Anti-impact circuit capable of being quickly powered on after power failure and application power supply circuit of anti-impact circuit

Abstract

The utility model relates to the technical field of circuit protection, in particular to an anti-impact circuit capable of being quickly powered on after power failure and an application power supply circuit thereof, and the anti-impact circuit comprises a current limiting piece, a switch assembly and a microcontroller, the current limiting piece, the switch assembly and the microcontroller are electrically connected in sequence; the current limiting piece is electrically connected with a target circuit, the current limiting piece is controlled by the switch assembly to be switched on or switched off, and the microcontroller controls the switch assembly to be switched on or switched off according to obtained detection data; the problem that the impact current generated by rapid power-on after power failure cannot be perfectly processed at present is solved.

Description

Technical Field

[0001] This utility model relates to the field of circuit protection technology, and in particular to an anti-impact circuit that allows for rapid power-on after a power outage and its application in power supply circuits. Background Technology

[0002] In the daily use of existing household appliances (such as air conditioners), the appliances are often subjected to scenarios where the user unplugs them and then suddenly plugs them back in to quickly power them on. This causes a drastic change in the voltage of the appliance's mainboard, generating an inrush current that impacts the mainboard circuit. This can easily damage the fast recovery diodes connected in series at the output terminal of the mainboard circuit to prevent reverse current, and in severe cases, it can even cause the mainboard circuit to burn out.

[0003] Existing home appliance mainboard circuits either ignore the impact of rapid power-on after a power outage on fast recovery diodes because the inrush current is short-lived, or they only use fuses connected in series at the circuit input for overcurrent breaking to cope with inrush currents. This requires frequent fuse replacements and also has the problem of ignoring inrush currents below the fusing value. Utility Model Content

[0004] To address the aforementioned shortcomings, the purpose of this invention is to propose an anti-impact circuit for rapid power-on after power failure and its application power supply circuit, thereby solving the problem that the inrush current generated by rapid power-on after power failure cannot be perfectly handled.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An anti-surge circuit for rapid power-on after power failure includes a current limiting component, a switching assembly, and a microcontroller; the current limiting component, the switching assembly, and the microcontroller are electrically connected in sequence; the current limiting component is electrically connected to a target circuit, and the current limiting component is controlled to be turned on or off by the switching assembly; the microcontroller controls the switching assembly to switch on or off based on acquired detection data.

[0007] Furthermore, the current limiting device is a PTC thermistor, which is connected in series with the target circuit.

[0008] Furthermore, the switching assembly includes a relay RY1, a diode D10, a transistor Q102, a resistor R6, and a resistor R142. The two contact pins of the relay RY1 are electrically connected to the two ends of the PTC thermistor, and the two coil pins of the relay RY1 are electrically connected to the cathode and anode of the diode D10, respectively. The cathode of the diode D10 is connected to a positive voltage, and the anode of the diode D10 is electrically connected to the collector of the transistor Q102. The emitter of the transistor Q102 is grounded, and the resistor R6 is connected in parallel between the emitter and base of the transistor Q102. The base of the transistor Q102 is connected in series with the resistor R142 and then electrically connected to the microcontroller.

[0009] Furthermore, it also includes a mains power detection circuit; the input terminal of the mains power detection circuit is electrically connected to the mains power input terminal of the target circuit, and the output terminal of the mains power detection circuit is electrically connected to the microcontroller.

[0010] Furthermore, the mains power detection circuit includes an isolation branch and a switch branch; the input terminal of the isolation branch is used as the input terminal of the mains power detection circuit, the output terminal of the isolation branch is electrically connected to the input terminal of the switch branch, and the output terminal of the switch branch is used as the output terminal of the mains power detection circuit.

[0011] Furthermore, the isolation branch includes a resistor R1, a diode D12, a resistor R24, and an optocoupler IC9; one end of the resistor R1 and the light source cathode of the optocoupler IC9 are both used as the input terminal of the isolation branch, and the light receiver emitter of the optocoupler IC9 is used as the output terminal of the isolation branch.

[0012] The other end of the resistor R1 is electrically connected to the anode of the diode D12, the cathode of the diode D12 is electrically connected to the anode of the light source of the optocoupler IC9, the resistor R24 ​​is connected in parallel between the anode and cathode of the light source of the optocoupler IC9, and the collector of the photodetector of the optocoupler IC9 is connected to a positive voltage.

