COMMUNICATION ADAPTER AND AIR CONDITIONING SYSTEM

Abstract

A communication adapter (21) comprises a high-voltage communicator (211) that performs high-voltage communication with an external device (20), and a low-voltage communicator (212) that performs low-voltage communication with a communication adapter (31). The low-voltage communicator (212) transmits communication data received by the high-voltage communicator (211) from the external device (20) to the communication adapter (31) via low-voltage communication. The high-voltage communicator (211) transmits the communication data received by the low-voltage communicator (212) from the communication adapter (31) to the external device (20) via high-voltage communication.

Description

Technical field

[0001] The present invention relates to a communication adapter and an air conditioning system. background

[0002] In air conditioning systems installed in office buildings, shops, or similar premises, a common configuration involves connecting an outdoor unit and an indoor unit with a three-core cable comprising a power line, a signal line, and a common line (for example, patent literature 1). In this configuration, a high voltage (for example, 200 VAC) is applied between the power line and the common line, which are connected to an external power supply, and the indoor unit is powered by the external power supply via the outdoor unit.

[0003] Air conditioning systems are also known that include separate external power supplies belonging to an outdoor unit and an indoor unit. In this configuration as well, communication between the outdoor and indoor units requires a shared line, and a high voltage is applied to this shared line. Citation list for patent literature

[0004] Patent literature 1: Japanese patent no. 6239143 Summary of the invention; Problem statement

[0005] In markets such as North America, the wiring between air conditioners (an outdoor unit and an indoor unit) generally requires low voltage (e.g., 24 VAC). When using air conditioning systems with the configuration described above in such countries, there is a high probability of high installation costs or that local contractors will refuse to perform the installation work. This is one of the factors preventing the expansion of distribution channels into these markets.

[0006] Therefore, there are circumstances under which proposals for a new technology are desirable that enables low-voltage wiring between air conditioners configured to communicate with each other at high voltage.

[0007] The present invention is made in view of the above-mentioned circumstances, and an object of the present invention is to provide a communication adapter and an air conditioning system that enable low-voltage wiring between air conditioners configured to communicate with each other at high voltage. Solution to the task

[0008] To solve the above-mentioned problem, a communication adapter according to the present invention comprises: a first communicator to communicate with an air conditioner based on a first voltage; and a second communicator to communicate with a device different from the air conditioner on the basis of a second voltage that is lower than the first voltage, wherein The second communicator, based on the second voltage, transmits communication data received from the air conditioner by the first communicator to the device, and The first communicator transmits communication data received from the device by the second communicator to the air conditioner based on the first voltage. Advantageous effects of the invention

[0009] The present invention enables low-voltage wiring between air conditioners configured to communicate with each other at a high voltage. Brief description of the drawings Fig. Figure 1 shows an overall configuration of an air conditioning system in embodiment 1; Fig. Figure 2 is a block diagram illustrating a configuration of a control unit contained in an external device in embodiment 1; Fig. Figure 3 is a circuit diagram illustrating configurations of a high-voltage communicator and a communication adapter of the external device in embodiment 1; Fig. Figure 4 shows an overall configuration of an air conditioning system in embodiment 2; Fig. Figure 5 shows an overall configuration of an air conditioning system in embodiment 3; Fig. Figure 6 is a timing diagram illustrating the operation of each of the communicators during the transmission of communication data from an external device to an internal device and during the transmission of communication data from the internal device to the external device in embodiment 3; Fig. Figure 7 shows an overall configuration of an air conditioning system in embodiment 4; and Fig. Figure 8 shows an overall configuration of an air conditioning system in embodiment 5. Description of the embodiments

[0010] The embodiments of the present invention are described in detail below with reference to the drawings. Design 1

[0011] Fig. Figure 1 shows an overall configuration of an air conditioning system 1 in embodiment 1. The air conditioning system 1 is an example of an air conditioning system according to the present invention. The air conditioning system 1 is a system that, for example, performs the air conditioning of a building, such as an office building or a shop, and comprises an outdoor unit 2 and an indoor unit 3. The air conditioning system 1 can comprise a plurality of indoor units 3. In the air conditioning system 1, an outdoor unit 20 and an indoor unit 30 are connected to each other via a refrigerant line (not shown) for the circulation of refrigerant. A communication adapter 21 of the outdoor unit 2 and a communication adapter 31 of the indoor unit 3 are communicatively connected to each other via a cable with two wires. Outdoor unit 2

[0012] The outdoor unit 2 comprises the outdoor device 20 and the communication adapter 21. The communication adapter 21 is located near the outdoor device 20. The communication adapter 21 can be located in a housing of the outdoor device 20. External device 20

[0013] The outdoor device 20 is an example of an air conditioning system according to the present invention and an example of an outdoor device according to the present invention. The outdoor device 20 comprises a power supply 200, a high-voltage communicator 201, and a control unit 202. The outdoor device 20 also includes mechanisms required for air conditioning (hereinafter referred to as the "main device of the outdoor device"), such as a compressor, an outdoor heat exchanger, an outdoor fan, and an expansion valve, which are not shown in the drawings.

[0014] Power supply 200 provides power to drive the outdoor device 20 based on the power input from an external power supply 4. That is, power supply 200 provides the power required for operation to each of the high-voltage communicators 201, the control unit 202, and the main unit of the outdoor device. The external power supply 4 is an AC power supply that delivers alternating current and is a commercial power supply that outputs, for example, a voltage of 200 V. The external power supply 4 could be a power supply that uses, for example, a private generator or a renewable energy source.

[0015] Although details will be described later, the high-voltage communicator 201 is a communication circuit for communicating with another device based on a first voltage (for example, a ground voltage of 200 V) and includes electronic components, such as a transistor and a photocoupler, as well as an integrated communication driver circuit (IC). Hereinafter, first-voltage-based communication will be referred to as high-voltage communication.

[0016] The control unit 202 performs the overall control of the external device 20. As in Fig. As shown in Figure 2, the control unit 202 comprises a central processing unit (CPU) 220, a read-only memory (ROM) 221, a read / write memory (RAM) 222, an input / output interface (I / O) 223, and an additional storage device 224. The control unit 202 performs operations, including generating communication data (command data or notification data) for the internal device 30, processing communication data received from the internal device 30, and controlling the external device main unit. The command data is data that specifies a command to another device, and the notification data is data to be sent to another device (for example, response data to received command data, or the like). Communication adapter 21

[0017] With reference to Fig. The communication adapter 21 is an example of a communication adapter according to the present invention and an example of an adapter for the outdoor device according to the present invention. The communication adapter 21 comprises an isolating power supply 210, a high-voltage communicator 211, a low-voltage communicator 212, and a control unit 213. The isolating power supply 210 is an example of an isolating power supply according to the present invention. The isolating power supply 210 is a power supply circuit in which the input and output are electrically isolated from each other by reinforced insulation, and the power to drive the communication adapter 21 is supplied based on the power input from the external power supply 4 via the outdoor device 20.This means that the isolating power supplier 210 supplies each of the high-voltage communicators 211, the low-voltage communicators 212 and the control unit 213 with the power required for their operation.

