JP6632736B2 - Energized state determination device - Google Patents

Description

  The present invention relates to a non-contact type energization state determination device. The energization state determination device of the present invention is suitable for use in, for example, the determination of the energization state of an NC (Numerical Control) machine tool or various manufacturing apparatuses.

  2. Description of the Related Art Conventionally, an energization state determination device that detects on / off of a direct current using an alternating current sensor has been known.

  In the device of Patent Literature 1, the open / close state of the current switch is determined by detecting an AC component included in a rising portion and an AC component included in a falling portion from a waveform of a current flowing through an electric wire.

  In the device of Patent Document 2, a set signal is input to an RS flip-flop when a rising component is detected from a waveform of a current flowing through an electric wire, and a reset signal is input to the RS flip-flop when a falling component is detected. To generate a DC detection signal.

JP 2009-65261A JP 2005-83879 A

  The devices disclosed in Patent Literature 1 and Patent Literature 2 are devices for direct current, and therefore cannot determine the energization state of alternating current.

  When an AC current flows through the wire, the output voltage of the AC current sensor changes between the minimum voltage and the maximum voltage around zero volt, and when the current stops at zero volt, the falling component Does not occur, the current stop cannot be detected as it is.

  For this reason, the user prepares a separate device for judging the energization state of the AC current, judges DC / AC of the current flowing through each wire, and then connects the energization state judgment device for DC or the AC. A decision must be made as to whether to connect an energization state determination device.

  For example, in order to inspect or monitor an NC machine tool or various manufacturing devices, etc., when it is desired to connect a conduction state determination device to each wire wired to the NC machine tool or the like, a DC / DC It is necessary to confirm the distinction of exchange.

  However, it is not always easy to determine the DC / AC of the current flowing through each wire. For this reason, it may take a lot of time and effort to connect the energization state determination device to each electric wire such as an NC machine tool. In addition, accurate inspection / monitoring, etc., may be required because the energization state determination device used is erroneous. May not be possible.

  The present invention has been made in view of such a situation, and has as its object to provide an energization state determination device that can be used without distinction between DC and AC.

An energization state determination device according to the present invention is an energization state determination device that determines an energization state of an electric wire through which a DC current or an AC current flows, and detects a temporal change in current of an electric wire to be determined and detects a detection signal wave. A non-contact type AC current sensor that outputs a signal, and the detection signal wave output from the AC current sensor is input to a comparator, and the comparator generates a rise detection pulse signal and a fall detection pulse signal, and detects the rise. A DC detection circuit that inputs a pulse signal and the falling detection pulse signal to a flip-flop circuit and generates and outputs a DC detection signal; and at least one of the rising detection pulse signal and the falling detection pulse signal from the DC detection circuit. Is input as an edge detection pulse signal and smoothed to generate and output an AC detection signal. Characterized in that it comprises a detection circuit.

In the present invention, it is preferable that the AC detection circuit further includes an AC detection stop circuit that stops output of the AC detection signal by the AC detection circuit when a current flowing through the electric wire is a pulse train of 1 kHz or less. .

  In the present invention, it is preferable that the AC detection circuit further includes a DC detection stop circuit that stops output of the DC detection signal by the DC detection circuit when a current flowing through the electric wire is AC.

  In the present invention, it is preferable that the AC detection circuit has a capacitor whose capacitance is adjusted so that the AC detection signal having a predetermined voltage or higher is output when the frequency of the edge detection pulse signal is higher than or equal to a predetermined value. .

  In the present invention, the DC detection circuit includes a first comparator that generates the rising detection pulse signal by comparing a signal value of the detection signal wave output from the AC current sensor with a predetermined first threshold value; A second comparator that generates the falling detection pulse signal by comparing a signal value of the detection signal wave output by the current sensor with a predetermined second threshold; and an active level when the rising detection pulse signal is input. An RS flip-flop that outputs the DC detection signal and outputs the DC detection signal at an inactive level when the falling detection pulse signal is input is desirably provided.

