JPS61166232A - Power supply circuit of submarine repeater - Google Patents

Abstract

PURPOSE:To decrease the attenuation of a low frequency signal and to decrease the effect on a polar electronic component by providing a resistor generating a trigger voltage of a thyristor with a searching current fed to a center conductor of a cable in the same polarity as the normal feeding direction at cable location searching. CONSTITUTION:The searching current with the same polarity as the normal feeding current is given from the direction of the center conductor 1 of the cable at the location retrieval of a submarine cable and the current is increased until a current flows to a Zener diode 6 and a resistor 7 once. A voltage is generated across the resistor 7 by the current and fed to a gate of a thyristor 9 as a gate voltage to turn on the thyristor 9. When the thyristor 9 is turned on, a current flowing to a common amplifier 9 and the Zener diode 6 flows all to the thyristor 9 and the equivalent resistance is nearly the same as when being applied with the opposite polarity. Further, the searching current is adjusted to a required value after the thyristor 9 is turned on.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a power supply circuit for a submarine repeater.

[Conventional technology]

To detect the position of a submarine cable, a search current consisting of a low-frequency signal superimposed on a direct current is supplied to the submarine cable, and this current flows and generates a magnetic field around the cable. The position of the undersea cable was accurately detected by sensing the sensor. Conventionally, this type of search method has been known as the electroding method, and a conceptual diagram is shown in FIG. A search current supplied from a search current power source 10 to the center conductor of a submarine coaxial cable 11 at a landing station is transmitted through a line in which the cable 11 and a repeater 12 are connected in cascade. There are two methods for applying the search current: one is to apply it in the same polarity as the normal power supply direction of the repeater, and the other is to apply it in the opposite polarity, which allows transmission with lower loss.

[Problem that the invention seeks to solve]

To use the conventional method described above for long-distance systems,
There were the following problems. FIG. 3 shows a power supply circuit diagram of a conventional repeater, and FIG. 4 shows its voltage and current characteristics. When a search current is applied to the center conductor 1.2 of the submarine cable with the same polarity as the normal power supply direction, the equivalent resistance of the power supply circuit is large (typically 1000 to 2Ω), which causes attenuation of the low frequency signal. It became so large that the magnetic field necessary for the magnetic sensor could not be obtained. On the other hand, when applied with reverse polarity, current flows through the Zener diode 6 shown in Figure 3, resulting in a small equivalent resistance (usually 1 to 10 Ω), low attenuation of low frequency signals, and long-distance systems. However, due to the operating resistance of the Zener diode, a voltage of about 1V is generated across both ends, which is applied to the circuit of the common amplifier 5 with the opposite polarity, and can be applied to polarized electronic devices such as semiconductor components and tantalum capacitors. There was a drawback that the parts were undesirable.

[Means for solving problems]

In the present invention, when searching for a cable position, a search current is supplied to the center conductor of the cable in the same polarity as the normal power supply direction, and a cyrisk bird is installed in parallel with a resistor that generates voltage and a Zener diode in a power supply circuit. This is a power supply circuit for a submarine repeater, characterized in that it has a thyristor controlled by the above-mentioned trigger voltage.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 and 2 are the center conductors of a submarine cable, 3 is a coil, 4 is a capacitor, and 5 is a central conductor of a submarine cable.
is a common amplifier, 6 is a Zener diode, 7.8 is a resistor, and 9 is a thyristor. In the embodiment, when searching for the location of a submarine cable, a search current with the same polarity as the normal power supply direction is applied from the direction of the cable's central conductor 1, and is once increased until the current flows through the Zener diode 6 and the resistor 7.

This current generates a voltage across the resistor 70, which is applied as a dart voltage to the thyristor 90 gate, turning the thyristor 9 on. When the thyristor 9 becomes CAN, all of the current flowing through the common amplifier 5 and the Zener diode 6 flows through the thyristor 9, resulting in the characteristics shown by the broken line in Figure 4, and the equivalent resistance value is the same as when applied with the opposite polarity as described above. It is almost equivalent to .

Further, the search current value can be adjusted to a required value after the thyristor 9 is turned on. On the other hand, the thyristor 9 can be turned off by stopping the supply of the search current, and the power supply circuit of the repeater automatically returns to its normal operating state.

〔Effect of the invention〕

As explained above, according to the present invention, the applied polarity of the search current for position searching can be the same as the polarity of the supply to a normal repeater, and a low frequency signal equivalent to that when applied with the opposite polarity can be obtained. The present invention has an effect that can be applied to long-distance systems because it requires only attenuation of 100% and has no effect on polarized electronic components.

[Brief explanation of drawings]

1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a conceptual diagram of cable position search using the electroding method,
FIG. 3 is a power supply circuit diagram of a conventional repeater, and FIG. 4 is a characteristic diagram showing the voltage and current characteristics of the repeater depending on the feeding direction. 1... Center conductor of submarine cable, 2... Center conductor of submarine cable, 3... Coil, 4... Capacitor,
5... Common amplifier, 6... Zener diode, 7
...Resistor, 8...Resistor, 9...Thyristor. Figure 1 Figure 2

Claims (1)

[Claims] (1) In a search device that supplies a search current that is a direct current with a low-frequency signal superimposed on a submarine cable and detects the cable position using the generated magnetic field, the search current is used to detect a thyristor installed in the power circuit of a submarine repeater during the search. A power supply circuit for a submarine repeater, characterized in that it operates by lowering the equivalent resistance of the power supply circuit.