JPS60249444A - Optical communication device - Google Patents

Abstract

PURPOSE:To reduce considerably the power consumption in an optical communication system by providing a constant current-constant voltage converting circuit in an optical repeater. CONSTITUTION:A constant current-constant voltage converting circuit 41 receives a small current I from a constant current source 1 through a conductor C1 and generates a certain voltage berween a Zener diode 412 and a resistor connected in series to this diode 412, and this voltage is supplied to a signal amplifying circuit 42. Even if the feeding current I is changed, the voltage supplied to the signal amplifying circuit 42 is made constant by a transistor TR411. In this case, the power consumption of optical repeaters 4 and 7 is not dependent upon the feeding current and is constant, and the power loss in the conductor is proportional to the square of the feeding current, and the supply voltage is dependent upon the feeding current. Consequently, the power consumption is reduced considerably if elements such as a communication distance, the power consumption of repeaters, etc. are taken into consideration to set an optimum feeding current.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical communication device, and more specifically, at least one optical repeater is provided in an optical communication system, and the optical repeater The present invention relates to a power feeding method for an optical communication device in which power is fed from a power feeding device provided on a transmitting side or a receiving side via a conductor such as an intervening pair of optical fibers.

The optical communication device according to the present invention is suitable not only for use in general optical communication but also for use in, for example, submarine optical communication systems where the distance between transmitting and receiving is long.

[Conventional technology]

Optical communication systems are already known, in which optical repeaters are provided in the middle to compensate for optical signal attenuation when communication distances are long. Since optical fiber cables have a small attenuation factor, the spacing between repeaters can be larger than when using coaxial cables, and the number of repeaters can be significantly reduced. For example, when using coaxial cables in submarine communications, the distance between repeaters is several kilometers, but
When using Hikari 7 Eyepa Cagle, the distance is about several tens of kilometers.

The power supply for the circuit for signal amplification in the optical repeater is provided by a power supply device, generally a constant current source, on the transmitting or receiving side, and by using a conductive intervening pair, which is also a reinforcing material for the optical fiber cable.

[Problem that the invention seeks to solve]

As shown in FIG. 2, the optical repeater is generally provided with a signal amplification circuit 42 consisting of a photoelectric conversion element, an amplification circuit, a light emitting element, etc., and an intervening conductor which is also a conductor to supply the necessary power to this circuit. A Zener diode 41' is used to output a desired voltage vR from the power supply current 2' provided through the pair c1, and this voltage vR is applied to the signal amplification circuit 42. The conventional power supply circuit 41' shown in FIG. is about 1-2A. This value indicates that the power supply current when using a coaxial cable is 100 to 200.
mA, it is significantly larger.

Since the power loss in the feeder line (intervening pair) is proportional to the square of the feeder current, the power feeder in conventional optical communication systems has become considerably large-scale to compensate for the power loss in the feeder line, and in the case of long-distance communication. This trend is remarkable.

In particular, the increase in power loss in the power supply conductor is an economic problem.

Due to such circumstances, power supply devices tend to have high voltages.

For example, when using a conventional coaxial cable, the power supply voltage is 5
Although it is 8 degrees kV, it is desired that the power supply voltage of the power supply device be about 15 kV even in optical communication systems, but as the voltage increases as mentioned above, it becomes difficult to select circuit components, and the mounting Problems arise, such as making it difficult to

[Means for solving problems]

In the present invention, the feeding current is made small in view of the fact that most of the feeding power is due to power loss in the feeding conductor, and the power loss increases in proportion to the square of the current. In this case, even if the power supply current is reduced, a certain amount of power required for the signal amplification circuit of the optical repeater must be secured, so a power supply circuit that supplies a certain amount of power based on the small power supply current is optically relayed. Provided inside the container. This power supply circuit will be small and highly reliable, taking into consideration the installation conditions and maintainability of the optical repeater.

Therefore, in the present invention, at least one optical repeater is provided in the original fiber path, and power is supplied from the power supply device provided at one end of the transmitting and receiving side to the electrical circuit in the optical repeater via the conductor, and the optical In an optical communication device in which a signal is amplified by a repeater, the optical repeater is provided with a constant current/constant voltage conversion circuit, the constant current/constant voltage conversion circuit supplies power to the electric circuit, and the power is supplied to the power supply device. An optical communication device is provided that is characterized by a reduced current.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an optical communication device as an embodiment of the present invention. In the same figure, transmitting side A and receiving side B (this may be reversed) are original fiber cables 3, 5, 6.8
and a plurality of optical repeaters 4.7 are provided between them. The original fiber cable consists of an optical fiber C2 for transmitting optical information and an intervening pair (conductor) CI, which serves as a reinforcing material for the optical fiber and also serves as a power supply line.
Consists of. Optical communication devices 2 and 9 are connected to the optical fiber C2 on the transmitting and receiving sides. On the other hand, the conductor C1 is provided with a power supply device, that is, a constant current source 1°10.