  ADVANTAGE OF THE INVENTION According to the energization state determination apparatus which concerns on this invention, it can be used, without judging DC / AC distinction of the electric wire used as a determination object.

  In the present invention, by providing the AC detection stop circuit, the DC detection circuit can detect the pulse train even when a pulse train current (DC) is flowing through the electric wire.

  In the present invention, by providing the DC detection stop circuit, it is easy for the user to recognize the DC / AC discrimination of the current flowing through the electric wire.

  In the present invention, by generating the AC detection signal of the AC detection circuit by adjusting the capacitance of the capacitor, the circuit configuration can be simplified and the cost can be reduced.

  In the present invention, a DC detection signal and an edge detection pulse signal can be generated with a simple circuit configuration by configuring the DC detection circuit using the first and second comparators and the RS flip-flop.

It is a figure showing the example of connection of the energization state judging device concerning one embodiment of the present invention. FIG. 2 is an external view illustrating a state in which the AC current sensor of FIG. 1 is closed. FIG. 2 is an external view illustrating a state in which the AC current sensor of FIG. 1 is open. FIG. 3 is a diagram illustrating a waveform of a rising detection signal output by the AC current sensor of FIG. 2. FIG. 3 is a diagram illustrating a waveform of a falling detection signal output by the AC current sensor of FIG. 2. FIG. 2 is an electronic circuit diagram illustrating a configuration of the signal processing circuit in FIG. 1. 5 is a truth table for explaining the operation of the first comparator in FIG. 4. 5 is a truth table for explaining an operation of the second comparator in FIG. 4. 5 is a truth table for explaining the operation of the RS flip-flop in FIG. FIG. 2 is a timing chart for explaining the operation of the signal processing circuit of FIG. 1.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a state in which an energization state determination device 100 according to the present embodiment is connected to a device to be inspected or monitored.

  As shown in FIG. 1, the conduction state determination device 100 according to the present embodiment includes an AC current sensor 10 and a signal processing circuit 20.

  In the example of FIG. 1, a display lamp L that is turned on by a 24 V DC power supply and a switch SW for switching the lighting state of the display lamp L are connected by a cable C (corresponding to the “electric wire” of the present invention). I have. The AC current sensor 10 detects the energized state of the cable C. The switch SW is not limited to a switch that merely turns on / off the display lamp L, but may be a switch that causes a device to be inspected or monitored to perform some function. Further, the switch SW may be a mechanical switch or a switching element circuit.

  The signal processing circuit 20 determines the ON / OFF state (that is, the open / closed state) of the switch SW using the signal waveform detected by the AC current sensor 10.

  Here, the AC current sensor 10 is a non-contact type, and in the present embodiment, a clamp type AC current sensor as shown in FIGS. 2A and 2B is used.

  2A and 2B are conceptual diagrams showing a specific example of the AC current sensor 10. FIG. As shown in FIGS. 2A and 2B, the AC current sensor 10 of the present embodiment includes a main body 11 and a U-shaped clamp 12. As shown in FIG. 2B, the alternating current sensor 10 can be opened by rotating the other end so that one end of the clamp portion 12 is separated from the main body portion 11. Then, as shown in FIG. 2A, the cable C is sandwiched between the main body 11 and the clamp 12 of the AC current sensor 10.

  The AC current sensor 10 converts a magnetic field induced by a current flowing through the cable C into a voltage. The current flowing through the cable C increases instantaneously when the switch SW is switched from the off state to the on state. Then, a magnetic field is excited by the transient current (that is, a current whose current value changes with time). The AC current sensor 10 detects the magnetic field and outputs a rising detection signal S1 having a voltage waveform corresponding to the change in the magnetic field. 3A and 6 show signal waveforms of the rising detection signal S1. The time width of the rising detection signal S1 is, for example, about 1 msec.

  After that, while the switch SW is maintained in the ON state, the value of the current flowing through the cable C does not substantially change, so that the AC current sensor 10 does not detect anything.

