JP2021032737A - Arc discharge detection circuit and arc discharge detector having arc discharge detection circuit - Google Patents

Abstract

To provide an arc discharge detection circuit that can detect a serial arc in an initial stage surely and more accurately with a simple configuration, and an arc discharge detector having the arc discharge detection circuit.SOLUTION: The arc discharge detection circuit has an RLC circuit and is connected between electric lines connected to a commercial power source. A CR circuit which includes a capacitor (C) and a resistor (R), of the RLC circuit, selects a high-frequency signal component from a current flowing through an electric line and makes the current pass through when the current includes a low-frequency AC signal supplied from the commercial power source with the high-frequency signal superimposed thereon. An inductor (L) converts the high-frequency signal component passed through by passage means into a voltage waveform, and outputs the waveform to the outside. The output leads to detection of the occurrence of an arc.SELECTED DRAWING: Figure 1

Description

The present invention relates to an arc discharge detection circuit that detects an arc discharge, and an arc discharge detection device provided with the arc discharge detection circuit.

There are two types of arc discharge: one that occurs between different poles (parallel arc) and one that occurs between the same poles (series arc). Since a large short-circuit current flows in the parallel arc discharge generated between different poles, various detection methods have been conventionally proposed. On the other hand, in the series arc discharge generated between the same poles, various energies are generated depending on the load current. In addition, the series arc discharge that occurs between the same poles is often minute and intermittent, and there are many places where it occurs, so it is uncertain. Therefore, its detection is difficult.

Therefore, most of the conventional devices for detecting arc discharge detect parallel arc discharge occurring between different poles, and few detect series arc discharge occurring between the same poles.

For example, the arc detector described in Patent Document 1 below also causes an arc short-circuit phenomenon involving an arc between core wires in a cord or indoor wiring that could not be detected by an instantaneous circuit breaker, that is, a parallel arc discharge that occurs between different poles. It is to detect. However, by applying this technology to the series arc discharge that occurs between the same poles in indoor wiring, the electric circuit is cut off and a fire is prevented.

Specifically, the arc detector according to Patent Document 1 below is a method of detecting a series arc when the effective value voltage of the outlet of the outlet becomes a predetermined voltage (for example, 70 V) or less. We are proposing a method for determining that an arc discharge is occurring due to an arc.

However, although the arc detector according to Patent Document 1 below can detect a series arc that causes a voltage drop of about 30 V, it cannot detect a series arc at an earlier stage that causes a voltage drop smaller than that. ..

Therefore, the present inventors have proposed an arc discharge detection circuit capable of detecting a series arc at an earlier stage in Patent Document 2 below. Specifically, an RC circuit consisting of a resistor (R) and a capacitor (C) is connected in parallel between the lines of the electric circuit, and this is detected when a high-frequency signal generated by a series arc passes through the RC circuit. It is a thing.

Japanese Unexamined Patent Publication No. 2001-045652 Japanese Patent Application No. 2018-074405

By the way, the arc discharge detection circuit according to Patent Document 2 can accurately detect an initial series arc that causes only a small voltage drop. After that, the present inventors continued to study and pursued an arc discharge detection circuit that had the same effect as that of Patent Document 2 and further improved the detection accuracy.

Specifically, the detection time is very short, the series arc that is difficult to detect can be detected more accurately, the high frequency signal generated by the series arc can be accurately distinguished from other high frequency noise, and the inductive load can be detected. We investigated an arc discharge detection circuit that can more accurately discriminate false positives.

Therefore, as a result of dealing with the above, the present invention has an arc discharge detection circuit capable of detecting a series arc in a more initial stage more reliably and more accurately, and the arc discharge detection circuit. It is an object of the present invention to provide an arc discharge detection device provided with the above.

In order to achieve the above object, the arc discharge detection circuit (10, 20) according to claim 1 is an arc discharge detection circuit connected in parallel between the lines of the electric circuit (EW) connected to the commercial power supply (P). (10,20), a terminal pair consisting of an RLC circuit consisting of a resistor (11,21), an inductor (12,22), and a capacitor (13,23), and terminals provided at both ends of the inductor. Of the RLC circuits, the CR circuit in which a capacitor and a resistor are connected is a circuit in which a high-frequency signal is superimposed on a low-frequency AC signal supplied from a commercial power supply as the current flowing through the electric circuit. The inductor functions as a passing means for selecting and passing a high-frequency signal component from the current, the inductor functions as a conversion means for converting the high-frequency signal component passed by the passing means into a voltage waveform, and the terminal pair is converted by the inductor. It functions as an external output means that outputs the voltage waveform to the outside, and by configuring the LC circuit that connects the inductor and the capacitor as a resonance circuit among the RLC circuits, the high frequency in the frequency range around the resonance frequency peculiar to the resonance circuit It is characterized in that a signal component is converted into a voltage waveform and the converted voltage waveform is output to the outside.

Further, the arc discharge detection circuit (10) according to claim 2 is the arc discharge detection circuit (10, 20) according to claim 1, wherein the LC circuit is a series LC circuit and the RLC circuit is a series. It is characterized in that the resistor (11) is connected in series to the LC circuit and is connected in parallel between the lines of the electric circuit.

Further, the arc discharge detection circuit (20) according to claim 3 is the arc discharge detection circuit (10, 20) according to claim 1, wherein the LC circuit is a parallel LC circuit and the RLC circuit is parallel. It is characterized in that a resistor (21) is connected in series to the LC circuit and is connected in parallel between the lines of the electric circuit.

In order to achieve the above object, the arc discharge detection device (100) according to claim 4 includes the arc discharge detection circuit (10, 20) according to any one of claims 1 to 3 and the arc discharge detection circuit. While the integrating means (30) that integrates the voltage waveform output from the above and generates a voltage waveform corresponding to the waveform width of the integrated voltage waveform, and the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage. , A level according to the time length of the pulse generating means (40) that generates a pulse signal of a predetermined voltage value and the pulse signal generated by the pulse generating means within a half cycle of the low frequency AC signal of the commercial power supply (P). When the potential generating means (90a, 90b, 91, 92, 93a, 93b, 93c) and the potential level generated by the potential generating means exceed a predetermined level, an arc discharge occurs. It is characterized by having an alarm signal output means (70) that generates an alarm signal indicating that and outputs the alarm signal to the outside.

In order to achieve the above object, the arc discharge detection device (200) according to claim 5 includes the arc discharge detection circuit (10, 20) according to any one of claims 1 to 3 and the arc discharge detection circuit. While the integrating means (30) that integrates the voltage waveform output from the above and generates a voltage waveform corresponding to the waveform width of the integrated voltage waveform, and the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage. , The number of pulse signals generated by the pulse generating means (40) for generating a pulse signal of a predetermined voltage value and the number of pulse signals generated by the pulse generating means within a half cycle of the low frequency AC signal of the commercial power supply (P) is two or more. A detection means (210, 220, 221, 222) for detecting the presence, and an alarm signal indicating that an arc discharge has occurred when two or more pulse signals are detected by the detection means are generated. It is characterized by having an alarm signal output means (70) for outputting to the outside.

In order to achieve the above object, the arc discharge detection device (300) according to claim 6 includes the arc discharge detection circuit (10, 20) according to any one of claims 1 to 3 and the arc discharge detection circuit. While the integrating means (30) that integrates the voltage waveform output from the above and generates a voltage waveform corresponding to the waveform width of the integrated voltage waveform, and the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage. , The first pulse generating means (40) that generates the first pulse signal of a predetermined voltage value, and the first pulse generated by the first pulse generating means within a half cycle of the low frequency AC signal of the commercial power supply (P). The potential generation means (90a, 90b, 91, 92, 93a, 93b, 93c) that generate a level of potential according to the time length of the signal and the potential level generated by the potential generation means are equal to or higher than a predetermined level. In this case, the second pulse generating means (320) that generates the second pulse signal having a predetermined time length longer than the time length of the first pulse signal and the second pulse signal generated by the second pulse generating means are predetermined. Using the delay means (320,321) that delays by the non-detection time and the second pulse signal delayed by the delay means as a trigger pulse, a third pulse signal having a time length longer than the time length of the second pulse signal is generated. When the next first pulse signal is generated by the first pulse generating means while the third pulse generating means (330) and the third pulse generating means generate the third pulse signal, the arc discharge occurs. It is characterized by having an alarm signal output means (70) that generates an alarm signal indicating that it has occurred and outputs it to the outside.

In order to achieve the above object, the arc discharge detection device (400) according to claim 7 includes the arc discharge detection circuit (10, 20) according to any one of claims 1 to 3 and the arc discharge detection circuit. While the integrating means (30) that integrates the voltage waveform output from the above and generates a voltage waveform corresponding to the waveform width of the integrated voltage waveform, and the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage. , The first pulse generating means (40) that generates the first pulse signal of a predetermined voltage value, and the first pulse generated by the first pulse generating means within a half cycle of the low frequency AC signal of the commercial power supply (P). The detection means (210, 220, 221, 222) for detecting that the number of signals is two or more and the first pulse signal generated by the first pulse generation means are used as trigger pulses of the first pulse signal. A second pulse generating means (320) that generates a second pulse signal having a predetermined time length longer than the time length, and a delay means that delays the second pulse signal generated by the second pulse generating means by a predetermined non-detection time. (320, 321) and the third pulse generating means (330) that generate a third pulse signal having a time length longer than the time length of the second pulse signal by using the second pulse signal delayed by the delay means as a trigger pulse. And, when two or more first pulse signals are detected by the detection means while the third pulse signal is being generated by the third pulse generation means, an alarm signal indicating that an arc discharge has occurred is generated. It is characterized by having an alarm signal output means (70) that is generated and output to the outside.

