CN101872956B - Leakage current detection protection circuit - Google Patents

Abstract

The invention discloses a leakage detection and protection circuit, which includes an induction coil for detecting leakage current, a self-detection coil for detecting low-resistance faults, a control chip, a tripping coil with a built-in iron core, a thyristor, a semi A wave rectifier diode and a power output indicator light are characterized in that: it also includes an auxiliary coil connected in series with the trip coil, and a normally closed switch device linked with the auxiliary coil; the trip coil, the auxiliary coil, and the auxiliary coil linked After the normally closed switch device is connected in series, it is connected between the live wire and the neutral wire of the power input terminal to form an analog leakage current generating circuit; when there is no current flowing in the auxiliary coil, the normally closed switch device is closed; when there is current flowing in the auxiliary coil, The normally closed switching device is open.

Description

Leakage detection protection circuit

technical field

The invention relates to a leakage detection and protection circuit, which can be installed in a power socket and a power plug with the function of leakage protection. Specifically, the electric leakage detection and protection circuit involved in the present invention not only has the functions of electric leakage detection and protection, but also, when the power input terminal of the electric leakage detection and protection circuit is connected to the power line in the wall, it can automatically generate a detection current to detect the electric leakage. Detect whether the protection circuit still has leakage protection function, and display the detection result. In addition, the leakage detection and protection circuit also has the function of protecting the power socket/power plug caused by instantaneous high voltage caused by lightning strike or other reasons; and it also has the function of preventing reverse wiring errors.

Background technique

With the continuous development of the power socket with leakage protection function (referred to as leakage protection socket, GFCI)/power plug industry, people have higher and higher requirements for the function, safety and reliability of leakage protection socket/plug. This makes people in the industry constantly devote themselves to researching and improving the leakage detection and protection circuit installed in the leakage protection socket/plug, so that the circuit is simpler, the function is stronger, and the work is more reliable.

Contents of the invention

In view of the above reasons, the main purpose of the present invention is to provide a leakage detection protection circuit installed in a power socket/plug with leakage detection protection function, which can automatically detect whether the leakage detection protection circuit still has the leakage protection function.

Another object of the present invention is to provide a leakage detection and protection circuit capable of protecting power sockets/plugs from damage caused by instantaneous high voltage caused by lightning strikes or other reasons.

Another object of the present invention is to provide a leakage detection and protection circuit with the function of preventing reverse wiring errors. If it does not work, it prevents the reset button of the power socket/plug from resetting, so that the power input terminal of the leakage detection protection circuit and the power output jack on the surface of the socket have no power output.

In order to achieve the above object, the present invention adopts the following technical solutions: a leakage detection and protection circuit, which includes an induction coil for detecting leakage current, a self-detection coil for detecting low resistance faults, a control chip, and a disconnector with a built-in iron core. A tripping coil, a thyristor, a half-wave rectifying diode, and a power output indicator light are characterized in that it also includes an auxiliary coil connected in series with the tripping coil, and a normally closed switch device linked with the auxiliary coil.

Description of drawings

Fig. 1 is the specific circuit diagram of Embodiment 1 of leakage detection and protection circuit of the present invention;

Fig. 1-1 is the specific circuit diagram of Embodiment 2 of the leakage detection and protection circuit of the present invention;

Fig. 2 is the specific circuit diagram of Embodiment 3 of the leakage detection and protection circuit of the present invention;

Fig. 2-1 is the specific circuit diagram of Embodiment 4 of the leakage detection and protection circuit of the present invention;

3 is a specific circuit diagram of Embodiment 5 of the leakage detection and protection circuit of the present invention;

Figure 3-1 is a specific circuit diagram of Embodiment 6 of the leakage detection and protection circuit of the present invention;

Fig. 4 is the specific circuit diagram of Embodiment 7 of the leakage detection and protection circuit of the present invention;

Figure 4-1 is a specific circuit diagram of Embodiment 8 of the leakage detection and protection circuit of the present invention;

5 is a specific circuit diagram of Embodiment 9 of the leakage detection and protection circuit of the present invention;

Figure 5-1 is a specific circuit diagram of embodiment 10 of the leakage detection and protection circuit of the present invention;

6 is a specific circuit diagram of Embodiment 11 of the leakage detection and protection circuit of the present invention;

Fig. 6-1 is a specific circuit diagram of Embodiment 12 of the leakage detection and protection circuit of the present invention.

Detailed ways

FIG. 1 is a specific circuit diagram of a leakage detection and protection circuit with leakage detection and protection functions installed in a power socket/plug with leakage protection function disclosed by the present invention. As shown in Figure 1, the leakage detection and protection circuit includes an induction coil L1 (1000:1) for detecting leakage current, a self-detection coil L2 (200:1) for detecting low-resistance faults, and a control chip IC1 (RV4145) , Two series-connected tripping coil L3 (SOL) and auxiliary coil L4, normally closed switch KR-4 linked with auxiliary coil L4, thyristor V4, half-wave rectifier diode V1, power output indicator lights V3, V5.

