDD is connected to the output end of the diode D3, the input end of the diode D3 is connected to the first end of the resistor R9, the second end of the resistor R9 is connected to the first end of the resistor R10, the second end of the resistor R10 is grounded, and the second end of the resistor R9 is connected to the function port DEM. The first end of the resistor R9 is also connected to the first end of the auxiliary winding of the transformer, and the second end of the auxiliary winding of the transformer is grounded. The feedback port FB is connected to the first end of the optocoupler OC, and the second end of the optocoupler OC is grounded. The current sampling port CS is connected to the first end of the resistor R11, the second end of the resistor R11 is grounded, and the power supply port VDD is also connected to the second end of the resistor R7.

[0052] It should be noted that the control chip 151 in this application is a KP22035WGA chip. During the startup phase, the KP22035WGA chip charges the power supply port VDD through the high-voltage port DRAIN. When the voltage of the power supply port VDD reaches the startup voltage, the high-voltage power supply is turned off. After the output is established, the KP22035WGA chip is powered by the auxiliary winding of the transformer. During the startup process, when the voltage of the power supply port VDD is lower than 2V, the high-voltage port DRAIN charges the capacitor EC3 with a small current to reduce the chip power consumption when the power supply port VDD is short-circuited to ground. When the voltage of the power supply port VDD exceeds 2V, the high-voltage port DRAIN increases the charging current of the capacitor EC3 to shorten the startup time.

[0053] In one embodiment, the output module 160 is connected to the conversion module 140, and the output module 160 is used to output a DC current when the conversion module 140 outputs a first DC signal to enable a load connected to the switching power supply to operate; or, the output module 160 is used to stop outputting the DC current when the conversion module 140 stops outputting the first DC signal.

[0054] Please refer to Figure 5 In one embodiment, the output module 160 includes a capacitor EC4, a first end of the capacitor EC4 is connected to the conversion module 140, that is, the first end of the capacitor EC4 is connected to the output end of the diode D5, the first end of the capacitor EC4 is used to connect to the load of the prompt circuit 100 of the switching power supply, and the second end of the capacitor EC4 is grounded.

[0055] In one embodiment, the prompt execution module 170 is connected to the output module 160, and the prompt execution module 170 is used to execute a prompt action to prompt the user under the drive of the direct current when the output module 160 outputs direct current, or the prompt execution module 170 stops executing the prompt action when the output module 160 stops outputting direct current.

[0056] In one embodiment, the prompt execution module 170 includes an indicator light component or an audio prompt component. The indicator light component can emit light to instruct the user, and the audio prompt component can play sound to prompt the user.

[0057] Please refer to Figure 5 In one embodiment, the prompt execution module 170 includes a resistor R17 and an indicator LED1. The first end of the resistor R17 is connected to the output module 160, that is, the first end of the resistor R17 is connected to the first end of the capacitor EC4, the second end of the resistor R17 is connected to the input end of the indicator LED1, and the output end of the indicator LED1 is grounded.

[0058] It should be noted that when the prompt circuit 100 of the switching power supply provided in the present application is operating normally, the AC input module 110 is connected to the input power supply, and after the AC detection module 130 detects that the AC input module 110 is connected to the input power supply, the AC input module 110 obtains the input AC signal. When the AC detection module 130 detects that the AC input module 110 is connected to the input power supply, the diode D1, the diode D2, the resistor R1, the resistor R2, the Zener diode ZD1 and the capacitor C1 in the AC detection module 130 will cause the switch tube M1 to turn on, and then the switch tube M2 will be disconnected due to the lack of conduction voltage, thereby generating a first signal. At this time, the feedback port FB in the KP22035WGA chip is normally connected to the circuit, and the input AC signal is rectified by the rectifier bridge BD1 in the AC input module 110, and then smoothed into a stable first AC signal by the capacitor EC1 in the input capacitor energy storage module 120. The first AC signal passes through the resistor R5 and the resistor R6 in the conversion module 140 to charge the capacitor EC3 in the control module 150. When the operating voltage of the power supply port VDD in the KP22035WGA chip connected to the capacitor EC3 reaches the IC start-up threshold, the KP22035WGA chip enters the working state, and the conversion module 140 is driven to work normally, converting the first AC signal into a first DC signal, and storing it in the capacitor EC4 in the output module 160, so that the load connected to the switching power supply prompt circuit 100 is used normally, and the indicator light LED1 forms a loop through the current limiting resistor R17, thereby lighting up normally.

