A socket circuit

Abstract

The utility model discloses a socket circuit relates to electric appliance field for saving the pipeline density and loop quantity of multi-socket installation. Socket circuit includes first branch path for accessing live wire, connects to socket live wire reed through first circuit breaker, second branch path for accessing zero line, connects to socket zero line reed through second circuit breaker, third branch path for accessing live wire, accesses zero line through first impedance circuit, first current detection circuit, socket live wire reed connects third branch path initially, MCU, connects first impedance circuit, first current detection circuit, first circuit breaker and second circuit breaker. When wiring, first loop accesses live wire, and second loop accesses zero line, and each socket circuit is connected to first loop and second loop, and can be. The utility model discloses a socket circuit only needs a group of loop pipeline to complete the wiring of multiple sockets, and the loop quantity of pipeline is saved greatly, and the cost is saved.

Description

Technical Field

[0001] This utility model relates to the field of electrical appliances, and in particular to a socket circuit. Background Technology

[0002] As a terminal facility for connecting electrical appliances, sockets are widely used in daily life.

[0003] A standard socket only contains live wire and neutral wire contacts. For safety reasons (such as safety regulations), electrical protection devices (such as circuit breakers or residual current devices) need to be designed at the front end of the socket to provide leakage protection or overcurrent protection. The wiring method for a standard socket is as follows: Figure 1 As shown, this is the main circuit breaker (air switch) that brings external power lines, such as those from the mains, into the room, and centrally arranges the power protection facilities for multiple circuits with the main circuit breaker, such as... Figure 1 The circuit breaker distribution box DB shown in the diagram then transmits the various circuits of high and low voltage electricity to the sockets at preset locations (such as each room) through pipelines. Figure 1 PJ*, CJ*, and KJ* in the text.

[0004] Traditional sockets result in wiring methods with numerous loops and dense conduits, leading to a large number of openings and grooves in buildings, reducing structural stability. Furthermore, the electrical protection devices in traditional socket wiring are located far from the wiring and appliances, making it difficult to precisely match the circuit breaker current to each appliance. This results in low-power appliances not being protected, and leakage current devices are prone to malfunction due to ground current generated by excessively long conduits. Utility Model Content

[0005] The purpose of this invention is to provide a socket circuit that addresses all or part of the problems mentioned above, providing a circuit basis for saving on the wiring density and number of circuits in multi-socket installations while meeting safety standards.

[0006] The technical solution adopted in this utility model is as follows: A socket circuit, comprising: The first branch is used to connect to the live wire, and is connected to the live wire spring of the socket via the first circuit breaker. The first circuit breaker is initially open. The second branch is used to connect to the neutral wire, and is connected to the neutral wire spring N of the socket via the second circuit breaker. The second circuit breaker is initially open. The third branch is used to connect the live wire, which is then connected to the neutral wire after passing through the first impedance circuit and the first current detection circuit; the live wire spring of the socket is initially connected to the third branch. The MCU (Microcontroller Unit) is connected to the first impedance circuit to adjust its impedance; connected to the first current detection circuit to receive the detected current; and connected to the first circuit breaker and the second circuit breaker to control their on / off states respectively.

[0007] The aforementioned socket circuit integrates electrical protection facilities within the socket itself. This allows each socket to be connected in parallel to the same pair of power lines, enabling centralized wiring of multiple sockets using only a single circuit. This significantly reduces conduit density and power line length during multi-socket installations, saving labor and material costs while minimizing potential safety hazards associated with multiple circuits. Furthermore, each socket circuit uses an MCU to control the on / off state of the live wire, providing local protection against leakage, short circuits, and foreign object intrusion, preventing electric shock and meeting safety regulations. The electrical facilities of the socket circuit can be integrated into an 86-size panel, resulting in a socket with the same shape and appearance as traditional sockets, compatible with traditional socket accessories. Current is detected locally at each socket, ensuring high accuracy and preventing false triggering of leakage and short circuit protection mechanisms. It also provides protection for low-power appliances.

[0008] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are: The socket circuit of this utility model integrates power protection facilities into the socket itself, thereby allowing the wiring layout of multiple sockets to be completed through the same set of circuit lines while meeting the mandatory requirements of safety regulations, which greatly saves the number of circuit lines and the length of transmission lines. Attached Figure Description

[0009] This utility model will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of traditional multi-socket wiring.

[0010] Figure 2 This is a circuit diagram of a socket circuit in one embodiment.

[0011] Figure 3 This is a circuit diagram of the first impedance circuit in one embodiment.

[0012] Figure 4 This is a circuit diagram of the first current detection circuit in one embodiment.

[0013] Figure 5 This is a circuit diagram of an electric field detection circuit in one embodiment.

[0014] Figure 6 This is a wiring diagram of a foreign object detection circuit in one embodiment.

[0015] Figure 7 This is a circuit diagram of a foreign object detection circuit in one embodiment.

