JPH07332746A - Controller for air conditioner - Google Patents

Abstract

PURPOSE:To facilitate wiring work and installation work without requiring a wiring dedicated to communication by transmitting and receiving high-frequency information signals, which are superimposed on a predetermined DC voltage, through a DC power line connected between an indoor unit and an outdoor unit. CONSTITUTION:A DC power source, which converts an inputted AC voltage into a DC voltage and decreases the DC voltage to a level of 1/n(n>1) to produce a predetermined DC voltage, is provided in an outdoor unit 2. The predetermined DC voltage is supplied to an indoor unit 1 as a source voltage through a DC power line 16, and communication between the outdoor unit 2 and the indoor unit 1 is carried out through the DC power line 16 by superimposing a high-frequency information signal on the predetermined DC voltage. In this case, the outdoor unit 2 side end of a wiring on a high-potential side of the DC power line 16 is connected to the DC power source with the aid of a coil, and the indoor unit 1 side end thereof is connected, with the aid of a coil, to an apparatus to which the DC voltage is supplied as a source voltage. By imparting a high-frequency impedance to the DC power line 16, high-frequency information signals are transmitted to and received by the interiors of both the indoor unit 1 and the outdoor unit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for communicating information signals between an indoor unit and an outdoor unit in an air conditioner, and more particularly to communication through a power line between the indoor unit and the outdoor unit. The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner, in order to transmit information signals such as various setting signals and abnormality signals between indoor units and outdoor units, signal lines corresponding to the number of units to be controlled are called power lines. Was provided separately. For this reason, when installing the air conditioner, the wiring work becomes complicated and the installability is deteriorated. In particular, in the case of a multi-type air conditioner, a large number of power lines and signal lines are drawn out from the outdoor unit, which has the drawback of increasing the size and increasing the cost.

As a means for solving such a problem, as disclosed in, for example, Japanese Patent Laid-Open No. 57-55341, the DC power supply voltage is supplied to the DC power supply voltage via an electric power line for supplying the DC power supply voltage from the outdoor unit to the indoor unit. An air conditioner has been proposed in which an indoor unit and an outdoor unit communicate by superimposing a high-frequency information signal. This will be briefly described below with reference to FIG.

In the figure, the outdoor unit 100 is provided with a stabilized DC power supply circuit 101, which converts an AC voltage from the external power supply 300 into a DC voltage.
This DC voltage is supplied as a power supply voltage to the control unit 102 of the outdoor unit 100 and the control unit 201 of the indoor unit 200 via the power line 500. Further, the outdoor unit 100 is provided with a transmission / reception circuit 103 controlled by the control unit 102, and the transmission / reception terminal thereof is connected to the power line 500 via the filter capacitor 106. Also in the indoor unit 200, the transmission / reception circuit 20 controlled by the control unit 201
2 is provided, and its transmission / reception terminal is connected to the power line 500 via the filter capacitor 205.

The control unit 201 includes an input unit 204 such as a sensor.
Information from the remote controller (not shown) and information from a remote controller (not shown) to control the output device 203 such as a fan motor.
An information signal is sent to the transmission / reception circuit 202. This information signal is sent to the power line 500 via the filter capacitor 205 and is superimposed on the DC voltage of the power line 500 to generate the outdoor unit 100.
Be transmitted to. In the outdoor unit 100, this information signal is separated by the filter capacitor 106, and the transmitting / receiving circuit 1
It is received at 03 and sent to the control unit 102. Based on this information signal, the control unit 101 controls the output device 104 such as a compressor or a fan motor.

When the control unit 102 also takes in the abnormality information from the input unit 105 such as a sensor, it stops the output device 104 and sends an abnormality information signal to the transmission / reception circuit 103 to filter the filter capacitor 106 and the power line 500. Is transmitted to the indoor unit 200 via. Indoor unit 200
Then, this abnormality information signal is received by the transmission / reception circuit 202 via the filter capacitor 205 and sent to the control unit 201. The control unit 201 controls the output device 203 according to the abnormality information signal.