[0013] Furthermore, the switching branch includes resistor R3, resistor R23, capacitor C14, transistor Q5, resistor R64, resistor R37, and capacitor C40; one end of resistor R23 is used as the input terminal of the switching branch, and one end of resistor R37 is used as the output terminal of the switching branch.

[0014] The other end of the resistor R23 is electrically connected to the base of the transistor Q5, the emitter of the transistor Q5 is grounded, the resistor R3 is connected in parallel between one end of the resistor R23 and the emitter of the transistor Q5, and the capacitor C14 is connected in parallel between the other end of the resistor R23 and the emitter of the transistor Q5.

[0015] One end of the resistor R64 is connected to the positive power supply, and the other end of the resistor R64 and the collector of the transistor Q5 are both electrically connected to the other end of the resistor R37. One end of the capacitor C40 is electrically connected to one end of the resistor R37, and the other end of the capacitor C40 is grounded.

[0016] A power supply circuit includes the aforementioned surge protection circuit for rapid power-on after power failure; it also includes a rectifier bridge BR1; the mains power wire is first connected in series with the current limiting component, and then electrically connected to the input terminal of the rectifier bridge BR1.

[0017] Furthermore, it also includes a fuse FUSE1, which is connected in series with the mains power line and the current limiting device, and then electrically connected to the input terminal of the rectifier bridge BR1.

[0018] The technical solution provided by this utility model can include the following beneficial effects: By setting up a linkage structure of current limiting device, switching component and microcontroller (such as MCU), dynamic regulation of the target circuit's surge current is realized. In scenarios of power failure and rapid power-on, the microcontroller monitors the target circuit in real time, acquires detection data, determines when the target circuit faces surge current and when the surge current exceeds the withstand capacity of the fast recovery diode, and then intelligently controls the switching component's action through the microcontroller's preset control method, so that the current limiting device connects the target circuit at the optimal current limiting time, suppressing all levels of surge current in the target circuit (unlike fuses which only suppress surge currents above the fusing value), and also avoids the increased power consumption caused by the current limiting device connecting the target circuit for a long time, and solves the disadvantage of the need for frequent replacement of traditional fuse overcurrent protection, significantly improving the safety of the target circuit. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circuit principle of an anti-shock circuit for rapid power-on after power failure and a power supply circuit, which is one embodiment of this utility model.

[0020] Figure 2 The diagram shown is of the mains power detection circuit.

[0021] The components include: current limiting component 1, switching assembly 2, microcontroller 3, relay RY1, diode D10, transistor Q102, resistor R6, resistor R142, mains power detection circuit 4, isolation branch 41, switching branch 42, resistor R1, diode D12, resistor R24, optocoupler IC9, resistor R3, resistor R23, capacitor C14, transistor Q5, resistor R64, resistor R37, capacitor C40, rectifier bridge BR1, and fuse FUSE1. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] In the description of embodiments of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0025] The following is combined with Figures 1 to 2 This invention describes an anti-shock circuit for rapid power-on after power failure and its application power supply circuit, according to an embodiment of the present invention.

[0026] An anti-impact circuit for rapid power-on after power failure includes a current limiting component 1, a switching component 2, and a microcontroller 3; the current limiting component 1, the switching component 2, and the microcontroller 3 are electrically connected in sequence; the current limiting component 1 is electrically connected to the target circuit, and the current limiting component 1 is controlled to be turned on or off by the switching component 2; the microcontroller 3 controls the switching of the switching component 2 according to the acquired detection data.

[0027] This utility model proposes a preferred embodiment of an anti-impact circuit for rapid power-on after a power outage, such as... Figure 1As shown, by setting up a linkage structure of current limiting component 1, switching component 2, and microcontroller 3 (such as MCU), dynamic regulation of the target circuit's surge current is achieved. In scenarios of power failure and rapid power-on, microcontroller 3 monitors the target circuit in real time, acquires detection data, determines when the target circuit faces surge current, and when the surge current exceeds the fast recovery diode's withstand capacity. Then, through a preset control method, microcontroller 3 intelligently controls the switching component 2 to operate, ensuring that current limiting component 1 connects to the target circuit at the optimal current-limiting moment. This suppresses surge currents of all levels in the target circuit (unlike fuses, which only suppress surge currents above the fusing value). It also avoids increased power consumption due to current limiting component 1 remaining connected to the target circuit for extended periods, and solves the drawback of frequent replacement of traditional fuse overcurrent protection, significantly improving the safety of the target circuit.

