A single-phase ac line connection state detection circuit

Abstract

The application discloses a single-phase alternating current line connection state detection circuit, which comprises a main control chip and a signal detection circuit. In the signal detection circuit, a circuit in which resistance two, resistance three, diode two, resistance four and resistance five are connected in series is connected in parallel with a circuit in which resistance six and resistance seven are connected in series, and then the negative electrode of diode one is connected in series; the negative electrode of diode one is connected with resistance two and resistance six; the positive electrode of resistance three is connected with the positive electrode of diode two; and the negative electrode of resistance four is connected with the negative electrode of diode two. The positive electrode of diode one is used as a firewire input end, a firewire signal terminal is led out between resistance two and resistance three; the positive electrode of diode two is used as a zero line input end, a zero line signal terminal is led out between resistance four and resistance five; and resistance five and resistance seven are used as a ground wire input end, a ground wire signal terminal is led out between resistance six and resistance seven.

Description

Technical Field

[0001] This invention belongs to the field of power detection technology, specifically relating to a single-phase AC line wiring status detection circuit. Background Technology

[0002] In building, renovation, and everyday electrical design, the wiring and socket installation of single-phase alternating current (AC) are always involved. Safe use of AC requires the correct wiring of the live, neutral, and ground wires. Therefore, it is necessary to check the AC wiring status during wiring construction to identify potential safety hazards such as missing ground wire, missing neutral wire, reversed live and neutral wires, or reversed live and ground wires.

[0003] In traditional detection circuits, such as... Figure 1 and Figure 2 As shown, the detection chip is first powered by a full-wave rectifier circuit, a three-terminal power supply chip U2, and a step-down circuit. Then, an optocoupler chip is used as the signal feedback element for each line. This existing technology uses many components, has a complex circuit structure, and is costly. Furthermore, the filter capacitor in the bridge rectifier circuit is prone to a weak short circuit when the detection plug is inserted or removed, causing the leakage current protection switch in the mains power line to trip. Summary of the Invention

[0004] The purpose of this invention is to simplify the single-phase AC circuit wiring status detection circuit. It proposes a single-phase AC line wiring status detection circuit that uses fewer components to achieve the same detection function as the prior art, while improving the reliability of the detection circuit.

[0005] This invention provides a single-phase AC line wiring status detection circuit, mainly including a main control chip and a signal detection circuit; the signal detection circuit includes diode one, diode two, resistor two, resistor three, resistor four, resistor five, resistor six, and resistor seven; wherein, the circuit in which resistor two, resistor three, diode two, resistor four, and resistor five are connected in series, and the circuit in which resistor six and resistor seven are connected in parallel, are then connected in series with the negative terminal of diode one, and the negative terminal of diode one is simultaneously connected to resistor two and resistor six; resistor three is connected to diode... The positive terminal of diode 1 is connected to the positive terminal of diode 2, and the negative terminal of diode 4 is connected to the negative terminal of diode 2. Diode 1's positive terminal serves as the live wire input, and a live wire signal terminal is led out between resistors 2 and 3. Diode 2's positive terminal serves as the neutral wire input, and a neutral wire signal terminal is led out between resistors 4 and 5. Resistor 5 and resistor 7 serve as the ground wire input, and a ground wire signal terminal is led out between resistors 6 and 7. The live wire signal terminal, the neutral wire signal terminal, and the ground wire signal terminal are each connected to one I / O port of the main control chip.

[0006] Further, the main control chip judges the three-wire single-phase alternating current wiring normal, lack of ground wire, lack of zero line, reversed connection of fire line and zero line, reversed connection of fire line and ground wire according to the voltage signals of the fire line signal terminal, the zero line signal terminal and the ground wire signal terminal.

[0007] As a preferred means, the single-phase alternating current wiring state detection circuit further comprises a power supply circuit; the power supply circuit is a half-wave rectification circuit, which is composed of a steady voltage diode, a capacitor one and a capacitor two connected in parallel between the fire line input terminal and the zero line input terminal, and a voltage dividing resistor one connected in series with the fire line input terminal; the capacitor one is an electrolytic capacitor.

[0008] As a preferred means, the single-phase alternating current wiring state detection circuit further comprises a display circuit; the display circuit is composed of three light emitting diodes with different colors, which are connected to a driving pin of the main control chip through voltage dividing resistors respectively.

[0009] Further, the display circuit can be replaced by a digital tube or a liquid crystal display screen.