The output devices 104 and 203 are supplied with power supply voltages from external power supplies 300 and 400, respectively. An information signal from a remote controller (not shown) is transmitted via the power line 500, and the transmission / reception circuit 202 of the indoor unit 200 receives the information signal.

[0008]

By the way, in the above-mentioned prior art, the transmission / reception circuits 103 and 202 are simply coupled to the power line 500 by the filter capacitors 106 and 205, which is particularly important for communication. No consideration is given to how to obtain impedances at both ends of these filter capacitors 103 and 202 and frequency characteristics for communication. Therefore, if the wiring does not have sufficient high-frequency impedance, the transmission impedance must be extremely small in order to transmit the information signal, which leads to an increase in power consumption.

Further, since a common filter capacitor is used for transmission and reception, if the transmission impedance is made sufficiently small as described above, the input impedance during reception becomes extremely small. Therefore, a means for amplifying the information signal or a means for switching the impedance between the time of transmission and the time of reception is required, resulting in an increase in scale and a significant increase in cost.

Furthermore, since the high frequency information signal is superimposed on the DC voltage in the power line between the indoor unit and the outdoor unit, the noise terminal voltage of the power line and the wiring radiation noise increase. In order to avoid this, a means for sufficiently attenuating the harmonic components is required before the filter capacitor, and there is a problem that the scale becomes large and the cost increases.

An object of the present invention is to solve such a problem and to simplify the configuration so that the communication via the power line can be favorably carried out, and at the same time, the noise terminal voltage and the radiation noise from the power line are effective. Another object of the present invention is to provide a control device for an air conditioner capable of suppressing the above.

[0012]

In order to achieve the above object, the present invention converts an input AC voltage into a DC voltage in an outdoor unit and reduces the voltage to 1 / n (where n> 1) to a predetermined level. A direct current power supply for generating a direct current voltage is provided, the predetermined direct current power supply is supplied to the indoor unit as a power supply voltage through the direct current power line, and the high frequency information signal is superimposed on the predetermined direct current voltage, thereby the direct current power line. In an air conditioner configured to perform communication between the outdoor unit and the indoor unit via the, for supplying a DC voltage from the outdoor unit to the indoor unit and transmitting an information signal between the indoor unit and the outdoor unit. The end of the high-potential side wiring of the DC power line in the outdoor unit is a DC power source that generates the DC voltage through the coil or the primary winding of the high-frequency transformer, and the end of the indoor unit is a coil or high-frequency transformer. Via primary winding And a means for transmitting and receiving the information signal inside the indoor unit and the outdoor unit respectively via a coupling capacitor in the DC power line. Connect to the wiring on the high potential side or the secondary winding of the high frequency transformer.

Further, according to the present invention, in the indoor unit and the outdoor unit, a noise removing capacitor is provided between the high potential side wiring and the low potential side wiring of the DC power line.

[0014]

It is possible to superimpose the information signal on the DC voltage of the DC power line without significantly attenuating the first-order component of the high-frequency modulated information signal to be transmitted and suppressing the harmonic component of the information signal. Also, high-frequency noise that enters the DC power line can be suppressed, and noise terminal voltage and radiation noise of the DC power line can be effectively reduced. Therefore, a dedicated communication line is unnecessary, and the configuration is simplified, and good communication between the outdoor unit and the indoor unit is possible.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an air conditioner according to the present invention, in which 1 is an indoor unit, 2 is an outdoor unit, 3 is an indoor fan motor, 4 is an indoor fan motor drive unit, 5 is a control power supply, 6 is an indoor microcomputer, 7 is an indoor interface unit, 8 is an AC-DC converter, 9 is an outdoor fan motor drive unit, 10 is an outdoor fan motor, 11 is an inverter,
Reference numeral 12 is a compressor, 13 is a DC-DC converter, 14 is an outdoor interface section, 15 is an outdoor microcomputer, 16 is a DC power line, and 17 is an AC power line.