The arc discharge detection device according to claim 8 is the arc discharge detection device (100, 200, 300, 400) according to any one of claims 4 to 7, wherein the integrating means is an arc discharge detection circuit (10, 20). ), Of the voltage waveforms output from), the voltage waveform on the positive side is integrated.

The reference numerals in parentheses of the above means indicate the correspondence with the specific means described in each embodiment described later.

According to the above configuration, the arc discharge detection circuit according to the present invention includes an RLC circuit including a resistor, an inductor, and a capacitor. This RLC circuit is connected in parallel between the lines of the electric circuit connected to the commercial power supply. In this state, when the current flowing through the electric circuit connected to the commercial power supply is a high-frequency signal superimposed on the low-frequency AC signal supplied from the commercial power supply, the CR circuit connecting the capacitor and the resistor. A high-frequency signal component is selected from the current by the passing means including the current and passes therethrough.

The passed high frequency signal is converted into a voltage waveform by a conversion means including an inductor. Further, the inductor includes a terminal pair consisting of terminals connected to both ends thereof, and outputs the converted voltage waveform to the outside. At this time, the LC circuit in which the inductor and the capacitor are connected constitutes a resonance circuit, so that the output in the frequency range around this resonance frequency is accurately detected to detect that an arc is generated. As described above, when the voltage waveform is output to the outside, it can be said that the voltage is generated by the high frequency signal.

When a series arc discharge occurs, a high-frequency signal is generated even in the initial stage and is superimposed on the low-frequency AC signal of the commercial power supply. Therefore, if such a low-frequency signal on which a high-frequency signal is superimposed is applied to the invention according to the above configuration, it is possible to detect a series arc at an earlier stage as compared with the conventional arc detector described above. ..

Further, even a weak high frequency signal in the initial stage of series arc discharge can be detected with high accuracy by forming a resonance circuit in the LC circuit. Therefore, it is possible to provide an arc discharge detection circuit capable of reliably and more accurately detecting an initial stage series arc with a simple structure, and an arc discharge detection device provided with the arc discharge detection circuit. ..

Further, according to the invention of claim 4, when the potential level corresponding to the time length of the pulse signal generated within the half cycle of the low frequency AC signal of the commercial power supply becomes a predetermined level or more, the said. Since the high-frequency signal is determined to be the high-frequency signal caused by the arc discharge and the alarm signal indicating the occurrence of the arc discharge is output to the outside, the arc discharge is selected from the high-frequency signals detected by the arc discharge detection circuit. High-frequency signals generated due to the above can be selected and detected, thereby preventing erroneous detection of arc discharge.

Further, in the invention according to claim 4, the arc discharge is detected based on the high frequency signal generated due to the arc discharge, that is, the arc discharge with almost no voltage drop can be detected. Therefore, it is possible to detect the series arc in the earlier stage more reliably and accurately.

Further, according to the invention of claim 5, when it is detected that the number of pulse signals generated within a half cycle of the low frequency AC signal of the commercial power supply is two or more, the high frequency signal is used. Since it is determined that the high frequency signal is caused by the arc discharge and the signal indicating the occurrence of the arc discharge is output to the outside, the arc discharge is the cause from the high frequency signals detected by the arc discharge detection circuit. The generated high frequency signal can be selected and detected, thereby preventing erroneous detection of arc discharge.

Further, according to the invention of claim 6, the next high frequency signal is detected from the arc discharge detection circuit after a predetermined non-detection period elapses after the first high frequency signal is detected by the arc discharge detection circuit. , The high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and a signal indicating the occurrence of arc discharge is output to the outside. Therefore, among the high-frequency signals detected by the arc discharge detection circuit, arc discharge High-frequency signals generated due to the above can be selected and detected, which can prevent erroneous detection of arc discharge.

Further, according to the invention of claim 7, the next high frequency signal is detected from the arc discharge detection circuit after a predetermined non-detection period elapses after the first high frequency signal is detected by the arc discharge detection circuit. , The high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and a signal indicating the occurrence of arc discharge is output to the outside. Therefore, among the high-frequency signals detected by the arc discharge detection circuit, arc discharge High-frequency signals generated due to the above can be selected and detected, which can prevent erroneous detection of arc discharge.

It is the schematic which shows the circuit structure of the arc discharge detection circuit which concerns on 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the capacitor included in the arc discharge detection circuit of FIG. It is a figure which shows the resonance frequency characteristic of the LC circuit included in the arc discharge detection circuit of FIG. It is the schematic which shows the circuit structure of the arc discharge detection circuit which concerns on 2nd Embodiment of this invention. It is the schematic which shows the front part part of the electronic circuit provided in the arc discharge detection apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows an example of the output signal obtained from the predetermined terminal pair of the electronic circuit of FIG. It is the schematic which shows the latter part of the electronic circuit provided in the arc discharge detection apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows an example of the output signal obtained from the predetermined terminal pair of the electronic circuit of FIG. It is the schematic which shows the latter part of the electronic circuit provided in the arc discharge detection apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows an example of the output signal obtained from the predetermined terminal pair of the electronic circuit of FIG. It is a figure which shows the circuit structure of the latter part part of the electronic circuit provided in the arc discharge detection apparatus which concerns on 5th Embodiment of this invention. It is a figure which shows an example of the output signal obtained from the predetermined terminal pair of the electronic circuit of FIG. It is a figure which shows the circuit structure of the latter part part of the electronic circuit provided in the arc discharge detection apparatus which concerns on 6th Embodiment of this invention. It is a figure which shows an example of the output signal obtained from the predetermined terminal pair of the electronic circuit of FIG. It is an external view which shows an example of the arc discharge detection apparatus which concerns on this invention. It is an external view which shows another example of the arc discharge detection apparatus which concerns on this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

When an initial series arc is generated on the electric circuit of a commercial power supply, a peculiar high frequency signal is generated accordingly. Then, this high-frequency signal is superimposed on the low-frequency (for example, 60 Hz) AC signal supplied by the commercial power supply and transmitted on the electric circuit. Here, the peculiar high-frequency signal is a signal having a frequency exceeding 10 kHz and is generated continuously or intermittently.

(First Embodiment)
The arc discharge detection circuit according to the first embodiment of the present invention selects and detects a high-frequency signal with high accuracy when a high-frequency signal is superimposed on a low-frequency AC signal of a commercial power source. Hereinafter, this principle, that is, the principle that a high-frequency signal can be selected from a low-frequency AC signal on which a high-frequency signal is superimposed and detected with high accuracy will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the arc discharge detection circuit 10 of the present embodiment is a circuit in which a resistor (R) 11, an inductor (L) 12 and a capacitor (C) 13 are connected in series (hereinafter referred to as “series RLC circuit”). ). At both ends of the inductor 12, terminal pairs 14-14'for outputting a detection signal to the outside are provided.

Further, the arc discharge detection circuit 10 is connected in parallel with the commercial power supply P between the lines of the indoor wiring EW of the commercial power supply P. Further, a load L is connected to the indoor wiring EW.

In the arc discharge detection circuit 10 configured as described above, first, the operation of a circuit (hereinafter referred to as “CR circuit”) in which the capacitor 13 and the resistor 11 are connected in series among the series RC circuits will be described. Here, the impedance of all the resistors including the resistor 11 is constant regardless of the frequency of the electric signal applied to the resistor. That is, the resistor has no impedance frequency characteristic.

In contrast, the impedance of all capacitors, including the capacitor 13, depends on the frequency of the electrical signal applied to that capacitor. FIG. 2 shows an example of the impedance frequency characteristics of the capacitor 13.

In FIG. 2, when the capacitance of the capacitor 13 is, for example, 0.1 μF, the impedance of the capacitor 13 is 35 kΩ when a low frequency (for example, 60 Hz) signal of a commercial power source is applied. On the other hand, when a high frequency (for example, 10 kHz) signal of arc discharge is applied, it is 150 Ω.

When a resistor 11 having a resistance value of, for example, 30 Ω is used, the impedance ratio between the capacitor 13 and the resistor 11 for a low frequency signal is 1167: 1, and the resistance value is, for example, 90 Ω. Even if the above is used, the impedance ratio of the capacitor 13 and the resistor 11 for the low frequency signal is 389: 1.

On the other hand, the impedance ratio between the capacitor 13 and the 30Ω resistor 11 for the high frequency signal is 5: 1, and the impedance ratio between the capacitor 13 and the 90Ω resistor 11 for the high frequency signal is 1.7: 1.

Further, when the capacitance of the capacitor 13 is even smaller, for example, 0.022 μF, the impedance ratio between the capacitor 13 and the 30Ω resistor 11 for a low frequency signal is 6667: 1, and the impedance with the 90Ω resistor 11 is The ratio is also 2222: 1, and the impedance of the capacitor 13 is further increased.

On the other hand, the impedance ratio of the capacitor 13 and the 30Ω resistor 11 for the high frequency signal is 23: 1, and the impedance ratio of the 90Ω resistor 11 is also 7.8: 1.

The above result shows that when a high-frequency signal of arc discharge is superimposed on a low-frequency signal of a commercial power supply and applied to a CR circuit in which a capacitor 13 and a resistor 11 are connected in series, the capacitor 13 passes a low-frequency signal component. The absence means that only high frequency signal components pass through the CR circuit.

Therefore, in a series RLC circuit including a CR circuit in which a capacitor 13 and a resistor 11 are connected in series like the arc discharge detection circuit 10 of the present embodiment, among the superimposed signals, the low frequency signal component is the capacitor 13. Since it does not pass through, no current flows through the resistor 11 and the inductor 12 due to the low frequency signal component. On the other hand, since the high frequency signal component passes through the capacitor 13, a current flows through the resistor 11 and the inductor 12 due to the high frequency signal component.