After the live wire HOT and neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit pass through the induction coil L1 (1000:1) for detecting leakage current and the self-detection coil L2 (200:1) for detecting low-resistance faults, The switches KR-2-1 and KR-2-2 linked with the power socket/plug reset button RESET are connected to the live wire and neutral wire output conductive socket in the single-phase three-wire power output jack on the surface of the power socket; at the same time, leakage current After detecting the hot wire HOT and neutral wire WHITE of the power input terminal LINE of the protection circuit, it passes through the induction coil L1 (1000:1) for detecting leakage current and the self-inspection coil L2 (200:1) for detecting low resistance faults, and then passes through Another group of switches KR-3-1 and KR-3-2 linked with the reset button RESET are connected to the hot wire HOT and the neutral wire WHITE of the power socket/plug power output terminal (load terminal) LOAD.

The signal output terminals of the induction coil L1 (1000:1) for detecting leakage current, the self-detection coil L2 (200:1) for detecting low-resistance faults, and the signal input terminals 1, 2, 3, and 7 of the control chip IC1 The control signal output terminal 5 of the control chip IC1 is connected to the trigger pole of the thyristor V4. The cathode of the thyristor V4 is connected to the zero line WHITE of the power input terminal LINE, and the anode of the thyristor V4 is connected to the hot wire HOT of the power input terminal through the tripping coil L3.

The working power input terminal 6 of the control chip IC1 is finally connected to the fire wire HOT of the power input terminal LINE through a resistor R3, a half-wave rectifier diode V1, and a tripping coil L3. The working ground pin 4 of the control chip IC1 is connected to the neutral line WHITE of the power input terminal LINE.

After the tripping coil L3, the auxiliary coil L4, and the normally closed switch KR-4 linked with the auxiliary coil L4 are connected in series, they are connected between the power input terminal LINE, the live wire HOT and the neutral wire WHITE, to form an automatic detection circuit for detecting whether the tripping coil L3 is intact. current loop. When there is no current flowing in the auxiliary coil L4, the normally closed switch KR-4 is closed; when there is current flowing in the auxiliary coil L4, a magnetic field is generated in the auxiliary coil L4, and the normally closed switch KR is turned on by the mechanical device in the power socket/power plug. -4 disconnected.

As shown in Figure 1, when the live wire HOT and the neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit are connected to the power line in the wall, since the normally closed switch KR-4 is closed, the live wire HOT of the power input terminal is disconnected in series. The buckle coil L3, the auxiliary coil L4, and the closed normally closed switch KR-4 are connected to the zero line WHITE of the power input terminal to form a closed loop. At this time, if the tripping coil L3 in the leakage detection protection circuit is intact and has no end of life, the closed loop automatically generates a passing current to detect whether the tripping coil L3 is intact.

Because there is a large current flowing in the trip coil L3 and the auxiliary coil L4, a magnetic field is generated in the trip coil L3 and the auxiliary coil L4, and the iron core built in the trip coil L3 and the auxiliary coil L4 moves, so that the normally closed switch KR- 4. Disconnect, detect the passage current of the tripping coil L3 disappears; at the same time, make the mechanical tripping device in the power socket/plug act, the guide lock and the lock hole in the power plug/socket are in a straight line, and wait for the reset button RESET to reset. At this time, press the reset button RESET, the push rod of the reset button pushes the latch downward to leave the lock hole, the lock hole returns to the original position, and the lock groove and the lock hole are matched, and the reset button RESET resets, so that the linkage with the reset button RESET The switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 are closed, the normally closed switch KR-4 is opened, the load end of the power socket/plug and the power output plug on the surface of the power socket There is a power output in the hole, and the power output indicators V3 and V5 are on between the live wire and the neutral wire of the power socket/plug power output terminal in parallel. In the reset state of the reset button, the switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 linked with the reset button RESET are closed, and the normally closed switch KR-4 is opened.

Conversely, if the life of the tripping coil L3 in the leakage detection and protection circuit is terminated at this time, and the leakage detection and protection circuit does not have the function of leakage detection and protection, then no large current flows in the tripping coil L3 and auxiliary coil L4, and the tripping coil L3 , There is no magnetic field in the auxiliary coil L4, the iron core built in the tripping coil L3 and auxiliary coil L4 does not move, the guide lock and the keyhole in the power socket/plug are always in a misaligned state, and the reset button RESET is always unable to reset. The switches KR-2-1, KR-2-2, KR-3-1, and KR-3-2 associated with the reset button RESET are not closed, and the power socket/plug load end LOAD and the power output jack on the surface of the power socket have no power supply Output, the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire at the power outlet/plug power output end are off. So far, the automatic detection process of the leakage detection protection circuit is completed.