[0010] As a preferred means, in the detection instrument product comprising the single-phase alternating current wiring state detection circuit, the fire line input terminal, the zero line input terminal and the ground wire input terminal are made into a plug suitable for a common three-hole socket.

[0011] Compared with the prior art, the topology of the present application is greatly simplified, and has a very obvious price advantage. The present application has the same detection function as the prior art, and avoids the defect that the detection plug of the prior art may appear leakage tripping in the instant of plugging and unplugging. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a topology structure diagram of the detection circuit of the prior art;

[0013] Figure 2 is a main control chip wiring diagram of the detection circuit of the prior art;

[0014] Figure 3 is a topology structure diagram of the detection circuit of the present application. DETAILED DESCRIPTION

[0015] The present application will be further described in detail below in combination with the drawings:

[0016] In this invention, the main control chip uses the JZ8P1521-SOP8, which is used in existing technology. Specific parameters can be obtained from the "Product Center" module (http: / / www.wxjzkj.com / about_product / MCUdpj053.html) on the homepage of Wuxi Jingzhe Technology Co., Ltd. (http: / / www.wxjzkj.com / ). The wiring of the main control chip is as follows... Figure 2 It is the same as the existing technology.

[0017] See appendix Figure 2 and 3 The present invention provides a single-phase AC line wiring status detection circuit, which mainly includes a main control chip U1, a signal detection circuit, a display circuit, and a power supply circuit.

[0018] The display circuit consists of three light-emitting diodes (LEDs) of different colors. Each of the three LEDs is connected to a driver pin of the main control chip through a voltage divider resistor. The three LEDs of different colors, either individually or in combination, display the status of the AC power connection as "normal, missing ground wire, missing neutral wire, live and neutral wires reversed, and live and ground wires reversed".

[0019] As an alternative, the display circuit can be replaced with a digital tube or an LCD screen. For those skilled in the art, using a microcontroller for data display is a conventional technique, and the display rules for wiring status can also be customized.

[0020] The signal detection circuit includes diode D1, diode D2, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, and resistor R7. The cathode of diode D1 is connected in series with resistors R2, R3, D2, R4, and R5, and also with resistors R6 and R7. Specifically, the circuit consisting of these series-connected resistors R2, R3, D2, R4, and R5, and R6 and R7, is connected in parallel and then connected in series with the cathode of diode D1. The cathode of diode D1 is also connected to both resistors R2 and R6. Resistor R3 is connected to the anode of diode D2, and resistor R4 is connected to the cathode of diode D2.

[0021] In the above signal detection circuit: the anode of diode one D1 is used as the live wire input end (ACL), a live wire signal terminal (IOSignerL) is led out between resistor two R2 and resistor three R3; the anode of diode two D2 is used as the zero wire input end (ACN), a zero wire signal terminal (IOSignerN) is led out between resistor four R4 and resistor five R5; resistor five R5 and resistor seven R7 are used as the ground wire input end (PE), a ground wire signal terminal (IOSignerG) is led out between resistor six R6 and resistor seven R7.

[0022] The live wire signal terminal (IOSignerL), the zero wire signal terminal (IOSignerN) and the ground wire signal terminal (IOSignerG) are connected to an I / O port of the master control chip U1 respectively.

[0023] In the specific detection instrument product, the live wire input end (ACL), the zero wire input end (ACN) and the ground wire input end (PE) can be made into plugs suitable for the common three-hole socket.

[0024] The power supply circuit is a half-wave rectification circuit, which is composed of a Zener diode ZD, a capacitor one C1 and a capacitor two C2 connected in parallel between the live wire input end (ACL) and the zero wire input end (ACN) of the detection circuit, and a voltage dividing resistor one R1 connected in series at the live wire input end (ACL). The Zener diode ZD can be used as a half-wave rectification element and can also define the maximum voltage for the power supply output. The capacitor one C1 is an electrolytic capacitor, the anode of which is used as the output of the power supply circuit and the cathode of which is grounded. The electrolytic capacitor has a large capacity and insulation resistance, and can absorb the impact voltage generated in the instant of plugging and unplugging of the detection plug, so as to avoid the occurrence of weak leakage current in the rectification and filtering circuit. The capacitor two C2 is a conventional filtering capacitor.

[0025] Since the single-phase alternating current of three-wire system is used, as long as the live wire is connected in the three wires, the chip power supply circuit of the present application can work normally.