[0016] Figure 8 This is a circuit diagram of a zero-crossing detection circuit in one embodiment.

[0017] Figure 9 This is a circuit diagram of an operational amplifier circuit in one embodiment.

[0018] Figure 10 This is a circuit diagram of the first driving circuit in one embodiment.

[0019] Figure 11 This is a circuit diagram of the second driving circuit in one embodiment.

[0020] Figure 12 This is a circuit diagram of an MCU in one embodiment.

[0021] Figure 13 The socket wiring method in this application is Figure 1 Wiring diagram in the implementation scenario. Detailed Implementation

[0022] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0023] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0024] In view of the shortcomings of traditional sockets, such as multiple circuits, high pipeline density, high material and construction costs, and unfriendly architecture, this application provides a socket circuit that aims to provide a basic circuit for reducing the number of pipeline circuits and overall cost when installing multiple sockets, and on this basis, to provide a basic circuit for improving power protection capabilities.

[0025] The socket circuit provided in the embodiments of this application, such as Figure 2 As shown, it includes the first branch, the second branch, the third branch, and the MCU.

[0026] The first branch circuit is used to connect to the live wire. Taking a socket used to connect to 220VAC as an example, the first branch circuit is used to connect to the 220VL line. The first branch circuit is connected to the live wire spring L of the socket via the first circuit breaker K1.

[0027] The second branch is used to connect to the neutral wire, i.e., the 220V N line. The second branch is connected to the neutral wire spring N of the socket via the second circuit breaker K2.

[0028] When an appliance is correctly inserted into a socket, its two live pins contact the live wire spring L and the neutral wire spring N of the socket, respectively.

[0029] The third branch is also used to connect to the live wire. It can be directly led out from the first branch or connected to the live wire independently. After passing through the first impedance circuit and the first current detection circuit, the third branch is connected to the neutral wire. The end connected to the neutral wire can be directly connected to the second branch or connected to the neutral wire independently. The impedance of the first impedance circuit is adjustable.

[0030] The MCU is connected to a first impedance circuit to adjust its impedance as needed, thereby regulating the current in the third branch. The MCU is also connected to a first current detection circuit to receive the current detected by that circuit. It should be noted that the first current detection circuit can detect the current in the third branch, or it can detect other currents that synchronously reflect changes in the third branch's current. The MCU is also connected to a first circuit breaker K1 and a second circuit breaker K2 to control their open or closed states, respectively. The initial state of both circuit breakers K1 and K2 is open, meaning the two spring contacts of the socket are not directly connected to the live wire initially, thus improving electrical safety.

[0031] The socket live wire spring L is connected to the third branch in the initial state.

[0032] Through the design of the above socket circuit, a third branch can be used to independently detect the mains power status without affecting the main power supply circuit. Based on this, the socket's live wire spring L is connected to the third branch. If a load or other conductive object is inserted into the socket spring J1 (including the live wire spring L and the neutral wire spring N, or possibly the ground wire spring E), the current detected by the first current detection circuit will change. The MCU monitors this current change to detect and identify the load connection, and then controls the on / off state of the first circuit breaker K1 and the second circuit breaker K2 based on the identification result, thus ensuring that the mains power is connected to the load under safe conditions. This socket circuit completes the safety protection action at the socket itself, eliminating the need for separate leakage protection devices such as circuit breakers. Multiple sockets can be directly connected to the same mains power transmission line, allowing multiple sockets to be installed through the same set of circuit lines, significantly reducing the number of circuit lines, saving materials and construction costs, and mitigating the safety hazards of multiple circuit lines. Multiple sockets are independent and do not interfere with each other; even if one socket malfunctions, it will not affect the normal operation of the others.

[0033] The resistance value of the first impedance circuit is adjustable, and in principle, an adjustable impedance element (such as a resistor) can be used. However, in some scenarios, this application requires rapid and repeated adjustment of the resistance value of the first impedance circuit; that is, after adjusting the impedance of the first impedance circuit from a reference impedance, it needs to return to the reference impedance. Therefore, as... Figure 3 As shown, in a preferred embodiment, the first impedance circuit is designed to include a first fixed resistor (which can be a single resistor or constructed from multiple resistors) and a first optocoupler U2. The first fixed resistor is connected in series in the third branch, the secondary side (i.e., the output side) of the first optocoupler U2 (such as the optocoupler SCR MOC3011M) is connected in parallel with the first fixed resistor, and the primary side (i.e., the input side) of the first optocoupler U2 is connected to the MCU.

[0034] Under the influence of the MCU input voltage, the luminous intensity of the primary side of the first optocoupler U2 will change, which will correspondingly change the impedance of its secondary side. The impedance of the secondary side determines the short-circuit effect on the first fixed circuit, thereby adjusting the impedance of the third branch. Furthermore, by turning off the first optocoupler U2, the MCU can quickly and accurately restore the resistance of the first impedance circuit to the first fixed resistor without requiring any additional adjustments.