When the leakage detection protection circuit has no end of life, it still has the leakage protection function. After the reset button RESET is reset, the power socket/plug power output terminal LOAD has power output. If there is leakage current in the power supply circuit, due to the power line HOT and zero line WHITE At the same time through the induction coil L1 (1000:1) and the self-detection coil L2 (200:1) used to detect the leakage current, the current vector sum in the two power lines is not zero, and L1 and L2 will immediately induce a certain value The voltage signal is input to the control chip IC1, and the control signal is output from pin 5 of IC1 to the trigger pole of the thyristor V4, and the thyristor V4 is triggered to conduct, and a current flows in the tripping coil L3, generating a magnetic field. The iron core makes an impact movement to trip the reset button RESET, cut off the output of the power supply, and the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire at the output end of the power socket/plug are extinguished, and the thyristor V4 is cut off. The leakage detection and protection circuit returns to the initial state, the normally closed switch KR-4 recovers from the open state to the closed state, the power input terminal LINE HOT of the leakage detection and protection circuit passes through the tripping coil L3, the auxiliary coil L4, and the closed normally closed switch KR -4 is connected to the zero line WHITE of the power input terminal to form a closed loop, and automatically generates the passage current for detecting the tripping coil. Repeat the above process, and the normally closed switch KR-4 is turned into an open state, waiting for the reset button RESET to reset.

The present invention can also manually generate a simulated leakage current by pressing the test button TEST to detect whether the life of the leakage protection socket is terminated. As shown in Figure 1, one end of the test switch KR-5 linked with the test button TEST is connected to the neutral line of the power supply input terminal through the analog leakage current limiting resistor R1, and the other end is connected to the live line HOT of the power supply output terminal.

When you want to check whether the function of the power socket/plug is normal, you can press the test button TEST to close the linked test switch KR-5, and manually generate a simulated leakage current. If the leakage detection protection circuit has no end of life, the reset button RESET trips, and the power socket/plug trips; if the power socket/plug does not have a reset state and the leakage detection protection circuit life ends, the reset button RESET is prevented from resetting.

In order to make the electric leakage detection and protection circuit work reliably, an anti-disturbance capacitor C5 is connected between the trigger electrode of the thyristor and the ground in the present invention. The control signal output from pin 5 of the control chip IC1 is filtered by the anti-interference capacitor C5 connected between the SCR trigger pole and the ground to suppress false triggering.

In the present invention, a power output indicator light V3 (LED1) and V5 (LED2) for indicating whether the power socket/power plug has power output is connected between the live wire and the neutral wire of the power output end of the leakage detection protection circuit. When the power outlet/plug has power output, V3 and V5 are on; otherwise, V3 and V5 are off.

In order to improve the service life of the power socket/power plug and avoid damage to the power socket/power plug caused by instantaneous high voltage caused by lightning strikes or other reasons, as shown in Figure 1, the leakage detection protection circuit disclosed by the present invention is at the power input terminal LINE The live wire HOT and the neutral wire WHITE are respectively connected with a sharp lightning protection metal sheet M1, M2 for discharge, and the sharp lightning protection metal sheets M1, M2 are placed quite well. In addition, the hot wire HOT/neutral wire WHITE of the power input end is also connected to the neutral wire WHITE/hot wire HOT of the power input end through the tripping coil L3 and a piezoresistor MOV.

When the live wire and neutral wire at the input end of the power supply cause instantaneous high voltage due to lightning strike or other reasons, the air medium between the sharp lightning protection metal sheet connected to the live wire at the input end and the sharp lightning protection metal sheet connected to the neutral wire at the input end is broken down , forming an air discharge, most of the high voltage is consumed by the lightning protection metal sheet, and a small part is consumed by the tripping coil L3 and the varistor MOV, thus protecting the leakage detection and protection circuit.

In a specific embodiment of the present invention, the varistor MOV is a surge suppression varistor, so that it can also prevent electrophoresis.

As shown in Fig. 1, the present invention also has a protection function against reverse wiring errors. As shown in the figure, the load end LOAD of the power socket/power plug and the single-phase three-wire power output jack on the surface of the socket pass through the switches KR-3-1, KR-3-2, and KR-2-1 linked with the reset button RESET. , KR-2-2 is connected to the live wire and the neutral wire of the power input terminal LINE, so when the installer mistakenly connects the power cord in the wall to the load terminal LOAD of the power socket/power plug, even if the normally closed switch KR-4 Closed, since a closed loop from the power input terminal LINE live wire HOT to the power supply input terminal LINE neutral wire WHITE cannot be formed, there is no current flowing in the tripping coil L3 and auxiliary coil L4, and the magnetic field cannot be generated to push the built-in iron core to move. The mechanical tripping device in the plug/power socket does not work, the reset button cannot be reset all the time, and the switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 linked with the reset button RESET are always It is disconnected and cannot be closed. The power socket/power plug input terminal LINE and the power jack on the surface of the socket have no power output. The power output indicator V5 is on, but the power output indicator V3 is not on, indicating that the wiring is wrong. The installer can reset the reset button only after the wiring is correct, the power output indicators V3 and V5 are on at the same time, and the power output of the power socket/plug has power output.

Figure 1-1 is a specific circuit diagram of Embodiment 2 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 2 of the leakage detection protection circuit shown in Figure 1-1 and Embodiment 1 shown in Figure 1 is that the anode of the thyristor V4 is input to the power supply of the leakage detection protection circuit through the switch KR-6, the tripping coil L3 Connect to the fire wire HOT of the terminal LINE. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE HOT through the normally closed contacts 66 and 88 of the switch KR-6 and the tripping coil L3; when there is current in the tripping coil L3 and the auxiliary coil L4 When the current flows through, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 Closed, the output terminal has power output, a pair of normally open contacts 67 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE fire wire HOT through the normally open contacts 67 and 88 of the switch KR-6 and the tripping coil L3 . The cathode of the thyristor V4 is connected to the neutral line of the power supply.