[0018] The high-voltage communicator 211 is an example of a first communicator according to the present invention. Although details are described later, the high-voltage communicator 211 is a communication circuit for high-voltage communication with another device and comprises electronic components, for example a transistor and a photocoupler, as well as a communication driver IC.

[0019] The low-voltage communicator 212 is an example of a second communicator according to the present invention. The low-voltage communicator 212 is a communication circuit for communicating with another device based on a second voltage that is lower than the first voltage (for example, a ground voltage of 5 V) and comprises electronic components, such as a transistor and a photocoupler, and a communication driver IC. Hereinafter, communication based on the second voltage is referred to as low-voltage communication. Examples of low-voltage communication protocols include unbalanced transmission such as RS232C, differential transmission such as RS-485, or a Controller Area Network (CAN), Ethernet (registered trademark), or the like.A connection interface on the side of the indoor unit 3 of the low-voltage communicator 212 has reinforced insulation or double insulation to the external power supply 4.

[0020] The control unit 213 comprises a CPU, a ROM, and a RAM, none of which are shown in the drawings, and performs the overall control of the communication adapter 21. The control unit 213 processes, including the transmission of, communication data received by the high-voltage communicator 211 from the outdoor device 20 via the low-voltage communicator 212 to the indoor unit 3, and the transmission of communication data received by the low-voltage communicator 212 from the indoor unit 3 via the high-voltage communicator 211 to the indoor device 20. Indoor unit 3

[0021] The indoor unit 3 comprises the indoor device 30 and the communication adapter 31. The communication adapter 31 is located near the indoor device 30. The communication adapter 31 can be located in a housing of the indoor device 30. Internal device 30

[0022] The indoor device 30 is an example of an air conditioning system according to the present invention and an example of an indoor device according to the present invention. The indoor device 30 comprises a power supply 300, a high-voltage communicator 301, and a control unit 302. The indoor device 30 also includes mechanisms required for air conditioning (hereinafter referred to as the "indoor device main unit"), such as an indoor heat exchanger, an electromagnetic valve, and an indoor fan, which are not shown in the drawings.

[0023] The power supply 300 outputs power to drive the indoor device 30 based on the power input from an external power supply 5. That is, the power supply 300 outputs the power required for operation to each of the high-voltage communicators 301, the control unit 302, and the indoor device main unit. The external power supply 5 could be, for example, a commercial power supply provided by a utility company. The external power supply 5 could be a power source that uses, for example, a private generator or renewable energy.

[0024] Although details will be described later, the high-voltage communicator 301 is a communication circuit for high-voltage communication with another device and includes electronic components, such as a transistor and a photocoupler, as well as a communication driver IC. Like the control unit 202 of the external device 20 (see Fig. 2) The control unit 302 comprises a CPU, a ROM, a RAM, an I / O interface, and an additional storage device and performs the overall control of the internal device 30. The control unit 302 carries out the operation, including the generation of communication data (command data or notification data) for the external device 20, the processing based on the communication data received from the external device 20, and the control of the main unit of the internal device. Communication adapter 31

[0025] The communication adapter 31 is an example of the communication adapter according to the present invention and an example of an adapter for the internal device according to the present invention. The communication adapter 31 comprises an isolating power supply 310, a high-voltage communicator 311, a low-voltage communicator 312, and a control unit 313. The isolating power supply 310 is an example of the isolating power supply according to the present invention. The isolating power supply 310 is a power supply in which the input and output are electrically isolated from each other by reinforced insulation and which, based on the power supplied by the external power supply 5 via the internal device 30, delivers power to drive the communication adapter 31.This means that the isolating power supply 310 provides each of the high-voltage communicators 311, the low-voltage communicators 312 and the control unit 313 with the power required for their operation.

[0026] The high-voltage communicator 311 is an example of the first communicator according to the present invention and an example of a third communicator according to the present invention. Although details are described later, the high-voltage communicator 311 is a communication circuit for high-voltage communication with another device and comprises electronic components, for example a transistor and a photocoupler, as well as a communication driver IC.

[0027] The low-voltage communicator 312 is an example of the second communicator and an example of a fourth communicator according to the present invention. The low-voltage communicator 312 is a communication circuit for low-voltage communication with another device and comprises electronic components, for example, a transistor and a photocoupler, as well as a communication driver IC. A connection interface on the external device side 2 of the low-voltage communicator 312 has reinforced insulation or double insulation for the external power supply 5.

[0028] The control unit 313 comprises a CPU, a ROM, and a RAM, none of which are shown in the drawings, and performs the overall control of the adapter 31. The control unit 313 processes communication data received by the high-voltage communicator 311 from the indoor device 30 and transmits it via the low-voltage communicator 312 to the outdoor device 2, and transmits communication data received by the low-voltage communicator 312 from the outdoor device 2 via the high-voltage communicator 311 to the indoor device 30. High-voltage communication

[0029] The high-voltage communication in the present embodiment, i.e., the high-voltage communication between the external device 20 and the communication adapter 21 and the high-voltage communication between the internal device 30 and the communication adapter 31, are described in detail below. Fig. Figure 3 is a circuit diagram illustrating a configuration of the high-voltage communicator 201 of the outdoor device 20 in the outdoor unit 2 and a configuration of the high-voltage communicator 211 of the communication adapter 21 in the outdoor unit 2. A configuration of the high-voltage communicator 301 of the indoor device 30 in the indoor unit 3 is the same as that shown in Figure 3. Fig. The configuration of the high-voltage communicator 211 shown in Figure 3, and the configuration of the high-voltage communicator 311 of the communication adapter 31 in the indoor unit 3, is the same as the configuration of the high-voltage communicator 201, as shown in Figure 3. Fig. 3 shown. High-voltage communicator 201

[0030] As in Fig. As shown in Figure 3, the high-voltage communicator 201 comprises a DC power supply 400, a transmission circuit 420, a receiving circuit 440, a communication driver IC 460, and a diode 470. The DC power supply 400 provides a communication current for serial communication. It converts the alternating current supplied by the external power supply 4 into direct current. The DC power supply 400 generates a communication voltage of Vc (V) based on the potential of a common line 6. The DC power supply 400 is a half-wave rectifier circuit comprising a resistor 401, a diode 402, a constant-voltage diode 403, and an electrolytic capacitor 404.

[0031] Resistor 401 is used to generate a DC voltage. One end of resistor 401 is connected to the external power supply 4 via a current line 7. The other end of resistor 401 is connected to the anode of diode 402. Diode 402 is a rectifier element that conducts current in only one direction, from the anode to the cathode. The cathode of diode 402 is connected to the cathode of constant voltage diode 403, the positive terminal of electrolytic capacitor 404, the emitter of a PNP transistor 422, the first end of resistor 423, and the collector of phototransistor 432 in photocoupler 430 of the transmission circuit 420.

