JPH0679040B2 - Power cable charge status indicator - Google Patents

Description

[Detailed Description of the Invention] "Industrial field of application" It is an object of the present invention to provide an indicator capable of easily confirming the presence or absence of charging in a power cable from the viewpoint of the power cable.

"Prior art" During maintenance and regular inspection of power cables (hereinafter abbreviated as "cables"), especially when many cables are laid in buildings, factories, etc. It may be necessary to identify the cable inside locally.

"Problems to be solved by the invention" Generally, it has been separately confirmed that the system is cut off, but if the installation is complicated, it is not possible to detect the charged or uncharged state from the cable jacket. Very effective.

"Means for Solving Problems" An insulating plate having elasticity is formed into a C-shaped cross section according to the outer diameter of the power cable, and an inner electrode and an outer electrode are adhered to both sides of the insulating plate to obtain a voltage acquisition plate. Make up.

A liquid crystal display is mounted on the surface of the voltage acquisition plate at any desired location. Then, both electrodes of the liquid crystal display are respectively connected to the inner surface electrode and the outer surface electrode of the voltage acquisition plate.

[Operation] By properly attaching the charging status indicator configured as described above to the cable, the presence or absence of charging of the cable is displayed.

[Example] Next, this example will be described with reference to the drawings.

FIG. 1 (a) is a front view showing a state in which the charge status indicator 1 is attached to the cable 2, and FIG. 1 (b) is a side view of the same.

The voltage acquisition plate 3 shown in FIGS. 1 (a) and 1 (b) has a metal vapor deposition or a metal foil attached on both inner and outer surfaces of an insulating plate 4 made of elastic material such as plastic as shown in FIG. The inner surface electrode 3a and the outer surface electrode 3b are combined to form a C-shape according to the outer diameter of the cable 2.

Since the C-shaped voltage acquisition plate 3 has elasticity when attached to the cable 2, the C-shaped voltage acquisition plate 3 can be fitted into the cable 2 with a slight push.

In FIG. 2, the cable 2 and the inner surface electrode 3a are shown separated from each other for the sake of clarity. However, due to the elasticity of the insulating plate 4 in the actual product, the inner surface electrode 3a is not attached to the outer surface of the cable 2. It comes into close contact.

The inner surface electrode 3a and the outer surface electrode 3b of the voltage acquisition plate 3 are connected to the electrodes of the liquid crystal display 5, respectively.

In the case of the cable 2 having no metal sheath, by mounting the charging status indicator 1 in this manner, it is possible to cause the liquid crystal display 5 to perform a predetermined display when the charging body 6 of the cable 2 is energized. I can. The liquid crystal display 5 consumes very little current for display, and sufficient energy for display can be obtained only by the electric field effect between the cable 2 and the voltage acquisition plate 3. FIG. 3 is an explanatory diagram showing a state of voltage acquisition to the liquid crystal display 5.

The liquid crystal display 5 includes an inner surface electrode 3a of the voltage acquisition plate 3 and an outer surface electrode.
Capacitance C2 between 3b and Charger 6-Capacitance between inner surface electrode 3a
A voltage proportionally applied by C1 and the electrostatic capacitance C3 between the outer surface electrode 3b and the ground E is applied.

FIG. 4 shows that the voltage acquisition plate 7 is made of one piece of metal or one of the C-shaped elastic insulating plates to which metal vapor deposition or metal foil is attached, and this voltage acquisition plate 7 is used for the liquid crystal display 5. The case where it is connected to one electrode is shown.

Although one electrode of the liquid crystal display 5 is left open, the external electrode of the voltage acquisition plate 3 shown in FIG. 2 due to the capacitance C ′ between the one electrode of the liquid crystal display 5 and the ground. This is an example of displaying without the effect of 3b.

The liquid crystal display 5 consumes little energy for display, and can display sharply if a threshold voltage of several volts is obtained.

"Effect of the invention" It is possible to obtain a highly sensitive display regardless of the charge indicator having a simple structure.

[Brief description of drawings]

FIG. 1 (a) is a front view showing a state in which a charge status indicator is attached to a cable, FIG. 1 (b) is a side view of the same, and FIG. 2 is an inner surface electrode and an outer surface electrode of a C-shaped voltage acquisition plate, respectively. FIG. 3 is a diagram showing a state of being connected to electrodes of a liquid crystal display, FIG. 3 is an explanatory diagram showing a state of voltage acquisition to the liquid crystal display, and FIG. 4 is a metal or C-shaped elastic insulation having one voltage acquisition plate. It is a figure which consists of what stuck metal vapor deposition or a metal foil on one side of a board.

Claims (1)

[Claims] 1. A flexible insulating plate is formed into a C-shaped cross section according to the outer diameter of a power cable, and an inner electrode and an outer electrode are adhered to both surfaces of the insulating plate to form a voltage acquisition plate. A charge state indicator for a power cable, wherein a liquid crystal display is attached to an arbitrary position on the surface of the voltage acquisition plate, and both electrodes of the liquid crystal display are connected to an inner electrode and an outer electrode of the voltage acquisition plate, respectively.