AC input line detection circuit and socket having the same

Abstract

The present invention discloses a detection circuit for an AC input line and a socket having the same, wherein the anode of a first diode D1 of the detection circuit for the AC input line is connected to a live wire terminal, the output end of the first diode D1 is connected to one end of a first resistor R1, the other end of the first resistor R1 is connected to one end of a fourth resistor R4, the other end of the fourth resistor R4 is connected to the anode of a second diode D2, and the cathode of the second diode D2 is connected to a neutral wire terminal; the anode of a third diode D3 is connected between the connection line between the first resistor R1 and the fourth resistor R4, and the cathode of the third diode D3 is connected to a ground wire terminal; the control end of a switch tube Q1 is connected between the connection line between the first resistor R1 and the fourth resistor R4, the input end of the switch tube Q1 is connected to a signal output end, and the output end of the switch tube Q1 is connected between the connection between the fourth resistor R4 and the anode of the second diode D2. The present invention can effectively detect abnormal ground wires and reverse connection of live and neutral wires.

Description

Technical Field

[0001] The invention relates to the technical field of power wiring, and in particular to a detection circuit for an AC input line and a socket having the same. Background Art

[0002] In the prior art, switches and sockets are mostly mechanically opened and closed, and cannot detect whether the ground wire is in good contact and whether the live wire and the neutral wire are connected in reverse. Since the equipment with a ground wire (three-plug) is usually grounded to the ground, or grounded through a Y capacitor, once the ground wire is bad, it will slightly cause the EMI performance to deteriorate, and seriously cause damage to other electrical equipment, especially during production testing, it is easy to burn out sensitive components of the tested circuit, and more seriously cause people to get electric shocks, endangering their lives. If the ground wire and the live wire are connected in reverse, the switch usually only turns off the neutral wire, while the live wire is still connected. Some equipment will have leakage tripping, and some short circuits will catch fire. These devices have no early warning and are prone to electric shock accidents or other disasters. At present, switches or sockets lack relevant detection and protection. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an AC input line detection circuit that can effectively detect ground line anomalies and reverse connection of live and neutral lines.

[0004] The present invention also provides a socket having the detection circuit of the AC input line.

[0005] According to the detection circuit of the AC input line of the embodiment of the first aspect of the present invention, a live wire terminal, a neutral wire terminal, a ground wire terminal, a signal output terminal, a first diode D1, a first resistor R1, a fourth resistor R4, a second diode D2, a third diode D3 and a switch tube Q1, the anode of the first diode D1 is connected to the live wire terminal, the output end of the first diode D1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to the neutral wire terminal; the anode of the third diode D3 is connected between the connection line of the first resistor R1 and the fourth resistor R4, and the cathode of the third diode D3 is connected to the ground wire terminal; the control end of the switch tube Q1 is connected between the connection line of the first resistor R1 and the fourth resistor R4, the input end of the switch tube Q1 is connected to the signal output end, and the output end of the switch tube Q1 is connected between the connection between the fourth resistor R4 and the anode of the second diode D2.

[0006] According to the detection circuit of the AC input line of the embodiment of the present invention, at least the following beneficial effects are achieved: when the circuit is normally turned on, a small current flows from the live wire terminal to the first diode D1, the first resistor R1 and the third diode D3. Due to the voltage clamping effect of the third diode D3, the voltage between the fourth resistor R4 and the second diode D2 is equal to the clamping voltage of the third diode D3, which is less than 1V, and the clamping voltage of the second diode D2 is the same as the clamping voltage of the third diode D3. Therefore, the fourth resistor R4 can hardly obtain voltage, so at this time, the switch tube Q1 is in the off state, and there is no signal change at the signal output end, so there is no signal output reflecting the abnormal situation. When the ground line is abnormal, that is, the impedance of the branch where the ground wire terminal and the third diode D3 are located increases or is open, the third diode D3 loses the voltage clamping effect, the node voltage between the first resistor R1 and the fourth resistor R4 increases, and the voltage obtained by the fourth resistor R4 is higher than the conduction voltage of the switch tube Q1 (usually 1 to 3V). At this time, the switch tube Q1 is turned on, and the signal at the signal output end changes, thereby outputting a signal of circuit abnormality. When the live wire and the neutral wire are connected in reverse, that is, the external live wire is connected to the neutral wire terminal, and the neutral wire is connected to the live wire terminal, at this time, since the neutral wire terminal and the ground wire terminal are almost at the same potential, the third diode D3 is not turned on, no current flows, and the current flows from the neutral wire terminal to the first diode D1, the first resistor R1, the fourth resistor R4 and the second diode D2. The fourth resistor R4 obtains sufficient bias to turn on the switch tube Q1, and the signal at the signal output terminal changes, thereby outputting a signal of circuit abnormality. In this way, through the above circuit, the abnormal ground wire and the reverse connection of the live wire and the neutral wire can be effectively detected.

