KR102263801B1 - Communication system using power line - Google Patents

Abstract

The present invention relates to a full duplex communication system using a power supply line and, more specifically, to a full duplex communication system using a power supply line, comprising a main device and a sub device operated with power supplied from the main device, and capable of transmitting voltage signal data having information by varying a voltage of the power supplied from the main device, and transmitting current signal data having information by varying the current from the sub device. To achieve the objective, in accordance with the present invention, the full duplex communication system using a power supply line includes a main device and at least one sub device operated with power supplied from the main device. The main device provides voltage signal data including information to the sub device by varying the voltage of a power supply line supplied to the sub device, and the sub device provides current signal data including information to the main device by varying an operation current of the power supply line supplied from the main device. Therefore, the main device and the sub device communicate with each other.

Description

Full-duplex communication system using power line {COMMUNICATION SYSTEM USING POWER LINE}

The present invention relates to a full-duplex communication system using a power line, and more particularly, it is composed of a main device and a slave device operated by being supplied with power from the main device, and the voltage having information by varying the voltage of the power supplied from the main device It relates to a full-duplex communication system using a power line capable of transmitting signal data and capable of transmitting current signal data having information by changing a current in a slave device.

In a system consisting of a main device (main device) and a slave device (sub device) operating dependently on the main device (main device), communication between the main device and the slave device exchanges data with each other through a separate communication line.

That is, separate power is applied to the main device and the subordinate device, and a separate communication line is installed between the main device and the subordinate device to perform communication, and the system is configured in such a way that the power line and the communication line are respectively connected. .

It goes without saying that the installation of such multi-line (power line, communication line) not only requires a lot of cost, but also requires a lot of manpower and money for maintenance and repair.

Accordingly, power line communication (PLC), which is a method for performing communication through a power line (or power line), has been developed.

The power line communication is a technology that transmits voice, text data, and video using a power line. It uses a power line without a communication line to provide not only high-speed Internet communication but also VoIP, home networking, home automation, and remote meter reading. It is a technology that can be used.

As one of the technologies using power line communication, a power line communication system having an integrated modem is disclosed in Korean Patent Publication No. 10-1400432.

The above technology forms a separate management server for effective communication between them in the current power line communication system that is running with different protocols, converts it into a protocol corresponding to the data transmitted in the management server, and then responds to the converted data. It relates to a power line communication system having an integrated modem for safely transmitting to a terminal.

In the conventional power line communication as described above, a PLC modem connected to the power line is essential. That is, when information, data, and signals configured between the power line and the terminal (device) and transmitted through the power line are simultaneously supplied to each terminal together with power, the analog signal is converted into digital data or digital data is converted into an analog signal. PLC modem should be provided.

However, since the PLC modem is connected to a high high voltage, safety against high voltage must be secured, a filtering unit for filtering distortion caused by voltage (or current) applied from the power line, and a signal for converting analog signals and digital signals to each other There is a problem in that various configurations such as a conversion unit and a modulation/demodulation unit for modulation/demodulation are required.

On the other hand, as a technique for performing communication between controllers through a power line, a communication device between controllers through a power line is disclosed in Korean Patent Registration No. 10-0559913.

The above technology allows the sub-controller to operate with the power supplied from the main controller through the power line, and allows the main controller and the sub-controller to communicate with each other through the power line, and can communicate by connecting several sub-controllers to one main controller in parallel. it is configured to

However, the above technique has a disadvantage in that sufficient power cannot be supplied to the auxiliary controller by the resistor R1 that mixes and transmits the transmission signal through the power line from the main controller and the resistor R1a that receives the voltage from the sub-controller. In addition, as a method of transmitting a mixed transmission signal on the power line, a configuration for detecting the mixed transmission signal on the power line should be added, and the reception signal should not be received during transmission and the transmission signal should not be transmitted during reception. There is a problem that I cannot.

That is, the above technique is the same technique as that of power line communication in which a transmission signal is loaded and transmitted on a power line, and there is a disadvantage in that bidirectional communication cannot be performed at the same time.

Registered Patent Publication No. 10-1400432 (2014. 05. 21.) Registered Patent Publication No. 10-0559913 (2006.03.06.)

The present invention has been devised to solve the above problems, and the problem to be solved in the present invention is to perform communication by varying the voltage applied to the power line or by varying the current for the power applied through the power line. An object of the present invention is to provide a full-duplex communication system using a power line.