As described above, in the arc discharge detection circuit 10, when the high frequency signal is superimposed on the low frequency AC signal, the CR circuit acts as a passing means for selecting and passing the high frequency signal component from the signal. As a result, in the arc discharge detection circuit 10 of the present embodiment, when a current flows through the inductor 12 and a voltage is generated at the terminal pairs 14-14'provided at both ends thereof, the voltage is high frequency. It can be said that it was generated by a signal.

Next, among the series RLC circuits, the operation of a circuit in which the inductor 12 and the capacitor 13 are connected in series (hereinafter referred to as “series LC circuit”) will be described.

The series LC circuit has a resonance phenomenon by appropriately selecting the inductance of the inductor 12, the capacitance of the capacitor 13, and the angular frequency ω (= 2πf, where “f” is the frequency of the signal flowing through the series LC circuit). Can be generated to form a resonant circuit (hereinafter referred to as "series LC resonant circuit").

The impedance of the series LC resonance circuit is minimized at the resonance frequency fr (= ωr / 2π, where ωr is the angular frequency when the resonance phenomenon occurs). Therefore, in the series LC resonance circuit, the current due to the high frequency signal component selectively passing through the CR circuit becomes large, the voltage applied to both ends of the inductor 12 becomes maximum, and the terminal pair 14-provided at both ends of the inductor 12 The output (voltage component) from 14'becomes large. As a result, in the arc discharge detection circuit 10 of the present embodiment, by specifying the resonance frequency fr, the output in the frequency range around the resonance frequency fr becomes clear and the detection accuracy is improved.

The resonance frequency fr (kHz) is obtained by fr = 1 / (2π√LC) from the inductance (mH) of the inductor L and the capacitance (μF) of the capacitor C. FIG. 3 is a diagram showing the resonance frequency characteristics of the LC circuit. The values in Table 3 are merely examples, and the resonance frequency used in the present invention is not limited to these values.

Since the series RLC circuit connects each component, that is, the capacitor 13, the resistor 11, and the inductor 12 in series, a current due to a high frequency signal of series arc discharge also flows through each component. Therefore, it is also possible to provide a terminal pair for outputting a voltage by a high frequency signal at both ends of the resistor 11. Actually, since the previous invention by the present inventors (the invention described in Patent Document 2 above) does not have the inductor 12, the voltage output by the high frequency signal is detected from the terminal pair provided at both ends of the resistor 11. There is.

However, when a current due to a high-frequency signal flows through the resistor 11, the voltage output from the terminal pair provided at both ends of the resistor 11 may decrease due to the power consumption due to the discharge at the resistor 11. Therefore, in the arc discharge detection circuit 10 of the present embodiment, the output voltage due to the extremely fine high frequency signal is accurately detected by obtaining the output voltage from the terminal pairs 14-14'provided at both ends of the inductor 12 which does not consume power. I am trying to do it.

In this way, if the voltage of the terminal pair 14-14'provided at both ends of the inductor 12 is monitored and it is detected that the voltage is generated, it can be seen that the voltage is generated by the high frequency signal.

However, the cause of generating a high-frequency signal is not only arc discharge but also switching surge and noise. Therefore, even if a voltage is generated at the terminal pair 14-14', the voltage is caused by series arc discharge. It cannot be concluded that it occurred. A method for identifying a high-frequency signal generated due to a series arc discharge from these various causes will be described in the arc discharge detection device according to the third to sixth embodiments shown below.

According to the principle described above, the arc discharge detection circuit 10 of the present embodiment can select and detect a high frequency signal from a low frequency AC signal on which a high frequency signal is superimposed.

The frequency of the high-frequency signal illustrated in FIG. 2, 10 kHz, is merely adopted for convenience to explain that the capacitor has impedance frequency characteristics, and indicates the frequency of the high-frequency signal actually generated by the series arc. Not at all.

Further, the resistance value of the resistor 11 used in the arc discharge detection circuit 10 of the present embodiment, the inductance of the inductor 12, and the capacitance of the capacitor 13 are not particularly limited. For example, the resistance value of the resistor 11 is preferably 50 to 300 Ω, more preferably 100 to 200 Ω. The inductance of the inductor 12 is preferably 0.5 to 2.0 mH. The capacitance of the capacitor 13 is preferably 0.03 to 0.2 μF. By specifying the resonance frequency by combining these, the detection accuracy of the frequency range around the resonance frequency is improved.

(Second Embodiment)
As shown in FIG. 4, the arc discharge detection circuit 20 according to the second embodiment of the present invention includes the resistor (R) 21 and the inductor (L) 22 as in the arc discharge detection circuit 10 of the first embodiment. Although it is composed of a capacitor (C) 23, the connection mode of the circuit element is different from that of the arc discharge detection circuit 10 of the first embodiment.

Similar to the arc discharge detection circuit 10 of the first embodiment, the arc discharge detection circuit 20 of the present embodiment selects the high frequency signal when the high frequency signal is superimposed on the low frequency AC signal of the commercial power supply P. It detects with high accuracy. Hereinafter, this principle, that is, the principle that a high-frequency signal can be selected from a low-frequency AC signal on which a high-frequency signal is superimposed and detected with high accuracy will be described with reference to FIG.

In FIG. 4, unlike the series RLC circuit in the first embodiment, the arc discharge detection circuit 20 of the present embodiment is a circuit in which the inductor (L) 22 and the capacitor (C) 23 are connected in parallel (hereinafter, “parallel”). It is composed of a circuit (hereinafter referred to as "parallel RLC circuit") in which a resistor (R) 21 is connected in series to a circuit (referred to as "LC circuit"). At both ends of the inductor 22, terminal pairs 24-24'for outputting a detection signal to the outside are provided.

Further, the arc discharge detection circuit 20 is connected in parallel with the commercial power supply P between the lines of the indoor wiring EW of the commercial power supply P. Further, a load L is connected to the indoor wiring EW.

In the arc discharge detection circuit 20 connected in this way, the operation of the CR circuit in which the resistor 21 and the capacitor 23 are connected in series among the parallel RLC circuits is included in the arc discharge detection circuit 10 of the first embodiment. It is the same as the CR circuit. However, the arc discharge detection circuit 20 of the present embodiment includes a circuit in which the inductor 22 and the capacitor 23 are connected in parallel (hereinafter referred to as "parallel LC circuit"). Even in this parallel LC circuit, a resonance phenomenon is caused by appropriately selecting the inductance of the inductor 22, the capacitance of the capacitor 23, and the angular frequency ω, and the resonance circuit (hereinafter referred to as “parallel LC resonance circuit”) is formed. Can be configured. The arc discharge detection circuit 20 of the present embodiment also uses this parallel LC resonance circuit to detect the series arc discharge with high accuracy.

Since the inductor 22 and the capacitor 23 are connected in parallel in the parallel LC resonance circuit, the impedance of the parallel LC resonance circuit becomes maximum at the resonance frequency fr. Therefore, in the parallel LC resonance circuit, the voltage applied to both ends of the inductor 22 becomes maximum, and the output from the terminal pair 24-24'provided at both ends of the inductor 22 becomes large. As a result, even in the arc discharge detection circuit 20 of the present embodiment, by specifying the resonance frequency fr, the output in the frequency range around the resonance frequency fr becomes clear and the detection accuracy is improved.

The arc discharge detection circuit 20 of the present embodiment may also detect the output of a high frequency signal from the terminal pairs provided at both ends of the resistor 21 as described in the arc discharge detection circuit 10 of the first embodiment. it can. However, in that case, as described in the arc discharge detection circuit 10 of the first embodiment, the voltage output from the terminal pair provided at both ends of the resistor 21 due to the power consumption due to the discharge at the resistor 21. There is a problem that Therefore, even in the arc discharge detection circuit 20 of the present embodiment, the output voltage due to the extremely fine high frequency signal is accurately detected by obtaining the output voltage from the terminal pairs 24-24'provided at both ends of the inductor 22 which does not consume power. I am trying to do it.

In this way, if the voltage of the terminal pair 24-24'provided at both ends of the inductor 22 is monitored and it is detected that the voltage is generated, it can be seen that the voltage is generated by the high frequency signal.

However, the cause of generating a high-frequency signal is not only arc discharge but also switching surge and noise. Therefore, even if a voltage is generated between terminals 24-24', the voltage is caused by series arc discharge. It cannot be concluded that it occurred. A method for identifying a high-frequency signal generated due to a series arc discharge from these various causes will be described in the arc discharge detection device according to the third to sixth embodiments shown below.

According to the principle described above, the arc discharge detection circuit 20 of the present embodiment can select and detect a high frequency signal from a low frequency AC signal on which a high frequency signal is superimposed.

The resistance value of the resistor 21 used in the arc discharge detection circuit 20 of the present embodiment, the inductance of the inductor 22 and the capacitance of the capacitor 23 are not particularly limited, and are the same as those of the arc discharge detection circuit 10 of the first embodiment. It is preferably in the same range. Further, by specifying the resonance frequency by combining these, the detection accuracy of the frequency range around the resonance frequency is improved.

(Third Embodiment)
The arc discharge detection device 100 according to the third embodiment of the present invention includes the arc discharge detection circuit 10 of the first embodiment as one of the components, and when a voltage is generated at the terminal pair 14-14'. , It is determined and detected whether or not it is caused by the series arc discharge. Hereinafter, the arc discharge detection device 100 of the present embodiment will be described with reference to FIGS. 5 to 8.