[0035] like Figure 4 As shown, in one optional implementation, the first current detection circuit includes a second optocoupler U3 (such as an optocoupler transistor TLP280-1). The primary side of the second optocoupler U3 is connected to the third branch, and the secondary side of the second optocoupler U3 is connected to the MCU. The magnitude of the current in the third branch determines the luminous intensity of the primary side of the second optocoupler U3, which in turn determines the impedance of its secondary side. The magnitude of the current in the secondary side of the second optocoupler U3 can synchronously reflect the degree of change in the current in the third branch.

[0036] Furthermore, to improve the output stability of the first current detection circuit, an RC filter is connected to the secondary side of the second optocoupler U3 to filter the current output from the secondary side of the second optocoupler U3, making the signal output to the MCU more stable and easier for the MCU to accurately identify.

[0037] In all the above embodiments, whether it is the first impedance circuit, the first current detection circuit, or the MUC, a DC power supply is required for operation. Here, a power supply circuit is connected to the third branch to convert the input AC power into low-voltage DC power output.

[0038] The power supply circuit can use conventional AC / DC power modules and DC / DC power modules. For example, a 20V output AC / DC power module (example) can be selected, and DC / DC power modules with 3.3V, 12V, etc. outputs can be connected to the AC / DC power module respectively.

[0039] Under normal circumstances, the third and first branches of the socket circuit need to be connected to the live wire; if the neutral wire is connected, it will not function properly. Therefore, in one optional embodiment, the socket circuit also includes an electric field detection circuit, which performs non-invasive detection of the connection polarity by detecting whether the third branch can generate an electric field.

[0040] For example, such as Figure 5 As shown, the electric field detection circuit includes a signal acquisition probe TW and a voltage discrimination circuit connected to the signal acquisition probe. The signal acquisition probe TW is positioned around the third branch (e.g., surrounding the third branch). The voltage discrimination circuit includes a Darlington transistor Q1. The signal acquisition probe TW is connected to the base of Q1, the emitter of Q1 is connected to the MCU (PA4_ADC4 pin), and the collector is connected to a test voltage (e.g., a 3.3V power supply). The MCU determines whether the live and neutral wires of the socket are reversed by detecting whether Q1 is conducting. If a high level is received from Q1, it indicates that the connection is not reversed; otherwise, the MCU issues an alarm through the connected warning circuit to remind on-site personnel to troubleshoot the reverse connection fault.

[0041] Using the socket circuit designed above, the MCU is configured to identify the load connection through the following logic: Record the initial current detected by the first current detection circuit. That is, the current detected by the first current detection circuit when both the first circuit breaker K1 and the second circuit breaker K2 are open and the first impedance circuit is connected to the reference impedance.

[0042] The second circuit breaker K2 is closed. When the second circuit breaker K2 is closed, if a load is inserted into the socket and the two spring contacts are connected, the third branch and the second branch will form a loop, and a small current will be generated in the second branch. Furthermore, if a person accidentally touches the socket's live wire spring contact L, or if another conductive object enters the socket's live wire spring contact L, a current will be generated to ground. The current generated above will be collected in the first current detection circuit of the third branch, thus increasing the current detected by the first current detection circuit. The coil power of the second circuit breaker K2 can be adjusted by adjusting the duty cycle of the control signal to prevent emissions.

[0043] The current detected by the first current detection circuit is continuously monitored.

[0044] When the current detected by the first current detection circuit increases, it indicates that a load has been connected or another conductive object has entered the circuit. At this time, the second circuit breaker K2 is opened to determine whether the current detected by the first current detection circuit has returned to its initial value. If a load is connected, there will be no current flowing through the load after K2 is opened, and the current detected by the first current detection circuit will return to its initial value. If the increased current is caused by factors such as electric shock or foreign object intrusion, the current detected by the first current detection circuit will not return to its initial value after K2 is opened.

[0045] If the current detected by the first current detection circuit does not return to the initial current, the impedance of the first impedance circuit is continuously reduced under the initial impedance, thereby continuously increasing the voltage at the socket live wire contact L to determine whether the current detected by the first current detection circuit has returned to the initial current. To ensure circuit safety, under the initial impedance (i.e., in the socket standby state), the current in the second branch is a microcurrent (below 0.5mA), which is imperceptible to the human body. If a human body comes into contact with the socket contact, during the voltage rise of the socket live wire contact L, the human body will react due to the continuous increase in voltage excitation, breaking the contact with the socket live wire contact L, making the socket live wire contact L open to ground, and the first current detection circuit restores the initial current. If a human body is electrocuted, the voltage at the socket live wire contact L starts to rise after the human body is electrocuted, rather than when the voltage rises to a risky level before electrocution occurs, thus filling the safety protection gap in the socket standby state. If the initial current is restored, it indicates accidental human contact. In this case, the first circuit breaker remains open, and an alarm indicating electric shock can be issued via the connected alarm circuit, for example, through the color, frequency, or intensity of an indicator light. If the initial current is not restored, it indicates neither load connection nor human electric shock, but rather a leakage current situation. In this case, the connected foreign object detection circuit will detect whether the leakage between the live wire contact L and the neutral wire contact N of the socket is caused by foreign object intrusion.