Another object of the present invention is to provide a full-duplex communication system using a power line capable of transmitting or receiving data in a process of transmitting data or receiving data.

A full-duplex communication system using a power line according to the present invention for solving the above problems is configured to include a main device and one or more subordinate devices operated by receiving power from the main device, wherein the main device is supplied to the subordinate device By varying the voltage of the power line, voltage signal data including information is provided to the subordinate device, and the subordinate device varies the operating current of the power line supplied from the main device to provide current signal data including information to the main device, , characterized in that the main device and the slave device communicate.

Here, the voltage signal data is generated by a first voltage relatively higher than the operating voltage of the slave device or a second voltage relatively lower than the operating voltage, and the current signal data is based on the operating voltage supplied from the main device. It is characterized in that it is generated by a first current relatively higher than the operating current or a second current relatively lower than the operating current.

In addition, the main device includes a main power circuit unit for converting the input power to the required power; a power control circuit unit controlling the power supplied from the main power circuit unit as a driving power of the subordinate device and applying it to the subordinate device; a current sensing circuit unit for sensing the current of the slave device; and controlling to generate and supply voltage signal data by varying the voltage supplied to the slave device through the power control circuit unit according to an input event, and detecting the current signal data based on the current sensed by the current sensing circuit unit It is characterized in that it includes a main control unit.

In addition, the subordinate device includes a subordinate power circuit unit for converting the voltage applied from the main device into an operating power supply; a voltage sensing circuit unit for sensing a voltage input to the subordinate power circuit unit; a subordinate control unit for detecting the voltage signal data based on the voltage sensed by the voltage sensing circuit unit and controlling the operating current of the power line to vary in response to the detected voltage signal data; It characterized in that it comprises a current control circuit unit for varying the operating current of the power line according to the control of the subordinate control unit and a charging circuit unit for maintaining the driving of the subordinate device in response to a change in the voltage applied from the main device.

According to the present invention, a signal for performing communication can be generated by a change in voltage applied to a power line and a change in current of a slave device, and communication is possible through the generated signal. has the advantage of being able to communicate with each other.

In addition, since data can be received not only in the process of transmitting data for communication, but also data can be transmitted in the process of receiving data, there is an advantage in that smooth data communication can be maintained.

In addition, since communication is possible without installing a separate communication line for data communication, there is an advantage in that the construction facility is simple and the installation cost can be reduced.

1 is a schematic configuration diagram of a full-duplex communication system using a power line according to the present invention;
2 is a schematic configuration diagram of a main device and a subordinate device applied to a full-duplex communication system using a power line according to the present invention;
3 is a graph of voltage change for generating voltage signal data in a full-duplex communication system using a power line according to the present invention;
4 is a graph of current change for generating current signal data in a full-duplex communication system using a power line according to the present invention;
5 is a circuit diagram of an embodiment of a power control circuit unit and a current sensing circuit unit applied to a main device of a full-duplex communication system using a power line according to the present invention;
6 is a circuit diagram of another embodiment of a power control circuit unit and a current sensing circuit unit applied to the main device of a full-duplex communication system using a power line according to the present invention;
7 is a circuit diagram according to an embodiment of a voltage sensing circuit unit applied to a slave device of a full-duplex communication system using a power line according to the present invention;
8 is a circuit diagram according to an embodiment of a current control circuit unit applied to a slave device of a full-duplex communication system using a power line according to the present invention.

Next, a preferred embodiment of a full-duplex communication system using a power line according to the present invention will be described in detail with reference to the drawings.

Hereinafter, the same reference numerals are used for technical elements having the same function, and repeated detailed descriptions are omitted to avoid overlapping descriptions.

In addition, the examples described below are illustratively shown in order to effectively show the preferred embodiments of the present invention, and should not be construed to limit the scope of the present invention.

The present invention is composed of a main device and a slave device that is supplied and operated from the main device, and can transmit voltage signal data having information by varying the voltage of power supplied from the main device, and the slave device transmits information by varying the current. It relates to a full-duplex communication system using a power line capable of transmitting current signal data.

1 is a schematic configuration diagram of a full-duplex communication system using a power line according to the present invention.

1, the full-duplex communication system using a power line according to the present invention supplies the main device 100 and the slave device 200 and the power supplied from the main device 100 to the slave device 200. It is configured to include a power line (10).