As shown in FIGS. 5 and 7, the arc discharge detection device 100 of the present embodiment mainly includes an arc discharge detection circuit 10, an integrator circuit 30, a comparator 40, and two power supply circuits 50 and 60 (the above are the above. It is composed of a monostable multivibrator 70 (see FIG. 7) and a monostable multivibrator 70 (see FIG. 7).

The arc discharge detection circuit 10 in FIG. 5 is the same as the arc discharge detection circuit 10 described above based on FIG. 1, and is connected between the lines of the indoor wiring EW of the commercial power supply P. The terminal Ta and the terminal Tb are taken from the different poles of the indoor wiring EW, respectively.

Two Zener diodes 80a and 80b are reversed between the connection point between the capacitor 13 and the resistor 11 in the arc discharge detection circuit 10 and one terminal 14'of the output terminal pair 14-14', respectively. Those connected in series in the direction are connected in parallel. Here, "connecting in series in opposite directions" means connecting the cathode of the Zener diode 80a and the cathode of the Zener diode 80b, and connecting both the Zener diodes 80a and 80b in series.

These two Zener diodes 80a and 80b are in the forward direction between the connection point between the capacitor 13 and the resistor 11 in the arc discharge detection circuit 10 and one terminal 14'of the output terminal pair 14-14'. Even if an excessive voltage is applied in any of the reverse directions, it functions as a protection circuit that does not apply a voltage equal to or higher than a predetermined value to the integration circuit 30 in the subsequent stage.

An integrating circuit 30 is connected to the output terminal pair 14-14'. The integrator circuit 30 is composed of a diode 31, two resistors 32 and 34, and a capacitor 33.

The anode of the diode 31 is connected to the terminal 14, and the cathode of the diode 31 is connected to each end of each of the two resistors 32, 34.

The other end of the resistor 32 is connected to the terminal 14', and the other end of the resistor 34 is connected to one end of the capacitor 33. The other end of the capacitor 33 is connected to the terminal 14'.

Terminals 35 and 35'are formed at both ends of the capacitor 33, respectively, forming a pair of output terminals 35-35'of the integrating circuit 30.

Assuming that a signal obtained by superimposing a high frequency signal due to arc discharge on a low frequency signal of the commercial power supply P (see FIG. 1) is applied to the terminal pair Ta-Tb, the output terminal pair 14-14 of the arc discharge detection circuit 10 is now applied. A voltage waveform corresponding to the high frequency signal is generated at ′ (the position indicated by the reference numeral “A” in FIG. 5). FIG. 6A shows an example of this voltage waveform.

Since the frequency of this voltage waveform is about 500 ns, it is difficult to detect it as it is, but if the length of the entire waveform, that is, the waveform width can be converted to about 100 μs, the detection becomes easy.

Therefore, the arc discharge detection device 100 of the present embodiment uses the integration circuit 30 to integrate the waveform components on the positive side of the high-frequency signal generated by the arc discharge at the output terminal pairs 14-14'of the arc discharge detection circuit 10. And it is converted to the waveform width.

FIG. 6B shows the result of converting the voltage waveform of FIG. 6A into the waveform width, and the position indicated by the reference numeral “B” in FIG. 5, that is, the output terminal pair 35-35 ′. The voltage waveform generated in is shown. As a result, the voltage waveform after conversion has a lower frequency than the voltage waveform before conversion, so that it is easy to handle.

A comparator 40 is connected to the output terminal pair 35-35'of the integrator circuit 30. The comparator 40 is composed of six resistors 41 to 46 and an operational amplifier 47.

One end of the resistor 41 of the comparator 40 is connected to the power supply circuit 50, and the other end of the resistor 41 is connected to each end of the resistor 42 and the resistor 43. The other end of the resistor 42 is grounded (G) at the terminal Tb. The resistor 41 and the resistor 42 function to divide the power supply voltage supplied from the power supply circuit 50. The power supply circuit 50 is connected to the terminal Ta and the terminal Tb, and converts the voltage of the commercial power supply P (for example, 100V) into the voltage for the operational amplifier 47 (for example, 6V). Since the power supply circuit 50 is composed of a commonly used and known circuit, the description of the circuit configuration will be omitted.

The other end of the resistor 43 is connected to the negative (−) side input end of the operational amplifier 47. One end of the resistor 44 is connected to the terminal 35, and the other end of the resistor 44 is connected to the positive (+) side input end of the operational amplifier 47.

Then, the resistor 45 is inserted between the output end and the + side input end of the operational amplifier 47 to form positive feedback.

Further, one end of the resistor 46 is connected to the output end of the operational amplifier 47, and the other end of the resistor 46 is grounded at the terminal Tb. Terminals 48 and 48'are formed at both ends of the resistor 46, respectively, forming a pair of output terminals 48-48'of the comparator 40.

As described above, the resistor 41 and the resistor 42 divide the power supply voltage supplied from the power supply circuit 50 so that, for example, a voltage of + 1.0 V is applied to the negative input end of the operational amplifier 47. As a result, the operational amplifier 47 outputs high (H), that is, the power supply voltage of the power supply circuit 50 (for example, + 6V) when a voltage of +1.0 V or higher is applied to the + side input terminal, while the + side input. When a voltage less than + 1.0V is applied to the end, low (L), for example 0V, is output.

Therefore, when the voltage waveform of FIG. 6B is input to the comparator 40, the comparator 40 outputs a + 6V “H” level only in the section where the input voltage is + 1.0V or more. FIG. 6C shows the output signal from the comparator 40, and shows the voltage waveform generated at the position indicated by the symbol “C” in FIG. 5, that is, the output terminal pair 48-48 ′.

The voltage of the voltage waveform after the waveform width conversion shown in FIG. 6B is + 1.0V or more between the time T0 and the time T1, so that the comparator 40 is as shown in FIG. 6C. In addition, a square wave pulse having a time length of 80 μs corresponding to the time from time T0 to time T1 is generated and output.

Of the output terminal pairs 48-48'of the comparator 40, one terminal 48 is a light emitting diode of the photocoupler 81 (divided into FIGS. 5 and 7) via a resistor 82 as shown in FIG. It is connected to the anode of 81a. The cathode of the light emitting diode 81a is connected to the other terminal 48'of the output terminal pair 48-48'.

Further, as shown in FIG. 7, one end of the resistor 83 is connected to the power supply Vcc (for example, 5V), and the other end of the resistor 83 is connected to the base of the transistor 87 and one end of the resistor 84. The other end of the resistor 84 is connected to the collector of the phototransistor 81b of the photocoupler 81 (described separately in FIGS. 5 and 7), and the emitter of the phototransistor 81b is grounded. The power supply Vcc is supplied by the power supply circuit 60 (see FIG. 5). The power supply circuit 60 is connected to the terminal Ta and the terminal Tb, and converts the voltage of the commercial power supply P (for example, 100V) into the voltage of the power supply Vcc (for example, 5V). Since the power supply circuit 60 is also configured by a commonly used known circuit like the power supply circuit 50, the description of the circuit configuration will be omitted.

The emitter of the transistor 87 is connected to the power supply Vcc, and the collector of the transistor 87 is connected to one end of the resistor 85. The other end of the resistor 85 is connected to one end of the resistor 86 and the input end of the NOT circuit 90a, and the other end of the resistor 86 is grounded.

The photocoupler 81 is used to electrically insulate the circuit including the circuits 10, 30, 40 up to the photocoupler 81 of the arc discharge detection device 100 and the circuit including the circuit 70 after the photocoupler 81. That is, since the circuit including the circuits 10, 30, 40 up to the photocoupler 81 of the arc discharge detection device 100 has lower power consumption than the circuit including the circuit 70 after the photocoupler 81, the former circuit 10, The circuit including the 30 and 40 may be affected by the circuit including the latter circuit 70, and the detection accuracy of the arc discharge may be deteriorated. Therefore, the photocoupler 81 plays a role of electrically separating the two so as not to deteriorate the detection accuracy.

The output end of the NOT circuit 90a is connected to the input end of the NOT circuit 90b, the output end of the NOT circuit 90b is connected to one end of the resistor 91, and the other end of the resistor 91 is one end of the capacitor 92 and the NOT circuit 93a. It is connected to the input end. The other end of the capacitor 92 is grounded.

The output end of the NOT circuit 93a is connected to the input end of the NOT circuit 93b, the output end of the NOT circuit 93b is connected to the input end of the NOT circuit 93c, and the output end of the NOT circuit 93c is the monostable multivibrator 70. It is connected to the input end.

The monostable multivibrator 70 is composed of two NAND circuits 71 and 72, a capacitor 73, and a resistor 74.

The output end of the NOT circuit 93c is connected to one input end of the NAND circuit 71, and the output end of the other NAND circuit 72 and the power supply Vcc via the resistor 94 are connected to the other input end of the NAND circuit 71. Is connected.

The output end of the NAND circuit 71 is connected to one end of the capacitor 73, and the other end of the capacitor 73 is connected to both input ends of the NAND circuit 72 and one end of the resistor 74. The other end of the resistor 74 is grounded.

The NAND circuit 72 is used as a NOT circuit. The output of the NAND circuit 71 is supplied to the subsequent circuit, in this embodiment, the alarm notification circuit 110 as the output of the monostable multivibrator 70 via the output terminal 75. The alarm notification circuit 110 is connected to the power supply Vcc and is grounded.

As described above, the output terminal pair 48-48'of the comparator 40 is connected to the series circuit of the resistor 82 and the light emitting diode 81a of the photocoupler 81 (see FIG. 5). When the rectangular wave pulse shown in FIG. 6C described above is output to the output terminal pair 48-48', the light emitting diode 81a is turned on at the rising edge of the rectangular wave pulse, that is, at time T0. It emits light. Correspondingly, the photodiode 81b is also turned on, the collector potential thereof becomes the ground level, and a current flows from the power supply Vcc to the resistor 83 and the resistor 84.

