Ground fault circuit interrupter with automatic monitoring

Abstract

The application discloses a grounding fault circuit breaker with automatic monitoring function, comprising a grounding fault circuit breaking module, an automatic monitoring circuit and an automatic and manual leakage detection circuit. After a reset button RESET is pressed and a test button TEST is pressed, when the tripping time of the grounding fault circuit breaker exceeds a set threshold, the MCU determines that the breaking is overtime, a discontinuous voltage is output from the 5th pin of the MCU, and at this time, a life termination alarm lamp R presents a flashing red alarm lamp. Compared with the prior art, the application solves the problem that the existing grounding fault circuit breaker cannot monitor whether the tripping time is normal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ground fault circuit interrupter, and particularly relates to a ground fault circuit interrupter with automatic monitoring function. BACKGROUND

[0002] Ground fault circuit interrupter (GFCI) is a new type of circuit breaker, which can prevent the damage of house wiring and protect people from electric shock. GFCI continuously monitors the current on the zero line and the fire line in the circuit. When everything is normal, the current on the two lines should be exactly the same. Once the fire line is directly grounded (for example, someone accidentally touches the fire line), the current on the fire line will suddenly increase, and the zero line will not. GFCI will immediately cut off the circuit to prevent electric shock and injury accidents after detecting this situation. Since GFCI can take action without waiting for the current to rise to a dangerous level, its response speed is much faster than that of traditional circuit breakers.

[0003] A test button is usually provided on the ground fault circuit interrupter. By pressing the test button, the residual current test can be realized to prevent electric shock and fire caused by ground arc.

[0004] The existing ground fault circuit interrupter has a single function. Pressing the test button can only realize the residual current test, and cannot monitor whether the tripping time is normal. SUMMARY

[0005] The purpose of the present application is to provide a ground fault circuit interrupter with automatic monitoring function to solve the problem that the existing ground fault circuit interrupter cannot monitor whether the tripping time is normal.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: a ground fault circuit interrupter with automatic monitoring function, comprising:

[0007] A ground fault circuit interrupting module, which comprises a mutual inductor coil L2, a mutual inductor coil L1, a chip U1, a bridge rectifier D1, a switching power supply circuit and an electromagnetic tripping circuit, the mutual inductor coil L2 is connected to the chip U1, the mutual inductor coil L1 is connected to the chip U1, the switching power supply circuit comprises a resistor R2, a resistor R5 and a capacitor C6, and the electromagnetic tripping circuit comprises an LB tripping coil, a diode D10 and a thyristor Q1;

[0008] An automatic monitoring circuit, which comprises an MCU, a zero-crossing detection sampling circuit, a load voltage sampling circuit and a voltage sampling detection circuit, the load voltage sampling circuit is connected to the 9th pin of the MCU, the voltage sampling detection circuit is connected to the 8th pin of the MCU, the load voltage sampling circuit comprises a diode D8, a resistor R26 and an optocoupler U5, and the diode D8 and the resistor R26 are connected in series;

[0009] The automatic and manual leakage detection circuit includes a reset button RESET, a test button TEST, a triode Q2, a working indicator lamp G and a life termination alarm lamp R, the 7th pin of the MCU is connected with the reset button RESET, the 6th pin of the MCU is connected with the test button TEST, the triode Q2 is connected with the 14th pin of the MCU, the collector of the triode Q2 is connected with a resistor R25, the resistor R25 is connected with the L polarity live wire end passing through the mutual inductor coil, the 3rd pin of the MCU is connected with the working indicator lamp G, and the 5th pin of the MCU is connected with the life termination alarm lamp R.

[0010] When the reset button RESET is pressed, the load end is electrified, rectified through a diode D8 and limited through a resistor R26, and then drives the input end of an optical coupler U5, the output end of the optical coupler U5 controls the 9th pin of the MCU to become low level, and the working indicator lamp G connected with the 3rd pin of the MCU is lighted.

[0011] When the unbalanced current exceeding 6MA passing through the L line and the N line of the mutual inductor coil does not trigger the thyristor Q1, the 8th pin of the MCU cannot be converted to low level, the MCU judges that the circuit is faulty and cannot play a protection role, the 5th pin of the MCU outputs an intermittent voltage, and at this time, the life termination alarm lamp R presents a red alarm lamp flashing.

[0012] When the test button TEST is pressed after the reset button RESET is pressed, and the tripping time of the grounding fault circuit breaker exceeds the set threshold value, the MCU determines that the breaking is overtime, the 5th pin of the MCU outputs an intermittent voltage, and at this time, the life termination alarm lamp R presents a red alarm lamp flashing.