In the circuit shown in Figure 1-1, a switch KR-6 is added between the anode of the thyristor and the live wire of the power supply, which can ensure that the thyristor V4 is quickly and reliably turned off during the process of detecting whether the life of the leakage detection protection circuit is terminated. , to prevent the tripping coil L3 or auxiliary coil L4 from being burned out during the detection process.

FIG. 2 is a specific circuit diagram of Embodiment 3 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 3 of the leakage detection and protection circuit shown in FIG. 2 and Embodiment 1 shown in FIG. 1 is that the switch KR-4 is replaced by a thermistor Rt.

When the live wire HOT and neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit are connected to the power line in the wall, the live wire HOT of the power input terminal is connected to the power input through the series tripping coil L3, auxiliary coil L4, thermistor Rt The terminal zero line WHITE is connected to form a closed loop, which automatically generates a pass-through current to detect whether the tripping coil L3 is intact. As the time of the passage current flowing through the thermistor Rt increases, the temperature of the thermistor Rt rises. When the temperature rises to a certain level, the thermistor Rt is disconnected, and the passage current of the detection trip coil L3 disappears. When the temperature of the thermistor Rt decreases, the thermistor Rt returns to a normal state.

Fig. 2-1 is a specific circuit diagram of Embodiment 4 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 4 of the leakage detection protection circuit shown in Figure 2-1 and Embodiment 3 shown in Figure 2 is that the anode of the thyristor V4 passes through the switch KR-6, the tripping coil L3 and the power supply of the leakage detection protection circuit The fire wire HOT of the input terminal LINE is connected. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE HOT through the normally closed contacts 66 and 88 of the switch KR-6 and the tripping coil L3; when there is current in the tripping coil L3 and the auxiliary coil L4 When the current flows through, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 Closed, the output terminal has power output, a pair of normally open contacts 67 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE fire wire HOT through the normally open contacts 67 and 88 of the switch KR-6 and the tripping coil L3 .

FIG. 3 is a specific circuit diagram of Embodiment 5 of the leakage detection and protection circuit of the present invention. As shown in the figure, after the tripping coil L3 and the auxiliary coil L4 are connected in series, one end is connected to the hot wire HOT of the power input terminal, and the other end is connected to the anode of the thyristor V4; one end of the normally closed switch KR-4 linked with the auxiliary coil L4 is connected to to the working power pin 6 of the DC power supply/control chip IC1, and the other end is connected to the trigger pole of the thyristor V4; when there is no current flowing in the auxiliary coil L4, the normally closed switch KR linked with the auxiliary coil L4- 4 closed; when there is current flowing in the auxiliary coil L4, a magnetic field is generated in the auxiliary coil L4, and the normally closed switch KR-4 is disconnected through the operation of the mechanical device in the power socket/power plug.

As shown in Figure 3, when the hot wire HOT and the neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit are connected to the power line in the wall, the normally closed switch KR-4 is closed, and the hot wire HOT of the power input terminal passes through the tripping coil L3 , the auxiliary coil L4, the closed normally closed switch KR-4 and the trigger pole of the thyristor V4 are connected.

At this time, if the tripping coil L3 and the thyristor V4 in the leakage detection protection circuit are intact and have no end of life, the trigger of the thyristor V4 is extremely high, the thyristor V4 is triggered to conduct, and the tripping coil L3 , There is a large current flowing in the auxiliary coil L4, a magnetic field is generated in the tripping coil L3 and the auxiliary coil L4, the iron core built in the tripping coil L3 and the auxiliary coil L4 operates, and the mechanical tripping device in the power socket/plug operates , so that the normally closed switch KR-4 is disconnected, and the signal to detect whether the tripping coil L3 and the thyristor V4 are intact disappears. At the same time, the guide lock and the lock hole in the power socket/power plug are in a straight line, waiting for the reset button RESET to reset. At this time, press the reset button RESET, the push rod of the reset button pushes the latch downward to leave the lock hole, the lock hole returns to the original position, and the lock groove and the lock hole are matched, and the reset button RESET resets, so that the linkage with the reset button RESET The switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 are closed, the normally closed switch KR-4 is always open, the load end of the power socket/plug LOAD and the power output on the surface of the power socket The jack has power output, and the power output indicators V3 and V5 are on between the live wire and the neutral wire at the power outlet/plug power output end in parallel.

Conversely, if the tripping coil L3 and/or thyristor V4 in the leakage detection protection circuit have expired at this time, they do not have the protection function of leakage detection, even if the trigger level of the thyristor V4 is extremely high, the thyristor V4 will also No conduction, no large current flows in the tripping coil L3 and auxiliary coil L4, no magnetic field is generated in the tripping coil L3 and auxiliary coil L4, the iron core built in the tripping coil L3 and auxiliary coil L4 does not operate, the power supply The guide lock and the lock hole in the socket/power plug are always misaligned, and the reset button RESET can never be reset. The switches KR-2-1, KR-2-2, KR-3-1, KR- linked with the reset button RESET 3-2 Not closed, the power socket/plug load end LOAD and the power output jack on the surface of the power socket have no power output, and the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire of the power socket/plug power output end are off. So far, the automatic detection process of the leakage detection protection circuit is completed.

