JP2015102862A - Core wire contrast device using static induction from power line or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus contactlessly contrasting a core wire of an optical drop cable.SOLUTION: Supporting lines (steel cores) of optical drop cables 11, 12, and 13 are insulation-coated and both ends thereof are opened, so that a voltage is generated by static induction from a power line or the like. An induction voltage generated between a contrast object cable and a suspension line 14 (an earth) is intermitted by electrically intermitting the interval between the contrast object cable and the suspension line 14 by a drop holder or the like. The intermission/non-intermission of the induction voltage of the cable is detected by an electrostatic sensor so as to discriminate the contrast object cable. This configuration can accurately contrast cables on any site without causing problems observed in the static induction method and the electromagnetic induction method.

Description

  The present invention relates to an apparatus for performing a core contact contrast between a drop holder or the like and an arbitrary point using a support wire (hereinafter referred to as “core wire”) of a steel core of an optical drop cable.

  The optical drop cable is suspended on a metal wire (hereinafter referred to as “suspending wire”) connected to the ground. A conventional non-contacting core wire contrast device applies an AC signal between a core wire and a suspension line from a drop holder, and detects the signal by electrostatic induction or electromagnetic induction.

  The conventional non-contacting core wire contrast device applies an AC signal between the core wire and the suspension wire from a drop holder or the like, and compares the core wire by detecting the signal by electromagnetic induction or electrostatic induction. There is a problem.

  The electrostatic induction method is difficult to discriminate because the detection level difference is small because the signal is induced by electrostatic induction in a core other than the core to which an AC signal is applied. In addition, when rainwater or the like adheres, the detection level of the sensor changes, so that there is a high possibility of erroneous determination.

  In the electromagnetic induction method, an alternating current signal is applied between the core wire and the suspension wire, and a weak current flowing through the electrostatic capacitance between the core wire and the suspension wire is detected. This method can be determined very clearly when the cable length is the same, but when cables having different lengths are mixed, the determination may be erroneous depending on the detection position.

  The present invention is intended to solve the problems of such a conventional cord contrast device, and to realize a cord contrast device capable of accurately discriminating even when cables having different lengths are mixed. It is intended.

  The optical drop cable is suspended from the suspension line and installed near the power line. When the core wire is in an open state, a voltage of 50 or 60 Hz (hereinafter “60 Hz”) is induced between the core wire and the suspension wire by electrostatic induction. Next, when the core wire and the suspension wire are electrically short-circuited in a drop holder or the like, the voltage disappears.

  The operation of the problem solving means is as follows. In the drop holder or the like, the controlled core wire and the suspension wire are electrically disconnected. The detected core wire can be determined by detecting the presence or absence of 60 Hz induced voltage in each core wire. In addition, the voltage ratio of 60 Hz due to interruption can be clearly discriminated at 20 dB or more.

  Since the induced voltage generated in the optical drop cable changes over a wide range depending on the positional relationship with the power line, automatic gain control is necessary, but the influence of automatic gain control is avoided by electrically connecting the core and the suspension line. can do.

  In a place where there is no effective electrostatic induction from the power line or in an underground wiring section, an AC signal of 60 Hz is applied from the oscillator between a core wire other than the controlled core wire and a suspension line, etc., in the same manner as described above. A determination can be made.

  In the construction of an optical drop cable, etc., it is possible to accurately perform the core line contrast without being affected by problems such as the mixing of cable lengths having different weather and lengths, and the apparatus can be easily and economically manufactured.

  Outline diagram of cable control   Transmitter block diagram   Electrostatic sensor   Receiver block diagram

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic diagram in the case where a cord contrast is performed. 11 to 13 are optical drop cables, 14 is a hanging line, 15 is a spiral hanger, 16 is a drop holder, 17 is an electrostatic sensor, 18 is a receiver, and 19 is a transmitter.

  The optical drop cables 11 to 13 are suspended from the suspension line 14 via the spiral hanger 15. The steel cores of the optical drop cables 11 to 13 are terminated at the drop holder 16 and only the optical fiber is wired to the closure (omitted).

  FIG. 2 shows a block diagram of the transmitter. 21 is a timer, 22 is a relay, 23 and 24 are terminals, 25 is an oscillator, and 26 and 27 are terminals. The timer 21 sends an intermittent signal to the relay 22 every 200 milliseconds to generate an intermittent state between the terminals 23 and 24. The oscillator 25 is used when there is no effective electrostatic induction from a power line or the like.

  FIG. 3 shows the structure of the electrostatic sensor. Reference numeral 31 denotes a case whose inner side is shielded, 32 an electrode, 33 an impedance converter, 34 a cord, and 35 a connector.

FIG. 4 shows a block diagram of the receiver. Reference numeral 41 is a connector, 42 is an automatic gain controller, 43 is a filter, 44 is an amplifier, and 45 is a display.
The receiver removes noise by the filter 43 and can cope with a wide range of inductive voltages by the 70 dB amplifier 44 and the automatic gain controller 42.

In the drop holder 16 of FIG. 1, the terminals 23 and 24 of the transmitter 19 are connected to the support line and the suspension line 14 of the optical drop cable 13 to generate an intermittent state. At the time of disconnection, a voltage of 60 Hz is generated in the optical drop cable 13 by electrostatic induction and disappears at the time of short circuit.
When 60 Hz is detected in the optical drop cables 11 to 13 by the electrostatic sensor and the receiver, 60 Hz is continuously generated in the optical drop cables 11 and 12, and the optical drop cable 13 is intermittent. In other words, the controlled optical drop cable can be identified by the presence or absence of 60 Hz induced voltage.

  In the construction of an optical drop cable or the like, the core wire is currently physically determined by groping. However, according to the present invention, since the cable can be easily and accurately determined, the work efficiency is improved.

11 Optical drop cable 12 Optical drop cable 13 Optical drop cable 14 Hanging line (connected to ground)
15 Spiral hanger 16 Drop holder 17 Electrostatic induction sensor 18 Receiver 19 Transmitter 21 Timer (intermittent every 200 milliseconds)
22 Relay 23 Terminal 24 Terminal 25 Oscillator 26 Terminal 27 Terminal 31 Case (Shield)
32 electrode 33 impedance converter 34 output cord 35 connector 41 connector 42 gain control 43 filter 44 amplifier 45 indicator (LED, buzzer)

Claims (2)

  Occurring between the supporting line (steel core) of the optical drop cable and the cable suspension line (earth) electrically, it is generated between the support line and the suspension line of the optical drop cable by electrostatic induction from the power line or oscillator signal. A discriminating method using intermittent induction voltage.   Optical drop cable contrast device according to the above method. Note that the frequency to be subjected to electrostatic induction is not limited to 60 Hz.

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