[0032] The constant voltage diode 403 is a diode that allows a small reverse current when a reverse voltage applied between an anode and the cathode is lower than a breakdown voltage, and a rapid reverse current when the reverse voltage is higher than or equal to the breakdown voltage. The voltage (breakdown voltage) across both ends of the constant voltage diode 403 is assumed to be Vc (V). The anode of the constant voltage diode 403 is connected to a negative terminal of the electrolytic capacitor 404 and to a cathode of a diode 426 of the transmission circuit 420. The electrolytic capacitor 404 is a capacitor that temporarily stores supplied energy and has a polarity.

[0033] The transmission circuit 420 is a circuit that transmits communication data by controlling a communication current flowing through a transmission path (i.e., through the high-voltage communicator 201, a communication line 8, the high-voltage communicator 211, the common line 6, and the high-voltage communicator 201 in that order). Specifically, the transmission circuit 420 does not inject a communication current into the transmission path while the level of a parallel output (PO) terminal of the communication driver IC 460 is high (H), and it injects a communication current into the transmission path while the level of the PO terminal of the communication driver IC 460 is low (L). The high level is, for example, 5 V and the low level is 0 V. The transfer circuit 420 comprises the PNP transistors 421 and 422, the resistors 423 to 425, the diode 426, a ground terminal 427 and the photocoupler 430.

[0034] The PNP transistor 421 is a switching element in which a current path (a path between an emitter and a collector) is arranged on the transmission path. The PNP transistor 421 is controlled to be in a conducting / non-conducting state opposite to that of the phototransistor 432 of the photocoupler 430. The emitter of the PNP transistor 421 is connected to a base of the PNP transistor 422 and to the second end of resistor 423. The collector of the PNP transistor 421 is connected to the first end of resistor 444 and to an anode of a light-emitting diode 451 of a photocoupler 450 in the receiver circuit 440. A base of the PNP transistor 421 is connected to a collector of the PNP transistor 422, a first end of the resistor 424 and an emitter of the phototransistor 432.

[0035] The PNP transistor 422, together with resistor 423, limits the communication current flowing through the transmission path. Resistor 423 is a current-limiting resistor placed on the transmission path. When the voltage between the emitter and the base of the PNP transistor 422 (the voltage across both ends of resistor 423) exceeds a saturation voltage (for example, 0.6 V) due to a communication current supplied by the DC power supply 400, the PNP transistor 422 is switched to the ON state. Then, current flows through resistor 424, and it is less likely to flow through the current path of the PNP transistor 421.This means that the upper limit of the communication current flowing through communication line 8, which connects the high-voltage communicator 201 of the external device 20 and the high-voltage communicator 211 of the communication adapter 21, is limited by the resistance value of resistor 423. As described above, the PNP transistor 422 and resistor 423 protect circuit elements (for example, the PNP transistor 421 and the photocoupler 450) of the high-voltage communicator 201.

[0036] Resistor 424 is a base resistor that limits the base current flowing through the PNP transistor 421. Resistor 424 is also a load resistor that limits the current flowing through the phototransistor 432. Resistor 425 limits the current flowing through the LED 431 of the photocoupler 430. One end of resistor 425 is connected to the anode of LED 431, and the other end of resistor 425 is connected to the PO terminal of the communication driver IC 460. Diode 426 is a rectifier element that conducts current in only one direction, from an anode to a cathode. Ground terminal 427 is a grounded terminal to which a ground potential is applied.

[0037] The photocoupler 430 is a component for the mutual electrical isolation of two circuits. The photocoupler 430 comprises the light-emitting diode (LED) 431 and the phototransistor 432. When a primary current flows through the LED 431 in the photocoupler 430, a secondary current flows through a current path of the phototransistor 432. Hereinafter, the current flowing through the LED 431 is referred to as the primary current, and the current flowing through the current path of the phototransistor 432 is referred to as the secondary current. Furthermore, a voltage applied between the anode and cathode of the LED 431 is referred to as the primary voltage, and a voltage applied between the emitter and collector of the phototransistor 432 is referred to as the secondary voltage.

[0038] When a primary voltage value is greater than or equal to a threshold value, the LED 431 supplies the primary current and emits light with an intensity corresponding to a current value of the primary current. The cathode of the LED 431 is connected to the ground terminal 427. The phototransistor 432 supplies the secondary current, corresponding to the secondary voltage and the intensity of the light emitted by the LED 431, from the collector to the emitter.

[0039] The operation of the transmission circuit 420 is described below. When the PO terminal of the communication driver IC 460 is high (H), current flows through the LED 431 via resistor 425. This turns the photocoupler 430 ON, and current supplied by the power supply 400 flows through the common line 6 via phototransistor 432, resistor 424, and diode 426. The voltage between the emitter and collector of phototransistor 432 in the ON state does not exceed the saturation voltage between the emitter and base of PNP transistor 421 (for example, about 0.6 V). Therefore, PNP transistor 421 turns OFF, and no communication current flows through the transmission path.

[0040] When the PO terminal of the communication driver IC 460 is at level L, no current flows through the LED 431. Thus, the photocoupler 430 is switched off, and the base current of the PNP transistor 421 flows via the common line 6 through resistor 424 and diode 426. This switches the PNP transistor 421 on, and a communication current flows through the transmission path.

[0041] The receiving circuit 440 is a circuit that receives communication data by monitoring a communication current flowing through the transmission path. Specifically, the receiving circuit 440 sets a parallel input (PI) terminal of the communication driver IC 460 to the high (H) level while the communication current flows through the transmission path, and sets the PI terminal of the communication driver IC 460 to the low (L) level when no communication current flows through the transmission path. The receiving circuit 440 comprises an NPN (negative-positive-negative) transistor 441, resistors 442 to 444, a power supply terminal 445, ground terminals 446 and 447, and the photocoupler 450.

[0042] The NPN transistor 441 is used to reduce the turn-off time of the photocoupler 450. One emitter of the NPN transistor 441 is connected to the ground terminal 446. One collector of the NPN transistor 441 is connected to the first end of resistor 442 and the PI terminal of the communication driver IC 460. One base of the NPN transistor 441 is connected to the first end of resistor 443 and to the collector of phototransistor 452 of the photocoupler 450. Resistor 442 pulls the PI terminal of the communication driver IC 460 high. The second end of resistor 442 is connected to the second end of resistor 443 and the power supply terminal 445.

[0043] Resistor 443 is a base resistor that limits the base current of the NPN transistor 441. Resistor 443 is also a load resistor that limits the current flowing through the phototransistor 452. Power supply terminal 445 is connected to power supply 200. The potential of power supply terminal 445 is the high level (for example, 5 V). Ground terminals 446 and 447 are grounded terminals to which ground potentials are applied. Ground terminals 446 and 447 can be considered to be connected together.

