Arc fault detection apparatus
The upgrade and maintenance of arc fault detection devices is achieved through infrared programming communication technology, which solves the problems of cumbersome operation, low safety, poor stability and poor compatibility in the existing technology, improves the safety and efficiency of upgrade and maintenance, and is suitable for special environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DELIXI ELECTRIC
- Filing Date
- 2025-04-25
- Publication Date
- 2026-06-09
Smart Images
Figure CN224341620U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of arc fault detection technology, and in particular to an arc fault detection device. Background Technology
[0002] An arc fault detection device (AFDD) is an intelligent protection device used to detect dangerous arc faults in electrical circuits and automatically disconnect the circuit. Currently, AFDDs are often connected to devices such as computers via physical connections, such as serial cables or USB cables, for firmware upgrades or parameter configuration to achieve AFDD upgrades and maintenance. However, this method of AFDD upgrades and maintenance has at least the following problems: 1. The physical connection between the AFDD and the computer makes operation cumbersome. 2. The insertion and removal of the physical connection can easily generate risks such as electrostatic discharge and short circuits, causing damage to the AFDD or other devices connected to it, resulting in low safety and stability during the upgrade and maintenance process. 3. In environments with special requirements for electrical connections or potential hazards, such as flammable, explosive, or humid environments, the upgrade and maintenance cannot be guaranteed to proceed normally. 4. Upgrades and maintenance can only be performed at the actual installation location of the AFDD, resulting in low efficiency and high operating costs. 5. The AFDD can only be upgraded and maintained by connecting to devices such as computers, leading to poor compatibility. In summary, these issues lead to inefficiencies and high risks in the upgrade and maintenance process of AFDD. Utility Model Content
[0003] This application provides an arc fault detection device that can be upgraded and maintained through infrared programming communication, which can solve the problems of inefficiency and high risk in the upgrade and maintenance process.
[0004] In a first aspect, this application provides an arc fault detection device, the arc fault detection device comprising: a control circuit and an infrared signal receiving circuit electrically connected to the control circuit;
[0005] The infrared signal receiving circuit is used to receive the infrared signal sent by the infrared signal transmitting circuit, convert the infrared signal into an electrical signal, and transmit the electrical signal to the control circuit.
[0006] The control circuit is used to analyze and process the electrical signal to obtain upgrade data, and perform corresponding operations based on the upgrade data to realize the upgrade and maintenance of the arc fault detection device.
[0007] The arc fault detection device provided in the first aspect can receive infrared signals sent by the infrared signal transmitting circuit through an infrared signal receiving circuit, convert the infrared signals into electrical signals, and transmit the electrical signals to the control circuit, allowing the control circuit to acquire the electrical signals. The control circuit can then analyze and process the electrical signals to obtain upgrade data and perform corresponding operations based on the upgrade data to achieve the upgrade and maintenance of the arc fault detection device. In other words, the arc fault detection device can be upgraded and maintained through infrared programming communication, thus possessing infrared programming functionality. This solves the problems of inefficiency and high risk in the upgrade and maintenance process.
[0008] In one possible design, the infrared signal receiving circuit includes: a first resistor, a first chip, and a second chip;
[0009] The first pin of the first chip is electrically connected to the first end of the first resistor, the second end of the first resistor is used to connect to the first power supply voltage, the second pin of the first chip is electrically connected to the first pin of the second chip, the third pin of the first chip is electrically connected to the second pin of the second chip, and the third and fourth pins of the second chip are both electrically connected to the control circuit.
[0010] The first chip is used to receive the infrared signal and transmit the infrared signal to the second chip;
[0011] The second chip is used to convert the infrared signal into the electrical signal.
[0012] In one possible design, the control circuit includes: a microcontroller, a second resistor, and a third resistor;
[0013] The first pin of the microcontroller is electrically connected to the third pin of the second chip, the second pin of the microcontroller is electrically connected to the fourth pin of the second chip, the third pin of the microcontroller is electrically connected to the first terminal of the second resistor, the fourth pin of the microcontroller is electrically connected to the first terminal of the third resistor, and the second terminals of the second resistor and the second terminal of the third resistor are both grounded.
[0014] The microcontroller is used to parse and verify the electrical signal according to a preset communication protocol, obtain the upgrade data, and store the upgrade data;
[0015] The microcontroller is also configured to perform the corresponding operations based on the stored upgrade data.
[0016] In one possible design, the arc fault detection device further includes: a sampling current output circuit, a power supply circuit, and a tripping circuit;
[0017] The input terminal of the sampling current output circuit is electrically connected to the live wire, the output terminal of the sampling current output circuit is electrically connected to the first input terminal of the control circuit, the input terminal of the power supply circuit is electrically connected to the neutral wire, the first output terminal of the power supply circuit is electrically connected to the second input terminal of the control circuit, the output terminal of the control circuit is electrically connected to the first terminal of the trip circuit, and the second terminal of the trip circuit is electrically connected to the external components in the arc fault detection device.
[0018] The sampling current output circuit is used to collect current from the live wire, obtain a sampling current signal, and transmit the sampling current signal to the control circuit.
[0019] The power supply circuit is used to sample voltage between the neutral wire and the live wire, obtain a sampled voltage signal, and transmit the sampled voltage signal to the control circuit.
[0020] The control circuit is further configured to generate a trip signal and transmit the trip signal to the trip circuit when it is determined that an arc signal exists in the sampled current signal based on the sampled voltage signal.
[0021] The tripping circuit is used to drive the external components to trip according to the tripping signal, so as to open the arc fault detection device.
[0022] In one possible design, the sampling current output circuit includes: a sampling circuit, a first amplifier circuit, a second amplifier circuit, a low-pass filter circuit, and a comparator circuit;
[0023] The sampling circuit is electrically connected to the input terminal of the first amplifier circuit and the live wire, respectively. The output terminal of the first amplifier circuit is electrically connected to the input terminal of the second amplifier circuit. The output terminal of the second amplifier circuit is electrically connected to the input terminal of the comparator circuit. The input terminal of the low-pass filter circuit is electrically connected between the output terminal of the first amplifier circuit and the input terminal of the second amplifier circuit. The output terminals of the comparator circuit and the low-pass filter circuit are both electrically connected to the first input terminal of the control circuit.
[0024] The sampling circuit is used to collect current from the live wire, obtain a first current signal, and transmit the first current signal to the first amplification circuit.
[0025] The first amplifier circuit is used to amplify the first current signal to obtain an amplified first current signal, and transmit the amplified first current signal to the second amplifier circuit and the low-pass filter circuit respectively.
[0026] The second amplifier circuit is used to amplify the amplified first current signal to obtain a high-frequency current signal, and to transmit the high-frequency current signal to the comparison circuit.