As a result, the base potential of the transistor 87 rises, the transistor 87 is turned on, and a current flows from the power supply Vcc to the resistor 85 and the resistor 86. Correspondingly, the potential at the connection point between the resistor 85 and the resistor 86, that is, the position indicated by the reference numeral “C” in FIG. 7, also increases.

Since this state continues until the square wave pulse falls, a square wave pulse having the same shape as the square wave pulse is generated at the connection point between the resistor 85 and the resistor 86. Therefore, the connection point between the resistor 85 and the resistor 86 is designated by the same reference numeral “C” as the output terminal pair 48-48 ′.

As described above, the input end of the NOT circuit 90a is connected to the connection point between the resistor 85 and the resistor 86, and the NOT circuit 90b is connected to the subsequent stage. FIG. 8A shows an example of a voltage waveform (rectangular wave pulse) at the connection point between the output end of the NOT circuit 90b and the resistor 91, that is, the position indicated by the reference numeral “D” in FIG. In FIG. 8A, the square wave pulses in the “non-detection” column on the left side are generated one by one within a half cycle (approximately 8 ms) when the frequency of the low-frequency AC signal of the commercial power supply P is “60 Hz”. An example is shown. On the other hand, in FIG. 8A, the rectangular wave pulses in the “detection” column on the right side show an example in which two pulses are generated in the same half cycle. In FIGS. 8 (a) to 8 (c), the waveforms shown by the broken lines show voltage waveforms every half cycle when the low-frequency AC signal of the commercial power supply P is full-wave rectified.

When a square wave pulse similar to that in FIG. 6 (c) is generated at the connection point C in FIG. 7 and the input of the NOT circuit 90a is switched from “L” to “H” due to the rise of the rectangular wave pulse, the NOT circuit The output of 90a switches from "H" to "L". In response to this, the output of the NOT circuit 90b is switched from "L" to "H". That is, since the states of "L" and "H" at the connection point C and the connection point D are the same, a square wave pulse having the same shape as the rectangular wave pulse generated at the connection point C is generated at the connection point D. ..

While the connection point D is “H”, current is supplied from the connection point D to the capacitor 92 via the resistor 91. Correspondingly, the potential of the capacitor 92, that is, the potential at the position indicated by the reference numeral “E” in FIG. 7 rises. FIG. 8B shows an example of the voltage waveform of the connection point E. In FIG. 8B, the threshold value Th shown by the broken line indicates the threshold value of the input voltage for the NOT circuit 93a connected to the connection point E to output “L”. Therefore, if the voltage at the connection point E, that is, the input voltage of the NOT circuit 93a is equal to or higher than the threshold value Th, the NOT circuit 93a outputs “L”, and if the voltage at the connection point E is less than the threshold value Th, the NOT circuit 93a is output. Outputs "H". Since there is no section in the voltage waveform in the “non-detection” column of FIG. 8 (b) that exceeds the threshold value Th, the NOT circuit 93a continuously outputs “H”. On the other hand, since the voltage waveform in the “non-detection” column of FIG. 8B has a section where the threshold value is Th, the NOT circuit 93a continuously outputs “L” in that section.

Since the threshold value Th is a value peculiar to the NOT circuit 93a, it does not fluctuate. In the present embodiment, by appropriately selecting the resistance value of the resistor 91 and the capacitance of the capacitor 92, the potential of the connection point E becomes the threshold value Th or more from the rectangular wave pulses applied to the connection point D. I try to identify the square wave pulse. Here, the specified rectangular wave pulse is, for example, a pulse that continues for a predetermined time width or longer. However, the pulse that continues for a predetermined time width or more may be composed of a plurality of pulses, not just one pulse.

The square wave pulse in the “non-detection” column of FIG. 8A shows an example in which one square wave pulse is generated within a half cycle of the low frequency AC signal of the commercial power supply P. In this case, since one square wave pulse does not form a pulse that continues for a predetermined time width or more, the capacitor 92 is not supplied with a charge sufficient to raise the potential of the connection point E to the threshold value Th or more.

On the other hand, the square wave pulse in the “detection” column of FIG. 8A shows an example in which two square wave pulses are generated within a half cycle of the low frequency AC signal of the commercial power supply P. In this case, since the two square wave pulses form a pulse that continues for a predetermined time width or more, a charge that causes the potential of the connection point E to rise above the threshold value Th is supplied to the capacitor 92.

Since the two NOT circuits 93a and 93b are connected between the connection point F and the connection point E, which are the output ends of the NOT circuit 93b, as in the case of the connection point D and the connection point C, they are connected. The states of "L" and "H" at the point F and the connection point E are the same. Therefore, if the input end of the NOT circuit 93a is "L", that is, if the voltage of the connection point E is less than the threshold value Th, the output end of the NOT circuit 93b, that is, the connection point F is also "L", and the NOT circuit If the input end of 93a is "H", that is, if the voltage at the connection point E is equal to or higher than the threshold value Th, the output end of the NOT circuit 93b, that is, the connection point F is also "H". Since there is no section in the voltage waveform in the “non-detection” column of FIG. 8 (b) that exceeds the threshold value Th, the voltage at the connection point F is as shown in the “non-detection” column of FIG. 8 (c). , Continue with "L". On the other hand, since the voltage waveform in the "non-detection" column of FIG. 8 (b) has a section where the threshold value is Th or more, the voltage at the connection point F is shown in the "detection" column of FIG. 8 (c). Continues that section "H".

As described above, the input end of the monostable multivibrator 70 is connected to the output end of the NOT circuit 93c. The NOT circuit 93c inverts and outputs "H" or "L" at the input terminal, that is, the connection point F. Therefore, if the voltage level of the connection point F is "L", the NOT circuit 93c outputs "H", and if the voltage level of the connection point F is "H", the NOT circuit 93c outputs "L". To do.

The monostable multivibrator 70 starts operation when the input drops from "H" to "L". Such a pulse that starts the operation of the monostable multivibrator 70 is called a trigger pulse.

When the monostable multivibrator 70 starts operating, a time constant determined by the capacitance of the capacitor 73 and the resistance value of the resistor 74, that is, a square wave pulse having a time length corresponding to the CR time constant is output from the output terminal 75. The rectangular wave pulse output by the monostable multivibrator 70 is for notifying that an arc discharge has occurred.

As described above, the arc discharge detection device 100 of the present embodiment has a rectangular wave pulse corresponding to the waveform width of the voltage waveform based on the voltage waveform corresponding to the high frequency signal detected from the arc discharge detection circuit 10. To generate. Then, a potential of a level corresponding to the time length of the pulse signal generated within a half cycle of the low-frequency AC signal of the commercial power supply P is generated, and when the generated potential level becomes equal to or higher than a predetermined level, an arc is generated. Generates an alarm signal indicating that a discharge has occurred and outputs it to the outside.

As described above, according to the arc discharge detection device 100 of the present embodiment, the potential level according to the time length of the pulse signal generated within the half cycle of the low frequency AC signal of the commercial power supply P becomes equal to or higher than a predetermined level. In this case, the high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and an alarm signal indicating the occurrence of arc discharge is output to the outside. Therefore, the high-frequency signal detected by the arc discharge detection circuit 10 is output. High-frequency signals generated due to arc discharge can be selected and detected from among them, and erroneous detection of arc discharge can be prevented.

Further, in the arc discharge detection device 100 of the present embodiment, the arc discharge is detected based on the high frequency signal generated due to the arc discharge, that is, the arc discharge with almost no voltage drop is also detected. Since this is possible, it is possible to detect the series arc in the earlier stage more reliably and accurately.

(Fourth Embodiment)
The arc discharge detection device 200 according to the fourth embodiment of the present invention has the arc discharge detection circuit 10 of the first embodiment as one of the components, similarly to the arc discharge detection device 100 of the third embodiment. When a voltage is generated at the terminal pair 14-14', it is determined and detected whether or not the voltage is caused by the series arc discharge. However, in the arc discharge detection device 200 of the present embodiment, the voltage generated at the terminal pair 14-14'is generated due to the series arc discharge with respect to the arc discharge detection device 100 of the third embodiment. The method of determining whether or not it is a thing is different. Hereinafter, the arc discharge detection device 200 of the present embodiment will be described with reference to FIGS. 9 and 10.

Due to the configuration of the arc discharge detection device 200 of the present embodiment, a part of the circuit after the phototransistor 81b of the photocoupler 81 is different from the arc discharge detection device 100 of the third embodiment. Therefore, as the circuit of the photocoupler 81 before the light emitting diode 81a, the circuit included in the arc discharge detection device 100 of the third embodiment is used as it is. Further, in the circuits after the phototransistor 81b of the photocoupler 81 included in the arc discharge detection device 200 of the present embodiment, the same components as those included in the arc discharge detection device 100 of the third embodiment are the same. Reference numerals will be given and the description thereof will be omitted.

As shown in FIG. 9, the input end of the monostable multivibrator 210 is connected to the collector of the photodiode 81b of the photocoupler 81. Like the monostable multivibrator 70, the monostable multivibrator 210 is composed of two NAND circuits 211 and 212, a capacitor 213, and a resistor 214. However, in the monostable multivibrator 210, the capacitance of the capacitor 213 and the resistance value of the resistor 214 are different from those of the monostable multivibrator 70. That is, the time lengths of the rectangular wave pulses output from the monostable multivibrator 210 are different.

The input end of the monostable multivibrator 210 is connected to the collector of the photodiode 81b of the photocoupler 81 as described above. Then, as described above in the third embodiment, the collector potential of the photodiode 81b drops to the ground level when the photocoupler 81 is operating, while the power supply Vcc when the photocoupler 81 is not operating. Potential level of. That is, the collector potential of the photodiode 81b is usually "H", and when the rectangular wave pulse of FIG. 10A is generated, it becomes "L" from the start to the end of the generation.