The optical repeaters 4 and 7 include signal amplification circuits 42 and 72 and a power supply 41.
．． 71 is provided. An embodiment of the optical repeater 4 will be described with reference to FIG. The signal amplification circuit 42 is the same as a conventional one, and includes a light receiving element 421 that receives an optical signal from the optical fiber C21 and converts it into an electrical signal, a transistor 422 that amplifies the signal of the light receiving element, and a transistor 422 that emits the amplified signal. The light emitting element 423 is emitted to the next optical fiber C2o.
Consists of etc. The power supply 41 supplies the necessary power to the signal amplification circuit 42, and is a constant current/constant voltage conversion power supply. As shown in FIG. 3, the constant current/constant voltage conversion circuit 41 is composed of a transistor 411, a Zener diode 412, and a resistor connected to each other. A constant current/constant voltage conversion circuit 41 receives a small current 1 from a constant current source 1 via a conductor c1, and generates a constant voltage between a Zener diode 412 and a resistor connected in series thereto. This is the signal amplification circuit 4
2. When the power supply current 1 changes, the transistor 411 keeps the voltage supplied to the signal amplification circuit 42 constant.

The same applies to other optical repeaters 7.

The constant current/constant voltage conversion circuit preferably has a high conversion efficiency; for example, a circuit using a transformer T as shown in FIG. 4 can be used. In Figure 4, the number 4
Both 11' and 412' are control circuits. Even in this case, a constant voltage can be applied to the signal amplification circuit 42.

FIG. 5 shows an equivalent circuit from the viewpoint of power consumption of the optical communication system when the constant current/constant voltage conversion circuit 4 is incorporated in this manner. In the same figure, Rclr RC2+
. . .+RCn indicates the resistance of the conductor in the optical fiber cable, and RR is isometrically expressed as the resistance of the power consumption PR in each optical repeater.

In other words, the power consumption within each optical repeater is the sum PR of the power consumption of the constant current/constant voltage conversion circuit itself and the power consumption of the signal amplification circuit.
It is expressed as R. This power consumption p is assumed to be constant for optical relay profits. Therefore, the total power consumption P of this system is the power consumption in the conductive optical repeater PH =
If n RRI, it is expressed as P=Pc+Pi. FIG. 6 illustrates this. Power consumption pR is constant because it does not depend on the power supply current. Power loss pc in a conductor is proportional to the square of the supply current. On the other hand, the supply voltage V depends on the supply current and has properties as shown in FIG.

The supply voltage V can be minimized if the power consumption of the repeater and the power consumption of the conductor are equal. On the other hand, from the viewpoint of minimizing total power consumption, it is better to keep the power supply current as small as possible. However, if it is made extremely small, problems will arise in the operation of the constant current/constant voltage conversion circuit and the problem of an increase in the power supply voltage, so the power supply current is set taking this into account.

The above relationship will be described below with specific examples. For example, 1
It is assumed that the power consumption in one optical repeater is 40 W, the resistance value of the intervening pair is lΩ/km, and the connections are made at an interval of 11000 k via 25 repeaters.

In a conventional optical communication system, when the power supply current is 2 A, the power consumption of the entire repeater is 1 kW, the conductor power loss is 4 kW, and a total of 5 kW of power is required.

The power supply voltage in this case is 2.5 kV. On the other hand, based on the present invention, when the feeding current is set to 0.5 A, the conductor power loss decreases to 0.25 kW, and the power consumption of the entire repeater remains the same as 1 kW, so the total power is 1. 25
kW, which is less than IA compared to the conventional case. The supply voltage in this case is 2.5'kV, which is the same as in the above case. Furthermore, in the present invention, the power supply current is set to 0.2A.
In this case, the conductor power loss is 0.04 kW, which is approximately 1/4 of the total power in the conventional case.

The power supply voltage in this case is 5.2 kV, and no problem arises from the viewpoint of high voltage.

As mentioned above, under the conditions of minimizing power consumption and suppressing the increase in power supply voltage to a certain limit, communication distance,
Set the optimal power supply current by taking into consideration factors such as the power consumption of the repeater.

〔Effect of the invention〕

As described above, according to the present invention, a constant current/constant voltage conversion circuit with a relatively simple circuit configuration is provided in an optical repeater, and the power consumption in an optical communication system is significantly reduced by reducing the power supply current. can be reduced to Further, according to the present invention, the power supply device can be downsized.

Note that the above effect becomes more noticeable as the communication distance increases.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an optical communication device as an embodiment of the present invention, FIG. 2 is a diagram showing a circuit inside a conventional optical repeater, and FIG. 3 is an optical repeater of the present invention in FIG. 4 is a diagram showing an example of the circuit inside the optical repeater of the present invention in FIG. 1, FIG. 5 is a diagram showing an equivalent circuit of FIG. 1, and FIG. is a characteristic curve diagram related to the device of the present invention. 1.10...Power supply device, 2.9...Optical communication device, 3
．． 5.6.8...Optical fiber cable, 4,7...
Optical repeater, 41.71...constant current/constant voltage conversion circuit,
42.72...Signal amplification circuit.

Claims (1)

[Claims] 1. At least one optical repeater is provided in the optical fiber path, and power is supplied from a power supply device provided at one end of the transmitting and receiving side to an electric circuit in the optical repeater via a conductor, In an optical communication device in which a signal is amplified by an optical repeater, a constant current/constant voltage conversion circuit is provided in the optical repeater, the constant current/constant voltage conversion circuit supplies power to the electric circuit, and the power supply is The device is characterized in that the power supply current to the device is reduced.
Optical communication equipment.