The main device 100 controls the slave device 200 to be described later or performs a function of processing data transmitted from the slave device 200 .

In this case, the main device 100 includes a device capable of generating a specific control signal or executing stored logic according to an input event.

In addition, the slave device 200 performs a function in response to the control signal transmitted from the main device 100 or performs a function of transmitting a response signal according to the performed logic to the main device. The slave device 200 may include a relay for turning on/off power, a sensor module for sensing environmental information, as well as a small controller.

For example, the subordinate device 200 is composed of a switch including an electronic relay for turning on and off a light, a motor, a sensor, a pump, etc., or detects environmental information such as temperature, humidity, carbon dioxide, etc., and returns the detected environmental information value. It may be composed of a temperature-humidity device that transmits, a fire detector, and the like.

The power line 10 applies the power supplied from the main device 100 to the subordinate device 200, and the power applied in the present invention may be a DC power source.

That is, the main device 100 transmits DC power to the subordinate device 200 through the power line 10, and the subordinate device 200 is driven by the power applied to the power line 10, It is composed of a single-phase two-wire type with a (+) power line and a (-) power line.

In this configuration, the subordinate device 200 may be configured in plurality to correspond to the main device 100 . In other words, a plurality of subordinate devices 200 may be connected by one main device 100 to form a network for controlling an area within a certain range or detecting environmental information.

2 is a schematic configuration diagram of a main device and a subordinate device applied to a full-duplex communication system using a power line according to the present invention.

2, the main device 100 supplies power to the slave device 200 through a power line, and changes the voltage of the supplied power line to transmit voltage signal data including information to the slave device 200 ) to perform the function provided.

The main device 100 is configured to include a main power circuit unit 110 , a power control circuit unit 120 , a current sensing circuit unit 130 , and a main control unit 140 .

The main power circuit unit 110 converts the input power into the required power, for example, converts the input AC or DC power into the power required for the operation of the main device 100 and supplies it to each component.

The power control circuit unit 120 controls the power supplied from the main power circuit unit 110 as the driving power of the subordinate device 200 and applies it to the subordinate device 200 .

At this time, the subordinate device 200 may be operated with DC power, and an appropriate voltage in consideration of the voltage drop according to the length of the power line 10 , that is, the distance between the main device 100 and the subordinate device 200 . This can be configured to be supplied.

The current sensing circuit unit 130 senses the current of the slave device 200 . In more detail, the current flowing through the power line 10 is sensed.

The main control unit 140 controls the main power circuit unit 110 , the power control circuit unit 120 , and the current sensing circuit unit 130 , and according to an input event, the subordinate device through the power control circuit unit 120 . The voltage supplied to 200 is varied to generate and supply voltage signal data, and the current signal data is detected based on the current sensed by the current sensing circuit unit 130 .

For example, the main control unit 140 generates data based on an event such as an “ON” signal or a signal input according to a button operation, and the power control circuit unit 120 based on the generated data. By varying the voltage supplied to the slave device 200 through a voltage signal data is generated and supplied.

That is, the main controller 140 varies the voltage of the operating power within the range of the operating power for driving the subordinate device 200 , and the voltage signal data includes the variable width and period of the voltage.

The slave device 200 is operated with the power output from the main device 100 , and performs a function of providing a response of the result of performing various operations under the control of the main device 100 to the main device 100 .

That is, the main device 100 and the slave device 200 exchange a control signal, a response signal, and the like through communication.

The subordinate device 200 is configured to include a subordinate power circuit unit 210 , a voltage sensing circuit unit 220 , a subordinate control unit 230 , a current control circuit unit 240 , and a charging circuit unit 250 .

The subordinate power circuit unit 210 changes or stabilizes the voltage applied from the main device 100 to the operating power, and converts it into power used in the subordinate device 200 and supplies it.

The voltage sensing circuit unit 220 performs a function of sensing a voltage input to the subordinate power circuit unit 210 .

The subordinate control unit 230 detects the voltage signal data based on the voltage sensed by the voltage sensing circuit unit 220 , and performs logic in response to the detected voltage signal data.

In addition, the subordinate control unit 230 performs an operation based on the detected voltage signal data, and generates current signal data with a response signal corresponding to the operation result.

In other words, the subordinate control unit 230 performs a corresponding logic based on the voltage signal data, which is the control signal transmitted from the main device 100 , and generates current signal data as a response signal of the performed result.