[0027] The comparison circuit is used to compare the magnitudes of the high-frequency current signal and the reference current signal to obtain the high-frequency signal in the sampled current signal.
[0028] The low-pass filter circuit is used to filter out high-frequency interference signals in the amplified first current signal to obtain low-frequency signals in the sampled current signal.
[0029] In one possible design, the first amplifier circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a first operational amplifier;
[0030] The first ends of the fourth resistor and the fifth resistor are both electrically connected to the sampling circuit. The second end of the fourth resistor is electrically connected to the inverting input of the first operational amplifier. The second end of the fifth resistor is electrically connected to the non-inverting input of the first operational amplifier. The output of the first operational amplifier and the first end of the sixth resistor are both electrically connected to the input of the second amplifier circuit. The second end of the sixth resistor is electrically connected between the second end of the fourth resistor and the inverting input of the first operational amplifier. The first end of the seventh resistor is used to connect to the second power supply voltage. The second ends of the seventh resistor and the first ends of the eighth resistor are both electrically connected between the second end of the fifth resistor and the non-inverting input of the first operational amplifier. The second end of the eighth resistor is grounded.
[0031] Alternatively, the second amplifier circuit may include: a first capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, and a second operational amplifier.
[0032] The first plate of the first capacitor is electrically connected to the output terminal of the first amplifier circuit and the first terminal of the ninth resistor, respectively. The second plate of the first capacitor is electrically connected to the non-inverting input terminal of the second operational amplifier. The first terminal of the tenth resistor is electrically connected between the second plate of the first capacitor and the non-inverting input terminal of the second operational amplifier. The first terminals of the eleventh resistor and the twelfth resistor are both electrically connected to the negative-inverting input terminal of the second operational amplifier. The second terminals of the tenth resistor and the eleventh resistor are both grounded. The second terminals of the ninth resistor, the twelfth resistor, and the output terminal of the second operational amplifier are all electrically connected to the input terminal of the comparator circuit.
[0033] Alternatively, the comparator circuit may include: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a comparator;
[0034] The first end of the thirteenth resistor is electrically connected to the output terminal of the second amplifier circuit, the second end of the thirteenth resistor is electrically connected to the non-inverting input terminal of the comparator, the first end of the fourteenth resistor is electrically connected between the second end of the thirteenth resistor and the non-inverting input terminal of the comparator, the first ends of the fifteenth resistor and the sixteenth resistor are both electrically connected to the negative input terminal of the comparator, the second end of the fourteenth resistor and the output terminal of the comparator are both electrically connected to the first input terminal of the control circuit, the second end of the fifteenth resistor is grounded, and the second end of the sixteenth resistor is used to connect to the second power supply voltage.
[0035] In one possible design, the sampling circuit includes: a first sampling resistor and a second sampling resistor; the first sampling resistor and the second sampling resistor are connected in parallel, and the first sampling resistor and the second sampling resistor connected in parallel are electrically connected to the live wire;
[0036] Alternatively, the low-pass filter circuit may include a second capacitor and a seventeenth resistor.
[0037] The first end of the seventeenth resistor is electrically connected between the output end of the first amplifier circuit and the input end of the second amplifier circuit. The second end of the seventeenth resistor and the first plate of the second capacitor are both electrically connected to the first input end of the control circuit. The second plate of the second capacitor is grounded.
[0038] In one possible design, the power supply circuit includes: an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, and a twenty-fifth resistor;
[0039] The first end of the eighteenth resistor is electrically connected to the neutral wire. The second end of the eighteenth resistor is electrically connected to the first end of the twenty-first resistor through the nineteenth and twentyth resistors. The second end of the twenty-first resistor is electrically connected to the first end of the twenty-second resistor. The second end of the twenty-second resistor is electrically connected to the second input terminal of the control circuit. The first end of the twenty-third resistor is used to connect to the first power supply voltage. The second ends of the twenty-third resistor and the first ends of the twenty-fourth resistor are both electrically connected to the first end of the twenty-fifth resistor. The second end of the twenty-fifth resistor is electrically connected between the second end of the twenty-first resistor and the first end of the twenty-second resistor. The second end of the twenty-fourth resistor is grounded.
[0040] In one possible design, the power supply circuit further includes: a first voltage divider circuit, a first diode, and a linear regulator;
[0041] The first terminal of the first voltage divider circuit is electrically connected to the neutral line, the second terminal of the first voltage divider circuit is electrically connected to the positive terminal of the first diode, the negative terminal of the first diode is electrically connected to the input terminal of the linear regulator, and the output terminal of the linear regulator is used to output the power supply voltage.
[0042] The first voltage divider circuit is used to collect voltage from the neutral line to obtain a first voltage signal, and then rectify it through the first diode to obtain a rectified first voltage signal.
[0043] The linear regulator is used to obtain the rectified first voltage signal from the first diode and step down the rectified first voltage signal to obtain the power supply voltage, which includes a first power supply voltage and a second power supply voltage.
[0044] In one possible design, the tripping circuit includes: a transistor, a second diode, a twenty-sixth resistor, a twenty-seventh resistor, and a twenty-eighth resistor;
[0045] The base of the transistor is electrically connected to the first end of the 26th resistor, the second end of the 26th resistor is electrically connected to the output end of the control circuit, the emitter of the transistor is electrically connected to the first end of the 27th resistor, the second end of the 27th resistor is used to connect to the first power supply voltage, the collector of the transistor is electrically connected to the anode of the second diode and the first end of the 28th resistor, the second end of the 28th resistor is grounded, and the cathode of the second diode is electrically connected to the external component.
[0046] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description
[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0048] Figure 1This is a schematic diagram of the structure of an arc fault detection device provided in an embodiment of this application;
[0049] Figure 2 for Figure 1 A schematic diagram of the infrared signal receiving circuit in the diagram;
[0050] Figure 3 for Figure 1 A schematic diagram of the control circuit in the diagram;
[0051] Figure 4 for Figure 1 A schematic diagram of the sampling current output circuit in the diagram;
[0052] Figure 5 for Figure 1 A schematic diagram of the power supply circuit and tripping circuit in the diagram.
[0053] Explanation of reference numerals in the attached figures:
[0054] 100. Arc fault detection device; 110. Control circuit; 120. Infrared signal receiving circuit; 130. Sampling current output circuit; 131. Sampling circuit; 132. First amplifier circuit; 133. Second amplifier circuit; 134. Low-pass filter circuit; 135. Comparison circuit; 140. Tripping circuit; 150. Power supply circuit; 151. First voltage divider circuit. Detailed Implementation
[0055] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0056] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0057] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.
[0058] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of an arc fault detection device provided in an embodiment of this application. Figure 1 As shown, the arc fault detection device 100 may include: a control circuit 110 and an infrared signal receiving circuit 120 electrically connected to the control circuit 110.