[0046] The foreign object detection circuit detects foreign object intrusion by measuring the impedance between the live wire contact L and the neutral wire contact N of the socket. The impedances of the load connection and the foreign object connection are different; this characteristic is used to distinguish between foreign object intrusion and the load connection.

[0047] like Figure 6 As shown, in one optional implementation, the socket live wire spring L is connected to the third branch via a third circuit breaker K3, which is also connected to a test voltage signal. Initially, the third circuit breaker K3 connects the socket live wire spring L and the third branch, and then disconnects the socket live wire spring L from the test voltage signal. The socket neutral wire spring N is connected to a foreign object detection circuit via a fourth circuit breaker K4, which is initially open. The MCU is connected to the third circuit breaker K3 to control the connection state between the socket live wire spring L and the third branch or the test voltage signal. The MCU is also connected to the fourth circuit breaker K4 to control its on / off state.

[0048] In a preferred embodiment, the third circuit breaker K3 is connected to a transient voltage suppression diode (TVS) on the pin connected to the test voltage signal. This TVS is used to suppress transient overvoltages in the circuit, protect the third circuit breaker K3 and subsequent circuits from voltage spikes, and improve the circuit's anti-interference capability and reliability.

[0049] The MCU detects foreign object intrusion through the following configuration: The third circuit breaker K3 connects the socket live wire spring L to the test voltage signal; the fourth circuit breaker K4 closes, thereby connecting the test voltage signal to the foreign object detection circuit (via the socket live wire spring L and the socket neutral wire spring N). Based on the voltage divider principle, the foreign object detection circuit reflects the detected impedance through a voltage signal.

[0050] Obtain the voltage signal output by the foreign object detection circuit, and determine whether there is foreign object intrusion based on the voltage signal.

[0051] Alternatively, the same function can be achieved by swapping the positions of the test voltage signal and the foreign object detection circuit, i.e., by connecting the test voltage signal to the fourth circuit breaker K4 and the foreign object detection circuit to the third circuit breaker K3.

[0052] like Figure 7 As shown, as an optional implementation, the foreign object detection circuit uses a Wheatstone bridge circuit for impedance detection.

[0053] Taking the foreign object detection circuit connected to the fourth circuit breaker K4 (the connection to the third circuit breaker K3 can be reversed similarly) as an example, the Wheatstone bridge circuit includes a resistor R15 connected to the fourth circuit breaker K4, which is grounded. It also includes a resistor R16 connected to a 3.3V power supply (i.e., the test voltage signal) and a resistor R17 connected in series with it and grounded. Preferably, the resistance values ​​of resistors R15, R16, and R17 are the same. A first signal terminal INRA is led out from the front end of resistor R15 (the end closest to the fourth circuit breaker K4), and a second signal terminal INNA is led out between resistors R16 and R17. Socket J1, resistors R15, R16, and R17 together form the Wheatstone bridge circuit. When a foreign object intrudes, this circuit will cause a change in the resistance of the R15 bridge arm. By comparing the changes in the resistance of the two bridge arms, the change in resistance is converted into a change in voltage, thereby achieving foreign object embedding detection. INRA and INNA are each connected to a differential analog-to-digital converter U8 (selection example: HX710A / B). Figure 7 Taking the HX710B as an example, the two differential signal input terminals are connected to the output terminal of the differential analog-to-digital converter U8, which is connected to the MCU to output the voltage difference between INNA and INRA. Specifically, the serial port DOUT and serial clock PD_SCK of the HX710B are connected to the MCU. DOUT outputs the processed serial port data, and PD_SCK receives the clock input from the MCU. The MCU obtains the voltage difference between INNA and INRA based on the serial port data received from DOUT. Based on a set reference value, when the voltage difference reaches the reference value, it indicates that the impedance between the two reeds has reached the foreign object intrusion judgment standard, and it is determined that foreign object intrusion has occurred.

[0054] Furthermore, since the socket is connected to alternating current (AC), the current direction changes periodically. When the MCU adjusts the impedance of the first impedance circuit or changes the on / off state of each circuit breaker, controlling the AC power at its zero-crossing point can effectively reduce circuit noise and the risk of sparking. Therefore, as an optional implementation, a zero-crossing detection circuit is connected to the third branch of the socket circuit.

