A three-hole socket test circuit

Abstract

The utility model provides a kind of three-hole socket test circuit, belong to socket electric leakage detection field, the circuit includes electric leakage protector test circuit, wiring state test circuit, single fire line test circuit, contact L, contact N and contact E;Socket correct wiring time, contact L connects fire line, contact N connects zero line, contact E connects ground wire;Contact N is connected with contact E by resistance R10, contact L is connected with contact E by resistance R11, R10 and R11 are the high resistance resistance of 10MΩ resistance value;The electric leakage protector test circuit is used to detect whether socket ground wire is connected;The wiring state test circuit is used to detect whether socket wiring is correct, and indicate wiring error category;The single fire line test circuit is used to detect and indicate that only single fire line is provided in socket.The utility model detects the connection condition of fire line, ground wire and zero line independently, improves the comprehensiveness and accuracy of test, and can also detect whether single fire line condition exists.

Description

Technical Field

[0001] This utility model belongs to the field of socket leakage detection, specifically relating to a test circuit for a three-hole socket. Background Technology

[0002] A socket tester is a portable testing instrument specifically designed to measure the wiring status of sockets. It may also include a basic residual current device (RCD) test function, making it ideal for household circuit installation and repair. However, current socket testers only offer basic RCD testing and cannot determine if a socket lacks a ground wire. If a user performs an RCD test when a ground wire is missing, the metal casing of the appliance may become electrified, posing a safety hazard.

[0003] Residual current circuit breakers use LEDs to indicate the wiring status of the socket. The conduction voltage of LEDs is generally between 1.8V and 3.6V. However, due to the imbalance of three phases in the actual power supply system, a voltage difference will be generated between the neutral wire and the ground wire. The voltage difference can be as large as tens of volts, which will cause the LED to light up and make the measurement results incorrect.

[0004] In addition, existing socket testers require a voltage difference in the three-hole socket to perform the test. If the socket only has a single live wire, the socket tester will judge it as missing a live wire, which is dangerous to repair. Utility Model Content

[0005] To address the problems in the prior art, this utility model proposes a three-hole socket test circuit. By independently detecting the connection status of the live wire, ground wire, and neutral wire, the comprehensiveness and accuracy of the test are improved. Furthermore, a human contact conductive trigger circuit is used to detect the status of a single live wire to determine whether there is a risk of electric shock.

[0006] The technical solution of this utility model is as follows: In a first aspect, this utility model provides a three-hole socket test circuit, which includes a leakage current protection test circuit, a wiring status test circuit, a single live wire test circuit, contact L, contact N, and contact E. When the socket is correctly wired, contact L is connected to the live wire, contact N is connected to the neutral wire, and contact E is connected to the ground wire. Contact N and contact E are connected through resistor R10, and contact L and contact E are connected through resistor R11. R10 and R11 are high-resistance resistors with a resistance of 10MΩ. The leakage current protection test circuit is used to detect whether the socket ground wire is connected; The wiring status test circuit is used to detect whether the socket wiring is correct and to indicate the type of wiring error; The single live wire test circuit is used to detect and indicate that the socket has only a single live wire.

[0007] Furthermore, the leakage current protection device test circuit includes a fourth current flow circuit and a fifth current flow circuit; The fourth current flow circuit includes a diode D4, a resistor R8, a resistor R9, and the light-emitting diode part of the optocoupler U1. The anode of the diode D4 is connected to the contact L, and the cathode is connected to the contact E in series with R9 and R8. The pin 1 and pin 2 of the light-emitting diode of the optocoupler U1 are connected in parallel across the resistor R8. The fifth current flow circuit includes a switch K1, a resistor R7, and a photoresistor section of an optocoupler U1. One end of the switch K1 is connected to contact L, and the other end is connected in series with the resistor R7 and connected to pin 3 of the photoresistor of the optocoupler U1. Pin 4 of the photoresistor is connected to contact E.