[0007] According to some embodiments of the present invention, a capacitor C1 is further included, one end of the capacitor C1 is connected to the control end of the switch tube Q1, and the other end of the capacitor C1 is connected to the output end of the switch tube Q1.

[0008] According to some embodiments of the present invention, a third resistor R3 is further connected in series between the first resistor R1 and the fourth resistor R4, an anode of the third diode D3 is connected between the connection between the third resistor R3 and the fourth resistor R4, and a control end of the switch tube Q1 is connected between the connection between the third resistor R3 and the fourth resistor R4.

[0009] According to some embodiments of the present invention, a second resistor R2 is further connected in series between the first resistor R1 and the third resistor R3.

[0010] According to some embodiments of the present invention, the switch tube Q1 is a MOS tube.

[0011] According to some embodiments of the present invention, the switch tube Q1 is an N-type MOS tube.

[0012] According to some embodiments of the present invention, the switch tube Q1 is a triode.

[0013] According to some embodiments of the present invention, the switch tube Q1 is an N-type transistor.

[0014] The socket according to the second aspect of the present invention comprises the detection circuit of the AC input line.

[0015] The socket according to the embodiment of the present invention has at least the following beneficial effects: when the circuit is normally turned on, a small current flows from the live wire terminal to the first diode D1, the first resistor R1 and the third diode D3. Due to the voltage clamping effect of the third diode D3, the voltage between the fourth resistor R4 and the second diode D2 is equal to the clamping voltage of the third diode D3, which is less than 1V, and the clamping voltage of the second diode D2 is the same as the clamping voltage of the third diode D3. Therefore, the fourth resistor R4 can hardly get any voltage, so at this time, the switch tube Q1 is in the off state, and there is no signal change at the signal output end, so there is no signal output reflecting the abnormal situation. When the ground line is abnormal, that is, the impedance of the branch where the ground line terminal and the third diode D3 are located increases or is open, the third diode D3 loses the voltage clamping effect, the node voltage between the first resistor R1 and the fourth resistor R4 increases, and the voltage obtained by the fourth resistor R4 is higher than the turn-on voltage of the switch tube Q1 (usually 1 to 3V). At this time, the switch tube Q1 is turned on, and the signal at the signal output end changes, thereby outputting a signal of circuit abnormality. When the live wire and the neutral wire are connected in reverse, that is, the external live wire is connected to the neutral wire terminal, and the neutral wire is connected to the live wire terminal, at this time, since the neutral wire terminal and the ground wire terminal are almost at the same potential, the third diode D3 is not turned on, no current flows, and the current flows from the neutral wire terminal to the first diode D1, the first resistor R1, the fourth resistor R4 and the second diode D2. The fourth resistor R4 obtains sufficient bias to turn on the switch tube Q1, and the signal at the signal output terminal changes, thereby outputting a signal of circuit abnormality. In this way, through the above circuit, the abnormal ground wire and the reverse connection of the live wire and the neutral wire can be effectively detected.

[0016] According to some embodiments of the present invention, a shell is further included, and the detection circuit of the AC input line is arranged in the shell.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1is a circuit diagram of a detection circuit for an AC input line according to a first embodiment of the present invention;

[0020] Figure 2 for Figure 1 The circuit diagram of the detection circuit of the AC input line shown is when the live wire and the neutral wire are connected reversely;

[0021] Figure 3 FIG. 4 is a circuit diagram of an AC input line detection circuit according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0025] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0026] Reference Figure 1According to an embodiment of the first aspect of the present invention, there is provided a detection circuit for an AC input line, comprising a live line terminal, a neutral line terminal, a ground line terminal, a signal output terminal, a first diode D1, a first resistor R1, a fourth resistor R4, a second diode D2, a third diode D3 and a switch tube Q1, wherein an anode of the first diode D1 is connected to the live line terminal, an output terminal of the first diode D1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to an anode of the second diode D2, and a cathode of the second diode D2 is connected to the neutral line terminal; an anode of the third diode D3 is connected between a connection line between the first resistor R1 and the fourth resistor R4, and a cathode of the third diode D3 is connected to the ground line terminal; a control terminal of the switch tube Q1 is connected between a connection line between the first resistor R1 and the fourth resistor R4, an input terminal of the switch tube Q1 is connected to the signal output terminal, and an output terminal of the switch tube Q1 is connected between the connection line between the fourth resistor R4 and the anode of the second diode D2.