The monostable multivibrator 210 starts operation when the input drops from "H" to "L". When the monostable multivibrator 210 starts operating, a time constant determined by the capacitance of the capacitor 213 and the resistance value of the resistor 214, that is, a square wave pulse having a time length corresponding to the CR time constant is output from the output terminal 215. FIG. 10B shows, as an example, a rectangular wave pulse having a time length of 7 ms generated at the position of the output terminal 215, that is, the position indicated by the reference numeral “G” in FIG. The reason why the monostable multivibrator 210 generates and outputs a rectangular wave pulse having a time length of 7 ms will be described later.

The output terminal 215 of the monostable multivibrator 210 is connected to one end of the resistor 220, and the other end of the resistor 220 is connected to one end of the capacitor 221 and one input end of the NAND circuit 222. The other input end of the NAND circuit 222 is connected to the connection point C between the resistor 85 and the resistor 86 described above in the third embodiment. The output end of the NAND circuit 222 is connected to the input end of the monostable multivibrator 70. The other end of the capacitor 221 is grounded.

When the output of the NAND circuit 222 switches from "H" to "L", it means that the two inputs of the NAND circuit 222 are both "H". That is, the monostable multivibrator 210 outputs a rectangular wave pulse, and the connection point between the resistor 85 and the resistor 86 is “H”. However, one input of the NAND circuit 222, that is, the input to which the output of the monostable multivibrator 210 is supplied, does not immediately become "H" even if "H" is output from the monostable multivibrator 210. .. This is because one input of the NAND circuit 222 becomes "H" after being delayed by a time corresponding to the CR time constant determined by the capacitance of the capacitor 221 and the resistance value of the resistor 220. In the present embodiment, for example, 1 ms (time from time T0 to time T1 in FIG. 10C) is adopted as this delay time. “1 ms” is adopted as the non-detection time in which the induced load is connected as the load L and the periodic pulse (hereinafter referred to as “induced load generation pulse”) generated at the start of the induced load is not detected. This is because the inductive load generation pulse is not a pulse generated due to the arc discharge, so it is necessary to make the inductive load generation pulse undetectable.

The inductive load generation pulse is often generated every cycle corresponding to a half cycle of the low-frequency AC signal of the commercial power supply P. When the frequency of the low-frequency AC signal of the commercial power supply P is "60 Hz", the half cycle is about 8 ms, and if "1 ms" is taken as the detection time of one induced load generation pulse, the next induction is taken. The interval until the load generation pulse is generated is 8 (ms) -1 (ms) = 7 (ms). This "7 ms" corresponds to the time length of the rectangular wave pulse generated by the monostable multivibrator 210. That is, the monostable multivibrator 210 outputs a rectangular wave pulse having a time length corresponding to the interval between adjacent induced load generation pulses.

FIG. 10C shows an example of a rectangular wave pulse generated at the connection point between the resistor 220 and the capacitor 221, that is, at the position indicated by the symbol “H” in FIG. The square wave pulse of FIG. 10 (c) rises with a delay of 2 ms from the rise of the square wave pulse having a time length of 7 ms of FIG. 10 (b) generated in synchronization with the square wave pulse of FIG. 10 (a), and the time. It is generated as a square wave pulse with a length of 5 ms. In this way, the 7 ms square wave pulse output from the monostable multivibrator 210 was delayed by 2 ms to generate the 5 ms square wave pulse, which is the trigger pulse of the 7 ms square wave pulse. In the example of FIG. 10A, this is to prevent detection of the square wave pulse generated at time T0 and time T2).

FIG. 10D shows an example of a rectangular wave pulse output from the output end of the NAND circuit 222, that is, the position indicated by the reference numeral “I” in FIG. As shown in FIG. 9D, when a square wave pulse having a time length of 5 ms in FIG. 10C is generated and a square wave pulse is generated at the connection point C, the NAND circuit 222 changes from “H” to “L”. Outputs a signal that falls to ". In response to this, the monostable multivibrator 70 starts operation. The rectangular wave pulse output by the monostable multivibrator 70 is for notifying that an arc discharge has occurred.

As described above, the arc discharge detection device 200 of the present embodiment has a rectangular wave pulse corresponding to the waveform width of the voltage waveform based on the voltage waveform corresponding to the high frequency signal detected from the arc discharge detection circuit 10. To generate. When it is detected that the number of pulse signals generated within the half cycle of the low-frequency AC signal of the commercial power supply P is two or more, it is determined that the high-frequency signal is a signal caused by an arc discharge. Then, an alarm signal indicating that an arc discharge has occurred is generated and output to the outside. Here, in order to detect that "the number of pulse signals generated within the half cycle of the low frequency AC signal of the commercial power supply P is two or more", the number of pulse signals generated within the half cycle of the low frequency AC signal of the commercial power supply P is within the half cycle. The first pulse signal of the pulse signals generated in is not detected.

As described above, according to the arc discharge detection device 200 of the present embodiment, when it is detected that the number of pulse signals generated within a half cycle of the low frequency AC signal of the commercial power supply P is two or more. , The high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and a signal indicating the occurrence of arc discharge is output to the outside. Therefore, among the high-frequency signals detected by the arc discharge detection circuit 10, the arc High-frequency signals generated due to discharge can be selected and detected, which can prevent erroneous detection of arc discharge.

(Fifth Embodiment)
The arc discharge detection device 300 according to the fifth embodiment of the present invention, like the arc discharge detection devices 100 and 200 of the third and fourth embodiments, has the arc of the first embodiment as one of the components. The discharge detection circuit 10 is provided, and when a voltage is generated at the terminal pair 14-14', it is determined and detected whether or not the voltage is caused by the series arc discharge. However, in the arc discharge detection device 300 of the present embodiment, the voltage generated at the terminal pair 14-14'is caused by the series arc discharge with respect to the arc discharge detection devices 100 and 200 of the third and fourth embodiments. The method of determining whether or not it has occurred is different. Hereinafter, the arc discharge detection device 300 of this embodiment will be described with reference to FIGS. 11 and 12.

Due to the configuration of the arc discharge detection device 300 of the present embodiment, a part of the circuit after the phototransistor 81b of the photocoupler 81 is different from that of the arc discharge detection device 100 of the third embodiment. Therefore, as the circuit of the photocoupler 81 before the light emitting diode 81a, the circuit included in the arc discharge detection device 100 of the third embodiment is used as it is. Further, in the circuits after the phototransistor 81b of the photocoupler 81 included in the arc discharge detection device 300 of the present embodiment, the same components as those included in the arc discharge detection device 100 of the third embodiment are the same. Reference numerals will be given and the description thereof will be omitted.

As shown in FIG. 11, the output end of the NOT circuit 93c is connected to the input end of the monostable multivibrator 310. Like the monostable multivibrator 70, the monostable multivibrator 310 is composed of two NAND circuits 311, 312, a capacitor 313, and a resistor 314. However, the monostable multivibrator 310 differs from the monostable multivibrator 70 in the capacitance of the capacitor 313 and the resistance value of the resistor 314. That is, the time lengths of the rectangular wave pulses output from the monostable multivibrator 310 are different.

When the NOT circuit 93c outputs a signal falling from “H” to “L”, the monostable multivibrator 310 outputs a rectangular wave pulse having a time length of 20 ms, as shown in FIG. 12 (c). Note that FIG. 12C shows a square wave pulse having a time length of 20 ms generated at the position of the output terminal 315, that is, the position indicated by the reference numeral “J” in FIG. As will be described later, the reason why the square wave pulse having a time length of 20 ms is output is that the square wave pulse having a time length of 20 ms is used as a trigger pulse, and the time length of the rising time is 40 ms, which is delayed by 10 ms from the rise of the trigger pulse. This is to generate a square wave pulse of.

The output terminal 315 of the monostable multivibrator 310 is connected to one end of the resistor 320, and the other end of the resistor 320 is connected to one end of the capacitor 321 and both input ends of the NAND circuit 322. The other end of the capacitor 321 is grounded.

Further, the output end of the NAND circuit 322 is connected to the input end of the monostable multivibrator 320.

As shown in FIG. 12C, when the output of the monostable multivibrator 310 is switched from “L” to “H” at time T10, a current flows through the resistor 320. This current supplies an electric charge to the capacitor 321 and flows until the capacitor 321 is fully charged. When the capacitor 321 is fully charged, no current flows through the resistor 320, and the potential at the connection point between the capacitor 321 and the resistor 320 rises to the maximum value. In response to this, the NAND circuit 322 switches the output value.

The NAND circuit 322 functions as a NOT circuit in the same manner as the NAND circuit 312. Therefore, when the input end of the NAND circuit 322 becomes "H", the output end of the NAND circuit 322 becomes "L".

Like the monostable multivibrator 310, the monostable multivibrator 330 is composed of two NAND circuits 331 and 332, a capacitor 333, and a resistor 334. However, the monostable multivibrator 330 differs from the monostable multivibrator 310 in the capacitance of the capacitor 333 and the resistance value of the resistor 334. That is, the time lengths of the rectangular wave pulses output from the monostable multivibrator 330 are different.

The monostable multivibrator 330 receives when a trigger pulse that falls from "H" to "L" is input, that is, when the output of the NAND circuit 322 is switched from "H" to "L". The operation is started and a square wave pulse having a time length of 40 ms is output (see FIG. 12 (d)).

