JP2022079006A - Ac voltage source approach detection electroscope - Google Patents

Abstract

To provide an approach detection electroscope for an AC voltage source, capable of calling attention that a voltage source is nearby only by being mounted on a body of an operator regardless of the consciousness of the operator.SOLUTION: Disclosed is an electroscope method for detecting approach of an AC voltage source which includes the steps of: measuring a voltage induced in a human body H by the approach of an AC voltage source at a first electrode 1 of a detection circuit; measuring the voltage to the ground G by a second electrode 2 of the same circuit; capturing a current flowing owing to the potential difference between the first electrode 1 and the second electrode 2 by the detection circuit 4; and displaying and warning the output derived from the detection circuit 4 when a human body H insulated from the ground G approaches the AC voltage source.SELECTED DRAWING: Figure 3

Description

The present invention gives an alarm when a worker approaches an AC voltage source in order to prevent an electric shock accident or equipment accident of the worker during inspection work of electrical equipment such as a building or factory, or electrical work such as repair work. It relates to an approach detection voltage detector for an AC voltage source that emits light.

As shown in FIG. 17, the conventional voltage detector of an AC voltage source is based on a human body that is capacitively coupled to the ground, and when the electrode of the voltage detector is brought close to the charging part, which is the object to be measured, it becomes a charging part. The detection circuit of the voltage detector detects the minute current flowing through the capacitance C1 between the voltage detector, the capacitance C2 between the voltage detector and the worker, and the capacitance C3 between the worker and the ground. If the current is equal to or higher than a certain value, it is determined that the object to be measured has a voltage, and this is displayed or an alarm is given.

This type of voltage detector has been widely used in the past, and in Patent Document 1, a voltage detector is attached to a wrist and an electrode is projected from the voltage detector body in the direction of the hand, and the voltage detector is used as an object to be measured. The voltage is detected by bringing them closer. Further, in Patent Document 2, the voltage detection electrode of the voltage detector is brought into close contact with the handle of the tool, and the operator holds the tool and brings the tool close to the object to be measured to detect and warn the voltage of the object to be measured. Is.

Japanese Unexamined Patent Publication No. 8-220151 Japanese Patent No. 6467447

For these voltage detectors, the voltage detector worn by the operator must be held over the object to be measured, or a tool held in the hand must be brought close to it. That is, the worker is required to use the voltage detector correctly without forgetting to perform the voltage detection. If either of these is missing, there is a high possibility that the accident will occur.

Therefore, in order to solve the above-mentioned problems, it is an object of the present invention to provide a voltage detector that can alert the operator that a voltage source is nearby by simply attaching it to the operator's body, regardless of the operator's consciousness. It was done.

The conventional voltage detector measures the voltage of an AC voltage source such as an electric wire and measures the inflow current to the human body coupled to the voltage source by capacitance. The voltage detector of the present invention is shown in FIG. The voltage V ₀₂ generated in the human body by the AC voltage source V ₀ , the capacitance C ₀₁ between the charging unit and the human body, and the capacitance C ₀₂ between the human body and the earth is measured, and the voltage is generated by the voltage. It differs greatly in that it measures the outflow current from the human body.

Specifically, the invention of claim 1 is a voltage detector that detects the approach of an AC voltage source, wherein the detection circuit comprises a first electrode that measures a voltage induced in a human body due to the approach of the AC voltage source. It has a second electrode that measures the voltage to the ground, and has a circuit that outputs a signal from the detection circuit when the human body approaches the AC voltage source, and the first electrode is a dielectric material between the first electrode and the human body. The second electrode is an AC voltage source approach detection detector having a shape in which the vertical projection area with respect to the first electrode is small and the area with respect to the ground is large.

Further, in the invention of claim 2, the dielectric interposed between the human body and the human body is any one of an insulating container for accommodating the first electrode and the second electrode, work clothes, a helmet, shoes, and a belt. , The AC voltage source approach detection voltage detector according to claim 1.