In the figure, the commercial AC voltage taken in by the indoor unit 1 is sent to the outdoor unit 2 via an AC power line 17. In the outdoor unit 2, this commercial AC voltage is converted into a DC voltage by the AC-DC converter 8. This DC voltage is
It becomes the power supply voltage for the outdoor fan motor drive unit 9 and the inverter 11, and also becomes 1 / n by the DC-DC converter 13.
(However, n> 1) times, and the voltage is supplied to the indoor unit 1 as a power supply voltage via the DC power line 16. In the indoor unit 1, the DC voltage supplied via the DC power line 16 is supplied to the indoor fan motor drive unit 4 as a power supply voltage, and is also supplied to the control power supply 5 to form the power supply voltage of the indoor microcomputer 6.

The outdoor unit 1 side of the DC power line 16 is connected to the A and B terminals of the outdoor interface unit 14, and the indoor unit 2 side is connected to the A and B terminals of the indoor interface unit 7. The C and D terminals of the outdoor interface unit 14 are connected to the outdoor microcomputer 15 and the F and E terminals are connected to the DC-DC converter 13, respectively, and the C and D terminals of the indoor interface unit 7 are connected to the indoor microcomputer 6 and F and E, respectively. The terminals are connected to the control power supply 5 and the indoor fan motor drive unit 4, respectively.
Therefore, the DC voltage output from the DC-DC converter 13 is applied to the outdoor interface unit 14 and the DC power line 1.
6, it is supplied to the indoor fan motor drive unit 4 and the control power source 5 via the indoor interface unit 7.

The outdoor microcomputer 15 is the indoor fan motor 10
The indoor microcomputer 6 controls the communication between the indoor unit 1 and the indoor unit 2 while controlling each part of the outdoor unit 2 such as the compressor and the compressor 12.
And controls communication with the outdoor unit 1.

When the information signal is transmitted from the outdoor unit 2 to the indoor unit 1, the information signal is output from the outdoor microcomputer 15, supplied to the outdoor interface unit 14, modulated into a high frequency signal, and supplied to the DC power line 16. DC-DC
It is superimposed on the DC voltage supplied from the converter 13.
As a result, the information signal is transmitted to the indoor unit 2 via the DC power line 16 and is received and demodulated by the indoor interface unit 7. The demodulated information signal is sent to the indoor microcomputer 6. Similarly, when the information signal is transmitted from the indoor unit 1 to the outdoor unit 2, the information signal is similarly output from the indoor microcomputer 6, modulated into a high frequency signal by the indoor interface unit 7, and supplied to the DC power line 16 to be DC-DC. It is superimposed on the DC voltage supplied from the converter 13. As a result, the information signal is transmitted to the outdoor unit 1 via the DC power line 16 and is received and demodulated by the outdoor interface unit 14. The demodulated information signal is sent to the outdoor microcomputer 15.

FIG. 2 shows the outdoor interface unit 1 shown in FIG.
4 is a circuit configuration diagram showing a specific example of 4, wherein 18 is a high frequency generation circuit, 19 is a modulation circuit, 20 is a signal output circuit, 21
1 is a receiving / demodulating circuit, L1 is a coil, C1 is a high frequency noise removing capacitor, C2 is a receiving coupling capacitor, and C3 is a transmitting coupling capacitor.
The same reference numerals are attached to the portions corresponding to.

In the figure, a coil L1 is provided between terminals A and F.
Are connected to each other, so that the DC power line 16 (FIG. 1) has a high frequency impedance. Also, the coil L1
A high frequency noise removing capacitor C1 is connected between terminals A and B on the DC power line 16 side. The signal output circuit 20 includes resistors R1, R2 and a transistor TR connected in series between a power supply terminal and a ground terminal.
The connection point of R1 and R2 is a coupling capacitor C3 for transmission.
The base of the transistor TR is connected to the output terminal of the modulation circuit 19. The input terminal of the modulation circuit 19 is the outdoor microcomputer 1 of FIG.
Connected to 5. A high frequency signal is also supplied to the modulation circuit 19 from the high frequency generation circuit 18 as a carrier wave. The input terminal of the reception modulation circuit 21 is connected to the A terminal via the reception coupling capacitor C2, and the output terminal is connected to the outdoor microcomputer 15 of FIG. 1 via the C terminal.