[0028] Furthermore, the current limiting component 1 is a PTC thermistor, which is connected in series with the target circuit.

[0029] In this embodiment, a PTC thermistor is used as the current limiting element 1. Utilizing its temperature-resistance positive correlation characteristic, the resistance value is automatically increased when the current is too large to achieve adaptive current limiting protection. This is better compatible with inrush currents below the fuse's melting point, and the current automatically recovers after the abnormality is cleared. Compared with fixed resistor or fuse solutions, it has the advantages of both adaptability and maintenance-free operation, and is particularly suitable for home appliance scenarios with frequent switching.

[0030] Furthermore, the switching assembly 2 includes a relay RY1, a diode D10, a transistor Q102, a resistor R6, and a resistor R142. The two contact pins of the relay RY1 are electrically connected to the two ends of the PTC thermistor, and the two coil pins of the relay RY1 are electrically connected to the cathode and anode of the diode D10, respectively. The cathode of the diode D10 is connected to the positive voltage, and the anode of the diode D10 is electrically connected to the collector of the transistor Q102. The emitter of the transistor Q102 is grounded, and the resistor R6 is connected in parallel between the emitter and base of the transistor Q102. The base of the transistor Q102 is connected in series with the resistor R142 and then electrically connected to the microcontroller 3.

[0031] In this embodiment, the control of the current limiting element 1 by the switch assembly 2 is mainly achieved by connecting the PTC thermistor through the relay RY1. During normal operation, the relay RY1 is energized to bypass (i.e. disconnect) the PTC thermistor, eliminating its conduction loss. In case of abnormality, the relay is released to connect the PTC thermistor to the current limiting (i.e. connect).

[0032] It should be noted that the microcontroller 3 uses the transistor Q102 drive circuit in conjunction with a resistor network to achieve reliable control of the relay RY1. The diode D10 freewheeling protects the coil of the relay RY1. The overall solution has a fast response speed, low power consumption and strong anti-interference ability.

[0033] Furthermore, it also includes a mains power detection circuit 4; the input terminal of the mains power detection circuit 4 is electrically connected to the mains power input terminal of the target circuit, and the output terminal of the mains power detection circuit 4 is electrically connected to the microcontroller 3.

[0034] In this embodiment, considering that the target circuit may fail to be recognized by the microcontroller 3 in time after being powered off and then quickly powered on by the user, the detection data acquired by the microcontroller 3 is usually preferably from multiple sources; among them, the mains voltage at the input terminal is particularly important to detect, as it best represents the moment of power failure or power-on. Therefore, a mains voltage detection circuit 4 is added (e.g., Figure 2 (As shown) is used for real-time monitoring of the input voltage status, enabling the microcontroller 3 to accurately determine the mains power on / off event, and to correlate it with the target circuit status (i.e., other detection data, such as...) Figure 1 The P+) in the circuit forms a closed-loop control; compared with the scheme that simply relies on the feedback of the detection data inside the target circuit, it can predict the impact risk in advance and actively intervene in the control, thereby improving the timeliness of the protection response.

[0035] Furthermore, the mains power detection circuit 4 includes an isolation branch 41 and a switch branch 42; the input terminal of the isolation branch 41 is used as the input terminal of the mains power detection circuit 4, the output terminal of the isolation branch 41 is electrically connected to the input terminal of the switch branch 42, and the output terminal of the switch branch 42 is used as the output terminal of the mains power detection circuit 4.

[0036] In this embodiment, when the detection data is mains power, since mains power is high voltage and the target circuit is low voltage, a detection architecture consisting of isolation branch 41 and switch branch 42 is required. The isolation branch 41 achieves electrical isolation between high and low voltage to prevent high voltage from entering and damaging the microcontroller 3, thus ensuring detection safety. The switch branch 42 converts the mains power status into a standard level signal, allowing the microcontroller 3 to identify whether the mains power is on or off.