The AC voltage source approach detection according to claim 1 or 2, wherein the first electrode is a flat plate and the second electrode has a pole shape standing on the flat plate of the first electrode. It was used as a voltage detector.

The invention according to claim 4 is the AC voltage source approach detection according to claim 1 or 2, wherein the first electrode is a flat plate, and the second electrode has a cylindrical shape standing on the flat plate of the first electrode. It was used as a voltage detector.

The invention according to claim 5 is the AC voltage source proximity detection voltage detector according to any one of claims 1 to 4, wherein the first electrode, the second electrode and the detection circuit are housed in an insulating container.

According to the invention of claim 1, if the voltage detector is mounted somewhere on the human body, a signal is output when the worker wearing the voltage detector approaches the voltage source. Therefore, in electrical work or the like, even if the operator forgets to approach the charging unit, it is possible to call attention and prevent accidents such as electric shock.

Further, according to the invention of claim 2, the work clothes, a helmet, shoes, and a belt are always worn by a worker during electrical work, and the first electrode and the second electrode are housed in any of these. It suffices to attach the insulated container, and it is easy to attach the voltage detector to the operator.

Further, according to the inventions of claims 3 and 4, the voltage generated between the electrode 1 and the electrode 2 becomes large, and the voltage V ₀₂ generated in the human body can be reliably captured.

Further, according to the invention of claim 5, since the voltage detector is housed in the insulating container, the insulating container can be easily attached to the operator, which is convenient.

It is a principle explanatory diagram which shows that the current which flows in the human body and the current which flows from a human body are generated when a human body approaches a voltage source. FIG. 5 is a schematic principle diagram of a main circuit relating to a voltage induced in a human body according to the first embodiment of the present invention. (A) is a schematic configuration diagram showing the principle of the detection circuit of the voltage detector of the first embodiment of the present invention, and (b) is the equivalent circuit diagram. (A) is an external front view of the voltage detector of the first embodiment of the present invention, (b) is a mounting state diagram of the voltage detector on a human body, and (c) is an exploded view of the electrodes of the voltage detector. Is. It is a perspective view which shows the shape example of the 2nd electrode of the voltage detector of Embodiment 1 of this invention. It is a comparative chart which shows the comparison of the sensitivity by the shape of the 2nd electrode of the voltage detector of Embodiment 1 of this invention. It is a block diagram of the detection circuit of the voltage detector of Embodiment 1 of this invention. It is a schematic vertical sectional view which shows an example of the voltage detector of Embodiment 2 of this invention. It is a perspective view which shows the electrode of the example of the voltage detector of Embodiment 2 of this invention. It is a schematic vertical sectional view which shows the other example of the voltage detector of Embodiment 2 of this invention. It is a perspective view which shows the electrode of another example of the voltage detector of Embodiment 2 of this invention. It is a side view which shows the state which the voltage detector of Embodiment 2 of this invention is attached to the helmet of a worker, (a) figure is the figure of clip fastening, (b) figure is the figure of band fastening. It is a side view which shows the state which the voltage detector of Embodiment 2 of this invention is attached to the work shoe, (a) figure is the figure which clipped the voltage detector to the heel, (b) figure is the toe of the voltage detector. It is a figure fastened with a band. It is a table and a graph of the value which measured the electric field strength with respect to the distance between a voltage source and a human body at each voltage. It is a graph which shows the measurement result of the electric field strength of a human body and the space around a head when a live line of a voltage of 3.3 kV is used as a voltage source. It is a table which measured the state of the alarm sound with respect to the distance to a human body when the live line of voltage 3.3kV was used as a voltage source using the voltage detector of Embodiment 2 of this invention. It is a schematic principle diagram of a conventional voltage detector.