[0059] The infrared signal receiving circuit 120 can receive the infrared signal sent by the infrared signal transmitting circuit, convert the infrared signal into an electrical signal, and transmit the electrical signal to the control circuit 110 so that the control circuit 110 can acquire the electrical signal.
[0060] The infrared signal transmitting circuit can be, for example, an infrared remote control or a dedicated infrared signal transmitter. The infrared signal transmitting circuit can send infrared signals according to a preset communication protocol. The infrared signals include upgrade commands and upgrade data. The upgrade data can be used for firmware upgrades or configuration parameter upgrades; this application does not specifically limit this.
[0061] Before a user upgrades or maintains the arc fault detection device 100, upgrade data, such as data for firmware and configuration parameter upgrades, needs to be set. This upgrade data is encoded and transmitted as an infrared signal via an infrared signal transmitting circuit. Typically, the upgrade data is divided into multiple data packets. Each data packet includes a certain number of bytes and carries checksum information such as CRC checksum to ensure the accuracy of the upgrade data.
[0062] The communication protocol specifies the signal modulation method, data transmission rate, and data packet structure. The signal modulation methods include Pulse Position Modulation (PPM) and Pulse Width Modulation (PWM). For example, when using PPM, different pulse positions represent different data bits.
[0063] Thus, the control circuit 110 can analyze and process the electrical signal to obtain upgrade data, and perform corresponding operations based on the upgrade data to realize the upgrade and maintenance of the arc fault detection device 100. In other words, the arc fault detection device 100 is upgraded and maintained via infrared programming communication, thus possessing infrared programming functionality. Furthermore, the arc fault detection device 100 requires no physical connection; upgrades and maintenance can be performed within a certain distance using a device with infrared emission capabilities. This is convenient and quick, especially suitable for installations inaccessible to some locations, effectively reducing maintenance time and workload. Simultaneously, it avoids the risks of electrostatic discharge and short circuits caused by plugging and unplugging physical connections, reducing damage to the arc fault detection device 100 or other devices connected to it due to improper operation, and improving the safety and stability of the upgrade and maintenance process. Furthermore, in environments with special requirements for electrical connections or potential hazards, infrared programming communication, which requires no electrical contact, better meets safety requirements, ensuring the normal upgrading and maintenance of the arc fault detection device 100 under special conditions. Additionally, through corresponding infrared communication equipment and software systems, the arc fault detection device 100 can be remotely controlled and managed to a certain extent, allowing users to perform batch upgrades and maintenance on multiple devices within a certain range without having to visit the actual installation location, improving management efficiency and reducing operating costs. Moreover, through infrared programming communication, the arc fault detection device 100 can interface with various common devices such as mobile phones and tablets, enhancing compatibility between the device and different devices and facilitating operation and management using various common devices. In summary, this solves the problems of inefficiency and high risk in the upgrade and maintenance process.
[0064] Among them, devices with infrared emission capabilities include infrared programmers, mobile phones or computers with infrared functionality, etc.
[0065] The arc fault detection device provided in this application receives infrared signals transmitted by an infrared signal transmitting circuit via an infrared signal receiving circuit, converts the infrared signals into electrical signals, and transmits the electrical signals to a control circuit, allowing the control circuit to acquire the electrical signals. The control circuit can then analyze and process the electrical signals to obtain upgrade data and perform corresponding operations based on the upgrade data to achieve upgrades and maintenance of the arc fault detection device. In other words, the arc fault detection device performs upgrades and maintenance via infrared programming communication, thus possessing infrared programming functionality. This solves the problems of inefficiency and high risk in the upgrade and maintenance process.
[0066] Based on the description of the above embodiments, an exemplary possible implementation of the infrared signal receiving circuit 120 is provided. (Refer to...) Figure 2 , Figure 2 for Figure 1 A schematic diagram of the mid-infrared signal receiving circuit. Figure 2 As shown, the infrared signal receiving circuit 120 may include: a first resistor R1, a first chip U2, and a second chip U3.
[0067] The first pin of the first chip U2 is electrically connected to the first end of the first resistor R1. The second end of the first resistor R1 is used to connect to the first power supply voltage DVCC. The second pin of the first chip U2 is electrically connected to the first pin of the second chip U3. The third pin of the first chip U2 is electrically connected to the second pin of the second chip U3. The third and fourth pins of the second chip U3 are both electrically connected to the control circuit 110.
[0068] The first chip U2 is used to receive infrared signals and transmit them to the second chip U3.
[0069] The first chip U2 senses changes in the intensity of infrared light through its internally integrated infrared receiver. When it receives an infrared signal, its internal phototransistor generates a corresponding current change, which in turn outputs an electrical signal.
[0070] The second chip, U3, is used to convert infrared signals into electrical signals.
[0071] Figure 2 The unmarked capacitors in the diagram serve functions such as power filtering, signal conditioning, and impedance matching, ensuring that the infrared signal receiving circuit 120 can operate stably and reliably.
[0072] The first chip U2 is an infrared photoelectric sensor, such as the TFDU4300. The presence or movement of the infrared signal emitting circuit can be detected by the first chip U2 to determine whether an infrared signal is present.
[0073] The first pin of the first chip U2 is connected to the first power supply voltage DVCC through a first resistor to provide the operating voltage for the first chip U2. The first and second pins of the first chip U2 are used for data communication with other chips to send or receive detected signals. The fourth pin of the first chip U2 is an enable or sleep control pin, used to control the operating state of the first chip U2. The fifth and sixth pins of the first chip U2 are associated with different power domains or logic levels to ensure that the first chip U2 can operate under appropriate voltage and logic conditions. The seventh pin of the first chip U2 is used to provide a reference potential.
[0074] The second chip, U3, is an integrated circuit for an infrared encoder or infrared decoder. The second chip, U3, can convert serial data from a UART bitstream into an IrDA standard bitstream (i.e., encoding), and can also convert an IrDA standard bitstream into a UART bitstream (i.e., decoding).
[0075] The third and fourth pins of the second chip U3 are used to receive electrical signals (i.e., serial communication signals) from the control circuit 110 and convert them into infrared signals, or to receive infrared signals and convert them into electrical signals. The first and second pins of the control circuit 110 are the transmit interrupt pin and receive interrupt pin, respectively. When data transmission or reception is complete, an interrupt signal is generated to notify the control circuit 110 to perform corresponding processing, improving data transmission efficiency. The seventh pin of the second chip U3 is used to obtain the operating voltage. The eighth pin of the second chip U3 is used to provide a reference potential.