The indoor interface section 7 of FIG.
Also has the same configuration.

Next, the communication control operation of this embodiment having such a configuration will be described. First, the communication of the information signal when the set temperature is changed by the remote controller will be described.

In FIG. 1, when the information signal for setting the predetermined temperature is input from the remote controller, the indoor microcomputer 6 analyzes the content thereof. If the information content is a change in the set temperature, the rotation speed of the indoor fan motor 3 is controlled, the rotation speeds of the outdoor fan motor 10 and the compressor 12 are calculated, and data corresponding to the values is created. . This data is output from the indoor microcomputer 6 as an information signal and supplied from the D terminal to the indoor interface section 7.

FIG. 3A shows a specific example of the format of such data. For example, one frame consists of 8 bits D0 to D7, a start bit ST is at the beginning and a stop bit is at the end. Each SP is added. The data is sequentially generated by the indoor microcomputer 6 in such frame units.

FIG. 3B shows a concrete example of the waveform of the information signal output from the indoor microcomputer 6 for the data shown in FIG. 3A. Here, the start bit ST is set to "L". "(Low level), stop bit SP
Is set to "H" (high level), and the data bits D0 to D7 are set to "H", depending on "1" and "0" bits.
The level is different from "L". For example, the data of this frame is (11000010).

The information signal shown in FIG. 3B is input from the D terminal to the indoor interface section 7 having the configuration shown in FIG. 2 and supplied to the modulation circuit 19. In this modulation circuit 19, the frequency f (for example, f = 3
A high frequency carrier wave of 8 kHz is supplied, and the information signal described above is modulated (for example, amplitude modulated). Figure 3 (c)
Shows the waveform of the modulated information signal output from the modulation circuit 19 in the case of amplitude modulation. The “H” period of the information signal before modulation shown in FIG. 3B is 0 level,
The "L" period is a high-frequency carrier signal that oscillates around the 0 level.

This modulated information signal is sent to the signal output circuit 2
0 is supplied to the base of the transistor TR, and the resistance R1,
It is output from the connection point of R2. The signal output circuit 20 has a low output impedance (for example, several tens of Ω), and the modulated information signal output from the signal output circuit 20 is supplied to the DC power line 16 via the transmission coupling capacitor C3 and superimposed on the DC voltage there. Transmitted.

The transmitted modulated information signal is transmitted to the outdoor interface section 14 having the configuration shown in FIG.
2 is supplied to the reception demodulation circuit 21 via the reception coupling capacitor C2 and demodulated into an information signal having the waveform shown in FIG. This demodulated information signal is supplied from the C terminal to the outdoor microcomputer 15 shown in FIG. The outdoor microcomputer 15 analyzes the received data sequence and operates the compressor 12 and the outdoor fan motor 10 at a predetermined rotation speed.

Further, the outdoor unit 1 returns data such as operating conditions and an abnormal signal to the indoor unit 2, and the communication procedure is the same as above.

Here, as shown in FIG. 2, the DC power line 16 has an impedance with respect to the information signal modulated by the coil L1. Therefore, the DC power line 16
The transfer function K0 at the frequency of the first order component of the modulated information signal for is approximately represented by the following equation.

[0032]

[Equation 1]

Here, f0 with respect to the above-mentioned carrier frequency f.
By setting ≦ f and C1 <C3, the primary component of the modulated information signal is not significantly attenuated,
It becomes possible to superimpose it on the DC voltage with the DC power line 16.

The modulated information signal output from the signal output circuit 20 contains harmonic components. Therefore,
By sufficiently increasing the input impedance of the reception demodulation circuit 21, the transfer function K1 at the frequency of this harmonic component with respect to the DC power line 16 is represented by the following equation, where R is the output impedance of the signal output circuit 20.