(Example 1 of the embodiment)
First, before explaining the voltage detection method and the voltage detector of the first embodiment of the present invention with reference to the drawings, the potentials of each part of the human body were measured. In the main circuit of the voltage detector of the first embodiment, " ₀ " is inserted in V and C to display the voltage and capacitance, but in the detection circuit, " ₀ " is inserted in V and C. Display without.

First, we examined how the potential distribution of the human body is. For this, as shown in FIG. 1, the potentials of both wrists, both ankles, and the head of the human body approaching the AC electric wire were measured using an AC potential radio measuring device.

From the measurement results, it was a natural result that an electric potential was generated in the hand extended to the AC electric wire side, but it was confirmed that an electric potential was also generated in the hand on the opposite side. In addition, there were many postures in which the potential on the foot side was higher than that on the hand extended toward the AC electric wire side. From this, it was found that the electric potential was generated in the whole human body. It was also found that the human body has a potential floating from the ground, and that potential is different in each part of the human body.

However, considering that the human body is a conductor of several kΩ and is isolated from the AC electric wire and the ground with an impedance of several MΩ or more, a potential difference of several tens of volts or more occurs so that the voltage detector operates in the human body. I can't think of that.

As a result of the examination, it was found that the measured AC potential radio measuring instrument does not measure the electrode potential from the ground, but shows the current level passing through the electrode. In addition, although the human body potential floats from the ground, the human body itself is in the same potential state, and the current value flowing through each part of the human body varies depending on the impedance relationship of the surroundings, and the AC potential wireless measurement is performed according to the current value. The measured value of the instrument was changing.

As shown in FIG. 1, when the human body H approaches the AC electric wire W of 100 V, the currents of i ₁ , i ₂ , and i ₃ flow from the AC electric wire W through the arm, the body, and the head to the human body H. Due to this current, the human body H is in a state of having an AC voltage from the earth G. Here, it is 30V. Then, the current i ₄ , the current i ₅ , the current i ₆ , and the current i ₇ flow out through the arm, both legs, and the head opposite to the AC electric wire W through the capacity between the human body H and the earth G due to the human body potential.

The current ratio varies greatly depending on the relationship between the AC wire W, the human body H, and the earth G, but in an environment where one hand is close to the AC wire W and there is a wall on the opposite side of the AC wire W, as shown in FIG. It became the current value. i ₁ = 0.1 μA, i ₂ = 0.2 μA, i ₃ = 0.1 μA, i ₄ = 0.02 μA, i ₅ = 0.18 μA, i ₆ = 0.18 μA, i ₇ = 0.02 μA. .. As a result, it is considered that the voltage detection operation can be performed even if the voltage detector is held on the arm opposite to the AC wire W, and the sensitivity of the foot is better than that of the arm.

Since the conventional general voltage detector is set to detect the current i ₁ and i ₂ levels from the electric wire when approaching the AC electric wire, it is possible to detect the current i ₄ and i ₇ from a low level human body. Outflow current cannot be detected. _In addition, since the human body = ground potential model is used, the flow of currents i5 and _i6 , which have relatively large current levels, is not used. Note that FIG. 1 shows a typical current distribution. In reality, current input and output occur in more diverse parts of the human body.

Further, under the condition that the insulation of the human body is poor and the human body has the same potential as the ground, _only the inflow currents of the currents i1 _{, i2} , and i3 can be used, so that the human body potential cannot be detected. When the human body was actually made to the same potential as the ground barefoot, the voltage detector on the opposite side of the AC wire did not react.

In this way, when the human body approaches the voltage source, a current flows from the voltage source to the human body through the arm, body, and head, and this current causes the human body to have an AC potential from the earth, and the human body potential causes the human body and the earth. It was found that current flows through the arm, legs, and head on the opposite side of the voltage source through the intercapacity.