[0026] As an alternative, the above power supply circuit can be cancelled in the present application, and a battery can be used to supply power to the master control chip.

[0027] The working process and principle of the single-phase alternating current line connection state detection circuit of the present application will be described in detail below.

[0028] The present application can be used to detect the conditions of normal connection, lack of ground wire, lack of zero wire, live wire and zero wire connected reversely, and live wire and ground wire connected reversely.

[0029] In the actual detection operation, if the detection circuit of the present application does not react (all the LEDs are not lit) when the detection plug is inserted into the three-hole socket (which can be a temporary test connection), it indicates that the live wire is missing in the line.

[0030] The following expressions: assume that the test when the three-wire power supply has been connected with the fire line; "positive half-wave" expression is based on the fire line input (ACL) as the reference. Ignore the diode voltage drop; signal terminal sampling period is not less than 0.1 seconds.

[0031] 1. The wiring is normal.

[0032] If the three-wire wiring is normal, the fire line input (ACL) and the zero line input (ACN) have a sinusoidal AC waveform, and the fire line input (ACL) and the ground line input (PE) also have a sinusoidal AC waveform.

[0033] The fire line detection signal is provided by resistor three R3. In the normal wiring state, the fire line signal terminal (IOSignerL) has a "amplitude one" voltage pulse output during the positive half-wave. Here "amplitude one" refers to the voltage peak on resistor three R3 during the positive half-wave. The fire line signal terminal (IOSignerL) has no output during the negative half-wave.

[0034] During the positive half-wave, the fire line input (ACL) and the zero line input (ACN) are connected through diode one D1, resistor two R2 and resistor three R3; during the negative half-wave, the fire line input (ACL) and the zero line input (ACN) are connected through zener diode ZD and resistor one R1. Since the potential of the zero line input (ACN) is always 0, there is always a continuous small amplitude voltage (low analog signal) output on the zero line signal terminal (IOSignerN) due to the internal resistance of the zero line.

[0035] The ground line detection signal is provided by resistor seven R7. In the normal wiring state, the ground line signal terminal (IOSignerG) has a "amplitude two" voltage pulse output during the positive half-wave. Here "amplitude two" refers to the voltage peak on resistor seven R7 during the positive half-wave. The ground line signal terminal (IOSignerG) has no output during the negative half-wave.

[0036] The main control chip determines that the wiring state is "normal" according to the "amplitude one" pulse output of the fire line signal terminal (IOSignerL), the low analog signal output of the zero line signal terminal (IOSignerN), and the "amplitude two" pulse output of the ground line signal terminal (IOSignerG), and instructs the display circuit to display in a certain predetermined color or color combination.

[0037] 2. The ground line is missing.

[0038] Referring to the attached Figure 3 If the ground line input (PE) is missing, and the fire line input (ACL) and the zero line input (ACN) are normal, then the fire line input (ACL) and the zero line input (ACN) have a sinusoidal AC waveform, and there is no current between the fire line input (ACL) and the ground line input (PE).

[0039] The live wire detection signal is provided by resistor three R3. In the wiring state of missing ground wire, the live wire signal terminal (IOSingerL) has a "amplitude one" voltage pulse output in the positive half wave. Here "amplitude one" refers to the voltage peak on resistor three R3 during the positive half wave. The live wire signal terminal (IOSingerL) has no output in the negative half wave.

[0040] In the positive half wave, the live wire input terminal (ACL) and the neutral wire input terminal (ACN) are connected through diode one D1, resistor two R2 and resistor three R3; in the negative half wave, the live wire input terminal (ACL) and the neutral wire input terminal (ACN) are connected through zener diode ZD and resistor one R1. Since the potential of the neutral wire input terminal (ACN) is always 0, there is always a continuous small amplitude voltage (low analog signal) output on the neutral wire signal terminal (IOSingerN) due to the internal resistance of the neutral wire.

[0041] The ground wire detection signal is provided by resistor two R2 and resistor three R3. In the wiring state of missing ground wire, the ground wire signal terminal (IOSingerG) has a "amplitude three" voltage pulse output in the positive half wave. Here "amplitude three" refers to the sum of the voltage peaks on resistor two R2 and resistor three R3, ignoring the voltage drop on diode one D1 during the positive half wave. Here "amplitude three" voltage is about 311V (220V*1.41). The ground wire signal terminal (IOSingerG) has no output in the negative half wave.