[0076] Based on the description of the above embodiments, an exemplary possible implementation of the control circuit 110 is provided. (Refer to...) Figure 3 , Figure 3 for Figure 1 A schematic diagram of the control circuit in the diagram. (See attached diagram.) Figure 3 As shown, the control circuit 110 may include: a microcontroller U1, a second resistor R2, and a third resistor R3.
[0077] The first pin of microcontroller U1 is electrically connected to the third pin of the second chip U3, the second pin of microcontroller U1 is electrically connected to the fourth pin of the second chip U3, the third pin of microcontroller U1 is electrically connected to the first end of the second resistor R2, the fourth pin of microcontroller U1 is electrically connected to the first end of the third resistor R3, and the second ends of the second resistor R2 and the third resistor R3 are both grounded.
[0078] The microcontroller U1 is used to parse and verify electrical signals according to a preset communication protocol, obtain upgrade data, and store the upgrade data.
[0079] The microcontroller U1 is also used to perform corresponding operations based on the stored upgrade data.
[0080] The microcontroller U1 can parse electrical signals according to a pre-defined communication protocol to identify the start and end markers of data packets, extract upgrade data, and perform verification. If the verification passes, the upgrade data is accurate; if the verification fails, the microcontroller U1 will request a retransmission of the upgrade data. After parsing and verification, the microcontroller U1 can store the upgrade data in the corresponding location within its internal memory, such as Flash memory. If the upgrade data is for firmware upgrades, the microcontroller U1 writes the upgrade data to a specific area of the Flash memory; if the upgrade data is for configuration parameter upgrades, the microcontroller U1 stores the upgrade data in the corresponding storage unit. After storing the upgrade data, the microcontroller U1 performs corresponding operations based on the upgrade data. For example, if the upgrade data is for firmware upgrades, the microcontroller U1 can perform operations such as restarting the system to load the new firmware. If the upgrade data is for configuration parameter upgrades, the microcontroller U1 can perform operations such as adjusting the operating mode according to the configuration parameters.
[0081] The model of the microcontroller U1 is, for example, STM32L431CB16.
[0082] The pins of microcontroller U1 electrically connected to the first power supply voltage DVCC provide operating voltage for the digital circuitry within U1. The pins of microcontroller U1 electrically connected to the second power supply voltage AVCC provide operating voltage for the analog circuitry within U1, such as the analog-to-digital converter (ADC). Pin 9 of microcontroller U1 is the reset pin, active when a low level is applied. When the potential of pin 9 of microcontroller U1 is pulled low, microcontroller U1 enters a reset state, initializing its built-in registers and circuits, restoring it to its default initial state. Pin 5 of microcontroller U1 is the analog signal input pin, used to connect to an external analog signal source to convert the analog signal into a digital signal via the ADC within U1. Pin 5 of microcontroller U1 is also used to receive the sampled voltage signal ADC_VIN. Pin 6 of controller U1 is used to receive the low-frequency signal ADC_LF from the sampled current signal for preprocessing the low-frequency signal ADC_LF. Pins 1 and 2 of controller U1 are used to receive and transmit data, respectively, enabling serial communication with other devices. Pins 10 and 11 of controller U1 are interfaces for serial line debugging (SWD). Pin 11 of controller U1 is a data input / output pin, and pin 10 is a clock pin. Pin 7 of controller U1 outputs a trip signal DIN1 to control the opening and closing of the arc fault detection device 100, thereby achieving circuit protection. Pin 8 of controller U1 is used to connect to the indicator circuit 160 to indicate information such as the operating status of the microcontroller U1. Pin 12 of controller U1 is used to receive the high-frequency signal COMP1 from the sampled current signal.
[0083] Among them, the first and second pins of the controller U1 are the communication terminals of the control circuit 110, the sixth and twelfth pins of the controller U1 are the first input terminals of the control circuit 110, the fifth pin of the microcontroller U1 is the second input terminal of the control circuit 110, and the seventh pin of the controller U1 is the output terminal of the control circuit 110.
[0084] Based on the description of the above embodiments, an exemplary possible implementation of the arc fault detection device 100 is provided. For example... Figure 1 As shown, the arc fault detection device 100 may further include: a sampling current output circuit 130, a power supply circuit 150, and a tripping circuit 140.
[0085] The input terminal of the sampling current output circuit 130 is electrically connected to the live wire L, the output terminal of the sampling current output circuit 130 is electrically connected to the first input terminal of the control circuit 110, the input terminal of the power supply circuit 150 is electrically connected to the neutral wire N, the first output terminal of the power supply circuit 150 is electrically connected to the second input terminal of the control circuit 110, the output terminal of the control circuit 110 is electrically connected to the first terminal of the trip circuit 140, and the second terminal of the trip circuit 140 is electrically connected to the external component TRIP in the arc fault detection device.
[0086] Figure 1 In the diagram, both L-IN and L-OUT are live wires (L).
[0087] The sampling current output circuit 130 is used to collect current from the live wire L, obtain the sampling current signal, and transmit the sampling current signal to the control circuit 110.
[0088] The power supply circuit 150 is used to sample the voltage between the neutral line N and the live line L, obtain the sampled voltage signal ADC_VIN, and transmit the sampled voltage signal ADC_VIN to the control circuit 110.
[0089] The control circuit 110 is also used to generate a trip signal DIN1 based on the sampled voltage signal ADC_VIN when it is determined that there is an arc signal in the sampled current signal, and to transmit the trip signal DIN1 to the trip circuit 140.
[0090] The trip circuit 140 is used to drive the external component TRIP to trip according to the trip signal DIN1, so as to open the arc fault detection device 100.
[0091] In some examples, the arc fault detection device 100 may also include an indicator circuit 160.
[0092] The indicator circuit 160 is electrically connected to the control circuit 110.
[0093] Indicator circuit 160 is used to indicate the operating status of control circuit 110, thereby indicating the operating status of arc fault detection device 100.
[0094] Based on the description of the above embodiments, an exemplary possible implementation of the sampling current output circuit 130 is provided. (Refer to...) Figure 4 , Figure 4 for Figure 1 A schematic diagram of the sampling current output circuit is shown. Figure 4 As shown, the sampling current output circuit 130 may include: a sampling circuit 131, a first amplifier circuit 132, a second amplifier circuit 133, a low-pass filter circuit 134, and a comparator circuit 135.
[0095] The sampling circuit 131 is electrically connected to the input terminal of the first amplifier circuit 132 and the live wire L, respectively. The output terminal of the first amplifier circuit 132 is electrically connected to the input terminal of the second amplifier circuit 133. The output terminal of the second amplifier circuit 133 is electrically connected to the input terminal of the comparator circuit 135. The input terminal of the low-pass filter circuit 134 is electrically connected between the output terminal of the first amplifier circuit 132 and the input terminal of the second amplifier circuit 133. The output terminals of the comparator circuit 135 and the low-pass filter circuit 134 are both electrically connected to the first input terminal of the control circuit 110.