[0008] Furthermore, the wiring status test circuit includes a first current flow circuit, a second current flow circuit, and a third current flow circuit; The first current flow circuit includes a diode D1, a resistor R1, a light-emitting diode LED1, and a resistor R2. The diode D1, resistor R1, and light-emitting diode LED1 are connected in series, and resistor R2 is connected in parallel with light-emitting diode LED1. The cathode of diode D1 is connected to contact point N, and the anode of light-emitting diode LED1 is connected to contact point L. The second current flow circuit includes diode D2, resistor R3, light-emitting diode LED2 and resistor R4. Diode D2, resistor R3 and light-emitting diode LED2 are connected in series, resistor R4 is connected in parallel with light-emitting diode LED2, the anode of diode D2 is connected to contact point N, and the cathode of light-emitting diode LED2 is connected to contact point E. The third current flow circuit includes diode D3, resistor R5, light-emitting diode LED3 and resistor R6. Diode D3, resistor R5 and light-emitting diode LED3 are connected in series, resistor R6 is connected in parallel with light-emitting diode LED3, the anode of diode D3 is connected to contact point L, and the cathode of light-emitting diode LED3 is connected to contact point E.

[0009] Furthermore, the single-wire test circuit includes an LCD display, Zener diodes DZ1 and DZ2, resistors R12 and R13, and a human contact conductive trigger. The positive terminals of Zener diodes DZ1 and DZ2 are connected together, and their negative terminals are connected in parallel across the LCD display. Resistor R12 is connected in parallel with the LCD display, and resistor R13 is connected in series with the LCD display and connected to the human contact conductive trigger.

[0010] Furthermore, when contact L is connected to the live wire only, and contact N and contact E are either left unconnected or both connected to the live wire, current enters from contact L, passes through resistor R11, LCD display, human contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display to indicate that the socket under test is energized. When contact N in the socket is connected to the live wire only, and contact L and contact E are either left unconnected or both connected to the live wire, current enters from contact N, passes through resistor R10, LCD display, human contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display to indicate that the socket under test is energized. When contact E in the socket is connected to the live wire only, and contacts L and N are either left unconnected or both connected to the live wire, current enters from contact E, passes through the LCD display, the human body contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display and indicating that the socket under test is energized.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention can automatically disable the leakage current protection device test function when a ground wire is missing, thereby enhancing circuit safety. In the wiring test circuit, each LED is connected in parallel with a resistor to control the voltage across the LED. The LED will light up only if the input voltage is greater than the preset voltage value, thus reducing human judgment error. By independently testing the connection between the live wire, neutral wire, and ground wire of the socket, the comprehensiveness and accuracy of the test are improved, and a diode is connected in series in each test circuit to ensure the singleness and safety of the current flow. By forming a circuit with a finger through a human contact conductive trigger, it is possible to detect if there is a single live wire in the socket, thus avoiding potential electrical hazards when repairing the socket. Attached Figure Description

[0012] Figure 1 This is a test circuit diagram for a three-hole socket. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0014] The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or collections thereof.

[0015] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0016] Example 1 This embodiment provides a three-hole socket test circuit, such as Figure 1 As shown, the circuit includes a leakage current protection test circuit, a wiring status test circuit, and a single live wire test circuit; contact L is connected to the live wire, contact N is connected to the neutral wire, contact E is connected to the ground wire, contact N and contact E are connected through resistor R10, and contact L and contact E are connected through resistor R11; R10 and R11 are high-resistance resistors with a resistance of 10MΩ.

[0017] The leakage current protection device test circuit includes a fourth current flow circuit and a fifth current flow circuit. The fourth current flow circuit includes a diode D4, a resistor R8, a resistor R9, and the light-emitting diode part of the optocoupler U1. The anode of the diode D4 is connected to the contact L, and the cathode is connected to the contact E in series with R9 and R8. The pins 1 and 2 of the light-emitting diode of the optocoupler U1 are connected in parallel across the resistor R8. The fifth current flow circuit includes a switch K1, a resistor R7, and the photoresistor part of the optocoupler U1. One end of the switch K1 is connected to the contact L, and the other end is connected in series with the resistor R7 and connected to the pin 3 of the photoresistor of the optocoupler U1. The pin 4 is connected to the contact E. When the three-hole socket test circuit is connected to the socket, current enters from the live wire. When the ground wire is properly connected, the current flows out from the ground wire after passing through diode D4, resistor R9, and the LED of optocoupler U1. The resistance of the photoresistor of optocoupler U1 decreases. When switch K1 is pressed, the fifth current flow circuit generates a leakage current, causing the leakage current protector to trip. When the ground wire is missing, due to the unidirectional nature of diode D4 and the high resistance of resistor R10 (10MΩ), the current in the fourth current flow circuit is very small, and optocoupler U1 cannot conduct. At this time, when switch K1 is pressed, the fifth current flow circuit will not generate a leakage current, and the automatic shielding of the leakage current protector function can avoid safety hazards.