When the leakage detection protection circuit has no end of life, it still has the leakage protection function. After the reset button RESET is reset, the power socket/plug power output terminal LOAD has power output. If there is leakage current in the power supply circuit, due to the power line HOT and zero line WHITE At the same time through the induction coil L1 (1000:1) and the self-detection coil L2 (200:1) used to detect the leakage current, the current vector sum in the two power lines is not zero, and L1 and L2 will immediately induce a certain value The voltage signal is input to the control chip IC1, and the control signal is output from pin 5 of IC1 to the trigger pole of the thyristor V4, and the thyristor V4 is triggered to conduct, and a current flows in the tripping coil L3, generating a magnetic field. The iron core makes an impact movement to trip the reset button RESET, cut off the output of the power supply, and the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire at the output end of the power socket/plug are extinguished, and the thyristor V4 is cut off. The leakage detection and protection circuit returns to the initial state, the normally closed switch KR-4 recovers from the open state to the closed state, the power input terminal LINE HOT of the leakage detection and protection circuit passes through the tripping coil L3, the auxiliary coil L4, and the closed normally closed switch KR -4 is connected to the trigger pole of the thyristor V4, repeat the above process, the normally closed switch KR-4 changes to the disconnected state, wait for the reset button RESET to reset, and the reset button can be reset only after the cause of the leakage is found out and the leakage fault is eliminated.

The anode of the thyristor V4 in FIG. 3 is connected to the live wire of the power input terminal through the tripping coil L3 and the auxiliary coil L4 connected in series.

Fig. 3-1 is a specific circuit diagram of Embodiment 6 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 6 of the leakage detection and protection circuit shown in Figure 3-1 and Embodiment 5 shown in Figure 3 is that the anode of the thyristor V4 passes through the switch KR-6, the tripping coil L3 and the auxiliary coil L4 in series. It is connected with the hot wire HOT of the power input terminal LINE of the leakage detection protection circuit. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE live wire HOT through the normally closed contacts 66 and 88 of the switch KR-6, the series tripping coil L3 and the auxiliary coil L4; when the tripping coil L3, When there is current flowing in the auxiliary coil L4, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1 , KR-3-2 is closed, the output terminal has power output, a pair of normally open contacts 67, 88 are closed, the anode of the thyristor V4 passes through the normally open contacts 67, 88 of the switch KR-6, and the tripping coil L3 connected in series And the auxiliary coil L4 is connected with the power input terminal LINE and the fire wire HOT. The cathode of the thyristor is connected to the zero line WHITE of the power supply.

FIG. 4 is a specific circuit diagram of Embodiment 7 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 7 of the leakage detection and protection circuit shown in FIG. 4 and Embodiment 1 shown in FIG. After the closed switch KR-4 is connected in series, it is connected between the power input terminal LINE, the live wire HOT and the neutral wire WHITE, to form a loop, and automatically generate the passage current for detecting the tripping coil L3. However, in the leakage detection and protection circuit shown in Figure 4, after the tripping coil L3, the auxiliary coil L4, and the normally closed switch KR-4 linked with the auxiliary coil L4 are connected in series, one end is connected to the power input terminal LINE and the other end is connected to the live wire HOT. The induction coil L1 (1000:1) used to detect the leakage current is connected to the zero line WHITE of the power supply of the self-detection coil L2 (200:1), forming a circuit for automatically generating analog leakage current.

As shown in Figure 4, when the live wire HOT and the neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit are connected to the power line in the wall, since the normally closed switch KR-4 is closed, the live wire HOT of the power input terminal is disconnected in series. Buckle coil L3, auxiliary coil L4, closed normally closed switch KR-4, resistor R3 and the neutral wire of the power supply passing through the induction coil L1 (1000:1) and the self-detection coil L2 (200:1) for detecting leakage current WHITE connected to form a closed loop, automatically generate analog leakage current.

At this time, if the leakage detection protection circuit is intact, has no end of life, and still has the leakage detection protection function, the induction coil L1 (1000:1) for detecting leakage current and the self-detection coil L2 (200 : 1) The signal output terminal outputs a signal to the control chip IC1, the pin 5 of the control chip IC1 outputs a control signal, triggers the thyristor V4, and the thyristor V4 is triggered to conduct, and the tripping coil L3 and the auxiliary coil L4 have When a large current flows, a magnetic field is generated in the tripping coil L3 and the auxiliary coil L4, the iron core built in the tripping coil L3 and the auxiliary coil L4 moves, the normally closed switch KR-4 is turned off, and the simulated leakage current disappears. At the same time, the power supply The mechanical release device in the socket/plug acts to open the lock in the power socket/power plug, the guide lock and the lock hole are in a straight line, and wait for the reset button RESET to reset. At this time, press the reset button RESET, and at the same time push the latch away from the lock hole, the lock hole returns to the original position, make the lock groove and the lock hole match, the reset button RESET can be reset, so that the switch KR-2 linked with the reset button RESET -1, KR-2-2, KR-3-1, KR-3-2 are closed, the normally closed switch KR-4 is always open, the power socket/plug load end LOAD and the power output jack on the surface of the power socket have power Output, connected in parallel between the live wire and the neutral wire at the power outlet/plug power output terminal, the power output indicator lights V3 and V5 are on.