  On the other hand, when the state of the switch SW changes from the on state to the off state, the current flowing through the cable C decreases instantaneously. Then, the magnetic field is excited by the transient current. The AC current sensor 10 detects this magnetic field and outputs a falling detection signal S2 of a voltage waveform corresponding to the time change of the magnetic field. 3B and 6 show signal waveforms of the falling detection signal S2. The time width of the fall detection signal S2 is, for example, about 1 msec.

  Thereafter, while the switch SW is maintained in the ON state, no current flows through the cable C, and the AC current sensor 10 does not detect anything.

  As described above, by using the AC current sensor 10, the rising and falling of the current flowing through the cable C can be detected only by sandwiching the cable C between the main body 11 and the clamp section 12. That is, it is not necessary to cut the cable C and connect an ammeter in series to measure the current.

  Note that, as shown in FIGS. 3A and 3B, the voltage changes in the opposite direction when the switch SW is turned on and when the switch SW is turned off. In this embodiment, a positive voltage is generated when the switch SW is turned on, and a negative voltage is generated when the switch S2 is turned off.

  The signal processing circuit 20 determines the energization state of the cable C using the rise detection signal S1 and the fall detection signal S2 included in the detection signal wave of the AC current sensor 10. If it is determined that a DC current is flowing through the cable C, the DC detection signal Sd is set to the active level (here, high level). The detection signal Sa is set to an active level (here, high level). When no current flows through the cable C, both the DC detection signal Sd and the AC detection signal Sa are at an inactive level (low level here).

  For this purpose, the signal processing circuit 20 includes a DC detection circuit 20A and an AC detection circuit 20B.

  First, the DC detection circuit 20A will be described.

  The DC detection circuit 20 </ b> A includes a CT (Current Transformer) detection signal output unit 21, a first comparator 22, a second comparator 23, and an RS (RESET-SET) flip-flop 24.

  The CT detection signal output unit 21 converts a detection signal wave (a signal wave including the rising detection signal S1 and the falling detection signal S2) from the AC current sensor 10 into a signal S3 amplified by a predetermined gain. Hereinafter, the output signal of the CT detection signal output unit 21 is referred to as a CT detection signal S3.

  The CT detection signal output section 21 outputs the rising detection signal S1 as a positive CT detection signal S3 and the falling detection signal S2 as a negative CT detection signal. Note that the sign of the detection signals S1 and S2 does not necessarily mean a positive potential and a negative potential. That is, it is positive that the potential exceeds the reference potential (the output potential of the CT detection signal output unit 21 when the AC current sensor 10 does not output, for example, 2.5 V in the example of FIG. 6 described later). Being below the potential is negative.

  The first comparator 22 extracts the above-described rising detection signal S1 from the CT detection signal S3 output to the CT detection signal output unit 21. For this purpose, the first comparator 22 compares the CT detection signal S3 with the first threshold voltage V1, and when the potential of the CT detection signal S3 is equal to or higher than the first threshold voltage V1, sets the output signal S4 to "0". (Low level), and when the potential of the CT detection signal S3 is lower than the first threshold voltage V1, the output signal S4 is set to '1' (high level). As a result, when the switch SW changes from off to on (when the AC current sensor 10 outputs the rising detection signal S1), the first comparator 22 outputs the signal value '0' as the rising detection pulse signal S4. (See FIG. 5A). This rising detection pulse signal S4 is supplied to the set input S of the RS flip-flop 24.

  The second comparator 23 extracts the above-mentioned falling detection signal S2 from the CT detection signal S3 output to the CT detection signal output unit 21. For this purpose, the second comparator 23 compares the CT detection signal S3 with the second threshold voltage V2. When the potential of the CT detection signal S3 is equal to or lower than the second threshold voltage V2, the second comparator 23 changes the output signal S5 to "0". (Low level), and when the potential of the CT detection signal S3 is higher than the second threshold voltage V2, the output signal S5 is set to '1' (high level). As a result, when the switch SW changes from on to off (when the AC current sensor 10 outputs the falling detection signal S2), the second comparator 23 sets the signal value '0' as the falling detection pulse signal S5. Output (see FIG. 5B). The falling detection pulse signal S5 is supplied to the reset input R of the RS flip-flop 24.