The present invention was made on the basis of this principle. The combined capacitance (series connection of C ₀₁ and C ₀₂ ) C ₀ of the closed circuit (hereinafter referred to as the main circuit) flowing from the voltage source W shown in FIG. 2 through the human body H to the ground G is expressed by the following equations 1 and 2. Become. Note that V ₀ is the potential of the voltage source W with respect to the earth G, V ₀₁ is the potential of the capacitance C ₀₁ between the voltage source W and the human body H, and V ₀₂ is the potential of the human body H with _respect to the earth G. Shows the potential.

Therefore, it becomes equations 3 and 4, and it can be seen that the human body H has an electric potential (V ₀₂ ) with respect to the earth G.

Further, since the formulas 5 and 6, the closer the human body H is to the charging portion (the d of C ₀₁ becomes smaller and the C ₀₁ becomes larger), the larger V ₀₂ becomes. As a result, if V ₀₂ can be detected, it can be detected that "a person (human body H) approaches the charging unit".

Further, FIG. 3A is a schematic configuration diagram showing the detection principle of the part A of FIG. 2, that is, the voltage detector A of the present invention. This voltage detector A is an armband type that is wrapped around the arm of the human body H, and is composed of a first electrode 1 and a second electrode 2. Here, C ₁ is the capacitance between the human body H and the first electrode 1, C ₂₁ is the capacitance between the first electrode 1 and the second electrode 2, and C ₂₂ is the capacitance between the human body H and the second electrode 2. The capacitance, C ₃₁ is the capacitance between the first electrode 1 and the ground G, and C ₃₂ is the capacitance between the second electrode 2 and the ground G.

Further, a detection circuit 4 is provided between the first electrode 1 and the second electrode 2. Then, as shown in FIG. 4, the first electrode 1, the second electrode 2 and the detection circuit 4 are attached to the surface of the armband-shaped strip 5, and the males are provided on the front and back surfaces of the ends of the strip 5. The female hook-and-loop fasteners 5a and 5b can be attached to the worker's arm.

The total combined capacity of the voltage detector A is expected to be the following equation 7. Further, the voltage _VC2 generated between the first electrode 1 and the second electrode 2 is given by the equation 8. This _VC2 is the voltage that enables detection.

From the above equation 8, if C ₁ is increased and _{C 2} is decreased, VC ₂ becomes large, and VC 2 effective for detection can be obtained. Further, if _{C 32} is large, a more effective VC 2 can be obtained. Further, if C ₂₂ is small, the current flowing through the detection circuit 4 can be increased, which is advantageous for detection.

Therefore, the C ₁ is increased by increasing the “S” of C = εS / d and decreasing the “d”. Therefore, the first electrode 1 has a large area and is a flexible electrode that can be wrapped around the human body H, and the shape of the electrode in contact with the second electrode 2 is made thinner so that C = εS / d. The "S" was made smaller, and the C ₂₁ was made smaller. The first electrode 1 shown in FIG. 4 has a square electrode plate 1a on both sides to increase the area, and the connecting portion 1b connecting these electrode plates 1a and 1a is a strip-shaped thin electrode plate, and has flexibility as a whole. I made it.

Further, the second electrode 2 reduces the vertical projection area with respect to the first electrode 1 to reduce the “S” and the C ₂₁ . Further, the vertical projection area with respect to the human body is reduced to reduce the "S", and the C ₂₂ is reduced. In addition, the area (side area) with respect to the space (earth) is secured, thereby increasing the C ₃₂ . The second electrode 2 shown in FIG. 4 has a cylindrical shape and is erected on the connection portion 1b of the first electrode 1.

With these configurations, the voltage _VC2 generated between the first electrode 1 and the second electrode 2 is increased to enable detection. Further, when the first electrode 1 is directly applied to the human body H and brought into close contact with the human body H, the C ₁ becomes infinite, the V _c 2 becomes large as shown in the equation 8, and the sensitivity becomes good.