[0044] Resistor 444 acts as a threshold resistor for LED 451. This means that when the communication current is very low and the voltage between the two ends of resistor 444 is lower than the forward voltage of LED 451, all the communication current flows through resistor 444 and no communication current flows through LED 451. Conversely, when the communication current is high and the voltage between the two ends of resistor 444 is higher than or equal to the forward voltage of LED 451, the communication current also flows through LED 451. The other end of resistor 444 is connected to the cathode of LED 451 and the anode of diode 470.

[0045] The photocoupler 450 has essentially the same configuration as the photocoupler 430. The photocoupler 450 comprises the light-emitting diode 451 and the phototransistor 452. When the primary current flows through the light-emitting diode 451 in the photocoupler 450, the secondary current flows through a current path of the phototransistor 452.

[0046] The operation of the receiver circuit 440 is described below. When a communication current flows through the transmission path, current flows through the LED 451 and the photocoupler 450 is switched ON. Thus, current flows from the power supply terminal 445 via resistor 443 and phototransistor 452 through the ground terminal 447. This switches the NPN transistor 441 OFF, no current flows through resistor 442, and the PI terminal of the communication driver IC 460 is set to the high level.

[0047] If no communication current flows through the transmission path, no current flows through LED 451 and photocoupler 450 is switched off. Consequently, no current flows through phototransistor 452 and NPN transistor 441 is switched on. As a result, current flows through resistor 442 and the PI terminal of communication driver IC 460 is set to low (L). When photocoupler 510 of adapter 211 is switched on, a small communication current flows through the transmission path. However, when a communication current flows through the transmission path, the voltage drop across resistor 444 is small and no current flows through LED 451. That is, when the communication current is small, photocoupler 450 is switched off. In the following, a case where the communication current is small is considered equivalent to a case where no communication current flows.

[0048] The communication driver IC 460 controls the photocoupler 430 of the transmission circuit 420 to transmit communication data. The communication driver IC 460 receives communication data based on the status of the photocoupler 450 of the receiver circuit 440. The communication driver IC 460 includes the PO terminal, which outputs a voltage at the high (H) or low (L) level, and the PI terminal, which inputs a voltage at the high (H) or low (L) level. The communication driver IC 460 switches the voltage level applied to the PO terminal between the high (H) and low (L) levels according to the communication data to be transmitted. The communication driver IC 460 determines whether a voltage applied to the PI terminal is at the high (H) or low (L) level. The communication driver IC 460 may include a digital input / output terminal.

[0049] Diode 470 is a rectifier element that conducts current exclusively in one direction, from the anode to the cathode. Diode 470 blocks any reverse current that could flow through the transmission path due to wiring errors or similar issues. The cathode of diode 470 is connected to the anode of diode 541 in high-voltage communicator 211. High-voltage communicator 211

[0050] The high-voltage communicator 211 of the communication adapter 21 comprises a transmission circuit 500, a receiving circuit 520, a communication driver IC 540, a diode 541, and a constant-voltage diode 542. The transmission circuit 500 is a circuit that transmits communication data by controlling a communication current flowing through the transmission path. Specifically, the transmission circuit 500 does not inject any communication current into the transmission path while the level of a PO terminal of the communication driver IC 540 is high (H), and it injects a communication current into the transmission path while the level of the PO terminal of the communication driver IC 540 is low (L). The transmission circuit 500 includes a PNP transistor 501, resistors 502 to 504, a ground terminal 505, and the photocoupler 510.

[0051] The PNP transistor 501 is a switching element with a current path on the transmission line. The PNP transistor 501 is controlled to be in a conducting / non-conducting state opposite to that of the phototransistor 512 of the photocoupler 510. An emitter of the PNP transistor 501 is connected to a collector of the phototransistor 512 and a cathode of the diode 541. A collector of the PNP transistor 501 is connected to the first end of resistor 502. A base of the PNP transistor 501 is connected to the first end of resistor 503 and an emitter of the phototransistor 512.

[0052] Resistor 502 is a resistor that limits the communication current flowing through the transmission path. One end of resistor 502 is connected to the anode of a light-emitting diode 531 of a photocoupler 530 in the receiver circuit 520. Resistor 503 is a base resistor that limits the base current flowing through the PNP transistor 501. Resistor 503 is also a load resistor that limits the current flowing through the phototransistor 512. The resistance value of resistor 503 is sufficiently larger than the resistance value of resistor 502. Therefore, the current value of a communication current flowing through resistor 503 when the photocoupler 510 is in the ON state is sufficiently smaller than the current value of a communication current flowing through resistor 502 when the photocoupler 510 is in the OFF state.

[0053] In this configuration, the photocoupler 450 of the high-voltage communicator 201 is switched to the OFF state when the photocoupler 510 is switched to the ON state, and the photocoupler 450 is switched to the ON state when the photocoupler 510 is switched to the OFF state. A second end of the resistor 503 is connected to a cathode of the light-emitting diode 531 and an anode of the constant-voltage diode 542.

[0054] Resistor 504 limits the current flowing through the LED 511 of the photocoupler 510. In other words, resistor 504 protects the circuit elements (such as the PNP transistor 501 and the photocoupler 530) of the high-voltage communicator 211. One end of resistor 504 is connected to the anode of LED 511. The other end of resistor 504 is connected to the PO terminal of the communication driver IC 540. Ground terminal 505 is a grounded terminal to which a ground potential is applied. Ground terminal 505 is connected to the cathode of LED 511.

[0055] The photocoupler 510 has essentially the same configuration as the photocoupler 430 in the transmission circuit 420 of the high-voltage communicator 201. The photocoupler 510 comprises the light-emitting diode 511 and the phototransistor 512. When the primary current flows through the light-emitting diode 511 in the photocoupler 510, the secondary current flows through a current path of the phototransistor 512.

[0056] The operation of the transmission circuit 500 is described below. When the PO terminal of the communication driver IC 540 is high (H), current flows through the LED 511 via resistor 504. This turns the photocoupler 510 ON, and a communication current supplied by communication line 8 flows through common line 6 via phototransistor 512 and resistor 503. However, the resistance of resistor 503 is high, and therefore the communication current flowing through it is low. The voltage between the emitter and collector of phototransistor 512 in the ON state does not exceed the saturation voltage between the emitter and base of PNP transistor 501 (for example, about 0.6 V). Therefore, PNP transistor 501 turns OFF, and only a small amount of communication current flows through the transmission path.

[0057] When the PO terminal of the communication driver IC 540 is at level L, no current flows through the LED 511. Therefore, the photocoupler 510 is switched to the OFF state, and the base current of the PNP transistor 501 flows through the common line 6 via the resistor 503. This switches the PNP transistor 501 to the ON state, and a communication current flows through the transmission path.