[0096] The sampling circuit 131 is used to collect current from the live wire L, obtain a first current signal, and transmit the first current signal to the first amplifier circuit 132.
[0097] The first amplifier circuit 132 is used to amplify the first current signal to obtain the amplified first current signal, and transmit the amplified first current signal to the second amplifier circuit 133 and the low-pass filter circuit 134 respectively.
[0098] The second amplifier circuit 133 is used to amplify the amplified first current signal to obtain a high-frequency current signal ADC_HF, and transmit the high-frequency current signal ADC_HF to the comparator circuit 135.
[0099] Comparator circuit 135 is used to compare the magnitudes of the high-frequency current signal ADC_HF and the reference current signal to obtain the high-frequency signal COMP1 in the sampled current signal.
[0100] Among them, the high-frequency signal COMP1 is a pulse signal.
[0101] The low-pass filter circuit 134 is used to filter out high-frequency interference signals in the amplified first current signal to obtain the low-frequency signal ADC_LF in the sampled current signal.
[0102] In some examples, the sampling current output circuit 130 may also include a third capacitor C3 and a diode group DC4.
[0103] The third capacitor C3 and the diode group DC4 are both connected in parallel with the sampling circuit 131.
[0104] The DC4 diode group consists of small-signal switching diodes used to prevent reverse current from damaging other components in the circuit. For example, a reverse electromotive force is generated when the switching transistor is turned off; the DC4 diode group can clamp this force to protect other components. The DC4 diode group may be model BAV99.
[0105] The third capacitor, C3, is used to reduce the impact of power supply noise on the circuit.
[0106] Based on the description of the above embodiments, an exemplary possible implementation of the first amplifier circuit 132 is provided. For example... Figure 4 As shown, the first amplifier circuit 132 may include: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a first operational amplifier UA1.
[0107] The first end of the fourth resistor R4 and the first end of the fifth resistor R5 are both electrically connected to the sampling circuit 131. The second end of the fourth resistor R4 is electrically connected to the inverting input of the first operational amplifier UA1. The second end of the fifth resistor R5 is electrically connected to the non-inverting input of the first operational amplifier UA1. The output of the first operational amplifier UA1 and the first end of the sixth resistor R6 are both electrically connected to the input of the second amplifier circuit 133. The second end of the sixth resistor R6 is electrically connected between the second end of the fourth resistor R4 and the inverting input of the first operational amplifier UA1. The first end of the seventh resistor R7 is used to connect to the second power supply voltage AVCC. The second end of the seventh resistor R7 and the first end of the eighth resistor R8 are both electrically connected between the second end of the fifth resistor R5 and the non-inverting input of the first operational amplifier UA1. The second end of the eighth resistor R8 is grounded.
[0108] In this circuit, the fourth resistor R4 and the fifth resistor R5 are used for current limiting to determine the amplitude of the first current signal input to the first operational amplifier UA1. The sixth resistor R6 is used to determine the strength of the feedback. The seventh resistor R7 and the eighth resistor R8 can form a bias circuit. The seventh resistor R7 and the eighth resistor R8 divide the second power supply voltage AVCC to provide a suitable DC bias voltage for the first operational amplifier UA1.
[0109] In some instances, the first amplifier circuit 132 may also include a fourth capacitor C4 and a seventh capacitor C7.
[0110] The seventh capacitor C7 is connected in parallel with the sixth resistor R6, and the fourth capacitor C4 is connected in parallel with the eighth resistor R8.
[0111] The seventh capacitor, C7, is used to filter out high-frequency noise, prevent self-oscillation in the circuit, and ensure the stable operation of the first operational amplifier, UA1. The fourth capacitor, C4, is used to filter out high-frequency noise in the bias circuit, making the DC bias voltage more stable.
[0112] Based on the description of the above embodiments, an exemplary possible implementation of the second amplifier circuit 133 is provided. Figure 4 As shown, the second amplifier circuit 133 may include: a first capacitor C1, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a second operational amplifier UA2.
[0113] The first plate of the first capacitor C1 is electrically connected to the output terminal of the first amplifier circuit 132 and the first terminal of the ninth resistor R9, respectively. The second plate of the first capacitor C1 is electrically connected to the non-inverting input terminal of the second operational amplifier UA2. The first terminal of the tenth resistor R10 is electrically connected between the second plate of the first capacitor C1 and the non-inverting input terminal of the second operational amplifier UA2. The first terminals of the eleventh resistor R11 and the twelfth resistor R12 are both electrically connected to the negative-inverting input terminal of the second operational amplifier UA2. The second terminals of the tenth resistor R10 and the eleventh resistor R11 are both grounded. The second terminals of the ninth resistor R9, the twelfth resistor R12, and the output terminal of the second operational amplifier UA2 are all electrically connected to the input terminal of the comparator circuit 135.
[0114] Among them, the ninth resistor R9 is used to adjust the amplitude of the amplified first current signal. The eleventh resistor R11 and the twelfth resistor R12 are used to adjust the characteristics of the amplified first current signal.
[0115] In some examples, the second amplifier circuit 133 may also include a fifth capacitor C5.
[0116] Among them, the fifth capacitor C5 can play the role of signal coupling, allowing AC signals to pass through while isolating DC signals.
[0117] Based on the description of the above embodiments, an exemplary possible implementation of the comparison circuit 135 is provided. Figure 4 As shown, the comparator circuit 135 may include: a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a comparator UA3.
[0118] The first end of the thirteenth resistor R13 is electrically connected to the output of the second amplifier circuit 133. The second end of the thirteenth resistor R13 is electrically connected to the non-inverting input of comparator UA3. The first end of the fourteenth resistor R14 is electrically connected between the second end of the thirteenth resistor R13 and the non-inverting input of comparator UA3. The first ends of the fifteenth resistor R15 and the sixteenth resistor R16 are both electrically connected to the negative input of comparator UA3. The second end of the fourteenth resistor R14 and the output of comparator UA3 are both electrically connected to the first input of control circuit 110. The second end of the fifteenth resistor R15 is grounded. The second end of the sixteenth resistor R16 is used to connect to the second power supply voltage AVCC.
[0119] In some examples, the comparator circuit 135 may also include: a twenty-ninth resistor R29 and a sixth capacitor C6.
[0120] The first end of the twenty-ninth resistor R29 is electrically connected to the output of comparator UA3. The second end of the twenty-ninth resistor R29 is electrically connected to the first input of control circuit 110 and the first plate of the sixth capacitor C6. The second plate of the sixth capacitor C6 is grounded.