[0037] It should be noted that the mains power is a 50Hz sinusoidal voltage waveform of alternating current. The period of one sinusoidal wave is 20ms (10ms is positive voltage and 10ms is negative voltage). If a negative voltage is detected for 20ms continuously, it proves that the user has unplugged the power supply (power off). Therefore, the microcontroller 3 can know this by detecting the switch of the switch branch 42.

[0038] Furthermore, the isolation branch 41 includes a resistor R1, a diode D12, a resistor R24, and an optocoupler IC9; one end of the resistor R1 and the light source cathode of the optocoupler IC9 are both used as the input terminal of the isolation branch 41, and the light receiver emitter of the optocoupler IC9 is used as the output terminal of the isolation branch 41.

[0039] The other end of resistor R1 is electrically connected to the anode of diode D12, the cathode of diode D12 is electrically connected to the anode of the light source of optocoupler IC9, resistor R24 ​​is connected in parallel between the anode and cathode of the light source of optocoupler IC9, and the collector of the photodetector of optocoupler IC9 is connected to the positive voltage.

[0040] In this embodiment, the isolation branch 41 preferably utilizes the characteristics of the optocoupler IC9 to achieve complete electrical isolation, while the peripheral circuit of the optocoupler IC9 is composed of resistor R1, diode D12 and resistor R24.

[0041] Furthermore, the switching branch 42 includes resistor R3, resistor R23, capacitor C14, transistor Q5, resistor R64, resistor R37 and capacitor C40; one end of resistor R23 is used as the input terminal of the switching branch 42, and one end of resistor R37 is used as the output terminal of the switching branch 42.

[0042] The other end of resistor R23 is electrically connected to the base of transistor Q5, the emitter of transistor Q5 is grounded, resistor R3 is connected in parallel between one end of resistor R23 and the emitter of transistor Q5, and capacitor C14 is connected in parallel between the other end of resistor R23 and the emitter of transistor Q5.

[0043] One end of resistor R64 is connected to the positive power supply. The other end of resistor R64 and the collector of transistor Q5 are both electrically connected to the other end of resistor R37. One end of capacitor C40 is electrically connected to one end of resistor R37, and the other end of capacitor C40 is grounded.

[0044] In this embodiment, the switch branch 42 is preferably composed of a transistor Q5 and its peripheral circuit, and a level signal is formed by the conduction or cutoff of the transistor Q5.

[0045] A power supply circuit includes the aforementioned surge protection circuit for rapid power-on after power failure; it also includes a rectifier bridge BR1; the mains power wire is first connected in series with a current limiting component 1, and then electrically connected to the input terminal of the rectifier bridge BR1.

[0046] This embodiment also proposes a preferred application circuit embodiment of an anti-surge circuit that enables rapid power-on after a power outage, such as... Figure 1 As shown, since the inrush current generated by rapid power-up after a power outage typically first appears in the motherboard's power circuit, the target circuit is preferably the power circuit. Connecting a current-limiting component 1 of the surge protection circuit before the rectifier bridge BR1 in the power circuit directly suppresses the inrush current on the AC side, protecting vulnerable components such as the rectifier bridge BR1, the subsequent electrolytic capacitor E1, and the fast recovery diode D630. Compared to traditional post-rectifier protection schemes, this provides more comprehensive protection and a more timely response.

[0047] Furthermore, it also includes a fuse FUSE1. The mains live wire is connected in series with the fuse FUSE1 and the current limiting element 1, and then electrically connected to the input terminal of the rectifier bridge BR1.

[0048] In this embodiment, the power supply circuit preferably includes a fuse FUSE1 in conjunction with a current limiting component 1 (PTC thermistor PTC1) to form a graded protection. The PTC thermistor PTC1 provides self-recovering current limiting protection for ordinary inrush currents, reducing the inrush current to below the fusing value of the fuse FUSE1. The fuse FUSE1, on the other hand, serves as a final overcurrent protection barrier or a backup protection for the PTC thermistor PTC1 in the event of severe inrush currents (where the current value is extremely high and the maximum current limiting of the PTC thermistor PTC1 still exceeds the fusing value). The two work together to avoid frequent replacement of the fuse FUSE1 due to overcurrent protection and ensure safe circuit breaking under extreme faults, significantly improving the reliability of the power supply circuit.