[0055] The zero-crossing detection circuit uses a zero-crossing detection chip (such as CN7102) to detect the zero-crossing point of the connected AC power. The zero-crossing detection circuit is connected to the MCU to transmit the detected zero-crossing point. The MCU performs corresponding actions based on the detected zero-crossing point. For example, when adjusting the primary current of the first optocoupler U2, the MCU controls the conduction angle of the first optocoupler U2 via a PWM signal, the phase of which is determined based on the detected zero-crossing point. Another example is when closing the first circuit breaker K1 and the second circuit breaker K2, the MCU controls the closing of the first circuit breaker K1 and the second circuit breaker K2 at the zero-crossing point to avoid sparking caused by voltage surges during switching at high voltage.

[0056] In one alternative implementation, such as Figure 8As shown, the zero-crossing detection circuit includes a zero-crossing detection chip CN7102, a third optocoupler U1, and peripheral circuitry. The VSS pin of CN7102 is connected to the third branch (i.e., connected to the live wire), the VIN pin is connected to the neutral wire (e.g., connected to the second branch) via series resistors R5 and R6, and the VDD pin serves as the output port connected to the third optocoupler U1. A filter capacitor C2 is also connected to the VSS pin to filter out high-frequency interference components in the AC voltage, making the voltage signal input to CN7102 more stable and improving the accuracy of zero-crossing detection. A current-limiting resistor R7 is connected to the VDD pin to limit the current flowing through the primary side (i.e., the internal LED) of the third optocoupler U1, preventing damage due to excessive current. The two ends of the primary side of the third optocoupler U1 are connected across the current-limiting resistor R7, with the positive input terminal of the primary side connected to the VSS pin via the filter capacitor C2. The positive terminal of the secondary side of the third optocoupler U1 is connected to the test voltage signal (e.g., a 3.3V power supply), and the negative terminal is grounded. The MCU is connected to the positive terminal of the secondary side of the third optocoupler U1. The live wire (220VL) and neutral wire (220VN) of the 220V AC mains power are input to the zero-crossing detection circuit. The neutral wire, after being divided by resistors R5 and R6, is input to the VIN pin of the CN7102. The live wire, through filter capacitor C2 and resistor R7, is connected to the VDD pin of the CN7102. The CN7102 performs zero-crossing detection on the input AC voltage. The output signal of the CN7102 is connected to the primary side of the third optocoupler U1 through the circuit. When a zero-crossing is detected, the CN7102 outputs a corresponding signal, causing the LED inside the third optocoupler U1 to light up, thereby turning on (or off) the internal phototransistor (i.e., the secondary side). The phototransistor side of the third optocoupler U1 is pulled up by a 3V3 power supply through resistor R8. The detection signal is output to the PA5_ADC5 pin of the microcontroller. Simultaneously, capacitor C3 filters the signal at the PA5_ADC5 pin, and GND provides a ground reference for the entire circuit. This enables zero-crossing detection from 220V AC mains power.

[0057] In addition, the socket circuit is designed with overcurrent protection, short-circuit protection, and leakage protection functions. A first current transformer is connected to the first branch for high current detection; leakage current sensors are connected to the first and second branches for leakage current detection; and a second current transformer is connected to the second branch for micro-current detection, which can be used to verify the load connection detection results.

[0058] The first current transformer, the second current transformer, and the leakage current sensor are connected to the MCU. The MCU controls the switching state and switching time of the first circuit breaker K1 based on the current detected by the first current transformer and the leakage current sensor.

[0059] Electrical protection includes leakage protection, short circuit protection, and overcurrent protection. Different electrical protection measures have different control strategies for the disconnection of the first circuit breaker K1 and the disconnection time. (1) Residual current protection The MCU performs leakage protection according to the following configuration: The leakage current detected by the leakage current sensor within a predetermined time (such as 100ms or other time length) after the first circuit breaker K1 and the second circuit breaker K2 are closed (at which time the load starts) is used as the base leakage current. This base leakage current is stored by the MCU for backup, and the base leakage current is re-determined each time the power supply to the first circuit breaker K1 is disconnected (such as when the load is unplugged) and then the power supply to the load is restored (such as when the first circuit breaker K1 is reclosed).

[0060] Determine if the base leakage current exceeds the first leakage current threshold. If it does, disconnect the first circuit breaker K1; otherwise, continue. The leakage current that should be generated when the load is just starting is small, for example, no higher than 8mA (or other nearby values). If it exceeds 8mA, it is considered a startup abnormality, an alarm is issued through the alarm circuit, and the first circuit breaker K1 is disconnected.

[0061] The second leakage current threshold is calculated based on the set leakage current increment range. For example, if the leakage current increment range is set to 10~20mA, and the measured base leakage current is 1mA, then the calculated second leakage current threshold is 11~21mA. That is, the second leakage current threshold I = i + k, where i is the base leakage current and k is the leakage current increment range.

[0062] The leakage current detected by the leakage current sensor is continuously monitored. If the leakage current reaches or exceeds the second leakage current threshold, the first circuit breaker is disconnected.