[0121] Among them, the twenty-ninth resistor R29 and the sixth capacitor C6 can filter the high-frequency signal COMP1 and improve the stability of the high-frequency signal COMP1.
[0122] Based on the description of the above embodiments, an exemplary possible implementation of the sampling circuit 131 is provided. Figure 4 As shown, the sampling circuit 131 may include: a first sampling resistor Rs1 and a second sampling resistor Rs2.
[0123] The first sampling resistor Rs1 and the second sampling resistor Rs2 are connected in parallel, and the first sampling resistor Rs1 and the second sampling resistor Rs2 after being connected in parallel are electrically connected to the live wire L.
[0124] The first sampling resistor Rs1 and the second sampling resistor Rs2 are, for example, constantan wire resistors. Current flows in from L-IN of the live wire L, passes through the first sampling resistor Rs1 and the second sampling resistor Rs2, and then flows out from L-OUT of the live wire L to achieve current acquisition.
[0125] Based on the description of the above embodiments, an exemplary possible implementation of the low-pass filter circuit 134 is provided. Figure 4 As shown, the low-pass filter circuit 134 may include: a second capacitor C2 and a seventeenth resistor R17.
[0126] The first end of the seventeenth resistor R17 is electrically connected between the output end of the first amplifier circuit 132 and the input end of the second amplifier circuit 133. The second end of the seventeenth resistor R17 and the first plate of the second capacitor C2 are both electrically connected to the first input end of the control circuit 110. The second plate of the second capacitor C2 is grounded.
[0127] For example, the impact of high-frequency noise on the sampling accuracy of the analog-to-digital converter (ADC) can be reduced by using the second capacitor C2 and the seventeenth resistor R17 before the analog signal is digitized.
[0128] Based on the description of the above embodiments, an exemplary possible implementation of the power supply circuit 150 is provided. (Refer to...) Figure 5 , Figure 5 for Figure 1 A schematic diagram of the power supply circuit and tripping circuit. (See attached diagram.) Figure 5As shown, the power supply circuit 150 may include: the eighteenth resistor R18, the nineteenth resistor R19, the twentieth resistor R20, the twenty-first resistor R21, the twenty-second resistor R22, the twenty-third resistor R23, the twenty-fourth resistor R24, and the twenty-fifth resistor R25.
[0129] The first end of the eighteenth resistor R18 is electrically connected to the neutral line N. The second end of the eighteenth resistor R18 is electrically connected to the first end of the twenty-first resistor R21 through the nineteenth resistor R19 and the twentieth resistor R20. The second end of the twenty-first resistor R21 is electrically connected to the first end of the twenty-second resistor R22. The second end of the twenty-second resistor R22 is electrically connected to the second input terminal of the control circuit 110. The first end of the twenty-third resistor R23 is used to connect to the first power supply voltage DVCC. The second end of the twenty-third resistor R23 and the first end of the twenty-fourth resistor R24 are both electrically connected to the first end of the twenty-fifth resistor R25. The second end of the twenty-fifth resistor R25 is electrically connected between the second end of the twenty-first resistor R21 and the first end of the twenty-second resistor R22. The second end of the twenty-fourth resistor R24 is grounded.
[0130] In some examples, the power supply circuit 150 may also include a third diode D3 and an eighth capacitor C8.
[0131] The negative terminal of the third diode D3 is electrically connected to the neutral line N, and the positive terminal of the third diode D3 is electrically connected to the first end of the eighteenth resistor R18. The first plate of the eighth capacitor C8 is electrically connected between the second end of the twenty-second resistor R22 and the second input terminal of the control circuit 110. The second plate of the eighth capacitor C8 is grounded.
[0132] The third diode, D3, acts as a clamp to prevent reverse voltage from damaging other components in the power supply circuit 150.
[0133] Based on the description of the above embodiments, another possible implementation of the power supply circuit 150 is exemplarily described. For example... Figure 5 As shown, the power supply circuit 150 may further include: a first voltage divider circuit 151, a first diode D1, and a linear regulator UC1.
[0134] The first terminal of the first voltage divider circuit 151 is electrically connected to the neutral line N, the second terminal of the first voltage divider circuit 151 is electrically connected to the positive terminal of the first diode D1, the negative terminal of the first diode D1 is electrically connected to the input terminal of the linear regulator UC1, and the output terminal of the linear regulator UC1 is used to output the power supply voltage.
[0135] The first voltage divider circuit 151 is used to collect voltage from the neutral line N to obtain a first voltage signal, and then rectify it through the first diode D1 to obtain a rectified first voltage signal.
[0136] The linear regulator UC1 is used to obtain the rectified first voltage signal from the first diode D1 and step down the rectified first voltage signal to obtain the power supply voltage, which includes: the first power supply voltage DVCC and the second power supply voltage AVCC.
[0137] Among them, the linear regulator UC1 can step down the rectified first voltage signal to stabilize the power supply voltage at, for example, 3.3V, so as to make the power supply voltage more stable.
[0138] In some examples, the power supply circuit 150 may also include: a thirty-third resistor R33, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a fourteenth capacitor C14, a fifteenth capacitor C15, a transient voltage suppressor diode TVS, a fourth diode D4, and an inductor CL1.
[0139] The first terminal of the thirty-third resistor R33 is electrically connected to the neutral line N. The second terminal of the thirty-third resistor R33 is electrically connected to the first terminal of the first voltage divider circuit 151. The first plates of the ninth capacitor C9, the tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12, and the negative terminal of the transient voltage suppressor diode TVS are all electrically connected between the negative terminal of the first diode D1 and the input terminal of the linear regulator UC1. The negative terminal of the fourth diode D4 is electrically connected between the second terminal of the first voltage divider circuit 151 and the positive terminal of the first diode D1. The first plate of the fourteenth capacitor C14 and the fifteenth capacitor C12 are electrically connected to the neutral line N. The first plate of capacitor 15 and the first terminal of inductor CL1 are both electrically connected to the output terminal of linear regulator UC1. The second terminal of inductor CL1 is used to output the second power supply voltage AVCC. The first plates of the fourteenth capacitor C14 and the fifteenth capacitor C15 are also used to output the first power supply voltage DVCC. The positive terminal of the fourth diode D4, the second plate of the ninth capacitor C9, the second plate of the tenth capacitor C10, the second plate of the eleventh capacitor C11, the second plate of the twelfth capacitor C12, the second plate of the fourteenth capacitor C14, the second plate of the fifteenth capacitor C15, and the positive terminal of transient voltage suppression diode TVS are all grounded.
[0140] Among them, capacitors C9 (ninth), C10 (tenth), C11 (eleventh), C12 (twelfth), C14 (fourteenth), and C15 (fifteenth) are all used for filtering to remove high-frequency noise from the power supply voltage, making the power supply voltage more stable. Inductor CL1 is used for energy storage and suppressing current surges. Inductor CL1, together with capacitors C14 (fourteenth) and C15 (fifteenth), can improve the stability of the power supply voltage.
