JP2020187067A - AC voltage source approach detection method and detection voltage detector - Google Patents

Abstract

An AC voltage source approach detection method and a detection voltage detector capable of calling attention to the proximity of a voltage source regardless of the worker's consciousness simply by wearing the device on the worker's body. In a voltage detection method for detecting the approach of an AC voltage source, a voltage induced in a human body (H) due to the approach of an AC voltage source is measured by a first electrode (1) of a detection circuit, and a voltage is measured by a second electrode (2) of the circuit. The voltage with respect to the ground G is measured, the current flowing due to the potential difference between the first electrode 1 and the second electrode 2 is detected by the detection circuit 4, and the human body H insulated from the ground G approaches the AC voltage source. When this occurs, the output derived from the detection circuit 4 is displayed and an alarm is issued. [Selection drawing] Fig. 3

Description

The present invention provides 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 a method of detecting the approach of an AC voltage source to be emitted and a voltage detector.

As shown in FIG. 8, 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 Patent Document 1 shows that a voltage detector is attached to a wrist and electrodes are 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 operator 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, the present invention provides a method and a voltage detector that can call attention to the presence of a voltage source by simply attaching it to the body of the worker regardless of the consciousness of the worker. It is the purpose.

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 that is capacitively coupled to the voltage source. 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 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 method of detecting the approach of an AC voltage source, in which the first electrode of the detection circuit measures the voltage induced in the human body by approaching the AC voltage source, and the circuit of the same circuit. When the voltage to the ground is measured by the second electrode, the current flowing due to the potential difference between the first electrode and the second electrode is captured by the detection circuit, and the human body insulated from the ground approaches the AC voltage source. This is an AC voltage source approach detection method that outputs a signal from the detection circuit.

Further, the invention of claim 2 is a voltage detector that detects the approach of an AC voltage source, in which the detection circuit has a first electrode for measuring a voltage induced in the human body due to the approach of the AC voltage source, and a voltage with respect to the ground. The AC voltage source approach detection voltage detector is provided with a second electrode for measurement and a circuit for outputting a signal from the detection circuit when a human body approaches the AC voltage source.

Further, in the third aspect of the invention, the first electrode is made of a conductor having a certain area that can be brought into close contact with the human body, and the second electrode has a small vertical projection area with respect to the first electrode and a large area with respect to the ground. The AC voltage source approach detection voltage detector according to claim 2, which is characterized by being composed of a conductor.

Further, in the invention of claim 4, the first electrode is provided with two flat plates at intervals, and these flat plates are connected by a narrow band-shaped connecting portion, and the second electrode is the connecting portion of the first electrode. The AC voltage source approach detection voltage detector according to claim 3, which has a cylindrical shape standing upright in.

The invention of claim 5 is the AC voltage according to any one of claims 2 to 4, wherein the voltage detector is provided on a band-shaped body wound around any of the arms, legs, torso, head, and neck of the human body. It was used as a source approach detection voltage detector.

According to the inventions of claims 1 and 2, if the voltage detector is mounted somewhere on the human body, a signal is output when the worker equipped with the voltage detector approaches the voltage source. Therefore, in electrical work or the like, even if an operator forgets to approach the charging unit, it is possible to call attention and prevent an accident such as an electric shock.

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 provided in the band-shaped body, the first electrode can be configured to be in close contact with the human body in a wider range, and the voltage V ₀₂ generated in the human body can be reliably captured. ..

It is a principle explanatory view 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. It is the principle schematic of the main circuit concerning the voltage induced in the human body of Embodiment 1 of this invention. (A) is a schematic configuration diagram showing the principle of the detection circuit of the voltage detector according to the first embodiment of the present invention, and (b) is the equivalent circuit diagram. (A) is an external front view of the voltage detector according to the first embodiment of the present invention, (b) is a state diagram of the voltage detector mounted on the 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 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 put in V and C to indicate the voltage and capacitance, but in the detection circuit, " ₀ " is put 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 wireless measuring device.

From the measurement results, it was natural 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 an electric potential floating from the ground, and that electric 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 V 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 radiometer does not measure the electrode potential from the ground, but shows the level of the current 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 vessel was changing.

As shown FIG. 1, the human body H approaches the AC electric wire W of 100 V, arm, torso, from AC wire W current _{i 1,} i 2, _{i 3} is through the head flow into 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, AC wire W on the opposite side of the arm through the capacitance between the human body H and the ground G by the human body potential, both feet, current _{i 4} through the head, a current _{i 5,} current _{i 6,} current _{i 7} flows out.

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.

In the conventional general electroscope, since it is configured to sense the current i _1, i ₂ level from the wire when approaching the AC wire, the body of such a low level of current i _4, i ₇ Outflow current cannot be detected. Further, since the thinking in the human body = ground potential models, are without using the flow of relatively large current is the current level i _5, i _6. Note that FIG. 1 shows a typical current distribution. In reality, the reality is that currents are input and output in more diverse parts of the human body.