However, the NAND circuit 322 does not immediately output "L" even if "H" is output from the monostable multivibrator 310. This is because the NAND circuit 322 outputs "L" after being delayed by a time corresponding to the CR time constant determined by the capacitance of the capacitor 321 and the resistance value of the resistor 320.

FIG. 12D shows an example of a rectangular wave pulse output from the output terminal 335 of the monostable multivibrator 330, that is, the position indicated by the reference numeral “K” in FIG. FIG. 12D shows how the monostable multivibrator 330 starts outputting a square wave pulse from time T11, which is delayed by 10 ms from time T10. This delay time "10 ms" corresponds to a half cycle when the frequency of the low frequency signal of the commercial power supply P is "50 Hz", and functions as a non-detection period for the next high frequency signal. The non-detection period with a time length of 10 ms is provided in this way because the high-frequency signal generated due to chattering or the like when power is supplied to the load L is replaced with the high-frequency signal generated due to the series arc discharge. This is because it is not misjudged. The time length of the non-detection period is not limited to "10 ms" and may be longer than this.

The output terminal 335 of the monostable multivibrator 330 is connected to one input end of the NAND circuit 340. The other input end of the NAND circuit 340 is connected to the output end of the NOT circuit 93c. The output end of the NAND circuit 340 is connected to the input end of the monostable multivibrator 70.

The NAND circuit 340 outputs "L" when both of the two inputs are "H", and outputs "H" in other cases.

FIG. 12E shows an example of a rectangular wave pulse output from the output end of the NAND circuit 340, that is, the position indicated by the reference numeral “L” in FIG. As shown in FIG. 12E, in the NAND circuit 340, when the NOT circuit 93c outputs a square wave pulse at time T12 while the monostable multivibrator 330 outputs a square wave pulse having a time length of 40 ms. In synchronization with this, a signal falling from "H" to "L" is output. In response to this, the monostable multivibrator 70 starts operation. FIG. 12 (f) shows an example of a rectangular wave pulse output from the output terminal 75 of the monostable multivibrator 70, that is, the position indicated by the reference numeral “M” in FIG. The rectangular wave pulse output by the monostable multivibrator 70 is for notifying that an arc discharge has occurred.

As described above, the arc discharge detection device 300 of the present embodiment has a first square wave corresponding to the waveform width of the voltage waveform based on the voltage waveform corresponding to the high frequency signal detected from the arc discharge detection circuit 10. A wave pulse is generated, a second square wave pulse having a predetermined time length (for example, 20 ms) is generated using the first square wave pulse as a trigger pulse, and further, the second square wave pulse is used as a trigger pulse. A third square wave pulse having a predetermined time length (for example, 40 ms) is generated by delaying the generation time of the second square wave pulse by a predetermined time (for example, 10 ms, which is a half cycle of the commercial power supply P). When the next high-frequency signal is detected from the arc discharge detection circuit 10 during the generation of the third square wave pulse, it is determined that the high-frequency signal is the signal caused by the arc discharge, and it is determined that the arc discharge has occurred. Generates the indicated alarm signal and outputs it to the outside.

Then, the predetermined delay time (for example, 10 ms) functions as a non-detection period for the next high frequency signal. The reason why such a non-detection period is provided is that when power is supplied to the load L, the high frequency signal generated due to chattering or the like is not erroneously determined as the high frequency signal generated due to the series arc discharge. Because. In the present embodiment, a period corresponding to a half cycle of the commercial power frequency is adopted as the non-detection period, but it is estimated that the high frequency signal generated due to chattering or the like converges within this period. This is because that. Of course, if it does not converge within this period, the non-detection period may be extended.

As described above, according to the arc discharge detection device 300 of the present embodiment, after the first high-frequency signal is detected by the arc discharge detection circuit 10 and a predetermined non-detection period elapses, the next high-frequency signal is the arc discharge detection circuit. When detected from 10, the high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and a signal indicating the occurrence of arc discharge is output to the outside. Therefore, the high frequency detected by the arc discharge detection circuit 10 A high-frequency signal generated due to an arc discharge can be selected and detected from the signals, thereby preventing erroneous detection of the arc discharge.

(Sixth Embodiment)
The arc discharge detection device 400 according to the sixth embodiment of the present invention has the same as the arc discharge detection devices 100, 200, 300 of the third to fifth embodiments, as one of the components of the first embodiment. The arc discharge detection circuit 10 is provided, and when a voltage is generated in the terminal pair 14-14', it is determined and detected whether or not the voltage is caused by the series arc discharge. However, in the arc discharge detection device 300 of the present embodiment, the voltage generated at the terminal pair 14-14'is a series arc discharge with respect to the arc discharge detection devices 100, 200, 300 of the third to fifth embodiments. The method of determining whether or not it was caused by is different. Hereinafter, the arc discharge detection device 400 of the present embodiment will be described with reference to FIGS. 13 and 14.

Due to the configuration of the arc discharge detection device 400 of the present embodiment, a part of the circuit after the phototransistor 81b of the photocoupler 81 is different from the arc discharge detection device 100 of the third embodiment. Therefore, as the circuit of the photocoupler 81 before the light emitting diode 81a, the circuit included in the arc discharge detection device 100 of the third embodiment is used as it is. Further, in the circuits after the phototransistor 81b of the photocoupler 81 included in the arc discharge detection device 400 of the present embodiment, the components included in the arc discharge detection devices 100, 200, 300 of the third to fifth embodiments. The same reference numerals are given to the same ones, and the description thereof will be omitted.

As shown in FIG. 13, the output end of the NAND circuit 222 is connected to both input ends of the NAND circuit 410, and the output end of the NAND circuit 410 is connected to one input end of the NAND circuit 411. Further, an output terminal 335 of the monostable multivibrator 330 is connected to the other input end of the NAND circuit 411. The output end of the NAND circuit 411 is connected to the input end of the monostable multivibrator 70.

The NAND circuit 410 inverts the output value of the NAND circuit 222 and outputs it. As described above with reference to FIG. 10D in the fourth embodiment, a square wave pulse is generated at the connection point C while a rectangular wave pulse (see FIG. 10C) is being generated from the monostable multivibrator 210. At that time, the NAND circuit 222 outputs a signal falling from "H" to "L". Therefore, at this time, the NAND circuit 410 outputs a signal rising from “L” to “H”, that is, a square wave pulse having the same shape as the square wave pulse generated at the connection point C.

FIG. 14 (f) shows an example of a rectangular wave pulse output from the output end of the NAND circuit 410, that is, the position indicated by the reference numeral “N” in FIG. As shown in FIG. 14 (f), a square wave pulse having a time length of 7 ms is output from the monostable multivibrator 210, and a square wave pulse having a time length of 5 ms is generated at the connection point H with a delay of a predetermined time (for example, 2 ms). If a square wave pulse is generated at the connection point C at time T3 while it is being generated, the NAND circuit 410 outputs a square wave pulse having the same shape as the square wave pulse generated at the connection point C.

The NAND circuit 411 outputs "NAND" of the output of the NAND circuit 410 and the output of the monostable multivibrator 330. That is, the NAND circuit 411 outputs "L" only when the output of the NAND circuit 410 is H "and the output of the monostable multivibrator 330 is H".

FIG. 14 (g) shows an example of a rectangular wave pulse output from the output end of the NAND circuit 411, that is, the position indicated by the symbol “O” in FIG. As shown in FIG. 14 (g), the NAND circuit 411 synchronizes with the output of the square wave pulse by the NAND circuit 410 while the monostable multivibrator 330 outputs the square wave pulse having a time length of 40 ms. Then, a signal falling from "H" to "L" is output. In response to this, the monostable multivibrator 70 starts operation. FIG. 14H shows an example of a rectangular wave pulse output from the output terminal 75 of the monostable multivibrator 70, that is, the position indicated by the reference numeral “P” in FIG. The rectangular wave pulse output by the monostable multivibrator 70 is for notifying that an arc discharge has occurred.

As described above, the arc discharge detection device 400 of the present embodiment has a first rectangle corresponding to the waveform width of the voltage waveform based on the voltage waveform corresponding to the high frequency signal detected from the arc discharge detection circuit 10. A wave pulse is generated, a second rectangular wave pulse having a predetermined time length (for example, 20 ms) is generated using the first rectangular wave pulse as a trigger pulse, and further, the second rectangular wave pulse is used as a trigger pulse. A third rectangular wave pulse having a predetermined time length (for example, 40 ms) is generated by delaying the generation time of the second rectangular wave pulse by a predetermined time (for example, 10 ms, which is a half cycle of the commercial power supply P). If it is detected during the generation of the third rectangular wave pulse that the number of pulse signals generated within the half cycle of the low frequency AC signal of the commercial power supply P is two or more, the high frequency signal is arc-discharged. Is determined to be the cause signal, and an alarm signal indicating that an arc discharge has occurred is generated and output to the outside.

As described above, according to the arc discharge detection device 400 of the present embodiment, after the first high-frequency signal is detected by the arc discharge detection circuit 10 and a predetermined non-detection period elapses, the next high-frequency signal is the arc discharge detection circuit. When detected from 10, the high-frequency signal is determined to be a high-frequency signal caused by arc discharge, and a signal indicating the occurrence of arc discharge is output to the outside. Therefore, the high frequency detected by the arc discharge detection circuit 10 A high-frequency signal generated due to an arc discharge can be selected and detected from the signals, thereby preventing erroneous detection of the arc discharge.

(7th Embodiment)
The arc discharge alarm device according to the seventh embodiment of the present invention has an alarm notification circuit 110 connected to the output side of the arc discharge detection devices 100, 200, 300, 400 of the third to sixth embodiments described above. ..

