JP3323640B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner of an indoor / outdoor unit separated type.

[0002]

2. Description of the Related Art The applicant has previously provided a modem circuit in an indoor unit and an outdoor unit, and sends a DC voltage generated by the outdoor unit to the indoor unit via a connection line, and a power supply voltage in the indoor unit. An indoor / outdoor air separation type air conditioner was proposed. Hereinafter, such an air conditioner will be described with reference to FIG.
However, in FIG. 5, 1 is a compressor, 2 is an indoor heat exchanger,
3 is an outdoor heat exchanger, 4 is a switching valve, 5 is a decompressor, 6 is an indoor blower, 7 is an outdoor blower, 8 is a commercial power supply, 9 is an indoor control circuit, 10 is an outdoor control circuit, 11 is a DC power supply circuit, 12
-A and 12-b are modulation / demodulation circuits, 13-a and 13-b are oscillation circuits, 14 is an indoor unit, 15 is an outdoor unit, 16 and 17 are connection lines, 18-a and 18-b are inductors, and 19- a, 1
9-b is a capacitor, 22 is an indoor power supply circuit, and 23 and 24
Is an outdoor power supply circuit, and 25 is a photocoupler.

In FIG. 5, a refrigeration cycle is constituted by a compressor 1, an indoor heat exchanger 2, an outdoor heat exchanger 3, a switching valve 4, and a pressure reducer 5. In the indoor unit 14, the indoor blower 6 is arranged in the indoor heat exchanger 2 in this refrigeration cycle, and in the outdoor unit 15, the outdoor blower 7 is also arranged in the outdoor heat exchanger 3.

Two connection lines 16 and 17 are provided between the indoor unit 14 and the outdoor unit 15, and one connection line 1
Reference numeral 6 denotes an indoor unit 14 which is connected to an outlet (not shown) in the room. Thereby, the commercial power supply voltage from the commercial power supply 8 is received by the indoor unit 14 and transmitted to the outdoor unit 15 via the connection line 16. In the outdoor unit 15, a DC power supply circuit 11 is provided, to which a commercial power supply voltage is supplied to form a DC voltage. This DC voltage is supplied to the outdoor power supply circuit 24.
To the indoor unit 14 via the connection line 17.
And becomes the power supply voltage of the indoor blower 6,
For example, 5 is supplied to the indoor power supply circuit 22 for the indoor control circuit 9, the modulation / demodulation circuit 12-a, the oscillation circuit 13-a, and the like.
V DC power supply voltage is formed. The indoor blower 6 is 30 ~
Since it operates at 40V, the DC power supply circuit 11
V DC voltage.

In the outdoor unit 15, the outdoor power supply circuit 24 forms a DC power supply voltage of, for example, 5 V for the modulation / demodulation circuit 12-b and the oscillation circuit 13-b. Further, an outdoor power supply circuit 23 is provided, whereby a DC power supply voltage of, for example, 5 V for the outdoor control circuit 10 is formed from the commercial power supply voltage from the connection line 16. The DC power supply circuit 11 is provided with a switching transformer, and is supplied with a commercial power supply voltage via the switching transformer, so that the DC power supply circuit 11 is insulated from the commercial power supply 8 in a DC manner.

The indoor control circuit 9 controls the operation of the compressor 1 and controls the indoor blower 6 and the outdoor blower 7 in accordance with the relationship between the indoor temperature detected by the temperature sensor and the set temperature. This is for performing control.
The outdoor control circuit 10 controls the outdoor unit 15 according to a command from the indoor control circuit 9. Therefore, communication of information signals between the indoor control circuit 9 and the outdoor control circuit 10 is necessary.
2-a and an oscillation circuit 13-a, and the outdoor unit 15 is provided with a modulation / demodulation circuit 12-b and an oscillation circuit 13-b, respectively.

The communication of the information signal is performed via a connection line 17 for transmitting a DC voltage. For this reason, in the indoor unit 14, the modulation / demodulation circuit 12-a is connected to one electric wire 17-a of the connection line 17 via the DC blocking capacitor 19-a. The other electric wire 17b is grounded. The information signal output from the transmission terminal of the indoor control circuit 9 is supplied to a modulation / demodulation circuit 12-a, and a carrier wave from the oscillation circuit 13-a is modulated to form a transmission information signal. This transmission information signal is supplied to the electric wire of the connection line 17 via the capacitor 19-a, is superimposed on the DC voltage there, and is transmitted to the outdoor unit 15 via the connection line 17.