Conversely, if the life of the leakage detection and protection circuit is terminated at this time, and there is no leakage detection and protection function, the thyristor V4 is not turned on, there is no large current flowing in the tripping coil L3, and there is no magnetic field in the tripping coil L3 and the auxiliary coil L4 generated, the iron core built in the tripping coil L3 and auxiliary coil L4 does not act, the reset button RESET cannot be reset all the time, and the switches KR-2-1, KR-2-2, KR-3-1 linked with the reset button RESET , KR-3-2 is not closed, the power socket/plug load end LOAD and the power output jack on the surface of the power socket have no power output, and the power output indicator V3 between the live wire and the neutral wire of the power socket/plug power output end is connected in parallel. V5 goes out.

When the leakage detection protection circuit is intact, there is no end of life, the lock hole has been opened, and the reset button RESET is reset, the power socket/plug power output terminal LOAD has power output. If there is leakage current in the power supply circuit, due to the power line HOT and neutral line WHITE passes through the induction coil L1 (1000:1) and the self-detection coil L2 (200:1) for detecting leakage current at the same time, the current vector sum in the two power lines is not zero, and L1 and L2 will immediately sense a certain The voltage signal of the value is input to the control chip IC1, and the control signal is output from pin 5 of IC1 to the trigger pole of the thyristor V4, and the thyristor V4 is triggered to conduct, and a current flows in the tripping coil L3, generating a magnetic field. The internal iron core makes an impact movement to trip the reset button RESET, cut off the output of the power supply, and the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire at the output end of the power socket/plug are extinguished, and the thyristor V4 is cut off. The leakage detection and protection circuit returns to the initial state, the normally closed switch KR-4 recovers from the open state to the closed state, the power input terminal LINE HOT of the leakage detection and protection circuit passes through the tripping coil L3, the auxiliary coil L4, and the closed normally closed switch KR -4 is connected to the zero line WHITE of the power input terminal to form a closed loop, and automatically generates an analog leakage current. Repeat the above process, and the normally closed switch KR-4 is turned into an open state again, waiting for the reset button RESET to reset.

Fig. 4-1 is a specific circuit diagram of Embodiment 8 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 8 of the leakage detection and protection circuit shown in Fig. 4-1 and Embodiment 7 shown in Fig. 4 is that the anode of the thyristor V4 is connected with the switch KR-6, the tripping coil L3 and the auxiliary coil L4 connected in series The leakage detection protection circuit power supply input terminal LINE is connected to the fire wire HOT. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE live wire HOT through the normally closed contacts 66 and 88 of the switch KR-6, the series tripping coil L3 and the auxiliary coil L4; when the tripping coil L3, When there is current flowing in the auxiliary coil L4, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1 , KR-3-2 is closed, the output terminal has power output, a pair of normally open contacts 67, 88 are closed, the anode of the thyristor V4 passes through the normally open contacts 67, 88 of the switch KR-6, and the tripping coil in series L3 and the auxiliary coil L4 are connected to the power input terminal LINE and the hot wire HOT, and the cathode of the thyristor V4 is connected to the power neutral wire.

FIG. 5 is a specific circuit diagram of Embodiment 9 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 9 of the leakage detection and protection circuit shown in FIG. 5 and Embodiment 1 shown in FIG. After the closed switch KR-4 is connected in series, it is connected between the power input terminal LINE, the live wire HOT and the neutral wire WHITE to form a closed loop, which automatically generates a pass current for detecting whether the tripping coil L3 is intact. However, the anode of the thyristor V4 in the leakage detection and protection circuit shown in FIG. 5 is connected to the live wire of the power input terminal through the tripping coil L3 and the auxiliary coil L4 connected in series. One end of the normally closed switch KR-4 linked with the auxiliary coil L4 is connected to the power line HOT passing through the induction coil L1 (1000:1) for detecting the leakage current and the self-detection coil L2 (200:1), and the other end is connected to the The switch KR-5 linked with the power socket/power plug test button TEST and the current limiting resistor R3 are connected in series with the power input terminal LINE neutral wire WHITE to form an analog leakage current generating circuit.

As shown in Figure 5, when the hot wire HOT and neutral wire WHITE of the power input terminal LINE of the leakage detection protection circuit are connected to the power wire in the wall, first press the test button TEST of the power socket/power plug to close the switch KR-5 , at this time, since the normally closed switch KR-4 is closed, the hot wire HOT at the input terminal of the power supply passes through the coils L1 and L2 and is connected to the zero line WHITE at the input terminal of the power supply through the closed normally closed switch KR-4 and the closed switch KR-5, forming The closed circuit generates an artificial analog leakage current, the mechanical device in the power socket/plug works, the lock hole is opened, and waits for the reset button to reset, which is the reset state of the power socket/plug.