[0018] The wiring status test circuit includes a first current flow circuit, a second current flow circuit, and a third current flow circuit. The first current flow circuit includes a diode D1, a resistor R1, a light-emitting diode LED1, and a resistor R2. Diode D1, resistor R1, and LED1 are connected in series, and resistor R2 is connected in parallel with LED1. The cathode of diode D1 is connected to contact point N, and the anode of LED1 is connected to contact point L. The second current flow circuit includes a diode D2, a resistor R3, a light-emitting diode LED2, and a resistor R4. Diode D2, resistor R3, and LED2 are connected in series, and resistor R4 is connected in parallel with LED2. The anode of diode D2 is connected to contact point N, and the cathode of LED2 is connected to contact point E. The third current flow circuit includes a diode D3, a resistor R5, a light-emitting diode LED3, and a resistor R6. Diode D3, resistor R5, and LED3 are connected in series, and resistor R6 is connected in parallel with LED3. The anode of diode D3 is connected to contact point L, and the cathode of LED3 is connected to contact point E. When the socket is wired correctly, current enters from contact L, flows out from contact E through the third current flow circuit, and LED3 lights up; current enters from contact L, flows out from contact N through the first current flow circuit, and LED1 lights up; the voltage between contact N and contact E is low, and due to the voltage division effect of resistor R4, LED2 cannot light up. When the live wire and neutral wire of the socket are reversed, i.e., contact N is the live wire and contact L is the neutral wire, the current enters from contact N, flows out from contact E through the second current flow circuit, and LED2 lights up; because the current flows in reverse during the negative half-cycle of the AC current, the current enters from contact L, flows out from contact N through the first current flow circuit, and LED1 lights up; the voltage between contact L and contact E is low, and due to the voltage division effect of resistor R6, LED3 cannot light up; When the live wire and ground wire of the socket are reversed, i.e., contact E is the live wire and contact L is the ground wire, during the negative half-cycle of the AC current, the current enters from contact N, flows through the second current flow circuit and exits from contact E, and LED2 lights up; the current enters from contact L, flows through the third current flow circuit and exits from contact E, and LED3 lights up; the voltage between contact L and contact N is low, and due to the voltage division effect of resistor R2, LED1 cannot light up. When the socket lacks a ground wire, current enters from contact L, flows through the first current flow circuit, and exits from contact N, lighting up LED1; due to the unidirectional conductivity of diodes D2 and D3, there is no current in the second and third current flow circuits, so LED2 and LED3 cannot light up. When the socket lacks a neutral wire, current enters from the L terminal, flows out from the contact E through the third current flow circuit, and LED3 lights up; current enters from the L terminal, flows out from the contact E through the first current flow circuit and the second current flow circuit, and LED1 and LED2 light up. The wiring status of the socket can be determined by observing the lighting status of LED1, LED2, and LED3.

[0019] The single-wire test circuit includes an LCD display, a Zener diode DZ1, a Zener diode DZ2, a resistor R12, a resistor R13, and a human contact conductive trigger. The positive terminals of Zener diodes DZ1 and DZ2 are connected together, and their negative terminals are connected in parallel across the LCD display. Resistor R12 is connected in parallel with the LCD display, and resistor R13 is connected in series with the LCD display and connected to the human contact conductive trigger. The human contact conductive trigger requires only 1 to 10 microamps of current to light up the LCD display when touched by a finger, ensuring human safety. The positive terminals of Zener diodes DZ1 and DZ2 are connected together, and their negative terminals are connected in parallel across the LCD display to prevent the LCD display from burning out due to excessive voltage. When contact L in the socket is connected to the live wire only, and contact N and contact E are either left floating or both connected to the live wire, current enters from contact L, passes through resistor R11, LCD display, human contact conductive trigger and forms a circuit with the finger, lighting up the symbol on the LCD display, indicating that the socket under test is energized. When contact N in the socket is connected to the live wire only, and contact L and contact E are either left unconnected or both connected to the live wire, current enters from contact N, passes through resistor R10, LCD display, human contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display to indicate that the socket under test is energized. When contact E in the socket is connected to the live wire only, and contacts L and N are either left unconnected or both connected to the live wire, current enters from contact E, passes through the LCD display, the human body contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display and indicating that the socket under test is energized.