[0059] After the AC input module 110 of the switching power supply provided in the present application is disconnected from the input power supply, the AC detection module 130 does not detect the AC input voltage, outputs a second signal, and the switch tube M1 does not obtain the conduction voltage, so the switch tube M1 is not turned on. The operating voltage of the power supply port VDD in the KP22035WGA chip drives the switch tube M2 through the resistor R7 and the resistor R8, and the switch tube M2 is turned on, thereby generating a second signal. At this time, the feedback port FB in the KP22035WGA chip is short-circuited to ground through the switch tube M2, and the KP22035WGA chip enters the protection state. After the KP22035WGA chip enters the protection state, the conversion module 140 cannot be driven to perform normal operation, so the charge in the capacitor EC4 in the output module 160 cannot be continuously supplied to the indicator LED1, so the indicator LED1 will go out instantly. The charge in the capacitor EC1 in the input capacitor energy storage module 120 will charge the capacitor EC3 in the control module 150 through the resistor R5 and the resistor R6 in the conversion module 140. The voltage in the power supply port VDD in the KP22035WGA chip can continuously enable the switch tube M2 until the charge in the capacitor EC3 is exhausted.

[0060] Please refer to Figure 6 In another embodiment, a switching power supply 10 is provided. The switching power supply 10 includes a prompt circuit 100 for the switching power supply. The prompt circuit 100 is used to prompt a user when the switching power supply is connected to an input power source, or to stop prompting the user when the switching power supply is disconnected from the input power source. Since the prompt circuit 100 of the switching power supply has been clearly explained in any of the above embodiments, it will not be repeated here.

[0061] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art of the present invention can make some simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A prompt circuit of a switching power supply, characterized in that: include: AC input module, input capacitor energy storage module, AC detection module, control module, conversion module, prompt execution module and output module; The AC input module is used to obtain an input AC power signal when it is connected to an input power source; The input capacitor energy storage module is connected to the AC input module and is used to store energy of the input AC signal to provide a first AC signal; The AC detection module is connected to the AC input module and is used to detect whether the connection between the AC input module and the input power supply is disconnected, and output a first signal when disconnection is detected, otherwise output a second signal; The control module includes a feedback terminal connected to the AC detection module. The control module has a working state and a protection state. The control module enters the working state in response to the second signal output by the AC detection module, and enters the protection state in response to the first signal output by the AC detection module. The conversion module includes a driving end and an input end, the driving end is connected to the control module, and the input end is connected to the input capacitor energy storage module. The conversion module is used to convert the first AC signal to obtain a first DC signal when the control module is in an operating state; the conversion module is also used to stop converting the first AC signal to stop outputting the first DC signal when the control module is in a protection state. The output module is connected to the conversion module and is configured to output a DC current when the conversion module outputs a first DC signal, so as to operate a load connected to the switching power supply; or to stop outputting the DC current when the conversion module stops outputting the first DC signal. The prompt execution module is connected to the output module and is used to execute a prompt action to prompt the user under the drive of the direct current when the output module outputs direct current, or to stop executing the prompt action when the output module stops outputting direct current.

2. The prompt circuit of the switching power supply according to claim 1, characterized in that: The AC detection module also includes an enable terminal. When the AC detection module detects that the AC input module is disconnected from the input power supply, the input capacitor energy storage module converts the remaining stored charge in the input capacitor energy storage module into a second AC signal and outputs the second AC signal to the enable terminal of the AC detection module until there is no remaining stored charge in the input capacitor energy storage module.