For example, when the information of the voltage signal data is “ON”, the slave device 200 performs a logic corresponding to “ON” and generates current signal data as a response signal of the result.

The current control circuit unit 240 varies the operating current of the power line according to the control of the subordinate control unit 230 .

The charging circuit unit 250 maintains the operation of the slave device 200 according to a temporary power line abnormality, or the operation of the slave device 200 is stopped due to a momentary voltage drop by the voltage signal data generated in the primary device 100 . In order to prevent this, the capacitor C1 is included. In this case, the charging circuit unit 150 may be configured to include a battery for charging power.

Next, a method of generating voltage signal data according to a change in voltage will be described.

3 is a graph showing a voltage change for generating voltage signal data in a full-duplex communication system using a power line according to the present invention.

Referring to FIG. 3, (a) of FIG. 3 shows a graph of voltage signal data generated by a first voltage Vref1 that is relatively lower than the operating voltage Vcc of the slave device, and (a) of FIG. b) shows a graph of voltage signal data generated by a second voltage Vref2 that is relatively higher than the operating voltage Vcc.

In this case, Vcc shown in FIG. 3 means the operating voltage of the slave device 200 , and may be expressed as Vcc, Vdd, Vee, or Vss, and is a voltage required for driving the slave device 200 .

In addition, the first voltage Vref1 and the second voltage Vref2 are relatively lower or higher than the operating voltage for a predetermined time, and when converted into data, correspond to 1 bit.

The first voltage Vref1 or the second voltage Vref2 may be applied differently depending on the operating voltage Vcc, but may be configured to vary within a voltage range in which the dependent device can operate.

4 is a graph showing a current change for generating current signal data in a full-duplex communication system using a power line according to the present invention.

4, (a) of FIG. 4 shows a graph of the current signal data generated by the first current Aref1 relatively lower than the operating current Avcc based on the operating voltage supplied from the main device. , (b) of FIG. 4 shows a graph of current signal data generated by the second current Aref2 relatively higher than the operating current Avcc based on the operating voltage supplied from the main device.

At this time, as in FIG. 3 , the first current Aref1 and the second current Aref2 are relatively higher or lower than the operating current for a predetermined time, and when converted into data, they correspond to 1 bit.

In the above, the operating current Avcc means an average current used in the slave device 200 according to the operation of the slave device 200 .

According to this, voltage signal data can be generated by the combination of the first voltage or the second voltage, and the current signal data can be generated by the combination of the first current or the second current, and the generated voltage signal data and According to the exchange of current signal data, the main device and the slave device communicate.

5 is a circuit diagram of an embodiment of a power control circuit unit and a current sensing circuit unit applied to the main device of a full-duplex communication system using a power line according to the present invention.

5, the first feedback module 121 for outputting the output voltage as the operating voltage of the slave device and the first voltage (or the second voltage, hereinafter referred to as "variable voltage") are set to Stabilizes the DC input voltage (DC_IN+) output from the second feedback module 122 and the main power circuit unit 110 (refer to FIG. 2 ) for outputting and, depending on the selection, the operating voltage or the second set in the first feedback module 121 A DC-DC converter 123 for outputting a variable voltage set in the feedback module 122 and one selected from the first feedback module 121 and the second feedback module 122 is supplied to the DC-DC converter 123 . It is configured to include a switching module 124 for connecting.

According to the above configuration, the switching module 124 according to a control signal of the main controller 140 (refer to FIG. 2 ) sets one selected from the first feedback module 121 or the second feedback module 122 . A voltage is input to the DC-DC converter 123, and the DC-DC converter 123 applies a corresponding voltage to the power line according to the inputted set voltage.

That is, when the first feedback module 121 is connected to the DC-DC converter 123 according to the switching operation of the switching module 124 , the operating voltage of the slave device is applied to the power line, and the When the second feedback module 122 is connected to the DC-DC converter 123 according to the switching operation, a variable voltage is applied to the power line.

As described above, according to the switching operation of the switching module 124, the operating voltage (Vcc) or the variable voltage (the first voltage or the second voltage) is applied to the power line, and the voltage signal data is generated by the combination of the operating voltage and the variable voltage. is transmitted to the slave device, and the slave device detects the voltage signal data and derives a control signal.

In addition, the main device 100 includes a current sensing circuit unit 130 to detect the current signal data transmitted from the slave device 200, and the current sensing circuit unit 130 includes a detection resistor ( Rs, shunt) and a current sensor 132 for detecting a change in current flowing through the detection resistor Rs.