[0058] The receiver circuit 520 is a circuit that receives communication data by monitoring a communication current flowing through the transmission path. Specifically, the receiver circuit 520 sets a PI terminal of the communication driver IC 540 to a high level (H) while a communication current flows through the transmission path, and sets the PI terminal of the communication driver IC 540 to a low level (L) while no communication current flows through the transmission path. The receiver circuit 520 comprises an NPN transistor 521, resistors 522 and 523, a power supply terminal 524, ground terminals 525 and 526, and the photocoupler 530.

[0059] The NPN transistor 521 is used to reduce the turn-off time of the photocoupler 530. One emitter of the NPN transistor 521 is connected to the ground terminal 525. One collector of the NPN transistor 521 is connected to the first end of resistor 522 and the PI terminal of the communication driver IC 540. One base of the NPN transistor 521 is connected to the first end of resistor 523 and to the collector of phototransistor 532 of the photocoupler 530. Resistor 522 pulls the PI terminal of the communication driver IC 540 high. The second end of resistor 522 is connected to the second end of resistor 523 and the power supply terminal 524.

[0060] Resistor 523 is a base resistor that limits the base current of the NPN transistor 521. Resistor 523 is also a load resistor that limits the current flowing through the phototransistor 532. Power supply terminal 524 is connected to the insulating power supply 210. The potential of power supply terminal 524 is the H level. Ground terminals 525 and 526 are grounded terminals to which ground potentials are applied. Ground terminals 525 and 526 can be considered to be connected together.

[0061] The photocoupler 530 has essentially the same configuration as the photocoupler 450 in the receiver circuit 440 of the high-voltage communicator 201. The photocoupler 530 comprises the light-emitting diode 531 and the phototransistor 532. When the primary current flows through the light-emitting diode 531 in the photocoupler 530, the secondary current flows through a current path of the phototransistor 532.

[0062] The operation of the receiver circuit 520 is described below. When a communication current flows through the transmission path, current flows through the LED 531 and the photocoupler 530 is switched ON. This allows current to flow from the power supply terminal 524 through the ground terminal 526, via resistor 523 and phototransistor 532. This switches the NPN transistor 521 OFF, prevents current from flowing through resistor 522, and sets the PI terminal of the communication driver IC 540 to the high level.

[0063] When no communication current flows through the transmission path, no current flows through LED 531 and photocoupler 530 is switched off. Consequently, no current flows through phototransistor 532 and NPN transistor 521 is switched on. As a result, current flows through resistor 522, and the PI pin of communication driver IC 540 is set to low (L).

[0064] The communication driver IC 540 controls the photocoupler 510 of the transmission circuit 500 to transmit communication data. The communication driver IC 540 receives communication data based on the status of the photocoupler 530 of the receiver circuit 520. The communication driver IC 540 includes the PO terminal, which outputs a voltage at the high (H) or low (L) level, and the PI terminal, which inputs a voltage at the high (H) or low (L) level. The communication driver IC 540 switches the level of the voltage applied to the PO terminal between the high (H) and low (L) levels according to the data to be transmitted. The communication driver IC 540 determines which of the high (H) and low (L) levels corresponds to the voltage applied to the PI terminal. The communication driver IC 540 may include a digital input / output terminal.

[0065] Diode 541 is a rectifier element that conducts current exclusively in one direction, from the anode to the cathode. Diode 541 blocks any reverse current that might flow through the transmission path due to wiring faults or similar issues. Constant voltage diode 542 is a diode that allows a small reverse current when a reverse voltage applied between the anode and cathode is lower than a breakdown voltage, and a rapid reverse current when the reverse voltage is higher than or equal to the breakdown voltage. Constant voltage diode 542 protects circuit elements (for example, PNP transistor 501, photocoupler 510, and photocoupler 530) of the high-voltage communicator 211.

[0066] Operation of the air conditioning system 1 Next, the operation relating to the sending and receiving of communication data in the air conditioning system 1 is described.

[0067] Transmission of communication data from the external device 20 to the internal device 30 (1) The external device 20 of the outdoor unit 2 transmits communication data to the communication adapter 21 via high-voltage communication. The communication data contains information specifying a transmission source and a transmission destination. (2) The communication adapter 21 receives the communication data from the external device 20 by means of high-voltage communication. (3) The communication adapter 21 transmits the communication data received from the external device 20 to the communication adapter 31 of the internal device 3 via low-voltage communication. (4) The communication adapter 31 of the indoor unit 3 receives the communication data from the communication adapter 21 of the outdoor unit 2 via low-voltage communication. (5) The communication adapter 31 transmits the communication data received from the external device 2 to the internal device 30 via high-voltage communication. (6) The internal device 30 receives the communication data from the communication adapter 31 by means of high-voltage communication. (7) The internal device 30 analyzes the received communication data and performs processing based on this communication data.

[0068] Transmission of communication data from the indoor device 30 to the outdoor device 20 (1) The internal device 30 of the indoor unit 3 transmits communication data to the communication adapter 31 via high-voltage communication. The communication data includes information specifying a transmission source and a transmission destination. (2) The communication adapter 31 receives the communication data from the internal device 30 by means of high-voltage communication. (3) The communication adapter 31 transmits the communication data received from the indoor device 30 to the communication adapter 21 of the outdoor device 2 via low-voltage communication. (4) The communication adapter 21 of the external device 2 receives the communication data via low-voltage communication from the communication adapter 31 of the internal device 3. (5) The communication adapter 21 transmits the communication data received from the indoor unit 3 to the outdoor device 20 via high-voltage communication. (6) The external device 20 receives the communication data from the communication adapter 21 via high-voltage communication. (7) The external device 20 analyzes the received communication data and performs processing based on this communication data.

[0069] As described above, the air conditioning system 1 in the present embodiment comprises the communication adapter 21, which performs high-voltage communication with the outdoor device 20 and low-voltage communication with a device different from the outdoor device 20, and the communication adapter 31, which performs high-voltage communication with the indoor device 30 and low-voltage communication with a device different from the indoor device 30. Therefore, if the outdoor device 20 and the communication adapter 21 are connected to each other, and the indoor device 30 and the communication adapter 31 are connected to each other at the factory, no high-voltage wiring work is required on site. Consequently, an expansion of sales channels into markets requiring low-voltage wiring between air conditioners is to be expected.

[0070] In the communication adapter 21, power is supplied from the external power supply 4 to the isolating power supply 210, but the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the indoor unit 3 side of the low-voltage communicator 212 has reinforced or double insulation from the external power supply 4. Similarly, in the communication adapter 31, although the isolating power supply 310 is powered by the external power supply 5, the input and output are electrically isolated from each other by reinforced insulation. Additionally, the connection interface on the outdoor unit 2 side of the low-voltage communicator 312 has reinforced or double insulation from the external power supply 5. This further promotes the expansion of distribution channels into the aforementioned markets. Design 2

[0071] Next, embodiment 2 of the present invention is described. In the following description, components common to embodiment 1 are designated with the same reference numerals, and the description of these components is omitted.