[0027] When the circuit is normally turned on, a small current flows from the live wire terminal to the first diode D1, the first resistor R1 and the third diode D3. Due to the voltage clamping effect of the third diode D3, the voltage between the fourth resistor R4 and the second diode D2 is equal to the clamping voltage of the third diode D3, which is less than 1V, and the clamping voltage of the second diode D2 is the same as the clamping voltage of the third diode D3. Therefore, the fourth resistor R4 hardly receives any voltage. Therefore, at this time, the switch tube Q1 is in the off state, and there is no signal change at the signal output end, so there is no signal output reflecting the abnormal situation.

[0028] When the ground line is abnormal, that is, the impedance of the branch where the ground line terminal and the third diode D3 are located increases or opens, the third diode D3 loses the voltage clamping function, and the node voltage between the first resistor R1 and the fourth resistor R4 increases. Usually, the fourth resistor R4 is set to obtain a voltage division greater than 3V when the ground line is abnormal, so as to ensure that the control terminal voltage of the switch tube Q1 is sufficient to turn on the switch tube Q1. At this time, the voltage obtained by the fourth resistor R4 is higher than the turn-on voltage of the switch tube Q1 (usually 1 to 3V). At this time, the switch tube Q1 is turned on, and the signal at the signal output end changes, thereby outputting a signal of circuit abnormality.

[0029] Reference Figure 2When the live wire and the neutral wire are connected in reverse, that is, the external live wire is connected to the neutral wire terminal, and the neutral wire is connected to the live wire terminal, at this time, since the neutral wire terminal and the ground wire terminal are almost at the same potential, the third diode D3 is not turned on, and no current flows through. The current flows from the neutral wire terminal to the first diode D1, the first resistor R1, the fourth resistor R4 and the second diode D2. The fourth resistor R4 obtains sufficient bias to turn on the switch tube Q1, and the signal at the signal output terminal changes, thereby outputting a signal of circuit abnormality. In this way, through the above circuit, the abnormal ground wire and the reverse connection of the live wire and the neutral wire can be effectively detected.

[0030] In some specific embodiments of the present invention, a capacitor C1 is further included, one end of the capacitor C1 is connected to the control end of the switch tube Q1, and the other end of the capacitor C1 is connected to the output end of the switch tube Q1. The capacitor C1 realizes the function of voltage smoothing.

[0031] Reference Figure 3 In some specific embodiments of the present invention, a third resistor R3 is connected in series between the first resistor R1 and the fourth resistor R4, the anode of the third diode D3 is connected between the connection line of the third resistor R3 and the fourth resistor R4, and the control end of the switch tube Q1 is connected between the connection line of the third resistor R3 and the fourth resistor R4. A second resistor R2 is connected in series between the first resistor R1 and the third resistor R3. By connecting the second resistor R2 and the third resistor R3 in series between the first resistor R1 and the fourth resistor R4, the withstand voltage of the resistor can be improved.

[0032] In some specific embodiments of the present invention, the switch tube Q1 is a MOS tube. The switch tube Q1 is an N-type MOS tube. Alternatively, the switch tube Q1 is a triode. The switch tube Q1 is an N-type triode.

[0033] A second aspect of the embodiments of the present invention provides a socket, comprising the detection circuit of the AC input line mentioned above, and further comprising a housing, wherein the detection circuit of the AC input line is arranged in the housing.