[0035]

[Equation 2]

FIG. 4 shows the signal output circuit 20 to the DC power line 1
It is a figure which shows the gain characteristic of the transfer function to 6 and, as can be seen from this, frequency f1 (for example, 200 kHz)
It is possible to suppress the above harmonic components.

When high frequency noise enters between the F and E terminals, the transfer function K2 from the F terminal to the A terminal is approximately represented by the following equation if the frequency is sufficiently high.

[0038]

[Equation 3]

Therefore, the frequency f2 (for example, 60 kHz)
It is possible to suppress higher harmonic components than z).

By the noise removing capacitor C1, not only the harmonic components of the modulated information signal but also the control power source 5
Even high-frequency noise from the (FIG. 1) side can be suppressed, and noise terminal voltage and radiation noise can be effectively reduced.

FIG. 5 is a circuit configuration diagram showing another specific example of the indoor interface section 7 and the outdoor interface section 14 in FIG. 1, in which L2 is a high frequency transformer, and the portions corresponding to those in FIG. Attached.

In this drawing, a high frequency transformer L2 is used in place of the coil L1 in FIG. 2, and a reception demodulation circuit 21 is provided on the secondary side of the high frequency transformer L2 via a reception coupling capacitor C2. Further, the signal output circuits 20 are respectively connected via the transmission coupling capacitor C3, and the other configurations are similar to those of the specific example shown in FIG.

In this specific example, the same effect as that of the specific example shown in FIG. 2 can be obtained.
By using 2, the outdoor microcomputer 15 DC power line 1
Insulation from the external microcomputer 15 can be achieved at the same time, and there is no need to insulate the transmission signal from the outdoor microcomputer 15, so that the circuit configuration becomes simple.

FIG. 6 is a block diagram showing another embodiment of the control device for an air conditioner according to the present invention. The indoor interface section 7 has the structure shown in FIG. The section 14 has the configuration shown in FIG. 5 using the high frequency transformer L2.

That is, since it is not necessary to insulate the signal on the indoor unit 2 side, the coil L having a cheaper circuit configuration is provided.
2 in which the configuration shown in FIG. 2 using 1 is used, and the signal isolation is required, the configuration shown in FIG. 5 is used, and the circuit isolation is performed using the high-frequency transformer L2 to provide the configuration shown in FIG. The power source of the signal output circuit 20 and the like can be shared with the power source of the outdoor microcomputer 15, and in the modulation circuit 19, a component for insulating the information signal from the outdoor microcomputer 15 can be deleted. Therefore, compared with the case where the circuit system of the interface units 7 and 14 of the indoor unit 2 and the outdoor unit 1 is unified to either one of FIGS.
Furthermore, the overall configuration is simplified, and the cost reduction effect is great.

Further, as shown in FIG. 5, a high frequency transformer L
By using 2 to insulate the circuit, the microcomputer 6
The high-frequency generating circuit 1 outputs the information signal after high-frequency modulation from
8 and the modulation circuit 19 are not needed, and the circuit configuration is further simplified.

FIG. 7 is a block diagram showing an outdoor unit side in still another embodiment of the control device for an air conditioner according to the present invention. 1A and 1B are indoor units, 14A and 14B are outdoor interface units, and 16A. , 16B are DC power lines, and parts corresponding to those in FIG.

This embodiment corresponds to a multi-system, and in FIG. 7, two indoor units 1A and 1B of the outdoor unit 1 are used.
Shows the case where is connected. In this case, the DC power lines wired from the outdoor unit 1 are the indoor units 1A and 1A, respectively.
Two DC power lines 16A, 16B wired between B and
The installation is greatly improved.

Further, here, since the AC power source is directly connected to the outdoor unit 2, the AC power line 17 between the indoor unit 2 and the outdoor unit 1 as in the embodiment shown in FIG. And the installability is further improved.

