JPH0244219Y2 - - Google Patents

Description

[Detailed description of the invention] A. Field of industrial application The present invention relates to a pressure detection device that detects the state of charge in a high-voltage circuit such as a power transmission line.

B. Prior art In general, high voltage exceeding 600 volts or special high voltage exceeding 7000 volts is transmitted to high voltage electrical circuits such as power transmission lines, and when detecting the presence or absence of charging on the high voltage electrical circuit, for example Connect the transformer,
There is a method of connecting an indicator light through the transformer, thereby lowering the voltage at the transformer and lighting the indicator light. However, in this case, an expensive transformer is required, and an economical problem remains. Therefore, in recent years, some devices use inexpensive electronic components such as capacitors and resistors to detect the state of charge in a high-voltage circuit.

For example, an example of a conventional pressure detection device is shown in FIG.
As shown in the figure, one end of a coupling capacitor 2 is connected to a high voltage line 1, and the other end of the coupling capacitor 2 is grounded via a resistor 3. In order to detect the current flowing between the other end of this coupling capacitor 2 and the ground,
A discharge tube 4 such as a neon lamp serving as an indicator light is connected in parallel to the resistor 3. When the voltage across the resistor 3 reaches a predetermined voltage value, that is, the discharge starting voltage of the discharge tube 4, a current flows into the discharge tube 4.
starts discharging and lights up. The state of charge of the high-voltage electric circuit 1 is detected based on whether or not the discharge tube 4 is lit.

By the way, in the conventional device, a shocking impulse was applied to the discharge tube 4 due to a surge current caused by lightning or the like, and the discharge tube 4 could be destroyed. If the discharge tube 4 is damaged due to the above causes, it becomes completely undetectable and reliability is significantly reduced. Furthermore, if the discharge tube 4 is installed near the high-voltage line 1, the operator will have to approach the high-voltage line 1 when detecting whether or not the discharge tube 4 is lit, which is extremely dangerous. In order to prevent this, it was necessary to extend the electric line 5 connected to the discharge tube 4. However, when the electric line 5 is extended, there is a capacitance between the electric line 5 and the ground, so the capacitor 6 is connected to the resistor 3 as shown in the figure.
The electric line 5 that should be extended is connected in parallel to
was limited in length. As a result, as described above, when detection occurs, the user has no choice but to approach the high-voltage electric line 1, making it difficult to prevent such danger.

C. Purpose of the invention The purpose of the invention is to safely and reliably detect the presence or absence of charging in a high-voltage circuit.

D. Structure of the invention The present invention connects a coupling capacitor between a high-voltage electric line and the ground, detects the alternating current flowing between the coupling capacitor and the ground by appropriate means, and lights up a discharge tube. two rectifiers that detect the alternating current flowing between the ground and the ground, and separately rectify the positive and negative half waves of the alternating current, and two rectifiers that respectively charge the half-wave rectified current in each rectifier. The capacitors are placed apart from the high-voltage circuit via shielded wires, and each capacitor flashes independently by repeating the start of lighting due to an increase in the charging voltage of each of the capacitors and the stop of lighting due to a decrease in the charging voltage during lighting discharge. It is equipped with two discharge tubes.

E. Embodiment FIG. 2 shows an embodiment of the pressure detection device according to the present invention. In the figure, 2' is a coupling capacitor, one end of which is connected to the high-voltage line 1, and the other end is grounded. Reference numerals 7 and 8 denote two rectifiers connected between the coupling capacitor 2' and the ground, and the rectifiers 7 and 8 separate the positive and negative half waves of the alternating current flowing between the coupling capacitor 2' and the ground. rectify to Reference numerals 9 and 10 denote two capacitors connected in parallel between the coupling capacitor 2' and the ground, respectively, and these capacitors 9 and 10 charge the current half-wave rectified by the rectifiers 7 and 8.
4', 4'' are discharge tubes such as neon lamps serving as indicator lights, and when the charging voltage of the capacitors 9, 10 reaches a predetermined voltage value, that is, the discharge starting voltage of the discharge tubes 4', 4'', the discharge tubes are turned off. 4' and 4'' start discharging and turn on. 11 is a surge absorber inserted and connected between the coupling capacitor 2' and the ground, and this surge absorber 11 is activated by the rectifier 7, when a surge current due to lightning or the like flows. 8 and capacitors 9 and 10 from being destroyed.
12 and 13 are resistors for preventing high voltage; 14 and 15 are resistors for adjusting the lighting time of the discharge tubes 4' and 4''; if the values of these resistors 14 and 15 are large, the discharge tubes 4' and 4'' are The current flowing through 4'' becomes smaller and its lighting time becomes longer. A coupling insulator 16 accommodates the above-mentioned components and makes the structure compact. 17 is an indicator light case, 18 is a shield wire such as a TV coaxial cable, and this is the above-mentioned coupling insulator 1.
6 and the indicator light case 17 are electrically connected to each other.