[0013] In summary, due to the adoption of the above technical scheme, the beneficial effects of the present application are:

[0014] 1、In the present application, the grounding fault circuit breaker has manual test tripping time and automatic monitoring functions. The manual test (TEST) circuit is controlled by the MCU, the tripping time is detected by the MCU, and the red indicator lamp is driven to alarm when the tripping time exceeds the standard specified time, so as to timely prompt replacement, but will not directly trip.

[0015] 2、In the present application, the automatic monitoring circuit realizes all-weather automatic detection through the MCU, detects the damage of the GFCI itself caused by the damage of various components, power devices, tripping coils and other elements in the leakage sensor, neutral line repeated grounding sensor, chip U1 and switching power supply loop, and avoids causing safety accidents. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0017] Fig. 1 It is a schematic diagram of circuit connection of the grounding fault circuit breaker with automatic monitoring function.

[0018] Fig. 2 It is a practical circuit diagram of the grounding fault circuit breaker with automatic monitoring function.

[0019] Fig. 3 It is a structural schematic diagram of the grounding fault circuit breaker with automatic monitoring function.

[0020] Legend:

[0021] 1, reset button RESET: 2, test button TEST. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] It should be noted that: similar numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0025] In the description of the embodiments of the present application, it should be noted that the orientation or position relationship indicated by the terms "upper", "inner" and the like is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship commonly placed when the product of the present application is used, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Embodiment 1

[0028] Please refer to Figs. 1-3 The present application provides a technical scheme: a grounding fault circuit breaker with automatic monitoring function, comprising:

[0029] The grounding fault circuit breaker module comprises a mutual inductor coil L2, a mutual inductor coil L1, a chip U1, a bridge rectifier D1, a switching power supply circuit and an electromagnetic tripping circuit, the mutual inductor coil L2 is connected to the chip U1, the mutual inductor coil L1 is connected to the chip U1, the switching power supply circuit comprises a resistor R2, a resistor R5 and a capacitor C6, and the electromagnetic tripping circuit comprises an LB tripping coil, a diode D10 and a thyristor Q1;

[0030] The automatic monitoring circuit comprises an MCU, a zero-crossing detection sampling circuit, a load voltage sampling circuit and a voltage sampling detection circuit, the load voltage sampling circuit is connected to the 9th pin of the MCU, the voltage sampling detection circuit is connected to the 8th pin of the MCU, the load voltage sampling circuit comprises a diode D8, a resistor R26 and an optocoupler U5, and the diode D8 and the resistor R26 are connected in series;

[0031] The automatic and manual leakage detection circuit comprises a reset button RESET1, a test button TEST2, a transistor Q2, a working indicator lamp G and a life termination alarm lamp R, the 7th pin of the MCU is connected to the reset button RESET1, the 6th pin of the MCU is connected to the test button TEST2, the transistor Q2 is connected to the 14th pin of the MCU, the collector of the transistor Q2 is connected to a resistor R25, the resistor R25 is connected to the L polarity live wire end passing through the mutual inductor coil, the 3rd pin of the MCU is connected to the working indicator lamp G, and the 5th pin of the MCU is connected to the life termination alarm lamp R;

[0032] When the reset button RESET1 is pressed, the load end is powered, rectified by the diode D8, limited by the resistor R26, and then drives the input end of the optocoupler U5, the output end of the optocoupler U5 controls the 9th pin of the MCU to become low level, and the working indicator lamp G connected to the 3rd pin of the MCU is lit;

[0033] When the unbalanced current through the transformer coil L line, N line more than 6MA, no trigger thyristor Q1 can not trigger, MCU 8th pin can not be converted to low, MCU fault protection can not play a role, MCU single-chip microcomputer 5th pin output a broken voltage, at this time the life termination alarm lamp R presents a flash of red alarm lamp;

[0034] After pressing the reset button RESET1, press the test button TEST2, when the tripping time of the ground fault circuit breaker exceeds the set threshold, the MCU determines that the breaking is timed out, and the 5th pin of the MCU outputs a broken voltage. At this time, the life termination alarm lamp R presents a flash of red alarm lamp.

[0035] The transformer coil L2 is a leakage sensor (1000:1) transformer coil, and the transformer coil L1 is a neutral line repeated grounding sensor (200:1) transformer coil. When the transformer coil L2 senses an unbalanced current exceeding 6MA or the transformer coil L1 detects neutral line repeated grounding, a high level is output from the 1st pin of the chip U1 through resistance R4 and capacitor C3 coupling to the chip U1, the thyristor Q1 is triggered to conduct through resistance R27, the LB tripping coil and the diode D10, the thyristor Q1 form a loop, and the tripping coil core pushes the mechanical action to cut off the power supply.