[0008] An inductor 18-a is provided between the connection point of the capacitor 19-a on the electric wire 17-a of the connection line 17 and the indoor blower 6, and an information signal transmission portion of the electric wire 17-a is provided. The indoor blower 6 is separated from the indoor blower 6 in an alternating manner so that a transmission information signal does not flow into the indoor blower 6. Moreover, the indoor blower 6 is more than the inductor 18-a.
On the side, the DC voltage on the connection line 7 is supplied to the indoor power supply circuit 22. As described above, even during transmission of the information signal,
The DC power supply voltage of each electrical component such as the indoor blower 6 and the indoor control circuit 9 is stable.

The above is the technique proposed earlier.

In the outdoor unit 15, the outdoor power supply circuit 23 generates a DC power supply voltage of 5 V necessary for the operation of the outdoor control circuit 10 from the commercial power supply voltage from the commercial power supply 8 and supplies the DC power supply voltage to the outdoor control circuit 10. To do it. In this case, it is conceivable that the DC power supply voltage of 5 V is also supplied to the modulation / demodulation circuit 12-b and the oscillation circuit 13-b, but the ground line of the outdoor power supply circuit 23 is electrically connected to the commercial power supply 8. Therefore, the DC power supply voltage of 5 V obtained by the outdoor power supply circuit 23 is used for the modulation / demodulation circuit 12-b and the oscillation circuit 13-b.
b, the outdoor power supply circuit 23 and the modem circuit 12
-B and the oscillation circuit 13-b, a high voltage from the commercial power supply 8 is applied to the indoor unit 14 through the connection line 17,
There is a risk of electric shock on the indoor unit 14 side. For this reason, the power supply voltage of the modulation / demodulation circuit 12-b and the oscillation circuit 13-b is, as shown in FIG.
Another outdoor power supply circuit 24 for generating a DC power supply voltage of 5 V from the low-voltage DC voltage is supplied to the modulation / demodulation circuit 12-b and the oscillation circuit 13-b.

The modulation / demodulation circuit 12-b also has an oscillation circuit 13-b
Is modulated with an information signal from the transmission terminal of the outdoor control circuit 10 to generate a transmission information signal, and the transmission information signal is sent to the electric wire 17-a via the capacitor 19-b and superimposed on a DC voltage, The signal is transmitted to the indoor unit 14 via the electric wire 17-a.

In this outdoor unit, the connection line 17 is also provided.
An inductor 18-b is provided between the connection point of the capacitor 19-b on the electric wire 17-a and the DC power supply circuit 11,
The information signal transmitting portion of the electric wire 17-a and the DC power supply circuit 11 are separated in an AC manner so that the transmission information signal does not flow into the DC power supply circuit 11. The DC voltage is supplied to the outdoor power supply circuit 24 on the DC power supply circuit 11 side of the inductor 18-b. From the above,
During the transmission of the information signal, the operation of the DC power supply circuit 11 is stabilized, and the DC power supply voltage of the modulation / demodulation circuit 12-b and the oscillation circuit 13-b is also stabilized.

In the indoor unit 14, the transmission information signal sent from the outdoor unit 15 via the connection line 17 is separated from the DC voltage by the capacitor 19-a, demodulated by the modulation / demodulation circuit 12-a, and received by the reception terminal. To the indoor control circuit 9. Similarly, also in the outdoor unit 15, the transmission information signal sent from the indoor unit 14 via the connection line 17 is separated from the DC voltage by the capacitor 19-b, demodulated by the modem circuit 12-b, and received. It is supplied to the outdoor control circuit 10 from the terminal.

Here, the outdoor control circuit 10 and the modem circuit 1
The exchange of the information signal with the 2-b
Is done through Therefore, the outdoor control circuit 10 and the modulation / demodulation circuit 12-b are electrically insulated from each other, and even if a high voltage of the commercial power supply 8 is applied to the outdoor control circuit 10,
And does not join the indoor unit 14. Therefore, there is no electric shock on the indoor unit 14 side.