  As described above, the RS flip-flop 24 receives the rising detection pulse signal S4 from the set input S and the falling detection pulse signal S5 from the reset input R.

  Here, when the RS flip-flop 24 inputs the rising detection pulse signal S4 (that is, when the input value of the set input S becomes “0”), the input value of the reset input R is “1” ( See FIG. 6). Therefore, the output value of the inverted output / Q of the RS flip-flop 24 becomes "1" (see FIG. 5C).

After the detection pulse signal S4 is input, the inverted output / Q of the RS flip-flop 24 is maintained at "1" while the signal values of the signals S4 and S5 are both "1" (see FIG. 5C).
On the other hand, when the RS flip-flop 24 inputs the falling detection pulse signal S5 (that is, when the input value of the reset input R becomes “0”), the input value of the set input S is “1” ( See FIG. 6). Therefore, the output value of the inverted output / Q of the RS flip-flop 24 becomes '0' (see FIG. 5C).

  As a result, the signal value of the inverted output / Q of the flip-flop 24 is “1” (high level) from the input of the rising detection pulse signal S4 to the input of the falling detection pulse signal S5. (See FIG. 6).

  Here, the period from when the RS flip-flop 24 inputs the rising detection pulse signal S4 to when the falling detection pulse signal S5 is input substantially coincides with the period from when the switch SW is turned on to when it is turned off. Therefore, the period substantially coincides with the period in which the current flows through the switch SW.

  The inverted output / Q of the RS flip-flop 24 is output from the DC detection circuit 20A as a DC detection signal Sd.

  Next, the AC detection circuit 20B will be described.

  As shown in FIG. 4, the AC detection circuit 20B includes an AC detection stop circuit 25, a smoothing circuit 26, and a reset circuit 27.

  The AC detection circuit 20B receives an edge detection signal (described later) from the DC detection circuit 20A and generates an AC detection signal Sa using the edge detection signal.

  The edge detection signal may be the above-described rising detection pulse signal S4, the falling detection pulse signal S5, or a signal obtained by combining these signals S4 and S5. In the present embodiment, a case will be described in which a rising detection pulse signal S4 is used as the edge detection signal.

  The AC detection stop circuit 25 receives the rising detection pulse signal S4 (that is, the edge detection signal) from the first comparator 22. Then, when the external control signal S6 is at a low level, the AC detection stop circuit 25 supplies the inversion pulse signal / S4 of the rising detection pulse signal S4 to the smoothing circuit 26. On the other hand, when the external control signal S6 is at a high level, the AC detection stop circuit 25 fixes the output to a low level and stops the operation of the AC detection circuit 20B. The external control signal S6 is set to a high level when the current flowing through the cable C is, for example, a pulse train (DC signal) of 1 kHz or less, and is set to a low level otherwise. The setting of the external control signal S6 is manually set by the user of the energization state determination device 100, but may be set automatically. The reason for providing the AC detection stop circuit 25 will be described later.

  The smoothing circuit 26 includes a diode 26a and a capacitor 26b. The diode 26a is connected to the output of the AC detection stop circuit 25 at the anode. The capacitor has one end connected to the cathode of the diode 26a and the other end connected to the ground line. Then, the cathode side potential of the diode 26a becomes the output of the smoothing circuit 26. The output of the smoothing circuit is output from the AC detection circuit 20B as an AC detection signal Sa (a signal indicating whether an AC current is supplied or not).

  When the external control signal S6 is at a low level, the inverted pulse signal / S4 is input to the anode of the diode 26a. The charge is accumulated in the capacitor 26b by the inverted pulse signal / S4. The diode 26a is provided to prevent the charge stored in the capacitor 26b from flowing to the output terminal of the AC detection stop circuit 25.