Accordingly, the current sensor 132 detects a change in the current of the power line, and transmits a current value of the detected current to the main controller 140 . The main controller 140 converts the change in current detected by the current sensor 132 into current signal data to receive information.

6 is a circuit diagram of another embodiment of a power control circuit unit and a current sensing circuit unit applied to the main device of a full-duplex communication system using a power line according to the present invention.

Referring to FIG. 6 attached, the power control circuit unit 120 is provided with a first terminal DC_A+ preset to an operating voltage and a second terminal DC_B+ preset to a variable voltage, and an output voltage of the first terminal A first switching device 125 for applying (operating voltage) to the power line and a second switching device 126 for applying an output voltage (variable voltage) of the second terminal to the power line are included.

At this time, diodes Da and Db for preventing the application of reverse voltage are installed on the output side of the first switching element 125 and the output side of the second switching element 126 , respectively.

In the state configured as described above, an operating voltage or a variable voltage is applied to the power line by one switching device selected from among the first switching device 125 and the second switching device 126 according to the control signal of the main controller 140 . will become

That is, a preset operating voltage is applied to the power line by the connection of the first switching element 125 , and a preset variable voltage is applied to the power line by the connection of the second switching element 126 .

In this way, an operating voltage Vcc or a variable voltage (first voltage or second voltage) is applied to the power line according to the operations of the first switching device 125 and the second switching device 126, and the operating voltage and The voltage signal data is transmitted to the slave device by the combination of the variable voltage, and the slave device detects the voltage signal data and derives a control signal.

Since the current sensing circuit unit 130 is the same as the circuit diagram shown in FIG. 5 , a detailed description thereof will be omitted.

7 is a circuit diagram according to an embodiment of a voltage sensing circuit unit applied to a slave device of a full-duplex communication system using a power line according to the present invention.

7, the voltage sensing circuit unit 220 constitutes a bridge circuit with three resistors R1, R2, R3 and a Zener diode D1, and a voltage sensor for detecting voltages at both ends of the bridge circuit. (221) is included.

Here, the Zener diode D1 maintains the constant voltage circuit by using the Zener breakdown phenomenon in which the voltage is constant even when the current changes in the reverse direction, and by changing the current in the current control circuit unit 240 to be described later. be able to

In this way, the voltage change of the power line detected by the voltage sensor 221 of the voltage sensing circuit unit 220 is recognized as voltage signal data by the subordinate control unit 230 to receive the control signal.

8 is a circuit diagram according to an embodiment of a current control circuit unit applied to a slave device of a full-duplex communication system using a power line according to the present invention.

8, the current control circuit unit 240 is connected in series to the current control resistor (R4) connected to the power line and the current control resistor (R4) to put the current control resistor (R4) to the power line It is configured to include a connection switching element (241).

Through the above configuration, when a signal (pulse) is input to the connection switching element 241, the current flows through the current control resistor R4 according to the operation of the connection switching element 241. According to the operation of (241), the current flowing through the current control resistor (R4) can be varied (currently increased).

Conversely, when a signal (pulse) is input to the connection switching device (241) and the current control resistor (R4) is input to the power line and blocks the signal (pulse), the wire connected to the current control resistor (R4) is opened and flows You can change the current (reduce the current).

Accordingly, a first current relatively lower than the operating current is generated by the drop-off of the current control resistor R4, and a second current relatively higher than the operating current is generated by the input of the current control resistor R4. and current signal data can be generated by turning on or off the current control resistor R4.

5 to 8 are circuit diagrams of an embodiment that can be applied to a full-duplex communication system using a power line according to the present invention, and the scope of the present invention is limited by the circuit diagrams of FIGS. 5 to 8. no.

Next, the communication process between the main device and the slave device will be described.

In a system in which the main unit and the subordinate device are configured one by one, it is not necessary to separately specify the main unit and the subordinate device, so the description of this configuration will be omitted.

In a system consisting of one main device and N slave devices, the main device can specify the slave device and communicate with the specified slave device, or communicate with all the slave devices connected to the entire system without specifying the slave device.

1. In the case of specifying a slave device (1:1 communication)

In the method of specifying the slave device to communicate with the main device, identification information (ID) is given to each slave device, and the voltage signal data includes the identification information and transmitted from the main device to the slave device.