[0063] By setting the current threshold for leakage protection using a dynamic baseline, it can adapt to loads of different power levels, providing precise leakage protection, including leakage protection for low-power appliances. Setting a second leakage current threshold as the tripping threshold can prevent false tripping caused by leakage current in the socket itself, even when the actual leakage current generated by the load is very small.

[0064] (2) Short circuit protection The MCU performs short-circuit protection according to the following configuration: The system continuously monitors the first current detected by the first current transformer after the first circuit breaker K1 and the second circuit breaker K2 are closed. If the first current reaches or exceeds the set short-circuit current threshold, the system calculates the trip current threshold based on the closing time of the first circuit breaker K1 and its rated current, and disconnects the first circuit breaker K1 when the first current reaches the trip current threshold.

[0065] For example, suppose the MCU triggers short-circuit protection when the first current reaches 48A (the short-circuit current threshold varies depending on the components selected in the socket circuit). The corresponding tripping current threshold is determined based on the load start-up time (i.e., the duration of the first circuit breaker K1's closure). 1) If the load startup time is within the first duration (e.g., 4 seconds, or other durations), then set the rated current X1 times (e.g., 5 times, or other multiples) as the short-circuit current threshold. 2) If the load startup time exceeds the first time but is within the second time (e.g., 8 seconds, or other times exceeding the first time), then set the rated current X2 (e.g., 10 times, or other times exceeding X1) as the short-circuit current threshold.

[0066] Normally, if a short circuit occurs, the current in the first branch will reach the short-circuit current threshold and trip within the second time period. Therefore, it is usually not necessary to consider the case where the load startup time exceeds the second time period. If this case still needs to be considered, then similarly, X3, X4, ... of the rated current can be set as the short-circuit current threshold for the corresponding load startup time.

[0067] By dynamically designing the short-circuit current threshold, it can be adapted to electrical appliances of different power ratings, avoiding false tripping of short-circuit protection.

[0068] (3) Overcurrent protection The MCU performs overcurrent protection according to the following configuration: The system continuously monitors the second current detected by the first current transformer after the first circuit breaker K1 and the second circuit breaker K2 are closed. If the second current exceeds the rated current of the first circuit breaker K1, the tripping time is calculated based on the magnitude of the second current and a set reference tripping time using an inverse correlation principle. The first circuit breaker is disconnected when the calculated tripping time is reached, starting from when the second current exceeds the rated current.

[0069] The tripping time of overcurrent protection is also dynamically determined, corresponding to the actual current of the first branch. The larger the current, the shorter the tripping time.

[0070] For example, if the rated current of the first current transformer is 10A (the rated current will vary depending on the specific model; this is just an example), and the detected second current exceeds 10A, the MCU will trigger overcurrent protection. The tripping time begins when the second current reaches the rated current (10A); the tripping time for a second current of 10A is set to 8 seconds (this can be any other duration). For every 1A the second current exceeds the rated current, the corresponding tripping time is shortened by 0.1 seconds. . This indicates the second current being detected; 10 indicates a rated current of 10A. If it is another rated current, corresponding adjustments should be made. When the timer reaches T, the first circuit breaker K1 is disconnected. The disconnection of the first circuit breaker K1 is instantaneous, for example, the tripping of the first circuit breaker K1 is completed within 7 milliseconds.

[0071] It should be noted that the current threshold, time threshold, etc. set in the above three power protection measures are all illustrative examples. They can be reasonably adjusted according to the selection of components, application scenarios, etc., without violating the design concept of this application.

[0072] The leakage current sensor, the first current transformer, and the second current transformer are connected to the two output terminals of the operational amplifier circuit for amplification to obtain the corresponding leakage current, large current, and micro current.

[0073] As an optional implementation method, such as Figure 9 As shown, the operational amplifier circuit processes the input signal through two stages of differential operational amplifiers U5 and U6 to obtain the corresponding detection result. S1-S2 are the two ends of the leakage current sensor, S3-S4 are the two ends of the first current transformer, and S5-S6 are the two ends of the second current transformer. The detected current, after being amplified by the two stages, is connected to the inverting input of the differential operational amplifier U7 after passing through resistor R31. The non-inverting input of U7 is connected to the reference voltage output by a voltage divider circuit composed of resistors R29, R30, and capacitor C19. U7 compares the voltages at the non-inverting and inverting inputs to generate a high-level or low-level emergency disconnect signal Q3-IN-6. This emergency disconnect signal Q3-IN-6 is connected to the drive circuit of the first circuit breaker K1 to urgently disconnect the first circuit breaker K1 in emergency situations such as overcurrent or short circuit.