The DC-DC converter 13 has a DC voltage output terminal separately for each of the outdoor interface sections 14A, 14B. In the outdoor interface units 14A and 14B, as shown in FIG.
The signal output circuit and the like are galvanically isolated from the DC power lines 16A and 16B by the high frequency transformer. Therefore, the signal output circuits of the outdoor interface units 14A and 14B can share the power source with the outdoor microcomputer 15, and the configuration is simple. Therefore, the cost reduction effect becomes large.

The above means that three or more indoor units are the outdoor units 1.
The same applies when connected to.

In the embodiment shown in FIG. 7, DC-D
The C converter 13 is provided with DC voltage output terminals for each of the plurality of outdoor interface units. However, as shown in FIG. 8, the DC-DC converter 13 is provided with a single output terminal, and a plurality of output terminals are provided from this output terminal. A DC voltage may be commonly supplied to the outdoor interface unit.

[0053]

As described above, according to the present invention,
Since the information signal is superimposed on the DC voltage and transmitted / received via the DC power line connected between the indoor unit and the outdoor unit, dedicated wiring for communication is not required and the number of wires between the indoor unit and the outdoor unit is small. Therefore, the wiring work and the installation work can be facilitated and the cost can be reduced.

Further, in the outdoor unit, the DC voltage is stepped down by the DC-DC converter to obtain a predetermined DC voltage, so that low voltage parts can be used as the parts such as the coupling capacitor and the cost can be reduced. It will be possible.

Furthermore, since the noise removing capacitor is inserted between the DC power lines, the harmonic components of the information signal to be transmitted are attenuated and the noise from the DC power source output through the coil is attenuated on the DC power lines. It is possible to obtain a great effect in suppressing noise terminal voltage and radiation noise from the DC power line.

Furthermore, when a high-frequency transformer is used in the signal output circuit, the high-frequency transformer insulates between the primary and the secondary, so that a circuit for insulation is not required, and the number of circuit parts is reduced. Since it can be reduced and the control power source such as the microcomputer can be shared, the effect of reducing the mounting area and the cost is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a control device for an air conditioner according to the present invention.

FIG. 2 is a circuit configuration diagram showing a specific example of an indoor interface unit and an outdoor interface unit in FIG.

FIG. 3 is a diagram showing a specific example of an information signal in the embodiment shown in FIG.

4 is a diagram showing a gain characteristic of a transfer function from the signal output circuit in FIG. 2 to a DC power line.

5 is a circuit configuration diagram showing another specific example of the indoor interface unit and the outdoor interface unit in FIG.

FIG. 6 is a block diagram showing another embodiment of the control device for an air conditioner according to the present invention.

FIG. 7 is a block diagram showing still another embodiment of the control device for the air conditioner according to the present invention.

FIG. 8 is a block diagram showing still another embodiment of the control device for an air conditioner according to the present invention.

FIG. 9 is a block diagram showing an example of a control device for a conventional air conditioner.

[Explanation of symbols]

 1, 1A, 1B Indoor unit 2 Outdoor unit 3 Indoor fan motor 4 Fan motor drive section 5 Control power supply 6 Indoor microcomputer 7 Indoor interface section 8 AC-DC converter 9 Outdoor fan motor drive section 10 Outdoor fan motor 11 Inverter 12 Compressor 13 DC-DC converter 14, 14A, 14B outdoor interface unit 15 outdoor microcomputer 16, 16A, 16B DC power line 17 AC power line 18 high frequency generation circuit 19 modulation circuit 20 signal output circuit 21 reception demodulation circuit L1 coil C1 noise removal capacitor C2 reception Coupling Capacitor C3 Transmission Coupling Capacitor L2 High Frequency Transformer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhito Miura 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Living Equipment Division, Hitachi, Ltd.