[0141] The fourth diode, D4, is a Zener diode used to stabilize the voltage. When the voltage of the first voltage signal exceeds the regulated value, the fourth diode D4 conducts, stabilizing the voltage of the first voltage signal within a certain range and protecting the subsequent circuits from excessive voltage. The transient voltage suppressor diode (TVS) is used to protect the power supply circuit 150 from transient high voltage surges such as lightning strikes and electrostatic discharges. When a transient high voltage occurs in the power supply circuit 150, the transient voltage suppressor diode TVS quickly conducts to discharge the high voltage, thereby protecting other components in the power supply circuit 150.
[0142] In some examples, the first voltage divider circuit 151 may include: a thirtieth resistor R30, a thirty-first resistor R21, a thirty-second resistor R32, and a thirteenth capacitor C13.
[0143] The first end of the thirtieth resistor R30 is electrically connected to the neutral line N. The first end of the thirtieth resistor R30 is electrically connected to the positive terminal of the first diode D1 through the thirty-first resistor R21 and the thirty-second resistor R32. The first plate of the thirteenth capacitor C13 is electrically connected to the first end of the thirtieth resistor R30. The second plate of the thirteenth capacitor C13 is electrically connected to the positive terminal of the first diode D1.
[0144] Based on the description of the above embodiments, an exemplary possible implementation of the tripping circuit 140 is provided. Figure 5 As shown, the trip circuit 140 may include: transistor Q1, second diode D2, twenty-sixth resistor R26, twenty-seventh resistor R27, and twenty-eighth resistor R28.
[0145] The base of transistor Q1 is electrically connected to the first terminal of the twenty-sixth resistor R26, the second terminal of the twenty-sixth resistor R26 is electrically connected to the output terminal of the control circuit 110, the emitter of transistor Q1 is electrically connected to the first terminal of the twenty-seventh resistor R27, the second terminal of the twenty-seventh resistor R27 is used to connect to the first power supply voltage DVCC, the collector of transistor Q1 is electrically connected to the anode of the second diode D2 and the first terminal of the twenty-eighth resistor R28, the second terminal of the twenty-eighth resistor R28 is grounded, and the cathode of the second diode D2 is electrically connected to the external component TRIP.
[0146] In some examples, the trip circuit 140 may also include: a fifth diode D5, a thirty-fourth resistor R34, and a sixteenth capacitor C16.
[0147] The cathode of the fifth diode D5 is electrically connected to the external component TRIP, the anode of the fifth diode D5 is electrically connected to the cathode of the second diode D2, the first terminal of the thirty-fourth resistor R34 is electrically connected between the emitter of transistor Q1 and the first terminal of the twenty-seventh resistor R27, the second terminal of the thirty-fourth resistor R34 is electrically connected between the base of transistor Q1 and the first terminal of the twenty-sixth resistor R26, the first plate of the sixteenth capacitor C16 is electrically connected to the collector of transistor Q1, and the second plate of the sixteenth capacitor C16 is grounded.
[0148] In this circuit, the fifth diode D5 is used in conjunction with the thirty-fourth resistor R34 to set the bias voltage of transistor Q1. The sixteenth capacitor C16 is used to filter out high-frequency signal interference. The fifth diode D5 acts as a clamp to prevent reverse voltage from damaging other components in the trip circuit 140.
[0149] in, Figure 4 and Figure 5 TP1, TP2, TP3, TP4, TP5 and TP6 are all detection points.
[0150] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An arc fault detection device, characterized in that, The arc fault detection device includes: a control circuit and an infrared signal receiving circuit electrically connected to the control circuit; The infrared signal receiving circuit is used to receive the infrared signal sent by the infrared signal transmitting circuit, convert the infrared signal into an electrical signal, and transmit the electrical signal to the control circuit. The control circuit is used to analyze and process the electrical signal to obtain upgrade data, and perform corresponding operations based on the upgrade data to realize the upgrade and maintenance of the arc fault detection device.
2. The arc fault detection device according to claim 1, characterized in that, The infrared signal receiving circuit includes: a first resistor, a first chip, and a second chip; The first pin of the first chip is electrically connected to the first end of the first resistor, the second end of the first resistor is used to connect to the first power supply voltage, the second pin of the first chip is electrically connected to the first pin of the second chip, the third pin of the first chip is electrically connected to the second pin of the second chip, and the third and fourth pins of the second chip are both electrically connected to the control circuit. The first chip is used to receive the infrared signal and transmit the infrared signal to the second chip; The second chip is used to convert the infrared signal into the electrical signal.
3. The arc fault detection device according to claim 2, characterized in that, The control circuit includes: a microcontroller, a second resistor, and a third resistor; The first pin of the microcontroller is electrically connected to the third pin of the second chip, the second pin of the microcontroller is electrically connected to the fourth pin of the second chip, the third pin of the microcontroller is electrically connected to the first terminal of the second resistor, the fourth pin of the microcontroller is electrically connected to the first terminal of the third resistor, and the second terminals of the second resistor and the second terminal of the third resistor are both grounded. The microcontroller is used to parse and verify the electrical signal according to a preset communication protocol, obtain the upgrade data, and store the upgrade data; The microcontroller is also configured to perform the corresponding operations based on the stored upgrade data.
4. The arc fault detection device according to claim 3, characterized in that, The arc fault detection device further includes: a sampling current output circuit, a power supply circuit, and a tripping circuit; The input terminal of the sampling current output circuit is electrically connected to the live wire, the output terminal of the sampling current output circuit is electrically connected to the first input terminal of the control circuit, the input terminal of the power supply circuit is electrically connected to the neutral wire, the first output terminal of the power supply circuit is electrically connected to the second input terminal of the control circuit, the output terminal of the control circuit is electrically connected to the first terminal of the trip circuit, and the second terminal of the trip circuit is electrically connected to the external components in the arc fault detection device. The sampling current output circuit is used to collect current from the live wire, obtain a sampling current signal, and transmit the sampling current signal to the control circuit. The power supply circuit is used to sample voltage between the neutral wire and the live wire, obtain a sampled voltage signal, and transmit the sampled voltage signal to the control circuit. The control circuit is further configured to generate a trip signal and transmit the trip signal to the trip circuit when it is determined that an arc signal exists in the sampled current signal based on the sampled voltage signal. The tripping circuit is used to drive the external components to trip according to the tripping signal, so as to open the arc fault detection device.