[0036] When the ground fault circuit breaker (GFCI) is reset, the load is powered on, and the diode D8 is rectified, R26 is current-limited, and then the light coupling U5 input end is driven, and the output end controls the 9th pin of the MCU to become low.

[0037] When the reset button RESET1 is pressed, the 7th pin of the MCU becomes low, the 14th pin of the MCU gets high, and after current limiting through resistance R3, the B electrode of the transistor Q2 is driven, the transistor Q2 is turned on, and after passing through the L polarity live wire end and N zero line end of the transformer coil, more than 6MA unbalanced current is obtained;

[0038] When the test button TEST2 is pressed, the 7th pin of the MCU becomes low, the 14th pin of the MCU gets high, and after current limiting through resistance R3, the B electrode of the transistor Q2 is driven, the transistor Q2 is turned on, and after passing through the L polarity live wire end and N zero line end of the transformer coil, more than 6MA unbalanced current is obtained, a pulse is generated at the 7th pin of the MCU, the B electrode of the transistor Q3 is controlled after current limiting through the current limiting resistance R27, the transistor Q3 is turned on, and after passing through the N polarity live wire end and L zero line end of the transformer coil, more than 6MA unbalanced current is obtained.

[0039] When the transformer coil senses more than 6MA unbalanced current, coupled to the chip U1 through the resistance R4, the 1 pin of the chip U1 outputs high level, and the resistance R27 triggers the silicon controlled rectifier Q1 to trigger conduction, and the trigger current is opposite to the phase of the action of the trip coil LB, and at the same time the silicon controlled rectifier Q1 is turned on, the diode D9 releases the voltage of the 8th pin of the MCU, and turns to low level, and the MCU judges that the circuit is normal.

[0040] The automatic monitoring circuit realizes automatic detection all day round through the MCU, detects the damage of the GFCI itself caused by the damage of various components, power devices, trip coils and the like in the leakage sensor, neutral line repeated grounding sensor, chip U1 and switching power supply loop, and avoids causing safety accidents.

[0041] Specifically, the zero-crossing detection sampling circuit includes the resistance R10 and the voltage stabilizing diode Z1. The zero-crossing detection sampling circuit is used for detecting the power frequency and phase, the resistance R10 plays a current limiting role, and the voltage stabilizing diode Z1 stabilizes voltage and protects the MCU.

[0042] Specifically, the voltage sampling detection circuit includes the diode D9, the resistance R34 and the voltage stabilizing diode Z3, and the diode D9 and the resistance R34 are connected in parallel and then connected to the electromagnetic trip circuit. The resistance R34 is a sampling resistance, obtains the voltage through the LB trip coil, and after the voltage is stabilized at 3.3V through the voltage stabilizing diode Z3, the voltage is input into the 8th pin of the MCU single-chip microcomputer. As a comparison voltage, if the voltage is 0V, it indicates that the LB trip coil is damaged due to disconnection.

[0043] Working principle: when the reset button RESET1 is pressed, the load end is powered, rectified through the diode D8 and limited in current through the resistance R26, and then drives the input end of the optical coupler U5, the output end of the optical coupler U5 controls the 9th pin of the MCU to become low level, and the working indicator lamp G (green LED) connected to the 3rd pin of the MCU is lit.

[0044] When more than 6MA unbalanced current passes through the transformer coil L and N line, because of disconnection or short circuit of the transformer coil, damage of the U1 chip or damage of the current limiting resistance providing power supply for the U1 chip, the silicon controlled rectifier Q1 cannot be triggered, and the 8th pin of the MCU cannot be changed to low level, the MCU judges that the circuit is faulty and cannot play a protection role, and the 5th pin of the MCU single-chip microcomputer outputs an intermittent voltage, at this time, the end-of-life alarm lamp R presents a flashing red alarm lamp.

[0045] After the reset button RESET1 is pressed, the test button TEST2 is pressed, and the ground fault circuit interrupter (GFCI) should be tripped immediately. If the tripping time exceeds 200MS, the MCU determines that the breaking is overtime, the 5th pin of the MCU single-chip microcomputer outputs an intermittent voltage, at this time, the end-of-life alarm lamp R presents a flashing red alarm lamp.

[0046] The working indicator light G is a green LED light, and the life termination alarm light R is a red LED light, which indicates the ground fault circuit breaker state, and the table below can be referred to.