[0015]

In the above-mentioned air conditioner, the outdoor unit 15 is provided with an outdoor power supply circuit 24 and a photocoupler 25 in order to prevent an electric shock due to a high voltage in the indoor unit 14. As a result, an increase in the number of parts, an increase in manufacturing cost, and an increase in circuit scale become problems.

An object of the present invention is to solve such a problem, secure communication between the indoor control circuit and the outdoor control circuit, and reduce the number of parts, the manufacturing cost, and the circuit scale. Another object of the present invention is to provide an air conditioner capable of maintaining electrical insulation between an indoor control circuit and an outdoor control circuit.

[0017]

In order to achieve the above object, according to the present invention, in an outdoor unit and an indoor unit, a connection between a modulation / demodulation circuit and a connection line for transmitting a DC voltage is made via a transformer.

[0018]

The modulation / demodulation circuit modulates a high-frequency carrier generated by the oscillation circuit with an information signal output from the indoor control circuit or the outdoor control circuit, and supplies the modulated signal to the primary side of the transformer. The same information signal as that of the primary side is output from the secondary side of the transformer, and is superimposed on the DC voltage for driving the indoor unit and transmitted.

Therefore, since the indoor control circuit and the outdoor control circuit are DC-insulated by the transformer, the outdoor unit does not need to be insulated by the photocoupler, so that the photocoupler is unnecessary and the variable tone circuit is not required. Since the power supply voltage of 5 V for the oscillator and the oscillation circuit may be supplied from the same outdoor power supply circuit as the outdoor control circuit, the outdoor power supply circuit for the outdoor control circuit, the modulation / demodulation circuit, and the oscillation circuit can be shared.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of an air conditioner according to the present invention, wherein 20-a and 20-b are transformers,
Reference numerals 6-a and 26-b denote capacitors, and portions corresponding to those in FIG.

In the figure, in the outdoor unit 15, the outdoor power supply circuit 23
A DC power supply voltage of V is formed and supplied to the outdoor control circuit 10, the modulation / demodulation circuit 12-b, the oscillation circuit 13-b, and the like. The modulation / demodulation circuit 12-b is connected to the non-grounded electric wire 17-a of the connection line 17 by a transformer 20-b via a capacitor 26-b. Also, the outdoor control circuit 1
0 transmission terminal and reception terminal are directly connected to the modulation / demodulation circuit 12-b.
It is connected to the. Also in the indoor unit 14, the modulation / demodulation circuit 12-a is connected to the transformer 20 through the capacitor 26-a.
-A of the connection line 17 which is not grounded due to -a
7-a.

In each of the transformers 20-a and 20-b, the modulation / demodulation circuits 12-a and 12-b side is the primary side.

The operation of transmitting an information signal from the indoor control circuit 9 to the outdoor control circuit 10 will be described with reference to FIG.

A transmission information signal as shown in FIG. 2A is output from the transmission terminal of the indoor control circuit 9 and is transmitted to the modulation / demodulation circuit 12.
-A, and modulates the carrier as shown in FIG. 2B from the oscillation circuit 13-a to form a transmission signal. Here, the frequency of the carrier is sufficiently higher than the frequency of the transmission information signal. This transmission signal is supplied to the primary side of the transformer 20-a via the capacitor 26-a.
A transmission signal having the same waveform as that of the primary side is output to the secondary side of -a. The transmission signal obtained on the secondary side is shown in FIG.
(C) As shown in FIG.
The data is transmitted to the outdoor unit 15 via a.

Here, the amplitude of the transmission signal is set smaller than the voltage value of the DC voltage. Thus, the transmission signal does not completely interrupt the transmission, and the indoor unit 1
4 can be supplied with sufficient power, and the DC power supply voltage of the indoor unit 14 is stabilized. As a result, the outdoor unit 15
, The size of the DC power supply circuit 11 can be reduced.

In the outdoor unit 15, the information signal superimposed on the DC voltage is supplied to the secondary side of the transformer 20-b, and its AC component, that is, the carrier wave modulated by the transmission information signal is converted into the primary signal of the transformer 20-b. To the capacitor 26-b
The signal is supplied to the modulation / demodulation circuit 12-b via the interface, demodulated into a reception information signal as shown in FIG. 2D, and supplied from the reception terminal to the outdoor control circuit 10.