[0034] Since the socket has the above-mentioned detection circuit of the AC input line, when the circuit is normally turned on, a small current flows from the live wire terminal to the first diode D1, the first resistor R1 and the third diode D3. Due to the voltage clamping effect of the third diode D3, the voltage between the fourth resistor R4 and the second diode D2 is equal to the clamping voltage of the third diode D3, which is less than 1V, and the clamping voltage of the second diode D2 is the same as the clamping voltage of the third diode D3. Therefore, the fourth resistor R4 can hardly get voltage, so at this time, the switch tube Q1 is in the off state, and there is no signal change at the signal output end, so there is no signal output reflecting the abnormal situation. When the ground line is abnormal, that is, the impedance of the branch where the ground line terminal and the third diode D3 are located increases or opens, the third diode D3 loses the voltage clamping effect, the node voltage between the first resistor R1 and the fourth resistor R4 increases, and the voltage obtained by the fourth resistor R4 is higher than the conduction voltage of the switch tube Q1 (usually 1 to 3V). At this time, the switch tube Q1 is turned on, and the signal at the signal output end changes, thereby outputting a signal of circuit abnormality. When the live wire and the neutral wire are connected in reverse, that is, the external live wire is connected to the neutral wire terminal, and the neutral wire is connected to the live wire terminal, at this time, since the neutral wire terminal and the ground wire terminal are almost at the same potential, the third diode D3 is not turned on, no current flows, and the current flows from the neutral wire terminal to the first diode D1, the first resistor R1, the fourth resistor R4 and the second diode D2. The fourth resistor R4 obtains sufficient bias to turn on the switch tube Q1, and the signal at the signal output terminal changes, thereby outputting a signal of circuit abnormality. In this way, through the above circuit, the abnormal ground wire and the reverse connection of the live wire and the neutral wire can be effectively detected.

[0035] In some specific embodiments, the socket may further include a control chip, a relay switch, and an auxiliary power supply, etc. The above-mentioned signal output terminal is connected to the control chip. When the control chip receives a signal of circuit abnormality, it issues a corresponding instruction to control the relay switch and the auxiliary power supply to disconnect, thereby cutting off the faulty input power supply to ensure the user's power safety. The detection circuit of the ground wire abnormality and the AC input line of the live wire and the neutral wire is mainly proposed here, and the control chip, relay switch, and auxiliary power supply are not described in detail.

[0036] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A detection circuit for an AC input line, characterized in that: include: a live wire terminal, a neutral wire terminal, a ground wire terminal, a signal output terminal, a first diode D1, a first resistor R1, a fourth resistor R4, a second diode D2, a third diode D3 and a switch tube Q1, wherein an anode of the first diode D1 is connected to the live wire terminal, an output terminal of the first diode D1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to an anode of the second diode D2, and a cathode of the second diode D2 is connected to the neutral wire terminal; an anode of the third diode D3 is connected between the connection line of the first resistor R1 and the fourth resistor R4, and a cathode of the third diode D3 is connected to the ground wire terminal; a control terminal of the switch tube Q1 is connected between the connection line of the first resistor R1 and the fourth resistor R4, an input terminal of the switch tube Q1 is connected to the signal output terminal, and an output terminal of the switch tube Q1 is connected between the connection line of the fourth resistor R4 and the anode of the second diode D2.

2. The detection circuit of the AC input line according to claim 1, characterized in that: It also includes a capacitor C1, one end of the capacitor C1 is connected to the control end of the switch tube Q1, and the other end of the capacitor C1 is connected to the output end of the switch tube Q1.

3. The detection circuit of the AC input line according to claim 1, characterized in that: A third resistor R3 is also connected in series between the first resistor R1 and the fourth resistor R4, an anode of the third diode D3 is connected between the connection between the third resistor R3 and the fourth resistor R4, and a control end of the switch tube Q1 is connected between the connection between the third resistor R3 and the fourth resistor R4.

4. The detection circuit for the AC input line according to claim 3, characterized in that: A second resistor R2 is connected in series between the first resistor R1 and the third resistor R3.

5. The detection circuit of the AC input line according to claim 1, characterized in that: The switch tube Q1 is a MOS tube.

6. The detection circuit for the AC input line according to claim 5, characterized in that: The switch tube Q1 is an N-type MOS tube.

7. The detection circuit for the AC input line according to claim 1, characterized in that: The switch tube Q1 is a triode.

8. The detection circuit for the AC input line according to claim 7, characterized in that: The switch tube Q1 is an N-type transistor.

9. A socket, characterized in that: A detection circuit comprising the AC input line as claimed in any one of claims 1 to 8.

10. The socket according to claim 9, characterized in that: It also includes a shell, and the detection circuit of the AC input line is arranged in the shell.

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