  Here, when the frequency of the inverted pulse signal / S4 (therefore, the frequency of the rising detection pulse signal S4) is equal to or higher than a predetermined value, the capacitance of the capacitor 26b becomes equal to the voltage between the terminals of the capacitor 26b (therefore, the AC detection signal Sa (Signal potential) exceeds a predetermined potential. When the frequency of the rising detection pulse signal S4 exceeds a predetermined value, the signal potential of the AC detection signal Sa output from the smoothing circuit 26 exceeds the predetermined potential, so that an AC current flows through the cable C. I can judge. On the other hand, when the frequency of the rising detection pulse signal S4 is equal to or lower than the predetermined value, the signal potential of the AC detection signal Sa output from the smoothing circuit 26 is equal to or lower than the predetermined potential. DC current is flowing or no current is flowing).

  In the present embodiment, the smoothing circuit 26 is configured with one diode 26a and one capacitor 26b. However, if the AC detection signal Sa can be generated by smoothing the edge detection pulse signal, A circuit having another configuration may be used. Further, a circuit for binarizing the AC detection signal Sa using a comparator or the like may be added.

  The reset circuit 27 corresponds to the “DC detection stop circuit” of the present invention. The reset circuit 27 supplies a reset signal S7 to a reset input R of the RS flip-flop 24.

  When the output signal value of the smoothing circuit 26 exceeds the above-described predetermined value (that is, when an alternating current is flowing through the cable C), the signal value of the reset signal S7 is set to a low level. As a result, the inverted output / Q of the RS flip-flop 24 is reset. The reset circuit 27 is provided with a time constant (for example, about 1 to 5 ms) so as not to output a signal having the time constant or less, so that the RS flip-flop 24 is not reset at the time of DC detection.

  On the other hand, when the output signal value of the smoothing circuit 26 is equal to or less than the above-described predetermined value (that is, when no AC current flows through the cable C), the reset circuit 27 outputs a high level as the reset signal S7. Even when the reset signal S7 is at the high level, the second comparator 23 does not prevent the fall detection pulse signal S5 supplied to the reset input R of the RS flip-flop 24 from switching between the high level and the low level. There is no.

  In the present embodiment, the operation of the DC detection circuit 20A is stopped by the reset circuit 27 continuously sending the reset signal to the RS flip-flop 24. However, the operation of the DC detection circuit 20A is stopped by another method. May be.

  The AC detection circuit 20B of the present embodiment operates even when the current flowing through the cable C is, for example, a pulse train of 1 kHz or less (accordingly, a DC current), and the reset circuit 27 stops the operation of the RS flip-flop 24. Therefore, when it is known that such a pulse train flows through the cable C, the external control signal S6 is set to a high level, and the inverted signal / S4 of the rising detection pulse signal S4 is smoothed by the AC detection circuit 20B. Desirably, it is not supplied to the circuit 26. Thus, the DC detection circuit 20A can output the DC detection signal Sd for reproducing the pulse train.

  Next, the overall operation of the energization state determination device 100 according to the present embodiment will be described.

  First, the user of the energization state determination device 100 clamps the AC current sensor 10 to the cable C (see FIG. 2A).

  Thereafter, when the switch SW is turned on and a current starts flowing through the cable C, the AC current sensor 10 outputs a rising detection signal S1 (see FIGS. 3A and 6).

  The CT detection signal output section 21 amplifies the rising detection signal S1 and outputs it as a CT detection signal S3 (see FIG. 6).

  Upon receiving the CT detection signal S3, the first comparator 22 outputs a signal value "0" as a rising detection pulse signal S4. At this time, the second comparator 23 does not output the falling detection pulse signal S5 (that is, the signal value of the falling detection pulse signal S5 is “1”).

  As a result, the set input S becomes "0" and the reset input R becomes "1". Therefore, the RS flip-flop 24 sets the output value of the inverted output / Q to “1” (high level) (see FIGS. 5C and 6).

  Thereafter, when the current flowing through the cable C is stabilized, the output of the AC current sensor 10 becomes substantially zero volt (see FIG. 6).