5. The arc fault detection device according to claim 4, characterized in that, The sampling current output circuit includes: a sampling circuit, a first amplifier circuit, a second amplifier circuit, a low-pass filter circuit, and a comparator circuit; The sampling circuit is electrically connected to the input terminal of the first amplifier circuit and the live wire, respectively. The output terminal of the first amplifier circuit is electrically connected to the input terminal of the second amplifier circuit. The output terminal of the second amplifier circuit is electrically connected to the input terminal of the comparator circuit. The input terminal of the low-pass filter circuit is electrically connected between the output terminal of the first amplifier circuit and the input terminal of the second amplifier circuit. The output terminals of the comparator circuit and the low-pass filter circuit are both electrically connected to the first input terminal of the control circuit. The sampling circuit is used to collect current from the live wire, obtain a first current signal, and transmit the first current signal to the first amplification circuit. The first amplifier circuit is used to amplify the first current signal to obtain an amplified first current signal, and transmit the amplified first current signal to the second amplifier circuit and the low-pass filter circuit respectively. The second amplifier circuit is used to amplify the amplified first current signal to obtain a high-frequency current signal, and to transmit the high-frequency current signal to the comparison circuit. The comparison circuit is used to compare the magnitudes of the high-frequency current signal and the reference current signal to obtain the high-frequency signal in the sampled current signal. The low-pass filter circuit is used to filter out high-frequency interference signals in the amplified first current signal to obtain low-frequency signals in the sampled current signal.
6. The arc fault detection device according to claim 5, characterized in that, The first amplifier circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a first operational amplifier; The first ends of the fourth resistor and the fifth resistor are both electrically connected to the sampling circuit. The second end of the fourth resistor is electrically connected to the inverting input of the first operational amplifier. The second end of the fifth resistor is electrically connected to the non-inverting input of the first operational amplifier. The output of the first operational amplifier and the first end of the sixth resistor are both electrically connected to the input of the second amplifier circuit. The second end of the sixth resistor is electrically connected between the second end of the fourth resistor and the inverting input of the first operational amplifier. The first end of the seventh resistor is used to connect to the second power supply voltage. The second ends of the seventh resistor and the first ends of the eighth resistor are both electrically connected between the second end of the fifth resistor and the non-inverting input of the first operational amplifier. The second end of the eighth resistor is grounded. Alternatively, the second amplifier circuit may include: a first capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, and a second operational amplifier. The first plate of the first capacitor is electrically connected to the output terminal of the first amplifier circuit and the first terminal of the ninth resistor, respectively. The second plate of the first capacitor is electrically connected to the non-inverting input terminal of the second operational amplifier. The first terminal of the tenth resistor is electrically connected between the second plate of the first capacitor and the non-inverting input terminal of the second operational amplifier. The first terminals of the eleventh resistor and the twelfth resistor are both electrically connected to the negative-inverting input terminal of the second operational amplifier. The second terminals of the tenth resistor and the eleventh resistor are both grounded. The second terminals of the ninth resistor, the twelfth resistor, and the output terminal of the second operational amplifier are all electrically connected to the input terminal of the comparator circuit. Alternatively, the comparator circuit may include: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a comparator; The first end of the thirteenth resistor is electrically connected to the output terminal of the second amplifier circuit, the second end of the thirteenth resistor is electrically connected to the non-inverting input terminal of the comparator, the first end of the fourteenth resistor is electrically connected between the second end of the thirteenth resistor and the non-inverting input terminal of the comparator, the first ends of the fifteenth resistor and the sixteenth resistor are both electrically connected to the negative input terminal of the comparator, the second end of the fourteenth resistor and the output terminal of the comparator are both electrically connected to the first input terminal of the control circuit, the second end of the fifteenth resistor is grounded, and the second end of the sixteenth resistor is used to connect to the second power supply voltage.
7. The arc fault detection device according to claim 5, characterized in that, The sampling circuit includes: a first sampling resistor and a second sampling resistor; the first sampling resistor and the second sampling resistor are connected in parallel, and the first sampling resistor and the second sampling resistor after being connected in parallel are electrically connected to the live wire; Alternatively, the low-pass filter circuit may include a second capacitor and a seventeenth resistor. The first end of the seventeenth resistor is electrically connected between the output end of the first amplifier circuit and the input end of the second amplifier circuit. The second end of the seventeenth resistor and the first plate of the second capacitor are both electrically connected to the first input end of the control circuit. The second plate of the second capacitor is grounded.
8. The arc fault detection device according to claim 6, characterized in that, The power supply circuit includes: the eighteenth resistor, the nineteenth resistor, the twentieth resistor, the twenty-first resistor, the twenty-second resistor, the twenty-third resistor, the twenty-fourth resistor, and the twenty-fifth resistor; The first end of the eighteenth resistor is electrically connected to the neutral wire. The second end of the eighteenth resistor is electrically connected to the first end of the twenty-first resistor through the nineteenth and twentyth resistors. The second end of the twenty-first resistor is electrically connected to the first end of the twenty-second resistor. The second end of the twenty-second resistor is electrically connected to the second input terminal of the control circuit. The first end of the twenty-third resistor is used to connect to the first power supply voltage. The second ends of the twenty-third resistor and the first ends of the twenty-fourth resistor are both electrically connected to the first end of the twenty-fifth resistor. The second end of the twenty-fifth resistor is electrically connected between the second end of the twenty-first resistor and the first end of the twenty-second resistor. The second end of the twenty-fourth resistor is grounded.
9. The arc fault detection device according to claim 8, characterized in that, The power supply circuit further includes: a first voltage divider circuit, a first diode, and a linear regulator; The first terminal of the first voltage divider circuit is electrically connected to the neutral line, the second terminal of the first voltage divider circuit is electrically connected to the positive terminal of the first diode, the negative terminal of the first diode is electrically connected to the input terminal of the linear regulator, and the output terminal of the linear regulator is used to output the power supply voltage. The first voltage divider circuit is used to collect voltage from the neutral line to obtain a first voltage signal, and then rectify it through the first diode to obtain a rectified first voltage signal. The linear regulator is used to obtain the rectified first voltage signal from the first diode and step down the rectified first voltage signal to obtain the power supply voltage, which includes the first power supply voltage and the second power supply voltage.
10. The arc fault detection device according to claim 4, characterized in that, The tripping circuit includes: a transistor, a second diode, a twenty-sixth resistor, a twenty-seventh resistor, and a twenty-eighth resistor; The base of the transistor is electrically connected to the first end of the 26th resistor, the second end of the 26th resistor is electrically connected to the output end of the control circuit, the emitter of the transistor is electrically connected to the first end of the 27th resistor, the second end of the 27th resistor is used to connect to the first power supply voltage, the collector of the transistor is electrically connected to the anode of the second diode and the first end of the 28th resistor, the second end of the 28th resistor is grounded, and the cathode of the second diode is electrically connected to the external component.