Further, the body of the insulation is poor, because the human body is not available only current flowing currents i _1, i _2, i ₃ in such conditions the earth at the same potential, can not be electroscopic the body potential. When the human body was actually exposed to the same potential as the ground barefoot, the voltage detector on the opposite side of the AC wire did not respond.

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

The present invention was made on the basis of this principle. Closed circuit flowing through the ground G from the voltage source W through the human body H as shown in FIG. 2 C ₀ (series connection of C ₀₁ and C ₀₂₎ combined capacitance (hereinafter, main circuit say), the number of the next 1, the number It becomes 2. 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 of C ₀₂ . Shows the potential.

Therefore, it becomes the number 3 and the number 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 numbers are 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. Female hook-and-loop fasteners 5a and 5b allow it to be worn on 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 the number 8. This _VC2 is the voltage that enables detection.

From the above equation 8, by increasing the _{C 1,} and by reducing the _{C 2, V C2} is increased, it is possible to obtain an effective _{V C2} to detection. 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 wraps around (closely adheres to) the human body H, and the shape of the electrode in contact with the second electrode 2 is reduced so that C = The "S" of εS / d was reduced, and the C ₂₁ was reduced. The first electrode 1 shown in FIG. 4 has a rectangular shape on both sides of the electrode plates 1a 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, an area (side area) with respect to the space (earth) is secured, thereby increasing C ₃₂ . The second electrode 2 shown in FIG. 4 has a cylindrical shape and is erected on the connecting 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, and as shown in the above equation 8, V _{c 2} becomes large 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, as shown in FIG. 5A, a disk-shaped one may be used, or as shown in FIG. 5B, two semicircular plates may be crossed in a cross shape. FIG. 5C shows the cylindrical second electrode 2. Each of these second electrodes 2 is placed on the connecting 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 whose second electrodes 2 are those of FIG. 5A, FIG. 5B, and FIG. 5C 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 second electrodes 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 is compared with the output signal of the reference voltage generation circuit 7. 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, the approach warning method for the AC voltage source by the voltage detector A of the present invention will be described.
The operator who wears 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 a potential of V ₀₂ . 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 . The potential difference V _C2 between the electrostatic capacitance C ₂₁ produced by the drain current i detected detection circuit 4, is greater than the output signal is the reference voltage and the potential difference V _C2 was amplified in the capacitance C ₂₁ by outgoing current i, An alarm sound is emitted from the sound 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 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 operator approaches 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 in close contact with 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 wound. The second electrode 2 may be separately attached to another part of the human body. Further, although the first electrode 1 is a flexible flat plate, the present invention is not limited to this, and a wide conductor such as a braided conductor may be used.

Further, in the first embodiment, the voice generator circuit 9 and the lighting display circuit 10 are provided in the voltage detector A, but without these, the output from the comparison circuit 8 is received by the transmission unit (not shown) and externally. It is also possible to send a signal wirelessly, receive it by a communication device or a terminal device provided separately from the detector A, and make an alarm or display on the device.

Although the first embodiment has been described above, this is presented as an example and is 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 Electroscope G Earth H Human body W Voltage source
1 1st electrode 1a Electrode plate 1b Connection part 2 2nd electrode 3 Substrate 4 Detection circuit
5 Band 5a Hook-and-loop fastener 5b Hook-and-loop fastener 6 Amplifier circuit 7 Reference voltage generation circuit 8 Comparison circuit 8 Audio generation circuit 9 Lighting display circuit 11 Power supply 12 Switch

Claims (5)

In the method of detecting the approach of the AC voltage source, the voltage induced in the human body by the approach of the AC voltage source is measured by the first electrode of the detection circuit, and the voltage with respect to the ground is measured by the second electrode of the same circuit. The detection circuit captures the current flowing due to the potential difference between the potential of the first electrode and the potential difference of the second electrode, and outputs a signal from the detection circuit when a human body insulated from the ground approaches the AC voltage source. , AC voltage source approach detection method. In the voltage detector that detects the approach of the AC voltage source, the detection circuit has a first electrode that measures the voltage induced in the human body due to the approach of the AC voltage source and a second electrode that measures the voltage to the ground. An AC voltage source approach detection voltage detector, further comprising a circuit that outputs a signal from the detection circuit when a human body approaches the AC voltage source. The first electrode is made of a conductor having a certain area that can be brought into close contact with the human body, and the second electrode is made of a conductor having a small vertical projection area with respect to the first electrode and a large area with respect to the ground. The AC voltage source approach detection voltage detector according to claim 2. The first electrode is provided with two flat plates at intervals, and these flat plates are connected by a narrow band-shaped connecting portion, and the second electrode has a cylindrical shape that stands up at the connecting portion of the first electrode. The AC voltage source approach detection voltage detector according to claim 3, which is characterized. The AC voltage source proximity detection test according to any one of claims 2 to 4, wherein the voltage detector is provided on a band-shaped body wrapped around any of the arms, legs, torso, head, and neck of the human body. Electric.