Claims (9)

[Claims] 1. An outdoor unit is provided with a DC power source for converting an input AC voltage into a DC voltage and reducing the DC voltage to 1 / n (where n> 1) to generate a predetermined DC voltage. The predetermined DC power source is supplied as a power supply voltage to the indoor unit via the DC power line, and by superimposing a high frequency information signal on the predetermined DC voltage, the outdoor unit and the indoor unit are connected via the DC power line. In the air conditioner configured to perform communication between the two, the end of the high-potential-side wiring in the DC power line inside the outdoor unit is connected to the DC power source via the coil, and the end inside the indoor unit is connected via the coil. Coupling means for transmitting and receiving the information signal inside the indoor unit and the outdoor unit by respectively connecting the devices to which the DC voltage is supplied as a power supply voltage and having a high-frequency impedance in the DC power line. Through the capacitor Control device for an air conditioner which is characterized in that connected to the wiring of the high potential side of the flow power line. 2. The control device for an air conditioner according to claim 1, wherein a noise removing capacitor is provided between the high potential wiring and the low potential side wiring of the DC power line. 3. An outdoor unit is provided with a DC power source for converting an input AC voltage into a DC voltage and reducing the DC voltage to 1 / n (where n> 1) to generate a predetermined DC voltage, The predetermined DC power source is supplied as a power supply voltage to the indoor unit via the DC power line, and by superimposing a high frequency information signal on the predetermined DC voltage, the outdoor unit and the indoor unit are connected via the DC power line. In the air conditioner adapted to perform communication between the DC power line, the end of the high-potential side wiring in the outdoor unit inside the outdoor unit is connected to the DC power source through the primary winding of the high frequency transformer, and the end inside the indoor unit. Units are respectively connected to the equipment to which the DC voltage is supplied as a power supply voltage via the primary side winding of the high frequency transformer, and the DC power line is provided with a high frequency impedance, inside the indoor unit and the outdoor unit, To send and receive the information signal Control of the means through the coupling capacitor air conditioner being characterized in that connected to the secondary winding of the high-frequency transformer. 4. The control device for an air conditioner according to claim 3, wherein a noise removing capacitor is provided between the high potential wiring and the low potential wiring of the DC power line. 5. An outdoor unit is provided with a DC power source for converting an input AC voltage into a DC voltage and reducing the DC voltage to 1 / n (where n> 1) to generate a predetermined DC voltage. The predetermined DC power source is supplied as a power supply voltage to the indoor unit via the DC power line, and by superimposing a high frequency information signal on the predetermined DC voltage, the outdoor unit and the indoor unit are connected via the DC power line. In the air conditioner adapted to perform communication between the DC power line, the end of the high-potential side wiring in the outdoor unit inside the outdoor unit is connected to the DC power source through the primary winding of the high frequency transformer, and the end inside the indoor unit. Units are respectively connected via a coil to the equipment to which the DC voltage is supplied as a power supply voltage so that the DC power line has a high frequency impedance, and in the indoor unit, means for transmitting and receiving the information signal is a coupling capacitor. Through In the outdoor unit, the means for transmitting and receiving the information signal is connected to the high potential side wiring of the DC power line, and is connected to the secondary side winding of the high frequency transformer via a coupling capacitor. Air conditioner control device. 6. The control device for an air conditioner according to claim 5, wherein a noise removing capacitor is provided between the high potential wiring and the low potential side wiring of the DC power line. 7. The transmission information signal supplied to the secondary winding of the high frequency transformer according to claim 3, wherein the transmission information signal is an information signal that is high frequency modulated inside a microcomputer. Air conditioner control device. 8. The indoor unit according to claim 1, wherein a plurality of the indoor units are provided, the DC power line is connected from the outdoor unit to each of the indoor units, and the DC unit of the outdoor unit is connected. A control device for an air conditioner, wherein a power source outputs a DC voltage for each of the DC power lines. 9. The indoor unit according to claim 1, wherein a plurality of the indoor units are provided, the DC power line is connected from the outdoor unit to each of the indoor units, and the DC unit of the outdoor unit is connected. A controller for an air conditioner, wherein a power source outputs a DC voltage commonly to each of the DC power lines.