The shape of the first electrode 1 is not limited to that shown in FIG. Further, the shape of the second electrode 2 is not limited to the cylindrical shape. For example, a disk-shaped one as shown in FIG. 5 (a) or a cross-shaped two semicircular plates may be used as shown in FIG. 5 (b). FIG. 5 (c) shows the cylindrical second electrode 2. Each of these second electrodes 2 is placed on the connection portion 1b of the first electrode 1 via a substrate 3 made of an insulating material.

In FIG. 6, a person wearing each of the detectors A having the second electrodes 2 of FIG. 5 (a), (b), and (c) is on the human body side (detector). The alarm buzzer sounds when approaching a voltage source with a constant voltage from the side of the arm without A (the side of the arm without A) and when approaching the voltage source from the sensor side (the side of the arm with detector A). I measured the distance.

As a result, it was demonstrated that among the three types of the second electrode 2, the cylindrical second electrode 2 shown in FIG. 5 (c) has the highest sensitivity.

Further, as shown in FIG. 7, the configuration of the detection circuit 4 includes an amplifier circuit 6 for amplifying a voltage VC2 generated by a current signal flowing through _{C 21} between the first electrode 1 and the second electrode 2, and a reference voltage. A sound generation circuit 9 and a lighting display circuit are provided only when a signal is output by a comparison circuit 8 in which a generation circuit 7 is provided and the output signal of the amplifier circuit 6 and the output signal of the reference voltage generation circuit 7 are compared. 10 operates. Further, the detection circuit 4 is provided with a power supply 11, and power is supplied to each circuit by turning on the switch 12 of the power supply 11.

Next, an approach warning method for an AC voltage source using the voltage detector A of the present invention will be described.
The operator wearing the voltage detector A first turns on the switch 12 of the detection circuit 4 during the work. Then, when the worker approaches the AC voltage source, a minute current flows into the worker. This current causes the human body to reach the potential of _V02 . The first electrode 1 is divided from the potential V ₀₂ via the capacitance C ₁ to become the potential V ₂ . The voltage of the second electrode 2 is the potential at which the current flowing out due to the potential V ₂ is divided by C ₂₁ and C ₃₂ . If the detection circuit 4 detects the potential difference VC2 between the capacitances _{C 21} generated by the outflow current i and the output signal obtained by amplifying the potential difference VC2 of the capacitance _{C 21} due to the outflow current i is larger than the reference voltage, An alarm sound is emitted from the voice generation circuit 9, and the lighting display circuit 10 lights up. From this, it can be seen that the worker wearing the voltage detector A has approached the AC voltage source. Further, even if the operator turns on the switch 12, the voice generation circuit 9 and the lighting display circuit 10 do not operate unless the switch 12 is close to the AC voltage source.

In the first embodiment, the voltage detector A is an armband type, but the present invention is not limited to this, as long as it is attached to any part of the head, neck, torso, legs, upper body, or lower body of the human body. good. Further, in the first embodiment, the voltage detector A is attached to the armband-shaped strip 5, but the present invention is not limited to this, and only the first electrode 1 is wound around the human body, and the first electrode 1 and the second electrode 2 are attached. The second electrode 2 may be separately attached to another part of the human body. Further, the first electrode 1 is a flexible flat plate, but the present invention is not limited to this, and any conductor such as a braided conductor may be used.

(Example 2 of the embodiment)
Next, the voltage detector B of the second embodiment of the present invention will be described with reference to FIGS. 8 to 13.

In the first embodiment, the first electrode 1 is a flexible electrode having a large area and wrapping around the human body H, and the shape of the electrode in contact with the second electrode 2 is reduced to C. = The "S" of εS / d was made smaller, and the C ₂₁ was made smaller. However, it was found that the electroscope can be detected by the above-mentioned principle even when the first electrode is not brought into close contact with the human body H. This is the second embodiment.

In one example of the voltage detector B in the second embodiment, as shown in FIGS. 8 and 9, a first electrode 16 made of a disk is housed inside a box-shaped insulating case 15, and the first electrode 16 is housed in the box-shaped insulating case 15. A rod-shaped second electrode 17 is provided vertically at the center of one surface of 16, and the same detection circuit 4 as in the first embodiment is provided between the first electrode and the second electrode. Further, a clip 15a is provided on the side surface of the insulating case 15.