  As a result, the signal value of the CT detection signal S3 output from the CT detection signal output unit 21 also becomes zero volt, whereby the output values of the first and second comparators 22 and 23 (that is, the set input S of the RS flip-flop 24) are set. And the signal value of the reset input R) are both '1'. Therefore, the value of the inverted output / Q of the RS flip-flop 24 is maintained at "1" (see FIGS. 5C and 6).

  Next, when the switch SW is turned off and the current stops flowing through the cable C, the AC current sensor 10 outputs a fall detection signal S2 (see FIGS. 3B and 6).

  The CT detection signal output unit 21 amplifies the falling detection signal S2 and outputs it as a CT detection signal S3 (see FIG. 6).

  Upon receiving the CT detection signal S3, the second comparator 23 outputs a signal value “0” as the falling detection pulse signal S5. At this time, the first comparator 22 does not output the rising detection pulse signal S4 (that is, the signal value of the rising detection pulse signal S4 is “1”).

  As a result, the set input S becomes "1" and the reset input R becomes "0". Therefore, the RS flip-flop 24 sets the output value of the inverted output / Q to “0” (low level) (see FIGS. 5C and 6).

  As described above, a waveform of the inverted output / Q as shown in FIG. 6 is formed. This inverted output / Q is output from the DC detection circuit 20A as a DC detection signal Sd.

  Here, when the current flowing through the cable C is an alternating current, the current flowing through the cable C repeats rising and falling even while the switch SW is kept on. Therefore, the AC current sensor 10 alternately outputs the rising detection signal S1 and the falling detection signal S2, even though the switch SW is maintained in the ON state. For example, when an AC signal of 50 Hz is flowing through the cable C, the AC current sensor 10 outputs a rising detection signal S1 or a falling detection signal S2 every 20 milliseconds.

  Also at this time, the CT detection signal output unit 21 converts the rising detection signal S1 and the falling detection signal S2 into a CT detection signal S3 and outputs the same.

  The first comparator 22 extracts the rising detection signal S1 from the CT detection signal S3 as in the case of DC. When the CT detection signal S3 corresponds to the rising detection signal S1, a signal value "0" is output as the rising detection pulse signal S4.

  The rising detection pulse signal S4 is input to the AC detection stop circuit 25.

  When the external control signal S6 is at a low level, the AC detection stop circuit 25 supplies an inversion pulse signal / S4 of the rising detection pulse signal S4 to the smoothing circuit 26 (described above).

  This inverted pulse signal / S4 is input to the smoothing circuit 26, and as a result, electric charges are accumulated in the capacitor 26b. When the current flowing through the cable C is an alternating current (that is, when the current flowing through the cable C exceeds the above-described predetermined value), the output voltage of the smoothing circuit 26 has a value exceeding the above-described predetermined potential. On the other hand, when the current flowing through the cable C is a DC current (that is, when the current flowing through the cable C is equal to or less than the above-described predetermined value), the output voltage of the smoothing circuit 26 has a value equal to or less than the above-described predetermined potential.

  As described above, the output potential of the smoothing circuit 26 is output to the outside as the AC detection signal Sa, and is also input to the reset circuit 27.

  The reset circuit 27 sets the signal value of the reset signal S7 to a low level when the output signal value of the smoothing circuit 26 exceeds the above-described predetermined value (that is, when the current flowing through the cable C is an alternating current). . As a result, the RS flip-flop 24 cannot output the DC detection signal Sd.

  On the other hand, the reset circuit 27 sets the signal value of the reset signal S7 to a high level when the output signal value of the smoothing circuit 26 is equal to or less than the above-described predetermined value (that is, when the current flowing through the cable C is DC). As a result, the RS flip-flop 24 can output the DC detection signal Sd.

  Thereafter, when the switch SW is turned off and the current stops flowing through the cable C, the output of the rising detection pulse signal S4 is stopped, and the output of the AC detection signal Sa is also stopped.