[0042] The main control chip judges that the wiring state is "missing ground wire" according to the "amplitude one" pulse output of the live wire signal terminal (IOSingerL), the low analog signal output of the neutral wire signal terminal (IOSingerN) and the "amplitude three" pulse output of the ground wire signal terminal (IOSingerG), and instructs the display circuit to display in a certain predetermined color or color combination.

[0043] 3. Missing neutral wire.

[0044] Referring to the accompanying drawings Figure 3 If the neutral wire is missing and the live wire input terminal (ACL) and the ground wire input terminal (PE) are normal, there is no current between the live wire input terminal (ACL) and the neutral wire input terminal (ACN), and there is a sinusoidal alternating current between the live wire input terminal (ACL) and the ground wire input terminal (PE).

[0045] When the neutral wire input terminal (ACN) is not wired, the potential is clamped to 0 due to the forced grounding between resistor three R3 and diode two D2, so the branch composed of diode two D2, resistor four R4 and resistor five R5 is not conductive, and the neutral wire signal terminal (IOSingerN) outputs 0.

[0046] The fire wire detection signal is provided by resistor six R6 and resistor seven R7. In the condition of missing neutral wire, the fire wire signal terminal (IOSignerL) has a "amplitude three" voltage pulse output in the positive half wave. Here "amplitude three" refers to the sum of the voltage peak value of resistor six R6 and resistor seven R7, ignoring the voltage drop of diode one D1 during the positive half wave. The "amplitude three" voltage is about 311V (220V*1.41). The fire wire signal terminal (IOSignerL) has no output in the negative half wave.

[0047] The ground wire detection signal is provided by resistor seven R7. In this wiring condition, the ground wire signal terminal (IOSignerG) has an "amplitude two" voltage pulse output in the positive half wave. Here "amplitude two" refers to the voltage peak value of resistor seven R7 during the positive half wave. The ground wire signal terminal (IOSignerG) has no output in the negative half wave.

[0048] According to the "amplitude three" pulse output of the fire wire signal terminal (IOSignerL), the 0 output of the neutral wire signal terminal (IOSignerN), and the "amplitude two" pulse output of the ground wire signal terminal (IOSignerG), the main control chip judges that the wiring condition is "missing neutral wire" and instructs the display circuit to display in a certain predetermined color or color combination.

[0049] 4. Fire wire and neutral wire are connected reversely.

[0050] Referring to the accompanying drawings Figure 3 If the fire wire and neutral wire are connected reversely, there is a sinusoidal AC between the fire wire input terminal (ACL) and the neutral wire input terminal (ACN), and there is also a sinusoidal AC between the neutral wire input terminal (ACN) and the ground wire input terminal (PE).

[0051] The fire wire detection signal is provided by resistor three R3. In the condition of fire wire and neutral wire connected reversely, the fire wire signal terminal (IOSignerL) has an "amplitude one" voltage pulse output in the positive half wave. Here "amplitude one" refers to the voltage peak value of resistor three R3 during the positive half wave. The fire wire signal terminal (IOSignerL) has no output in the negative half wave.

[0052] The positive half wave neutral wire detection signal is provided by resistor two R2 and resistor three R3, and the negative half wave neutral wire detection signal is provided by resistor five R5. In this wiring condition, the neutral wire signal terminal (IOSignerN) has a continuous large amplitude voltage (high analog signal) output in the positive and negative half waves.

[0053] The ground detection signal is provided by resistor two R2 and resistor three R3. In this connection state, the ground signal terminal (IOSignerG) has a "magnitude three" voltage pulse output in the positive half wave. Here "magnitude three" refers to the sum of the voltage peaks on resistor two R2 and resistor three R3, ignoring the voltage drop on diode one D1 during the positive half wave. The "magnitude three" voltage is about 311V (220V*1.41) here. The ground signal terminal (IOSignerG) has no output in the negative half wave.

[0054] The master control chip judges that the connection state is "fire line zero line reversed" according to the "magnitude one" pulse output of the fire wire signal terminal (IOSignerL), the high analog signal output of the zero line signal terminal (IOSignerN), and the "magnitude three" pulse output of the ground signal terminal (IOSignerG), and instructs the display circuit to display in a certain predetermined color or color combination.

[0055] 5. Fire line and ground line reversed.