Further, in another example of the voltage detector B in the second embodiment, as shown in FIGS. 10 and 11, a first electrode 18 made of a disk is housed inside a box-shaped insulating case 15, and the first electrode 18 is housed in the box-shaped insulating case 15. A vertically cylindrical second electrode 19 is provided at the center of one surface of the one electrode 18, and a detection circuit 4 same as that of the first embodiment is provided between the first electrode and the second electrode. ing. Further, a clip 15a is provided on the side surface of the insulating case 15.

Then, as shown in FIG. 12A, the voltage detector B has an insulating case 15 attached to the rear portion of the working helmet 20 by a clip 15a. The clip 15a in FIG. 10A is a clip slightly different from the configurations shown in FIGS. 8 and 10, but has the same gripping function. Further, as shown in the figure (b), the insulating case 15 may be attached to the working helmet 20 by the band 21. Further, as shown in FIG. 13A, the insulating case 15 can be attached to the heel of the work shoe 22 by the clip 15a. Further, as shown in (b), the insulating case 15 can be attached to the instep side of the toe of the work shoe 22 by the band 23.

In this way, the first electrode 16 or 18 is attached to the human body H via the dielectric 20 helmet 20, the work shoes 22, and the insulating case 15, but when the human body H approaches the voltage source W, it is a worker. A minute current flows into the human body H. Therefore, the capacitance C ₁ between the human body H and the first electrode 16 or 18 is smaller than that of the first embodiment, but the current between the first electrode 16 or 18 and the second electrode 17 or 19 Is generated, this is caught by the detection circuit 14, and an alarm is issued.

Hereinafter, a verification test was conducted on the voltage detector B.
First, the conditions of distance and electric field strength were measured for each voltage of the AC voltage source.

The electric field strength was measured using a digital electromagnetic wave measuring instrument (GM3120). For human body charging, the electric field strength was measured by pressing the electrode portion against the body. Further, the GND of the measuring instrument is connected to the GND with a cable.

FIG. 14 is a table and a graph showing the value of the electric field strength with respect to the distance between the voltage source and the human body at each voltage showing the measurement result. Looking at these, when the AC voltage source had a voltage of 1 kV, 96 V / m was measured when the distance between the voltage source and the human body was 110 cm, and 240 V / m was measured when the distance between the voltage source and the human body was 3 kV. As a result, it was found that an electric field strength of 96 V / m was detected at a distance of about 1 m with respect to a voltage source of 1 kV or more.

Next, FIG. 15 shows the results of measuring the electric field strength of the human body and the space around the head when the AC voltage source is a live line of 3 kV. Further, FIG. 16 shows a case where the voltage detector B is attached to the rear part of the helmet, and how the alarm sound operates depending on the distance from the 3 kV power supply due to the shapes of the first electrode and the second electrode. Was measured.

In FIG. 16, the “sensor-side electrode” refers to the second electrode, and the “human body-side electrode” indicates the first electrode. Further, "forward approach" indicates a case where the human body approaches forward toward the live line, and "backward approach" indicates a case where the human body approaches the live line backward. "Short siren" is almost continuous sound, "Short 4" sounds 4 times in 10 seconds, "Short 10" sounds 10 times in 10 seconds, "Short 30" sounds 30 times in 10 seconds. It means that an alarm sounds. Therefore, "short 4" means that the electric field strength is weak, and "short series" means that the electric field strength is strong.

From this table, the second electrode of No. 3 is a rod type with a length of 10 mm, and the square plate type with a first electrode of 60 x 30 mm is "forward approach" at a distance of 110 cm 5 times in 10 seconds. An alarm sounds, and in "backward approach", the alarm sounds 5 times every 10 seconds at a distance of 210 cm. In addition, the second electrode of No. 1 is a rod type with a length of 20 mm, and the disk type with a diameter of 40 mm is a "forward approach", and a "short 30" alarm sounds at a distance of 70 cm. In "backward approach", the alarm sound of "short 4" sounds at 230 cm.