As shown in FIGS. 7, 9, 11 and 13, an alarm notification circuit 110 is connected to each output side of the arc discharge detection devices 100, 200, 300, and 400. When a rectangular wave pulse is output from the monostable multivibrator 70 (see FIGS. 12 (f) and 14 (h)), the alarm notification circuit 110 performs an alarm notification accordingly. Here, as a specific example of the alarm notification, notification by sound such as a buzzer, notification by light such as a red rotating lamp, notification by vibration of a vibrator or the like, and the like can be considered. That is, the alarm may be in any form as long as it can be notified in a form that can be perceived by a person.

As described above, according to the arc discharge alarm device of the present embodiment, when an arc discharge occurs, the person directly notifies the person that the arc discharge has occurred, so that the person causes a fire or the like caused by the arc discharge. You can take precautions before you do.

Further, instead of the alarm notification circuit 110, a breaker that cuts off the electric circuit of the commercial power supply P may be provided. According to this, when an arc discharge occurs, the electric circuit of the commercial power supply P is automatically cut off, so that the person does not need to take any precautionary measures against a fire caused by the arc discharge.

(8th Embodiment)
FIG. 15 is a perspective view showing the appearance of the arc discharge alarm device 500 according to the eighth embodiment of the present invention.

The arc discharge alarm device 500 of the present embodiment is provided with the arc discharge alarm device of the seventh embodiment in its housing, and has two power cords 501 connected to the terminal Ta and the terminal Tb, respectively, and a power supply. Each end of the cord 501 is provided with a terminal 502.

The terminal 502 is connected to a distribution board (not shown) provided in each home.

According to the arc discharge alarm device 500 of the present embodiment, one device can detect and warn the series arc discharge of the power supply line in the house.

(9th Embodiment)
FIG. 16 is a perspective view showing the appearance of the arc discharge alarm devices 600 and 610 according to the ninth embodiment of the present invention.

Both the arc discharge alarm devices 600 and 610 of the present embodiment can be used by being plugged into an outlet 700 installed in each home.

The arc discharge alarm device 600 includes a power cord 601 similar to the power cord 501 of the arc discharge alarm device 500 of the eighth embodiment, and an outlet plug 602 provided at the end of the power cord 601.

On the other hand, the arc discharge alarm device 610 is provided with the blade 611 of the outlet plug directly provided in the housing.

According to the arc discharge alarm devices 600 and 610 of the present embodiment, the arc discharge alarm devices 600 and 610 of the present embodiment can be installed between the lines of the indoor wiring EW of the commercial power supply P even if the electrician is not qualified. Can be installed.

In carrying out the present invention, the following various modifications are given without being limited to each of the above embodiments.
(1) In the arc discharge detection circuit and the arc discharge detection device of each of the above embodiments, the arc discharge is based on a time corresponding to a half cycle of the power supply frequency of the commercial power supply (for example, 8 ms when the power supply frequency is 60 Hz). I tried to detect high frequency signals caused by, but it is not limited to this.
(2) In the arc discharge detection devices 100, 200, 300, 400 of the third to sixth embodiments, the arc discharge detection circuit 10 of the first embodiment is provided as one of the components. Instead of this, the arc discharge detection circuit 20 of the second embodiment may be provided.
(3) In the arc discharge detection devices 100, 200, 300, 400 of the third to sixth embodiments, a monostable multivibrator is used in order to generate a rectangular wave pulse having a long time length, but the present invention is limited to this. Instead, an unstable multivibrator may be used, or another circuit may be used. In short, any one may be used as long as it can generate a rectangular wave pulse having a required time length.
(4) In the arc discharge detection device of the present embodiment, a square wave pulse is used as a signal for notifying that an arc discharge has occurred, but the pulse signal is not limited to a signal of another shape such as a sine wave or a sawtooth wave. But it may be.

10, 20 ... Arc discharge detection circuit,
11,21 ... Resistor, 12,22 ... Inductor, 13,23 ... Capacitor,
14, 14', 24, 24'... Output terminal,
30 ... Integrator circuit, 31 ... Diode,
40 ... Comparator, 47 ... Op Amp,
50, 60 ... Power supply circuit,
70, 210, 310, 330 ... Stable multivibrator,
80a, 80b ... Zener diode, 81 ... Photocoupler,
81a ... light emitting diode, 81b ... phototransistor,
87 ... Transistor,
90a, 90b, 93a, 93b, 93c ... NOT circuit,
100, 200, 300, 400 ... Arc discharge detector,
500, 600 ... Arc discharge alarm device,
P ... Commercial power supply, EW ... Indoor wiring, L ... Load.

Claims (8)

It is an arc discharge detection circuit that is connected in parallel between the lines of the electric circuit connected to the commercial power supply.
An RLC circuit consisting of a resistor, an inductor, and a capacitor,
A terminal pair consisting of terminals provided at both ends of the inductor,
With
Among the RLC circuits, the CR circuit in which the capacitor and the resistor are connected is a circuit in which a high-frequency signal is superimposed on a low-frequency AC signal supplied from the commercial power supply as a current flowing through the electric circuit. It functions as a passing means for selecting and passing high-frequency signal components from the current.
The inductor functions as a conversion means for converting a high-frequency signal component passed by the passing means into a voltage waveform.
The terminal pair functions as an external output means for outputting the voltage waveform converted by the inductor to the outside.
Among the RLC circuits, by configuring an LC circuit in which the inductor and the capacitor are connected as a resonance circuit, a high frequency signal component in the frequency range around the resonance frequency peculiar to the resonance circuit is converted into a voltage waveform, and the conversion is performed. Output the voltage waveform to the outside,
An arc discharge detection circuit characterized by this. The LC circuit is a series LC circuit.
The RLC circuit is connected in parallel between the lines of the electric circuit with the resistor connected in series to the series LC circuit.
The arc discharge detection circuit according to claim 1. The LC circuit is a parallel LC circuit.
The RLC circuit is connected in parallel between the lines of the electric circuit with the resistor connected in series to the parallel LC circuit.
The arc discharge detection circuit according to claim 1. The arc discharge detection circuit according to any one of claims 1 to 3.
An integrating means that integrates the voltage waveform output from the arc discharge detection circuit and generates a voltage waveform according to the waveform width of the integrated voltage waveform.
A pulse generating means that generates a pulse signal having a predetermined voltage value while the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage.
A potential generating means that generates a potential at a level corresponding to the time length of the pulse signal generated by the pulse generating means within a half cycle of the low-frequency AC signal of the commercial power source.
An alarm signal output means that generates an alarm signal indicating that an arc discharge has occurred and outputs the alarm signal to the outside when the potential level generated by the potential generation means exceeds a predetermined level.
An arc discharge detection device characterized by having. The arc discharge detection circuit according to any one of claims 1 to 3.
An integrating means that integrates the voltage waveform output from the arc discharge detection circuit and generates a voltage waveform according to the waveform width of the integrated voltage waveform.
A pulse generating means that generates a pulse signal having a predetermined voltage value while the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage.
A detection means for detecting that the number of pulse signals generated by the pulse generation means is two or more within a half cycle of the low-frequency AC signal of the commercial power source.
An alarm signal output means that generates an alarm signal indicating that an arc discharge has occurred and outputs the alarm signal to the outside when two or more pulse signals are detected by the detection means.
An arc discharge detection device characterized by having. The arc discharge detection circuit according to any one of claims 1 to 3.
An integrating means that integrates the voltage waveform output from the arc discharge detection circuit and generates a voltage waveform according to the waveform width of the integrated voltage waveform.
A first pulse generating means that generates a first pulse signal having a predetermined voltage value while the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage.
A potential generating means that generates a potential at a level corresponding to the time length of the first pulse signal generated by the first pulse generating means within a half cycle of the low frequency AC signal of the commercial power source.
A second pulse generating means that generates a second pulse signal having a predetermined time length longer than the time length of the first pulse signal when the potential level generated by the potential generating means becomes a predetermined level or higher.
A delay means for delaying the second pulse signal generated by the second pulse generation means by a predetermined non-detection time, and a delay means.
A third pulse generating means that generates a third pulse signal having a time length longer than the time length of the second pulse signal by using the second pulse signal delayed by the delay means as a trigger pulse.
An alarm signal indicating that an arc discharge has occurred when the next first pulse signal is generated by the first pulse generating means while the third pulse signal is being generated by the third pulse generating means. Signal output means for alarm that generates and outputs to the outside,
An arc discharge detection device characterized by having. The arc discharge detection circuit according to any one of claims 1 to 3.
An integrating means that integrates the voltage waveform output from the arc discharge detection circuit and generates a voltage waveform according to the waveform width of the integrated voltage waveform.
A first pulse generating means that generates a first pulse signal having a predetermined voltage value while the voltage waveform generated by the integrating means is equal to or higher than a predetermined threshold voltage.
A detection means for detecting that the number of first pulse signals generated by the first pulse generation means is two or more within a half cycle of the low frequency AC signal of the commercial power supply.
A second pulse generating means that generates a second pulse signal having a predetermined time length longer than the time length of the first pulse signal by using the first pulse signal generated by the first pulse generating means as a trigger pulse.
A delay means for delaying the second pulse signal generated by the second pulse generation means by a predetermined non-detection time, and a delay means.
A third pulse generating means that generates a third pulse signal having a time length longer than the time length of the second pulse signal by using the second pulse signal delayed by the delay means as a trigger pulse.
When two or more first pulse signals are detected by the detection means while the third pulse signal is being generated by the third pulse generation means, an alarm signal indicating that an arc discharge has occurred is generated. Alarm signal output means to generate and output to the outside,
An arc discharge detection device characterized by having. The arc discharge detection device according to any one of claims 4 to 7, wherein the integrating means integrates a voltage waveform on the positive side of the voltage waveform output from the arc discharge detection circuit.