[0056] Referring to the accompanying drawings Figure 3 If the fire line and ground line are reversed, there is a sinusoidal alternating current between the fire wire input terminal (ACL) and the ground wire input terminal (PE), and there is also a sinusoidal alternating current between the zero wire input terminal (ACL) and the ground wire input terminal (PE).

[0057] The fire wire detection signal is provided by resistor two R2. In this connection state, the fire wire signal terminal (IOSignerL) has a "magnitude four" voltage pulse output in the positive half wave. The fire wire signal terminal (IOSignerL) has no output in the negative half wave.

[0058] Resistor four R4 provides a positive half wave zero line detection signal. In the negative half wave, the zero line signal terminal (IOSignerN) is actually connected to the "fire line". Therefore, in this connection state, the zero line signal terminal (IOSignerN) has a continuous large amplitude voltage (high analog signal) output in the positive and negative half waves.

[0059] Resistor six R6 provides a positive half wave ground detection signal. In the negative half wave, the ground signal terminal (IOSignerG) is actually connected to the "fire line". Therefore, in this connection state, the ground signal terminal (IOSignerG) has a continuous large amplitude voltage (high analog signal) output in the positive and negative half waves.

[0060] The master control chip judges that the connection state is "fire line and ground line reversed" according to the "magnitude four" pulse output of the fire wire signal terminal (IOSignerL), the high analog signal output of the zero line signal terminal (IOSignerN), and the high analog signal output of the ground signal terminal (IOSignerG), and instructs the display circuit to display in a certain predetermined color or color combination.

[0061] With the attached Figure 1 Compared with the prior single-phase AC wiring state detection circuit shown in the drawings, the topology of the present application is greatly simplified, and the rectifier bridge, power chip U2 and optocoupler element are omitted, which has a very obvious price advantage. The present application has the same detection function as the prior art, and avoids the defect that the detection plug may appear electric leakage tripping at the instant of plugging and unplugging.

[0062] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0063] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments that those skilled in the art can understand.

[0064] The present application is not limited to the above description of the embodiments, and those skilled in the art can make improvements and modifications on the basis of the disclosure of the present application without creative labor, which should be within the protection scope of the present application.

Claims

1.A single-phase AC line connection state detection circuit, characterized in that: it mainly comprises a master control chip and a signal detection circuit; the signal detection circuit comprises a diode one, a diode two, a resistor two, a resistor three, a resistor four, a resistor five, a resistor six and a resistor seven; wherein the resistor two, the resistor three, the diode two, the resistor four and the resistor five are connected in series, and the resistor six and the resistor seven are connected in series, and the series connection of the resistor two, the resistor three, the diode two, the resistor four and the resistor five and the series connection of the resistor six and the resistor seven are connected in parallel with the negative electrode of the diode one, and the negative electrode of the diode one is connected with the resistor two and the resistor six; the resistor three is connected with the positive electrode of the diode two, and the resistor four is connected with the negative electrode of the diode two; wherein the positive electrode of the diode one is used as a live wire input end, a live wire signal terminal is led out between the resistor two and the resistor three; the positive electrode of the diode two is used as a zero line input end, a zero line signal terminal is led out between the resistor four and the resistor five; the resistor five and the resistor seven are used as a ground wire input end, a ground wire signal terminal is led out between the resistor six and the resistor seven; the live wire signal terminal, the zero line signal terminal and the ground wire signal terminal are connected with an I / O port of the master control chip respectively. 2.The single-phase AC line connection state detection circuit according to claim 1, characterized in that: it further comprises a power supply circuit; the power supply circuit is a half-wave rectification circuit, which is composed of a stabilizing diode, a capacitor one and a capacitor two connected in parallel between the live wire input end and the zero line input end, and a voltage dividing resistor one connected in series with the live wire input end; the capacitor one is an electrolytic capacitor. 3.The single-phase AC line connection state detection circuit according to claim 1, characterized in that: it further comprises a display circuit; the display circuit is composed of three light-emitting diodes of different colors, and the three diodes are connected to a driving pin of the master control chip through voltage dividing resistors respectively. 4.The single-phase AC line connection state detection circuit according to claim 3, characterized in that: the display circuit can be replaced by a digital tube or a liquid crystal display screen. 5.The single-phase AC line connection state detection circuit according to any one of claims 1-4, characterized in that: the live wire input end, the zero line input end and the ground wire input end are made into a plug that is adapted to a common three-hole socket.

Images