In addition, the second electrode of No. 2 is a cylinder with a diameter of 35 mm and a height of 7 mm, and the disk type with a diameter of 40 mm is a disc type with a diameter of 40 mm. In "backward approach", the alarm sound of "short 15" sounds at 330 cm. In addition, even if the second electrode of No. 4 is a rod type with a length of 10 mm and the first electrode is a disk type with a diameter of 40 mm, even if it is "forward approach", a "short 27" alarm sounds at a distance of 190 cm, and "Short 27" sounds. In "backward approach", the alarm sound of "short 4" sounds at 330 cm.

As described above, when the AC power supply is 1000 V or more, preferably 3000 V or more, the first electrode is not in close contact with the human body, and the first electrode is via a dielectric such as a helmet or an insulating case of a detector. However, it fully demonstrates the function of the voltage detector. When the first electrode is brought into close contact with the human body, the detection may be uncertain due to the influence of sweat or the like, but when the first electrode is passed through a dielectric in this way, it is not affected by sweat or the like.

However, from the results in the table of FIG. 16 above, in the use of the voltage detector in electrical work, the voltage detector having the configuration of Nos. 3, 2 and 4 that sounds an alarm sound at a position 100 cm away from the power supply is practical. be.

In the first and second embodiments described above, the voltage detector A or B is provided with the sound generation circuit 9 and the lighting display circuit 10, but the output from the comparison circuit 8 is transmitted from the transmission unit (not shown) without these. It is also possible to receive the signal by wirelessly sending it to the outside, receive it by a communication device or a terminal device provided separately from the voltage detector A, and make an alarm or display on the device.

Although the first and second embodiments have been described above, they are presented as examples and are not intended to limit the scope of the invention. The present invention can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

A voltage detector B voltage detector G earth H human body W voltage source
1 1st electrode 1a Electrode plate 1b Connection part 2 2nd electrode 3 Board 4 Detection circuit
5 Band 5a Surface fastener 5b Surface fastener 6 Amplification circuit 7 Reference current generation circuit 8 Comparison circuit 8 Voice generation circuit 9 Lighting display circuit 11 Power supply 12 Switch 15 Insulation case 15a Clip 16 1st electrode 17 2nd electrode 18 1st electrode 19 2nd electrode 20 Helmet 21 Band 22 Work shoes 23 Band

Claims (5)

In a voltage detector that detects the approach of an AC voltage source, the detection circuit consists of a first electrode that measures the voltage induced in the human body due to the approach to the AC voltage source, and a second electrode that measures the voltage to the ground. The first electrode comprises a circuit that outputs a signal from the detection circuit when the human body approaches the AC voltage source, and the first electrode is made of a plate having a certain area between the AC voltage source and the human body via a dielectric. An AC voltage source proximity detection voltage detector characterized in that the two electrodes have a shape in which the vertical projection area with respect to the first electrode is small and the area with respect to the ground is large. The claims are characterized in that the dielectric interposed between the human body and the human body is an insulating container for accommodating the first electrode and the second electrode, and one of work clothes, a helmet, shoes, and a belt. The AC voltage source approach detection voltage detector according to 1. The AC voltage source proximity detection voltage detector according to claim 1 or 2, wherein the first electrode is a flat plate, and the second electrode has a pole shape standing on the flat plate of the first electrode. The AC voltage source proximity detection voltage detector according to claim 1 or 2, wherein the first electrode is a flat plate, and the second electrode has a cylindrical shape standing on the flat plate of the first electrode. The AC voltage source proximity detection voltage detector according to any one of claims 1 to 4, wherein the first electrode, the second electrode, and the detection circuit are housed in an insulating container.

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