[0074] like Figure 10The diagram shows the first drive circuit for controlling the on / off state of the first circuit breaker K1 using an MCU. The coil of the first circuit breaker K1 is connected in series with transistor Q2. The base of transistor Q2 is connected to the NC pin of analog switch chip Q3. The input terminal COM (common terminal) of analog switch chip Q3 is connected to the MCU, and the enable terminal IN of analog switch chip Q3 is connected to the emergency disconnect signal Q3-IN-6. Under normal conditions, i.e., when there is no emergency such as overcurrent, short circuit, or leakage, the emergency disconnect signal Q3-IN-6 outputs a high level. Analog switch chip Q3 connects its COM and NC pins, allowing the MCU to control the on / off state of transistor Q2, thereby controlling the on / off state of the first circuit breaker K1. In an emergency, the emergency disconnect signal Q3-IN-6 changes to a low level, connecting the COM and NO pins of analog switch chip Q3, turning off transistor Q2, and tripping the first circuit breaker K1. Additionally, an LED D4 is connected between the NO and IN pins of analog switch chip Q3. In an emergency, a high level input on the COM pin will illuminate the LED D4 via the NO pin, serving as an alarm for the emergency.

[0075] For other circuit breakers, such as the second circuit breaker K2, the third circuit breaker K3, and the fourth circuit breaker K4, there is no need to consider emergency shutdown; the on / off status can be directly controlled by the MCU.

[0076] like Figure 11 As shown, the MCU drives the second circuit breaker K2, the third circuit breaker K3 and the fourth circuit breaker K4 respectively through the second driving circuit.

[0077] Taking the second circuit breaker K2 as an example (the same applies to the third circuit breaker K3 and the fourth circuit breaker K4), the coil of the second circuit breaker K2 is connected in series with the transistor Q4. The base of the transistor Q4 is connected to the MCU. The MCU controls the on / off state of the second circuit breaker K2 by controlling the on / off state of the transistor Q4 (for the third circuit breaker K3, its on state corresponds to connecting the third branch, and its off state corresponds to connecting the test voltage signal / foreign object detection circuit).

[0078] The MCU serves as the control center of the socket circuit. Any device with logic processing capabilities, such as a PLC or FPGA, can be selected. Data exchange and signal transmission with various module circuits are achieved through I / O ports. Figure 12 The example shown is an STM32F030C8T6 microcontroller (and necessary peripheral circuitry) used as the MCU. Obviously, based on the design concept of this application, those skilled in the art can certainly choose other models or types of logic devices as the MCU for the socket circuit, and the logic functions configured on each pin can also be interchanged or adjusted accordingly.

[0079] The socket circuit can be used in two-hole sockets or three-hole sockets. For three-hole sockets, a fourth branch can be designed directly for the ground spring E. This fourth branch is used to connect to the ground wire.

[0080] By routing the aforementioned socket circuitry onto an 86-type PCB (Printed Circuit Board), and then assembling the PCB into a socket housing of the same shape and size as a traditional 86-type socket, a socket with local power protection capabilities can be obtained. When installing multiple such sockets, only one main line (including live and neutral wires) needs to be laid through each installation point. The socket circuits at each point are then connected to this main line. Thus, wiring for all sockets (circuits) is completed through a single loop of conduit, significantly reducing the number of conduit loops and saving material and construction costs.

[0081] The above-described socket circuit achieves cost savings in conduit loops through the following socket wiring method, which is based on the socket circuits proposed in the above embodiments. The socket wiring method includes: Connect the first loop to the live wire (220VL) and the second loop to the neutral wire (220VN). A loop refers to a circular circuit formed by connecting the beginning and end to the same node, allowing for breaks and branches; it does not refer to a single, integral loop coil. For example, one end of the first / second loop can be connected to the live / neutral node at the entrance to the house, and the other end can pass through various socket installation locations and also connect to the live / neutral node.

[0082] Connect the first and third branches of at least one socket circuit (multiple circuits are required in most applications) to the first loop, and connect the second branch to the second loop.

[0083] It should be noted that although both the first and third branches of the socket circuit need to be connected to the live wire, for the socket circuit, they can be connected to the mains live wire through the same terminal (which can be a single connection point or a cable), and then the first and third branches can be connected to that terminal separately. Alternatively, the first and third branches can be connected to the mains live wire separately. The former method can save on installation work.

[0084] like Figure 13 The image shows the wiring method used for the above-described socket in conjunction with... Figure 1 Wiring diagrams for the same requirements. (Comparison) Figure 13 and Figure 1As can be seen, by adopting the socket circuit and socket wiring method designed in this application, only one loop (including necessary branches) is needed to complete the wiring of all sockets. Only one set of conduit is needed to reach any socket point, with no duplicate lines, significantly reducing the number of conduit loops and saving on the material costs of power transmission lines and the installation costs of construction personnel. Furthermore, the loop-forming wiring method, compared to the non-loop-forming wiring method, only increases the line length from the last socket to the starting point, with almost no increase in overall cost, but it ensures that any socket can be powered from two directions. If one direction fails, the other direction can still supply power normally, improving the reliability of the socket operation.

[0085] It should be noted that the circuit modules shown in the accompanying drawings are merely examples for implementing the technical solution of this application. Some components are preferred designs and can be omitted to achieve the technical solution of this application, such as isolation capacitors. Furthermore, the selection and construction of components (such as chips and peripheral circuits) in each circuit module can be replaced to achieve the same function.