[0049] The shock-resistant circuit for rapid power-on after power failure according to the embodiments of the present invention, as well as other components and operations of the power supply circuit, are known to those skilled in the art and will not be described in detail here.

[0050] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A circuit for protecting against a surge after a quick power-up after a power-down, characterized by: It includes a current limiting device, a switching assembly, and a microcontroller; the current limiting device, the switching assembly, and the microcontroller are electrically connected in sequence; the current limiting device is electrically connected to the target circuit, and the current limiting device is controlled to be turned on or off by the switching assembly; the microcontroller controls the switching of the switching assembly based on the acquired detection data.

2. The anti-inrush circuit according to claim 1, wherein: The current limiting device is a PTC thermistor, which is connected in series with the target circuit.

3. The anti-inrush circuit according to claim 2, wherein: The switching assembly includes a relay RY1, a diode D10, a transistor Q102, a resistor R6, and a resistor R142. The two contact pins of the relay RY1 are electrically connected to the two ends of the PTC thermistor, and the two coil pins of the relay RY1 are electrically connected to the cathode and anode of the diode D10, respectively. The cathode of the diode D10 is connected to a positive voltage, and the anode of the diode D10 is electrically connected to the collector of the transistor Q102. The emitter of the transistor Q102 is grounded, and the resistor R6 is connected in parallel between the emitter and base of the transistor Q102. The base of the transistor Q102 is connected in series with the resistor R142 and then electrically connected to the microcontroller.

4. The anti-inrush circuit according to claim 1, wherein: It also includes an AC power detection circuit; the input terminal of the AC power detection circuit is electrically connected to the AC power input terminal of the target circuit, and the output terminal of the AC power detection circuit is electrically connected to the microcontroller.

5. The anti-inrush circuit according to claim 4, wherein: The mains power detection circuit includes an isolation branch and a switch branch; the input terminal of the isolation branch is used as the input terminal of the mains power detection circuit, the output terminal of the isolation branch is electrically connected to the input terminal of the switch branch, and the output terminal of the switch branch is used as the output terminal of the mains power detection circuit.

6. The anti-inrush circuit according to claim 5, wherein: The isolation branch includes a resistor R1, a diode D12, a resistor R24, and an optocoupler IC9; one end of the resistor R1 and the light source cathode of the optocoupler IC9 are both used as the input terminal of the isolation branch, and the light receiver emitter of the optocoupler IC9 is used as the output terminal of the isolation branch. The other end of the resistor R1 is electrically connected to the anode of the diode D12, the cathode of the diode D12 is electrically connected to the anode of the light source of the optocoupler IC9, the resistor R24 ​​is connected in parallel between the anode and cathode of the light source of the optocoupler IC9, and the collector of the photodetector of the optocoupler IC9 is connected to a positive voltage.

7. The anti-inrush circuit according to claim 5, wherein: The switching branch includes resistor R3, resistor R23, capacitor C14, transistor Q5, resistor R64, resistor R37, and capacitor C40; one end of resistor R23 is used as the input terminal of the switching branch, and one end of resistor R37 is used as the output terminal of the switching branch. The other end of the resistor R23 is electrically connected to the base of the transistor Q5, the emitter of the transistor Q5 is grounded, the resistor R3 is connected in parallel between one end of the resistor R23 and the emitter of the transistor Q5, and the capacitor C14 is connected in parallel between the other end of the resistor R23 and the emitter of the transistor Q5. One end of the resistor R64 is connected to the positive power supply, and the other end of the resistor R64 and the collector of the transistor Q5 are both electrically connected to the other end of the resistor R37. One end of the capacitor C40 is electrically connected to one end of the resistor R37, and the other end of the capacitor C40 is grounded.

8. A power supply circuit, characterized by: It includes an anti-impact circuit for rapid power-on after power failure as described in any one of claims 1 to 7; it also includes a rectifier bridge BR1; the mains power line is first connected in series with the current limiting component, and then electrically connected to the input terminal of the rectifier bridge BR1.

9. A power supply circuit as claimed in claim 8, characterized in that: It also includes a fuse FUSE1, and the mains power line is connected in series with the fuse FUSE1 and the current limiting device, and then electrically connected to the input terminal of the rectifier bridge BR1.

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