[0072] Fig. Figure 4 illustrates an overall configuration of an air conditioning system 1A in embodiment 2. The air conditioning system 1A is an example of the air conditioning system according to the present invention. The air conditioning system 1A is a system that, for example, performs the air conditioning of a building, such as an office building or a shop, and comprises an outdoor unit 2A and an indoor unit 3A. The air conditioning system 1A can comprise a plurality of indoor units 3A. Outdoor unit 2A

[0073] The outdoor unit 2A comprises an outdoor device 20A and a communication adapter 21A. The communication adapter 21A is located near the outdoor device 20A. The communication adapter 21A can be located inside a housing of the outdoor device 20A. External device 20A

[0074] The outdoor device 20A is an example of the air conditioner according to the present invention and an example of the outdoor device according to the present invention. Like the outdoor device 20 in embodiment 1, the outdoor device 20A comprises the power supply 200, the high-voltage communicator 201, the control unit 202, and the main unit of the outdoor device (not shown). The outdoor device 20A differs from the outdoor device 20 in that the outdoor device 20A is configured to supply power from the power supply 200 to the isolating power supply 210 of the communication adapter 21A. In all other respects, the configuration of the outdoor device 20A is the same as that of the outdoor device 20. Communication adapter 21A

[0075] The communication adapter 21A is an example of the communication adapter according to the present invention and an example of the adapter for the external device according to the present invention. Like the communication adapter 21 in embodiment 1, the communication adapter 21A comprises the isolating power supply 210, the high-voltage communicator 211, the low-voltage communicator 212, and the control unit 213. The communication adapter 21A differs from the communication adapter 21 in that the communication adapter 21A is configured to supply power from the power supply 200 of the external device 20A to the isolating power supply 210 instead of the external power supply 4. In all other respects, the configuration of the communication adapter 21A is the same as that of the communication adapter 21. Indoor unit 3A

[0076] The indoor unit 3A comprises an indoor device 30A and a communication adapter 31A. The communication adapter 31A is located near the indoor device 30A. The communication adapter 31A can be located within a housing of the indoor device 30A. Internal device 30A

[0077] The interior device 30A is an example of the air conditioning system according to the present invention and an example of the interior device according to the present invention. Like the interior device 30 in embodiment 1, the interior device 30A comprises the power supply 300, the high-voltage communicator 301, the control unit 302, and the interior device main unit (not shown). The interior device 30A differs from the interior device 30 in that the interior device 30A is configured to supply power from the power supply 300 to the isolating power supply 310 of the communication adapter 31A. In all other respects, the configuration of the interior device 30A is the same as that of the interior device 30. Communication adapter 31A

[0078] The communication adapter 31A is an example of the communication adapter according to the present invention and an example of the adapter for the indoor device according to the present invention. Like the communication adapter 31 in embodiment 1, the communication adapter 31A comprises the isolating power supply 310, the high-voltage communicator 311, the low-voltage communicator 312, and the control unit 313. The communication adapter 31A differs from the communication adapter 31 in that the communication adapter 31A is configured to supply power from the power supply 300 of the indoor device 30A to the isolating power supply 310 instead of the external power supply 5. In all other respects, the configuration of the communication adapter 31A is the same as that of the communication adapter 31.

[0079] As described above, the air conditioning system 1A in the present embodiment comprises the communication adapter 21A, which performs high-voltage communication with the outdoor unit 20A and low-voltage communication with a device different from the outdoor unit 20A, and the communication adapter 31A, which performs high-voltage communication with the indoor unit 30A and low-voltage communication with a device different from the indoor unit 30A. Therefore, when the outdoor unit 20A and the communication adapter 21A are connected, and the indoor unit 30A and the communication adapter 31A are connected, when shipped from the factory, no high-voltage wiring work is required on site. Consequently, an expansion of sales channels into markets requiring low-voltage wiring between air conditioners can be expected.

[0080] In communication adapter 21A, power is supplied from the power supply 200 of the outdoor unit 20 to the isolating power supply 210, but the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the indoor unit 3A side of the low-voltage communicator 212 has reinforced insulation or double insulation from the external power supply 4. Similarly, in communication adapter 31A, although power is supplied from the power supply 300 of the indoor unit 30A to the isolating power supply 310, the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the outdoor unit 2A side of the low-voltage communicator 312 has reinforced insulation or double insulation from the external power supply 5.This will further promote the expansion of distribution channels into the aforementioned markets.

[0081] The output voltage of power supply 200 of the external device (20A) is lower than the output voltage of external power supply 4. Therefore, the isolating power supply 210 in the adapter (21A) can be smaller. Similarly, the output voltage of power supply 300 of the internal device (30A) is lower than the output voltage of external power supply 5. Therefore, the isolating power supply 310 in the adapter (31A) can be smaller. embodiment 3

[0082] Next, embodiment 3 of the present invention is described. In the following description, components common to embodiment 1 are designated with the same reference numerals, and the description of these components is omitted.

[0083] Fig. Figure 5 illustrates an overall configuration of an air conditioning system 1B in embodiment 3. The air conditioning system 1B is an example of the air conditioning system according to the present invention. The air conditioning system 1B is a system that, for example, performs the air conditioning of a building, such as an office building or a shop, and comprises an outdoor unit 2B and an indoor unit 3B. The air conditioning system 1B can comprise a plurality of indoor units 3B. Outdoor unit 2B

[0084] The outdoor unit 2B comprises the outdoor device 20 and a communication adapter 21B. The communication adapter 21B is located near the outdoor device 20. The communication adapter 21B can be located inside the housing of the outdoor device 20. Communication adapter 21B

[0085] The communication adapter 21B is an example of the communication adapter according to the present invention and an example of the adapter for the external device according to the present invention. The communication adapter 21B comprises the isolating power supply 210, the high-voltage communicator 211, and a low-voltage communicator 212A. The low-voltage communicator 212A is an example of the second communicator according to the present invention. Like the low-voltage communicator 212 in embodiment 1, the low-voltage communicator 212A is a communication circuit for low-voltage communication with another device and comprises electronic components, for example, a transistor and a photocoupler, as well as a communication driver IC.