[0047] Table 1: Indicator light state table

[0048]

[0049]

[0050] The ground fault circuit breaker has a manual test tripping time and automatic monitoring function. The manual test (TEST) circuit is controlled by the MCU, the tripping time is detected by the MCU, and the red indicator light is driven to alarm when the tripping time exceeds the standard specified time, prompting replacement in time, but will not directly trip.

[0051] Embodiment 2

[0052] The embodiment further makes the following improved technical solutions on the basis of the above embodiment: a resistor R3 is arranged between the 14th pin of the MCU and the triode Q2.

[0053] The resistor R3 is used for current limiting, and the high level output by the 14th pin of the MCU controls the triode Q2 to be turned on after current limiting by the resistor R3.

[0054] Embodiment 3

[0055] The embodiment further makes the following improved technical solutions on the basis of the above embodiment: the ground fault circuit breaker further comprises a USB interface adaptation circuit.

[0056] The ground fault circuit breaker is integrated with a USB power board, and the USB interface of the USB interface adaptation circuit has USB-A and Type-C interfaces, which can provide DC 5V to charge mobile phones, tablet computers, digital cameras and other electrical appliances. The USB power board adopts existing general technology, and will not be described in detail.

[0057] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A ground fault circuit interrupter with automatic monitoring, comprising: The ground fault circuit breaker comprises a mutual inductor coil L2, a mutual inductor coil L1, a chip U1, a bridge rectifier D1, a switching power supply circuit and an electromagnetic tripping circuit, the mutual inductor coil L2 is connected to the chip U1, the mutual inductor coil L1 is connected to the chip U1, the switching power supply circuit comprises a resistor R2, a resistor R5 and a capacitor C6, and the electromagnetic tripping circuit comprises an LB tripping coil, a diode D10 and a thyristor Q1. The automatic monitoring circuit comprises an MCU, a zero-crossing detection sampling circuit, a load voltage sampling circuit and a voltage sampling detection circuit, the load voltage sampling circuit is connected to the 9th pin of the MCU, the voltage sampling detection circuit is connected to the 8th pin of the MCU, the load voltage sampling circuit comprises a diode D8, a resistor R26 and an optocoupler U5, and the diode D8 and the resistor R26 are connected in series. The automatic and manual leakage detection circuit comprises a reset button RESET, a test button TEST, a triode Q2, a working indicator lamp G and a life termination alarm lamp R, the 7th pin of the MCU is connected to the reset button RESET, the 6th pin of the MCU is connected to the test button TEST, the triode Q2 is connected to the 14th pin of the MCU, the collector of the triode Q2 is connected to a resistor R25, the resistor R25 is connected to the L polarity live wire end passing through the mutual inductor coil, the 3rd pin of the MCU is connected to the working indicator lamp G, and the 5th pin of the MCU is connected to the life termination alarm lamp R. When the reset button RESET is pressed, the load end is powered, rectified by the diode D8, current-limited by the resistor R26, and then drives the input end of the optocoupler U5, the output end of the optocoupler U5 controls the 9th pin of the MCU to become low level, and the working indicator lamp G connected to the 3rd pin of the MCU is lit. When the unbalanced current exceeding 6MA passing through the mutual inductor coil L line and N line does not trigger the thyristor Q1, the 8th pin of the MCU cannot be converted to low level, the MCU judgment circuit fails to play a protection role, the 5th pin of the MCU outputs an intermittent voltage, and at this time, the life termination alarm lamp R presents a red alarm lamp that flashes. When the test button TEST is pressed after the reset button RESET is pressed, and the tripping time of the ground fault circuit breaker exceeds the set threshold, the MCU determines that the breaking is overtime, the 5th pin of the MCU outputs an intermittent voltage, and at this time, the life termination alarm lamp R presents a red alarm lamp that flashes. A resistor R3 is arranged between the 14th pin of the MCU and the triode Q2.

2. The ground fault circuit interrupter with automatic monitoring function according to claim 1, wherein, The zero-crossing detection sampling circuit comprises a resistor R10 and a zener diode Z1.

3. The ground fault circuit interrupter with automatic monitoring function according to claim 1, wherein, The voltage sampling detection circuit comprises a diode D9, a resistor R34 and a zener diode Z3, and the diode D9, the resistor R34 and the zener diode Z3 are connected in parallel and then connected to the electromagnetic tripping circuit.

4. The ground fault circuit interrupter with automatic monitoring function according to claim 1, wherein, The ground fault circuit breaker further comprises a USB interface adaptation circuit.

5. The ground fault circuit interrupter with automatic monitoring capability of claim 1, wherein, ​

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