3. The prompt circuit of the switching power supply according to claim 2, characterized in that: The AC detection module includes a switch module, a control end of the switch module is connected to the AC input module to obtain a first signal or a second signal, and an output end of the switch module is an enable end of the AC detection module.

4. The prompt circuit of the switching power supply according to claim 3, characterized in that: The switch module includes a switch tube M1 and a switch tube M2. The control end of the switch tube M1 is the control end of the switch module. The first end of the switch tube M1 is connected to the control end of the switch tube M2, and the second end of the switch tube M1 is grounded. The first end of the switch tube M2 is connected to the feedback end of the control module, and the second end of the switch tube M2 is grounded.

5. The prompt circuit of the switching power supply according to claim 4, characterized in that: The AC detection module also includes a resistor R1, a resistor R2, a resistor R3, a resistor R7, a resistor R8, a diode D1, a diode D2, a Zener diode ZD1 and a capacitor C1; the input end of the diode D1 is connected to the AC input module, the input end of the diode D2 is connected to the AC input module, the output end of the diode D1 is connected to the output end of the diode D2, the output end of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2, and the second end of the resistor R2 is connected to the output end of the Zener diode ZD2. The input end of the voltage-stabilizing diode ZD2 is grounded; the second end of the resistor R2 is connected to the first end of the resistor R3, and the second end of the resistor R3 is grounded; the second end of the resistor R2 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is grounded; the second end of the resistor R2 is connected to the control end of the switch tube M1, one end of the switch tube M1 is connected to the first end of the resistor R7, the second end of the resistor R7 is the enable end of the AC detection module, and is connected to the control module, the first end of the resistor R7 is also connected to the first end of the resistor R8, and the second end of the resistor R8 is grounded.

6. The prompt circuit of the switching power supply according to claim 1, wherein: The control module includes a control chip, which includes a power supply port, a feedback port and a high-voltage port. The power supply port is used to connect to the input end of the conversion module, the feedback port is the feedback end of the control module, and the high-voltage port is used to connect to the driving end of the conversion module.

7. The prompt circuit of the switching power supply according to claim 6, characterized in that: The control module also includes a resistor R9, a resistor R10, a resistor R11, a capacitor EC3, a diode D3, an optocoupler OC and an auxiliary winding of a transformer; the control chip also includes a function port, a ground port and a current sampling port; the power supply port is also connected to the first end of the capacitor EC3, the second end of the capacitor EC3 is grounded, and the second end of the capacitor EC3 is also connected to the ground port; the power supply port is connected to the output end of the diode D3, the input end of the diode D3 is connected to the first end of the resistor R9, the second end of the resistor R9 is connected to the first end of the resistor R10, the second end of the resistor R10 is grounded, and the second end of the resistor R9 is connected to the function port; the first end of the resistor R9 is also connected to the first end of the auxiliary winding of the transformer, and the second end of the auxiliary winding of the transformer is grounded; the feedback port is connected to the first end of the optocoupler OC, and the second end of the optocoupler OC is grounded; the current sampling port is connected to the first end of the resistor R11, and the second end of the resistor R11 is grounded; the power supply port is also connected to the second end of the resistor R7.

8. The prompt circuit of the switching power supply according to claim 1, wherein: The prompt execution module includes an indicator light component or an audio prompt component. The indicator light component can emit light to instruct the user, and the audio prompt component can play sound to prompt the user.

9. The prompt circuit of the switching power supply according to claim 8, characterized in that: The prompt execution module includes a resistor R17 and an indicator light LED1. The first end of the resistor R17 is used to connect to the output module, the second end of the resistor R17 is connected to the input end of the indicator light LED1, and the output end of the indicator light LED1 is grounded.

10. A switching power supply, characterized in that: include: The prompt circuit of the switching power supply according to any one of claims 1 to 9, configured to prompt a user when the switching power supply is connected to an input power supply; Alternatively, it can be used to stop prompting the user when the switching power supply disconnects the input power.

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