[0086] The low-voltage communicator 212A communicates with another device via full-duplex communication (for example, four-wire RS-485). A transmit signal line and a receive signal line are cross-connected between the high-voltage communicator 211 and the low-voltage communicator 212A, allowing them to be interchanged. As in embodiment 1, a connection interface on the side of the indoor unit 3B of the low-voltage communicator 212A has reinforced or double insulation for the external power supply 4. Indoor unit 3B

[0087] The indoor unit 3B comprises the indoor device 30 and a communication adapter 31B. The communication adapter 31B is located near the indoor device 30. The communication adapter 31B can be located inside the housing of the indoor device 30. Communication adapter 31B

[0088] The communication adapter 31B is an example of the communication adapter according to the present invention and an example of the adapter for the internal device according to the present invention. The communication adapter 31B comprises the isolating power supply 310, the high-voltage communicator 311, and a low-voltage communicator 312A. The low-voltage communicator 312A is an example of the second communicator according to the present invention and an example of the fourth communicator according to the present invention. Like the low-voltage communicator 312 in embodiment 1, the low-voltage communicator 312A is a communication circuit for low-voltage communication with another device and comprises electronic components, for example, a transistor and a photocoupler, as well as a communication driver IC.

[0089] The low-voltage communicator 312A communicates with another device via full-duplex communication (for example, four-wire RS-485). A transmit signal line and a receive signal line are cross-connected between the high-voltage communicator 311 and the low-voltage communicator 312A, allowing them to be exchanged. As in embodiment 1, a connection interface on the external device side 2B of the low-voltage communicator 312A has reinforced or double insulation for the external power supply 5.

[0090] Fig. Figure 6 is a timing diagram showing the operation of each of the communicators (high-voltage communicator 201, high-voltage communicator 211, low-voltage communicator 212A, high-voltage communicator 301, high-voltage communicator 311 and low-voltage communicator 312A) during the transmission of communication data from the external device 20 to the internal device 30 and during the transmission of communication data from the internal device 30 to the external device 20 in the air conditioning system 1B. Fig. 6. The ON state of a high-voltage communicator indicates a state in which the transmission path is conductive, i.e., a state in which a communication current flows through the transmission path, and the OFF state of a high-voltage communicator indicates a state in which the transmission path is non-conductive, i.e., no communication current flows through the transmission path.

[0091] As described above, the air conditioning system 1B in the present embodiment comprises the communication adapter 21B, which performs high-voltage communication with the outdoor unit 20 and low-voltage communication with a device other than the outdoor unit 20, and the communication adapter 31B, which performs high-voltage communication with the indoor unit 30 and low-voltage communication with a device other than the indoor unit 30. Therefore, when the outdoor unit 20 and the communication adapter 21B are connected and the indoor unit 30 and the communication adapter 31B are connected when shipped from the factory, no high-voltage wiring work is required on site. Consequently, an expansion of sales channels into markets requiring low-voltage wiring between air conditioners can be expected.

[0092] In communication adapter 21B, power is supplied from the external power supply 4 to the isolating power supply 210, but the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the indoor unit 3B side of the low-voltage communicator 212A has reinforced or double insulation from the external power supply 4. Similarly, in communication adapter 31B, although the isolating power supply 310 is powered by the external power supply 5, the input and output are electrically isolated from each other by reinforced insulation. Additionally, the connection interface on the outdoor unit 2B side of the low-voltage communicator 312A has reinforced or double insulation from the external power supply 5. This further promotes the expansion of sales channels into the aforementioned markets.

[0093] In communication adapter 21B, the low-voltage communicator 212A communicates with another device via full-duplex communication, and a transmit signal line and a receive signal line are cross-connected between the high-voltage communicator 211 and the low-voltage communicator 212A, allowing them to be exchanged. Therefore, in embodiment 1, communication adapter 21B does not require a control unit 213 and can thus be smaller. Similarly, in communication adapter 31B, the low-voltage communicator 312A communicates with another device via full-duplex communication, and a transmit signal line and a receive signal line are cross-connected between the high-voltage communicator 311 and the low-voltage communicator 312A, allowing them to be exchanged.Therefore, the communication adapter 31B in embodiment 1 does not require a control unit 313 and can therefore be smaller. Design 4

[0094] Next, embodiment 4 of the present invention is described. In the following description, components common to embodiment 1 are designated with the same reference numerals, and the description of these components is omitted.

[0095] Fig. Figure 7 shows an overall configuration of an air conditioning system 1C in embodiment 4. The air conditioning system 1C is an example of the air conditioning system according to the present invention. The air conditioning system 1C is a system that performs the air conditioning of, for example, a building, such as an office building or a shop, and comprises the outdoor device 2 and an indoor device 30B. The air conditioning system 1C can comprise a plurality of indoor devices 30B.

[0096] The indoor device 30B is an example of the indoor device according to the present invention. The indoor device 30B comprises an isolating power supply 303, a low-voltage communicator 304, the control device 302, and the indoor device main unit (not shown). The isolating power supply 303 is a power supply circuit in which the input and output are electrically isolated from each other by reinforced insulation and supply to each of the low-voltage communicators 304, the control unit 302, and the main device indoor unit the power required for their operation based on the power input from the external power supply 5.

[0097] The low-voltage communicator 304 is a communication circuit for low-voltage communication with another device and comprises electronic components, such as a transistor and a photocoupler, as well as a communication driver IC. A low-voltage communication protocol could be, for example, an unbalanced transmission such as RS232C, a differential transmission such as RS-485, or CAN, Ethernet (registered trademark), or the like. A connection interface on the side of the outdoor unit 2 of the low-voltage communicator 304 has reinforced insulation or double insulation to the external power supply 5.

[0098] As described above, the air conditioning system 1C in the present embodiment comprises the communication adapter 21, which performs high-voltage communication with the outdoor unit 20 and low-voltage communication with a unit other than the outdoor unit 20, and the indoor unit 30B, which is configured to perform low-voltage communication with a unit other than the outdoor unit 20. The factory connection of the outdoor unit 20 and the communication adapter 21 eliminates the need for on-site high-voltage wiring. Therefore, an expansion of sales channels into markets requiring low-voltage wiring between air conditioners is anticipated.

[0099] In the communication adapter 21, power is supplied from the external power supply 4 to the isolating power supply 210, but the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the side of the internal device 30B of the low-voltage communicator 212 has reinforced or double insulation from the external power supply 4. In the internal device 30B, power is supplied from the external power supply 5 to the isolating power supply 303, but the input and output are electrically isolated from each other by reinforced insulation. Additionally, the connection interface on the external device side 2 of the low-voltage communicator 304 has reinforced or double insulation from the external power supply 5. This further promotes the expansion of distribution channels into the aforementioned markets. Design 5

[0100] Next, embodiment 5 of the present invention is described. In the following description, components common to embodiment 1 are designated with the same reference numerals, and the description of these components is omitted.

[0101] Fig. Figure 8 shows an overall configuration of an air conditioning system 1D in embodiment 5. The air conditioning system 1D is an example of the air conditioning system according to the present invention. The air conditioning system 1D is a system that, for example, performs the air conditioning of a building, such as an office building or a shop, and comprises an outdoor unit 20B and the indoor unit 3. The air conditioning system 1D can comprise a plurality of indoor units 3.