[0020] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A test circuit for a three-hole socket, characterized in that, The circuit includes a leakage current protection test circuit, a wiring status test circuit, a single live wire test circuit, contact L, contact N, and contact E; when the socket is correctly wired, contact L is connected to the live wire, contact N is connected to the neutral wire, and contact E is connected to the ground wire; contact N and contact E are connected through resistor R10, and contact L and contact E are connected through resistor R11, where R10 and R11 are high-resistance resistors with a resistance of 10MΩ; The leakage current protection test circuit is used to detect whether the socket ground wire is connected; The wiring status test circuit is used to detect whether the socket wiring is correct and to indicate the type of wiring error; The single live wire test circuit is used to detect and indicate that the socket has only a single live wire.

2. The three-hole socket test circuit according to claim 1, characterized in that, The leakage current protection device test circuit includes a fourth current flow circuit and a fifth current flow circuit. The fourth current flow circuit includes a diode D4, a resistor R8, a resistor R9, and the light-emitting diode part of the optocoupler U1. The anode of the diode D4 is connected to the contact L, and the cathode is connected to the contact E in series with R9 and R8. The pin 1 and pin 2 of the light-emitting diode of the optocoupler U1 are connected in parallel across the resistor R8. The fifth current flow circuit includes a switch K1, a resistor R7, and a photoresistor section of an optocoupler U1. One end of the switch K1 is connected to contact L, and the other end is connected in series with the resistor R7 and connected to pin 3 of the photoresistor of the optocoupler U1. Pin 4 of the photoresistor is connected to contact E.

3. The three-hole socket test circuit according to claim 1, characterized in that, The wiring status test circuit includes a first current flow circuit, a second current flow circuit, and a third current flow circuit. The first current flow circuit includes a diode D1, a resistor R1, a light-emitting diode LED1, and a resistor R2. The diode D1, resistor R1, and light-emitting diode LED1 are connected in series, and resistor R2 is connected in parallel with light-emitting diode LED1. The cathode of diode D1 is connected to contact point N, and the anode of light-emitting diode LED1 is connected to contact point L. The second current flow circuit includes diode D2, resistor R3, light-emitting diode LED2 and resistor R4. Diode D2, resistor R3 and light-emitting diode LED2 are connected in series, resistor R4 is connected in parallel with light-emitting diode LED2, the anode of diode D2 is connected to contact point N, and the cathode of light-emitting diode LED2 is connected to contact point E. The third current flow circuit includes diode D3, resistor R5, light-emitting diode LED3 and resistor R6. Diode D3, resistor R5 and light-emitting diode LED3 are connected in series, resistor R6 is connected in parallel with light-emitting diode LED3, the anode of diode D3 is connected to contact point L, and the cathode of light-emitting diode LED3 is connected to contact point E.

4. The three-hole socket test circuit according to claim 1, characterized in that, The single-wire test circuit includes an LCD display, a Zener diode DZ1, a Zener diode DZ2, a resistor R12, a resistor R13, and a human contact conductive trigger. The positive terminals of Zener diodes DZ1 and DZ2 are connected together, and their negative terminals are connected in parallel across the LCD display. Resistor R12 is connected in parallel with the LCD display, and resistor R13 is connected in series with the LCD display and connected to the human contact conductive trigger.

5. A three-hole socket test circuit according to claim 4, characterized in that, When contact L is connected to the live wire only, and contact N and contact E are either left floating or both connected to the live wire, current enters from contact L, passes through resistor R11, LCD display, human contact conductive trigger and forms a circuit with the finger, lighting up the symbol on the LCD display to indicate that the socket under test is energized. When contact N in the socket is connected to the live wire only, and contact L and contact E are either left unconnected or both connected to the live wire, current enters from contact N, passes through resistor R10, LCD display, human contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display to indicate that the socket under test is energized. When contact E in the socket is connected to the live wire only, and contacts L and N are either left unconnected or both connected to the live wire, current enters from contact E, passes through the LCD display, the human body contact conductive trigger, and forms a circuit with the finger, illuminating the symbol on the LCD display and indicating that the socket under test is energized.

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