[0086] In summary, the socket circuit proposed in this application overturns the traditional socket design concept, achieving power protection at the local end, changing the wiring method when installing multiple sockets, significantly reducing the number of conduit loops, and although all sockets (circuits) are connected through the same set of lines, the operation of each socket circuit is independent and does not affect each other. The socket circuit of this application does not use large-volume components, and the entire socket circuit can be integrated on an 86-size panel (PCB board), thus obtaining a socket with the same shape and size as a traditional 86-size socket. No special treatment is required during installation and wiring; the opening and wiring are still the same as traditional sockets, and it is compatible with all facilities of traditional sockets.

[0087] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A socket circuit, characterized in that, include: The first branch is used to connect to the live wire, and is connected to the live wire spring of the socket via the first circuit breaker. The first circuit breaker is initially open. The second branch is used to connect to the neutral wire, which is connected to the neutral wire spring of the socket via the second circuit breaker. The second circuit breaker is initially open. The third branch is used to connect the live wire, which is then connected to the neutral wire after passing through the first impedance circuit and the first current detection circuit; the live wire spring of the socket is initially connected to the third branch. The microcontroller unit (MCU) is connected to the first impedance circuit to adjust its impedance; connected to the first current detection circuit to receive the detected current; and connected to the first circuit breaker and the second circuit breaker to control their on / off states respectively.

2. The socket circuit as described in claim 1, characterized in that, The first impedance circuit includes a first fixed resistor and a first optocoupler; the first fixed resistor is connected in series in the third branch; the secondary side of the first optocoupler is connected in parallel with the first fixed resistor, and the primary side is connected to the MCU.

3. The socket circuit as described in claim 1 or 2, characterized in that, It also includes a foreign object detection circuit connected to the MCU; the socket live wire spring is connected to the third branch via a third circuit breaker, and the third circuit breaker is also connected to a test voltage signal; the third circuit breaker initially connects the socket live wire spring and the third branch, and disconnects the socket live wire spring and the test voltage signal. The socket neutral wire spring is connected to the foreign object detection circuit via the fourth circuit breaker, and the fourth circuit breaker is initially open; The MCU is connected to the third circuit breaker to control the connection status between the socket live wire spring and the third branch or the test voltage signal; it is also connected to the fourth circuit breaker to control the on / off status. Alternatively, the socket live wire spring is connected to the third branch via a third circuit breaker, and the third circuit breaker is also connected to the foreign object detection circuit; the third circuit breaker initially connects the socket live wire spring and the third branch, and disconnects the socket live wire spring and the foreign object detection circuit. The socket neutral wire spring is connected to the test voltage signal via the fourth circuit breaker, and the fourth circuit breaker is initially open; The MCU is connected to the third circuit breaker to control the connection status between the socket live wire spring and the third branch or the foreign object detection circuit; it is also connected to the fourth circuit breaker to control the on / off status.

4. The socket circuit as described in claim 3, characterized in that, When the test voltage signal is applied, the foreign object detection circuit identifies whether a foreign object has entered the socket by detecting the impedance between the live wire spring and the neutral wire spring.

5. The socket circuit as described in claim 3, characterized in that, The foreign object detection circuit includes a resistor R15 connected to the fourth / third circuit breaker, which is grounded; it also includes a resistor R16 connected to the test voltage signal and a resistor R17 connected in series with it and grounded; a first signal terminal INRA is led out from one end of the resistor R15 near the fourth / third circuit breaker, and a second signal terminal INNA is led out from between the resistors R16 and R17; the first signal terminal INRA and the second signal terminal INNA are respectively connected to the two differential signal input terminals of the differential analog-to-digital converter, and the output terminal of the differential analog-to-digital converter is connected to the MCU.

6. The socket circuit as described in claim 1, characterized in that, A first current transformer is connected to the first branch; a leakage current sensor is connected to the first branch and the second branch; the first current transformer and the leakage current sensor are respectively connected to the MCU.

7. The socket circuit as described in claim 1, characterized in that, The third branch is connected to a zero-crossing detection circuit; the zero-crossing detection circuit includes a zero-crossing detection chip CN7102, a third optocoupler, and peripheral circuitry; the VSS pin of CN7102 is connected to the third branch, and a filter capacitor C2 is also connected to the VSS pin; the VIN pin is connected to the neutral line via a series resistor R5 and a resistor R6; the VDD pin is connected to the third optocoupler, and a current-limiting resistor R7 is also connected to the VDD pin; the two ends of the primary side of the third optocoupler are connected across the two ends of the input resistor R7, wherein the positive input terminal of the primary side is connected to the VSS pin of CN7102 via the filter capacitor C2; the positive terminal of the secondary side is connected to the test voltage signal, the negative terminal is grounded, and the positive terminal of the secondary side is connected to the MCU.

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