  As described above, in the conduction state determination device 100 of the present embodiment, when a DC current flows through the cable C, the DC detection circuit 20A outputs the high level / low level of the DC detection signal Sd in accordance with the ON / OFF of the switch SW. The level is switched, and the AC detection circuit 20B sets the AC detection signal Sa to an inactive level. On the other hand, when an AC current is flowing through the cable C, the AC detection circuit 20B switches the potential (active / inactive) of the AC detection signal Sa according to ON / OFF of the switch SW, and the DC detection circuit 20A performs the DC detection. Does not output the signal Sd. Therefore, according to the energization state determination device 100 of the present embodiment, both the determination of the energization state and the determination of DC / AC can be performed. Therefore, according to the energization state determination device 100 of the present embodiment, when monitoring the energization state, the user does not need to check the DC / AC distinction of the current flowing through the cable C.

  Further, in the present embodiment, since the AC detection stop circuit 25 is provided, when a pulse train current flows through the cable C, it is possible to prevent a false recognition that an AC current is flowing.

  Further, in the present embodiment, since the reset circuit 27 is provided, when the AC current is flowing through the cable C, the DC detection signal Sd is not output. For this reason, according to the present embodiment, the user can easily recognize the DC / AC discrimination of the flowing current.

  In addition, according to the present embodiment, since the AC detection signal Sa of the AC detection circuit 20B is generated by adjusting the capacitance of the capacitor 26b, the circuit configuration can be simplified and the cost can be reduced.

  Furthermore, in the present embodiment, the DC detection circuit 20A is configured using the first and second comparators 22 and 23 and the RS flip-flop 24, so that the DC detection signal Sd and the edge detection pulse signal ( In the present embodiment, the rising detection pulse signal S4) can be generated.

DESCRIPTION OF SYMBOLS 10 AC current sensor 11 Main part 12 Clamp part 20 Signal processing circuit 20A DC detection circuit 20B AC detection circuit 21 Detection signal output part 22 Comparator 23 Comparator 24 Flip-flop 25 AC detection stop circuit 26 Smoothing circuit 26a Diode 26b Capacitor 27 Reset circuit 100 Energized state determination device

Claims (5)

An energization state determination device that determines an energization state of an electric wire through which a DC current or an AC current flows,
A non-contact type AC current sensor that outputs a detection signal wave by detecting a temporal change in the current of the electric wire to be determined,
The detection signal wave output from the AC current sensor is input to a comparator, the comparator generates a rising detection pulse signal and a falling detection pulse signal, and the rising detection pulse signal and the falling detection pulse signal are flip-flop A DC detection circuit that inputs to the circuit, generates and outputs a DC detection signal,
An AC detection circuit that generates and outputs an AC detection signal by inputting and smoothing at least one of the rising detection pulse signal or the falling detection pulse signal as an edge detection pulse signal from the DC detection circuit,
An energization state determination device, comprising: The AC detection circuit further includes an AC detection stop circuit that stops the output of the AC detection signal by the AC detection circuit when a current flowing through the electric wire is a pulse train of 1 kHz or less. 2. The energization state determination device according to 1.   The AC detection circuit according to claim 1 or 2, further comprising: a DC detection stop circuit that stops output of the DC detection signal by the DC detection circuit when a current flowing through the electric wire is AC. An energization state determination circuit as described.   The said AC detection circuit has a capacitor whose capacitance was adjusted so that the AC detection signal of a predetermined voltage or more was output when the frequency of the edge detection pulse signal was a predetermined value or more. An energization state determination device according to any one of claims 1 to 3. The DC detection circuit,
A first comparator that generates the rising detection pulse signal by comparing a signal value of the detection signal wave output by the AC current sensor with a predetermined first threshold value;
A second comparator that generates the falling detection pulse signal by comparing a signal value of the detection signal wave output by the AC current sensor with a predetermined second threshold value;
An RS flip-flop that outputs the DC detection signal at an active level when the rising detection pulse signal is input, and outputs the DC detection signal at an inactive level when the falling detection pulse signal is input,
The energization state determination device according to any one of claims 1 to 4, further comprising:

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