At this time, if the leakage detection protection circuit is intact, has no end of life, and still has the leakage detection protection function, the induction coil L1 (1000:1) for detecting leakage current and the self-detection coil L2 (200 : 1) The signal output terminal outputs a signal to the control chip IC1, the pin 5 of the control chip IC1 outputs a control signal, triggers the thyristor V4, and the thyristor V4 is triggered to conduct, and the tripping coil L3 and the auxiliary coil L4 have When a large current flows, a magnetic field is generated in the tripping coil L3 and the auxiliary coil L4, and the iron core built in the tripping coil L3 and the auxiliary coil L4 acts to make the normally closed switch KR-4 open, and the simulated leakage current disappears; at the same time, Make the mechanical tripping device in the power socket/plug act, the guide lock and the lock hole in the power socket/plug are in a straight line state, and wait for the reset button RESET to reset. At this time, press the reset button RESET, and at the same time push the latch to the lower side of the reset button to leave the lock hole, the lock hole returns to the original position, the lock groove and the lock hole match, the reset button RESET resets, so that the linkage with the reset button RESET The switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 are closed, the normally closed switch KR-4 is opened, the load end of the power socket/plug and the power output plug on the surface of the power socket There is a power output in the hole, and the power output indicators V3 and V5 are on between the live wire and the neutral wire of the power socket/plug power output terminal in parallel.

Conversely, if the life of the leakage detection and protection circuit is terminated at this time, and there is no leakage detection and protection function, the thyristor V4 is not turned on, and there is no large current flowing in the tripping coil L3 and the auxiliary coil L4, and the tripping coil L3 and the auxiliary coil There is no magnetic field generated in L4, the iron core built in the tripping coil L3 and auxiliary coil L4 does not move, the guide lock and the keyhole in the power socket/plug are always misaligned, and the reset button RESET can never be reset, and the reset button RESET The linked switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 are not closed, the power socket/plug load end LOAD and the power output jack on the surface of the power socket have no power output, parallel connection The power output indicators V3 and V5 between the live wire and the neutral wire at the power outlet/plug power output end are extinguished.

When the leakage detection protection circuit is intact and there is no end of life, after the reset button RESET is reset, the power socket/plug power output terminal LOAD has power output. For the induction coil L1 (1000:1) and the self-detection coil L2 (200:1) for detecting leakage current, the vector sum of the currents in the two power lines is not zero, and L1 and L2 will immediately induce a certain value of voltage signal input To the control chip IC1, the control signal is output from pin 5 of IC1 to the trigger pole of the thyristor V4, the thyristor V4 is triggered and turned on, the tripping coil L3 and the auxiliary coil L4 have current flowing through them, generating a magnetic field, and the internal The iron core makes an impact movement to trip the reset button RESET, cut off the output of the power supply, and the power output indicators V3 and V5 connected in parallel between the live wire and the neutral wire at the output end of the power socket/plug are extinguished, and the thyristor V4 is cut off. The leakage detection protection circuit returns to the initial state, and the normally closed switch KR-4 returns to the closed state from the open state. If you want to check whether the power socket/plug still has the leakage detection function, you can press the test button TEST to close the switch KR-5, and the power input terminal LINE HOT of the leakage detection protection circuit passes through the coils L1 and L2 through the closed normally closed switch KR -4. The closed switch KR-5 is connected to the zero line WHITE of the power input terminal to form a closed loop to generate a simulated leakage current. Repeat the above process, the normally closed switch KR-4 is disconnected, and wait for the reset button RESET to reset.

Another difference between Embodiment 9 of the leakage detection protection circuit shown in FIG. 5 and Embodiment 1 shown in FIG. 1 is that the leakage detection protection circuit shown in FIG. 5 also includes a mechanism linked with the auxiliary coil L4. When the current flows, the auxiliary coil L4 opens the light hole G through this mechanism to indicate that the leakage detection protection circuit is intact.

Fig. 5-1 is a specific circuit diagram of Embodiment 10 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 10 of the leakage detection and protection circuit shown in Fig. 5-1 and Embodiment 9 shown in Fig. 5 is that the anode of the thyristor V4 is connected to The leakage detection protection circuit power supply input terminal LINE is connected to the fire wire HOT. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE live wire HOT through the normally closed contacts 66 and 88 of the switch KR-6, the series tripping coil L3 and the auxiliary coil L4; when the tripping coil L3, When there is current flowing in the auxiliary coil L4, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1 , KR-3-2 is closed, the output terminal has power output, a pair of normally open contacts 67, 88 are closed, the anode of the thyristor V4 passes through the normally open contacts 67, 88 of the switch KR-6, and the tripping coil L3 connected in series And the auxiliary coil L4 is connected with the power input terminal LINE and the fire wire HOT.

FIG. 6 is a specific circuit diagram of Embodiment 11 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 11 of the leakage detection and protection circuit shown in FIG. 6 and Embodiment 9 shown in FIG. 5 is that the leakage detection and protection circuit shown in FIG. 5 also includes a mechanism linked with the auxiliary coil L4. Out of time, the auxiliary coil L4 activates the mechanism through the mechanical device in the power socket/power plug, and opens the light hole G to indicate that the leakage detection protection circuit is intact. The leakage detection and protection circuit shown in Figure 6 includes a pointer N1 linked with the auxiliary coil L4. When there is current flowing in the auxiliary coil L4, the auxiliary coil L4 moves the pointer N1 through the mechanical device in the power socket/power plug, indicating leakage detection The protection circuit still has the protection function of leakage detection, and if the detection is successful, the reset button can be reset.