Therefore, when the high voltage line 1 is in a charged state, an alternating current flows between the high voltage line 1 and the ground via the coupling capacitor 2', and the positive and negative half waves of the current flowing between the coupling capacitor 2' and the ground are generated. The rectifiers 7 and 8 rectify the signals separately. This half-wave rectified current charges the capacitors 9 and 10, respectively, and when this charging voltage reaches a predetermined voltage value, that is, the discharge starting voltage of the discharge tubes 4' and 4'', the charging voltage changes to the shield wires 18 and 10. 1
8 to the discharge tubes 4', 4'', and the discharge tubes 4', 4'' start discharging and light up. When the charging voltage of capacitors 9 and 10 decreases due to this discharge,
The discharge tubes 4', 4'' stop discharging and turn off. Then, when the charging voltage of the capacitors 9, 10 rises and reaches the discharge start voltage again, the discharge tubes 4', 4'' start discharging and turn on. Therefore, the discharge tubes 4', 4'' are individually flashed by repeating the above operation. In this case, the lighting time of the discharge tubes 4', 4'' is adjusted by changing the resistance values of the resistors 14, 15. It is also possible to separately shift the discharge tubes 4', 4'' and blink them.

F. Effects of the invention According to the invention, the structure is simpler and the installation is easier than that of conventionally used transformers. In addition, since the discharge tube, which is an indicator light, is lit by the charging voltage of the capacitor, the brightness when lit is high.
Moreover, since the discharge tube blinks by repeating the start of lighting due to an increase in the charging voltage of each of the capacitors and the stop of lighting due to a decrease in the charging voltage during lighting discharge, it is easy to detect whether or not the lamp is lit. Furthermore, since the positive and negative half-waves of the alternating current flowing between the high-voltage power line and the ground are separately used to light the two discharge tubes independently, there is no possibility that one discharge tube may become disconnected or short-circuited. Even if a failure occurs, it does not affect the other discharge tube, and the other discharge tube can be operated normally, which greatly improves reliability. The present invention is designed to convert alternating current in the high-voltage line into direct current to light the discharge tube. Therefore, the discharge tube is separated from the high-voltage line by a shielded wire to a predetermined distance to determine whether the discharge tube is lit or not. This makes it possible to detect the high-voltage electrical circuit, and prevents dangers caused by workers approaching high-voltage electrical circuits, greatly improving safety during detection.

[Brief explanation of the drawing]

FIG. 1 is a schematic wiring diagram showing an example of a conventional pressure testing device, and FIG. 2 is a wiring diagram showing an embodiment of the pressure testing device according to the present invention. 1...High voltage circuit, 2, 2'...Coupling capacitor,
4, 4', 4''... Indicator light, 7, 8... Rectifier,
9,10... Capacitor.

Claims (1)

[Scope of utility model registration request] Connect a coupling capacitor between the high voltage line and the ground,
In a device that lights a discharge tube by detecting the alternating current flowing between the coupling capacitor and the ground by appropriate means, the alternating current flowing between the coupling capacitor and the ground is detected, and the positive and negative polarities of the alternating current are detected. Two rectifiers that separately rectify half-waves, two capacitors that respectively charge the half-wave rectified current in each rectifier, and are separated from the high-voltage power line via shielded wires, and each of the capacitors is A pressure measuring device characterized by being provided with two discharge tubes that flash and display independently by repeatedly starting lighting due to an increase in charging voltage and stopping lighting due to a decrease in charging voltage during lighting discharge.