[0102] The outdoor device 20B comprises an isolating power supply 203, a low-voltage communicator 204, the control device 202, and the outdoor device main unit (not shown). The isolating power supply 203 is a power supply circuit in which the input and output are electrically isolated from each other by reinforced insulation and supplies the power required for operation to each of the low-voltage communicators 204, the control unit 202, and the outdoor device main unit based on the power input from the external power supply 4.

[0103] The low-voltage communicator 204 is a communication circuit for low-voltage communication with another device and comprises electronic components, such as a transistor and a photocoupler, as well as a communication driver IC. A low-voltage communication protocol could be, for example, one-way transmission such as RS232C, differential transmission such as RS-485, or CAN, Ethernet (registered trademark), or the like. A connection interface on the indoor unit 3 side of the low-voltage communicator 204 has reinforced insulation or double insulation to the external power supply 4.

[0104] As described above, the air conditioning system 1D in the present embodiment comprises the outdoor device 20B, which is configured to perform low-voltage communication with another device, and the communication adapter 31, which performs low-voltage communication with a device other than the indoor device 30. The factory connection of the indoor device 30 and the communication adapter 31 thus eliminates the need for high-voltage wiring on site. Consequently, an expansion of sales channels into markets requiring low-voltage wiring between air conditioners is expected.

[0105] In the communication adapter 31, power is indeed supplied from the external power supply 5 to the isolating power supply 310, but the input and output are electrically isolated from each other by reinforced insulation. Furthermore, the connection interface on the side of the outdoor unit 20B of the low-voltage communicator 312 has reinforced or double insulation from the external power supply 5. In the outdoor unit 20B, power is indeed supplied from the external power supply 4 to the isolating power supply 203, but the input and output are electrically isolated from each other by reinforced insulation. Additionally, the connection interface on the side of the indoor unit 3 of the low-voltage communicator 204 has reinforced or double insulation from the external power supply 4. This further promotes the expansion of distribution channels into the aforementioned markets.

[0106] The present invention is not limited to the embodiments described above, and various modifications are of course possible without departing from the core of the present invention. For example, the technical ideas of the embodiments described above can be combined as required.

[0107] The foregoing describes some exemplary embodiments for explanatory purposes. Although specific embodiments have been presented in the preceding discussion, those skilled in the art will recognize that changes in form and detail can be made without departing from the general spirit and scope of the invention. Accordingly, the description and drawings are to be regarded as illustrative rather than limiting. This detailed description is therefore not to be understood as limiting, and the scope of the invention is defined only by the claims it comprises, together with the entire range of equivalents to which those claims refer. Industrial applicability

[0108] The present invention can be suitably applied to a system for air conditioning a building. List of reference symbols 1, 1A, 1B, 1C, 1D Air conditioning system 2, 2A, 2B Outdoor unit 3, 3A, 3B Indoor unit 4, 5 External power supply 6 Joint Management 7 Power line 8 Communication line 20, 20A, 20B External device 21, 21A, 21B, 31, 31A, 31B communication adapter 30, 30A, 30B Internal device 200, 300 energy suppliers 201, 211, 301, 311 High-voltage communicator 202, 213, 302, 313 Control unit 203, 210, 303, 310 Insulating energy supplier 204, 212, 212A, 304, 312, 312 Low-voltage communicator 220 CPU 221 ROM 222 RAM 223 I / O interface 224 Auxiliary storage device 400 DC power supply 401, 423, 424, 425, 442, 443, 444, 502, 503, 504, 522, 523 Resistance 402, 426, 470, 541 Diode 403, 542 Constant voltage diode 404 Electrolytic capacitor 420, 500 transmission circuit 421, 422, 501 PNP transistor 427, 446, 447, 505, 525, 526 Grounding connection 430, 450, 510, 530 photocouplers 431, 451, 511, 531 Light-emitting diode 432, 452, 512, 532 phototransistor 440, 520 receiving circuit 441, 521 NPN transistor 445, 524 Energy supply connection 460, 540 Communication Driver IC QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 6239143

[0004]

Claims

[1] A communication adapter comprising: a first communicator for communicating with an air conditioner on the basis of a first voltage; and a second communicator for communicating with a device different from the air conditioner, based on a second voltage lower than the first voltage, wherein The second communicator, based on the second voltage, transmits communication data received from the first communicator by the air conditioner to the device and The first communicator transmits communication data received from the device by the second communicator to the air conditioner based on the first voltage. [2] Communication adapter according to claim 1, further comprising: an isolating power supply in which the input and output are electrically isolated from each other, wherein the isolating power supply is configured to output power to operate the communication adapter based on the power supplied from an external power supply. [3] Communication adapter according to claim 1 or 2, wherein a connection interface with the device in the second communicator has reinforced insulation or double insulation for external power supply. [4] Communication adapter according to any one of claims 1 to 3, wherein the second communicator and the device communicate with each other via full-duplex communication and A transmission signal line and a reception signal line are connected between the first communicator and the second communicator in order to exchange information. [5] An air conditioning system, comprising: an external device for conducting communication based on a first voltage; an internal device for conducting communication based on the first voltage; an adapter for the external device; and an adapter for the indoor device, the adapter for the outdoor device comprising: a first communicator for communicating with the external device on the basis of the first voltage, and a second communicator for communicating with the adapter for the indoor device based on a second voltage that is lower than the first voltage, wherein the second communicator transmits communication data received from the first communicator at the external device to the adapter for the internal device based on the second voltage, The first communicator transmits communication data received from the second communicator via the adapter for the indoor device to the outdoor device based on the first voltage. The adapter for the internal device includes: a third communicator for communicating with the internal device based on the first voltage and a fourth communicator for communicating with the adapter for the external device based on the second voltage, wherein the fourth communicator, based on the second voltage, transmits communication data received from the third communicator of the indoor device to the adapter for the outdoor device and The third communicator, based on the first voltage, transmits communication data received by the fourth communicator from the adapter for the external device to the internal device. [6] An air conditioning system, comprising: an external device for conducting communication based on a first voltage; an internal device for conducting communication based on a second voltage that is lower than the first voltage; and a communication adapter, whereby The communication adapter includes: a first communicator for communicating with the external device based on the first voltage and a second communicator for communicating with the internal device based on the second voltage, wherein the second communicator transmits communication data received from the first communicator at the external device to the internal device based on the second voltage, and The first communicator transmits communication data received from the second communicator in the indoor device to the outdoor device based on the first voltage. [7] An air conditioning system, comprising: an internal device for carrying out communication based on a first voltage; an external device for conducting communication based on a second voltage that is lower than the first voltage; and a communication adapter, whereby the communication adapter includes a first communicator for communicating with the internal device based on the first voltage, and a second communicator for communicating with the external device based on the second voltage, wherein the second communicator transmits communication data received from the first communicator of the indoor device to the outdoor device based on the second voltage and The first communicator transmits communication data received from the external device by the second communicator to the internal device based on the first voltage.

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