JPH0785279B2 - Proximity alarm sensor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an approach alarm device used in high-voltage wiring work and the like, and more specifically to a sensor of the proximity alarm device.

2. Description of the Related Art In high-voltage wiring, for example, live-line work with a line voltage of 6000 V, an electric shock may occur if a part of the human body of an operator touches the live line.

Therefore, in order to prevent electric shock accidents, workers not only wear various protective equipment and protective equipment, but also work with an approach alarm that notifies that the work clothes are approaching the live line. .

Conventional approach alarms, when the alarm itself approaches a live line,
It is configured to issue an alarm upon receiving electrostatic induction from a live line.

Problems to be Solved by the Invention In the conventional example, the induction electrode directly receives the electrostatic induction from the live line to issue an alarm, but its detection characteristics change depending on the positional relationship between the alarm device and the live line. Therefore, the alarm may or may not be output depending on the positional relationship between the worker wearing the alarm device and the live line.

For example, when an alarm device is put in a chest pocket and working, even if the hand is extended upwards and it comes close enough to almost come into contact with the live line, the alarm is not issued unless the alarm device itself approaches the live line. .

Moreover, since the alarm device has directivity, the alarm sensitivity is affected by the positional relationship between the live line and the induction electrode of the alarm device.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sensor of an approach alarm device that can reliably detect the approach of a worker to a live line.

Means for Solving the Problems The present invention is a sensor for an approach alarm device, characterized in that an upper electrode and a lower electrode are provided at intervals in an electrode holder, and a contact portion is formed on the both electrodes.

When the operator attaches the electrode holder to the ankle, the contact parts of the upper and lower electrodes come into contact with the operator's skin.

Then, when a part of the worker's body approaches the live line, an induced current flows from the live line to the ground via the human body.

Since the induced current flowing through the human body flows through the upper and lower electrodes, the potential difference between the two electrodes is detected, and thereby the approach to the live line is detected.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings.
In the figure, 1 is a sensor of an approach alarm device, which is an electrode holder 2
And upper and lower electrodes 3 and 4.

For the electrode holder 2, for example, a cylindrical supporter as shown in FIG. 1 is used.

Contact portions 3a and 4a are formed on the upper and lower electrodes 3 and 4, respectively. As the electrodes 3 and 4, for example, a ring-shaped conductive tape is used.

The upper electrode 3 and the lower electrode 4 are provided at intervals in the axial direction, and the output end thereof is connected to the comparator 6 via the amplifier 5 of the detection transmission unit S as shown in FIG.

This comparator 6 is connected to an oscillator 8 via an FM modulator 7.

The signal of the transmitter 8 is received by the FM receiver 9 of the reception alarm unit A shown in FIG. 5, and this FM receiver 9 is an FM detector.
It is connected to the buzzer 12 via the amplifier 10 and the amplifier 11.

As shown in FIG. 2, when the human body 13 approaches the high voltage electric wire (live line) 14, the human body 13 passes through the human body 13 and the ground.
Induction current 16 flows through 15. The induced current 16 increases as the human body 13 approaches the high voltage electric wire 14. Since the human body 13 is not a perfect conductor, an induced potential difference occurs on the surface of the human body. FIG. 3 shows an equivalent circuit at this time, where C1 is the capacitance between the high voltage wire 14 and the human body, H is the human body part, V is the human body induction potential, C2 is the human body capacitance, R represents the human body 13 total resistance.

This potential difference is determined by the surface of the human body, the high voltage wire 14, and the electrostatic capacitance C1.

In other words, it is determined by the distance between the human body 13 and the high voltage electric wire 14.

Therefore, by detecting the potential difference between the two points induced from the human body 13, the approach to the high voltage electric wire 14 can be detected.

The potential difference between the two points induced from the human body 13 is detected as follows.

When the worker B puts the reception alarm unit A in the arm pocket and attaches the electrode holder 2 of the detection transmission unit S to the ankle 17, the contact portions 3a and 4a of the upper and lower electrodes of the electrode holder 2 are attached.
However, since it comes into contact with the skin, the electrodes 3 and 4 come into contact with the resistor R at a distance as shown in FIG.

In this state, when the worker approaches the high voltage electric wire 14 as shown in FIG. 2, an induced current 16 flows in the human body 13.

This induced current 16 also flows to the upper and lower electrodes 3 and 4,
Then, the induced potential difference between both electrodes is detected.

The induced potential difference thus detected is amplified by the amplifier 5 and then compared with the alarm level by the comparator 6. When the dielectric potential exceeds the alarm level, the FM modulator 7 is activated and the transmitter From 8, FM signal is transmitted.

The signal from the transmitter 8 is received by the FM receiver 9,
After being detected by the detector 10, the buzzer 12 is amplified by the amplifier 11.
Enter and give an alarm.

In this embodiment, the so-called separation type approach alarm device in which the detection transmission unit S and the reception warning unit A are separated has been described, but the detection transmission unit S and the reception warning unit A are integrated. Needless to say, the same applies to the alarm device.

EFFECTS OF THE INVENTION According to the present invention, the upper electrode and the lower electrode are provided in the electrode holder at intervals as described above, and the contact portions are formed on the both electrodes. Contact with operator's skin.

Therefore, when the worker approaches the high-voltage electric wire or the like, the induced current flowing in the human body flows to both electrodes through the contact portion, so that the difference in the induced potential can be reliably detected.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a state of use, FIG. 3 is an equivalent circuit of the human body in the state of FIG. 2, FIG. 4 is a block diagram of a detection transmission part of the approach alarm device, and FIG. 5 is a reception alarm part of the approach alarm device. It is a block diagram of. 1 ... Sensor 2 ... Electrode holder 3 ... Upper electrode 4 ... Lower electrode 3a, 4a ... Contact part

Claims (3)

[Claims] 1. A sensor for a proximity alarm, wherein an upper electrode and a lower electrode are provided on an electrode holder with a space therebetween, and a contact portion is formed on both electrodes. 2. The sensor for an approach alarm device according to claim 1, wherein the electrode holder is a cylindrical supporter. 3. The sensor for an approach alarm device according to claim 1, wherein the upper electrode and the lower electrode are conductive tapes.