The slave device analyzes the voltage signal data transmitted from the main device and, when the identification information included in the voltage signal data is its own identification information, converts the current signal data including response information to the control information included in the voltage signal data to the main device. will send

In this process, communication with all the subordinate devices connected to the power line is performed by repeating the above process N times.

Although the voltage signal data is described as "transmission" or "transmission" of current signal data in the above, in the full-duplex communication system using the power line of the present invention, the voltage change is detected and received by the slave device, and the current change is detected by the main device. It is to be understood that the description of "transmission" is for ease of explanation as to receive it through the

2. If the dependent device is not specified (1:N)

In the method of not specifying the slave device to communicate with from the main device, identification information (ID) is given to each slave device, and only control information is included in the voltage signal data and transmitted from the main device to the slave device.

The slave device analyzes the voltage signal data transmitted from the main device and transmits the current signal data including its identification information and response information to the main device.

At this time, the main device sets the necessary time according to the response of the slave device in advance, and the slave device sequentially transmits the current signal data from 1 to N times sequentially according to the order of the identification information to the main device, and to the main device When the set time elapses, the main device is configured to terminate communication with the slave device.

According to the present invention, a signal for performing communication can be generated by a change in voltage applied to a power line and a change in current of a slave device, and communication is possible through the generated signal. can communicate with each other. In addition, since data can be received not only in the process of transmitting data for communication, but also data can be transmitted in the process of receiving data, smooth data communication can be maintained and a separate communication line for data communication is not installed. Since communication is possible without the need for communication, there is an advantage in that the construction facility is simple and the cost required for installation can be reduced.

In the above, a preferred embodiment of a full-duplex communication system using a power line according to the present invention has been described, but the present invention is not limited thereto, and various modifications are made within the scope of the claims, the description of the invention, and the accompanying drawings. It is possible to do so, and this is also within the scope of the present invention.

10: power line 100: main unit
110: main power circuit unit 120: power control circuit unit
130: current sensing circuit unit 140: main control unit
200: subordinate device 210: subordinate power circuit unit
220: voltage sensing circuit unit 230: subordinate control unit
240: current control circuit unit 250: charging circuit unit

Claims (5)

It is configured to include a main device and one or more subordinate devices operated by receiving power from the main device,
The main device provides voltage signal data including information to the slave device by varying the voltage of the power line supplied to the slave device,
The slave device provides current signal data including information to the primary device by varying the operating current of the power line supplied from the primary device, so that the primary device and the slave device communicate,
The main device transmits DC power to the subordinate device through the power line, and the subordinate device is driven by power applied to the power line,
The claim is
a main power circuit unit for converting input power into required power;
a power control circuit unit controlling the power supplied from the main power circuit unit as a driving power of the subordinate device and applying it to the subordinate device;
a current sensing circuit unit for sensing the current of the slave device; and
Main control for controlling to generate and supply voltage signal data by varying the voltage supplied to the slave device through the power control circuit unit according to an input event, and detecting the current signal data based on the current sensed by the current sensing circuit unit part;
includes,
The power control circuit unit,
a first terminal preset to an operating voltage for driving the slave device;
a second terminal preset to a variable voltage generating the voltage signal data;
a first switching element for applying the operating voltage of the first terminal to a power line; and
a second switching element for applying the variable voltage of the second terminal to the power line;
A full-duplex communication system using a power line, characterized in that it comprises a.
The method according to claim 1,
The voltage signal data is
A full-duplex communication system using a power line, characterized in that it is generated by a first voltage relatively higher than the operating voltage of the slave device or a second voltage relatively lower than the operating voltage.
The method according to claim 1,
The current signal data is
A full-duplex communication system using a power line, characterized in that it is generated by a relatively higher first current or a relatively lower second current than an operating current based on the operating voltage supplied from the main device.
delete The method according to claim 1,
The subordinate device is
a subordinate power circuit unit converting the voltage applied from the main device into operating power and supplying it;
a voltage sensing circuit unit for sensing a voltage input to the subordinate power circuit unit;
a subordinate control unit for detecting the voltage signal data based on the voltage sensed by the voltage sensing circuit unit and controlling the operating current of the power line to vary in response to the detected voltage signal data;
a current control circuit unit for varying the operating current of the power line according to the control of the subordinate control unit; and
a charging circuit unit for maintaining the driving of the slave device in response to a change in voltage applied from the main device;
A full-duplex communication system using a power line comprising a.

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