Fig. 6-1 is a specific circuit diagram of Embodiment 12 of the leakage detection and protection circuit of the present invention. The difference between Embodiment 12 of the leakage detection and protection circuit shown in Figure 6-1 and Embodiment 11 shown in Figure 6 is that the anode of the thyristor V4 is connected with the switch KR-6, the tripping coil L3 and the auxiliary coil L4 in series. The leakage detection protection circuit power supply input terminal LINE is connected to the fire wire HOT. The switch KR-6 includes a pair of normally closed contacts 66, 88 and a pair of normally open contacts 67, 88; when there is no current flowing in the tripping coil L3 and the auxiliary coil L4, the pair of normally closed contacts of the switch KR-6 Points 66 and 88 are closed, and the anode of the thyristor V4 is connected to the power input terminal LINE live wire HOT through the normally closed contacts 66 and 88 of the switch KR-6, the series tripping coil L3 and the auxiliary coil L4; when the tripping coil L3, When there is current flowing in the auxiliary coil L4, a pair of normally closed contacts 66 and 88 of the switch KR-6 are disconnected, the reset button resets successfully, and the power switches KR-2-1, KR-2-2, KR-3-1 , KR-3-2 is closed, the output terminal has power output, a pair of normally open contacts 67, 88 are closed, the anode of the thyristor V4 passes through the normally open contacts 67, 88 of the switch KR-6, and the tripping coil L3 connected in series And the auxiliary coil L4 is connected with the power input terminal LINE and the fire wire HOT.

In summary, since the present invention adopts the above technical solutions, the leakage detection and protection circuit disclosed in the present invention has the following outstanding advantages:

(1) The leakage detection and protection circuit of the present invention adopts a double-coil design, that is, two series-connected tripping coil L3 and auxiliary coil L4. Its advantages: open the lock in the power socket/plug in advance through the auxiliary coil L4, wait for the reset button to reset, and reduce the burden on the tripping coil L3; Protected socket end of life prevents power socket/plug from resetting. Ingenious design, easy to use, and simpler operation.

(2) When the power socket/plug power input terminal is connected to the power cord in the wall, it can automatically or press the test button TEST to generate a detection current to detect whether the power socket/plug still has the leakage protection function, that is, whether the life is terminated.

(3) It has the protection function of preventing damage caused by lightning strikes and instantaneous high voltage caused by other reasons to the leakage protection socket.

(4) It has a protection function to prevent reverse wiring errors.

The above are specific embodiments of the present invention and the applied technical principles. Any equivalent transformation based on the technical solution of the present invention falls within the scope of protection of the present invention.

Claims (2)

1. leakage current detection protection circuit, it comprise induction coil (L1) for detection of leakage current, for detection of the low resistance fault from magnetic test coil (L2), control chip (IC1), the tripping coil (L3) that is built-in with iron core, controllable silicon (V4), halfwave rectifier diode (V1), power supply output indicator (V3, V5), it is characterized in that: it also comprise an ancillary coil (L4) of connecting with tripping coil (L3), with the normally closed switch device of ancillary coil (L4) interlock;

Described tripping coil (L3), ancillary coil (L4), with after the normally closed switch device of ancillary coil (L4) interlock is connected, be connected between power input (LINE) live wire (HOT) and the zero line (WHITE), form the loop, produce for detection of tripping coil intact passage current whether;

When not having electric current to flow through in the ancillary coil (L4) and reset button when being trip status, described normally closed switch device is in closure; In ancillary coil (L4), have electric current flow through/when reset button is reset mode, the driven disconnection of described normally closed switch device.

2. leakage current detection protection circuit according to claim 1, it is characterized in that: this leakage current detection protection circuit also comprises a switch (KR-6), this switch (KR-6) comprises a pair of normally-closed contact (66,88) and a pair of normally opened contact (67,88); Described controllable silicon anode links to each other with the power input live wire by switch (KR-6), tripping coil (L3);

When no current flows through in described tripping coil (L3), the ancillary coil (L4), a pair of normally-closed contact of switch (KR-6) (66,88) closure; Described controllable silicon (V4) anode links to each other with power input (LINE) live wire (HOT) by normally-closed contact (66,88), the tripping coil (L3) of switch (KR-6);

When having electric current to flow through in tripping coil (L3), the ancillary coil (L4), the a pair of normally-closed contact of switch (KR-6) (66,88) disconnects, the reset button success that resets, mains switch (KR-2-1, KR-2-2, KR-3-1, KR-3-2) closure, output has power supply output, a pair of normally opened contact (67,88) closure, controllable silicon (V4) anode links to each other with power input (LINE) live wire (HOT) by normally opened contact (67,88), the tripping coil (L3) of switch (KR-6);

The negative electrode of controllable silicon (V4) links to each other with zero-power line.

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