When the signal is transmitted from the outdoor control circuit 10 to the indoor control circuit 9, the same operation is performed on the reverse route, and communication is performed.

Here, in the transformers 20-a and 20-b, the primary side and the secondary side are electrically insulated.
Since the outdoor control circuit 10 and the indoor control circuit 9 are electrically separated from each other, even if a high voltage is output from the outdoor control circuit 10, it is not applied to the indoor control circuit 9. Therefore, there is no risk of electric shock on the indoor unit 14 side.

As described above, in this embodiment, the outdoor power supply circuit 24 and the photocoupler 25 in the air conditioner described with reference to FIG. 5 are unnecessary, and the risk of electric shock in the indoor unit 14 can be eliminated. By reducing the number of points, it is possible to suppress an increase in manufacturing cost and to realize a reduction in circuit scale.

FIG. 3 is a block diagram showing another embodiment of the air conditioner according to the present invention, wherein reference numerals 21-a and 21-b denote microcomputers, and portions corresponding to those in FIG. A duplicate description will be omitted.

In the figure, a microcomputer 21-a in the indoor control circuit 9 and a microcomputer 21-b in the outdoor control circuit 10
4A, as shown in FIG. 4 (a), forms a transmission information signal that is intermittent at a high frequency and outputs the transmission information signal from a transmission terminal. , And supplied to the primary side of the transformer 20-a or 20-b. Thereby, in the electric wire 17-a, as in the embodiment shown in FIG. 1, FIG.
The transmission signal is superimposed on the DC voltage and sent to the outdoor unit 14 or the indoor unit 15 as shown in FIG.

Further, as shown in FIG.
The transmission signal superimposed on the DC voltage at 7 is sent to the indoor unit 14 or the outdoor unit 15 by the transformer 20-a.
Alternatively, the signal is received via the modem 20-b, demodulated by the modem 12-a or 12-b as shown in FIG. 4C, and supplied from the reception terminal to the indoor control circuit 9 or 10.

In this way, in this embodiment, the same effects as those of the embodiment shown in FIG. 1 can be obtained. Further, the microcomputers 21-a and 21-b provide the oscillation circuits 13-a and 13-a in FIG.
13-b, so that the number of parts can be further reduced, the production cost can be reduced,
The circuit scale can be reduced.

[0034]

As described above, according to the present invention,
Since the indoor control circuit and the outdoor control circuit can be electrically insulated while enabling communication between the indoor control circuit and the outdoor control circuit, a high voltage is not applied from the outdoor control circuit to the indoor control circuit. This eliminates the risk of electric shock on the indoor unit side. Also, in the outdoor unit, a common power supply circuit of 5 V can be used for the outdoor power supply circuit, the outdoor control circuit, the modulation / demodulation circuit, and the oscillation circuit, so that a dedicated power supply circuit and a photocoupler are not required for the modulation / demodulation circuit and the oscillation circuit. , The production cost, and the circuit scale can be reduced.

Further, according to the present invention, in the indoor unit and the outdoor unit, it is not necessary to provide an oscillation circuit in the modulation / demodulation circuit, and the number of parts, the manufacturing cost, and the circuit scale can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing signals of respective units in FIG.

FIG. 3 is a block diagram showing another embodiment of the air conditioner according to the present invention.

FIG. 4 is a diagram showing signals of respective units in FIG. 3;

FIG. 5 is a block diagram illustrating an example of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Indoor heat exchanger 3 Outdoor heat exchanger 4 Switching valve 5 Pressure reducer 6 Indoor blower 7 Outdoor blower 8 Commercial power supply 9 Indoor control circuit 10 Outdoor control circuit 11 DC power supply circuit 12-a, 12-b Modulation / demodulation circuit 13 -A, 13-b oscillation circuit 14 indoor unit 15 outdoor unit 16, 17 connection line 20-a, 20-b transformer 21-a, 21-b microcomputer 22 indoor power supply circuit 23 outdoor power supply circuit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Koji Kato, Inventor Koji Kato 800, Oda-machi, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Hitachi, Ltd. Living Equipment Division (56) References JP-A-62-108948 (JP, A) JP-A-62-175548 (JP, A) JP-A-6-2930 (JP, A) JP-A-2-294125 (JP, A) Japanese Utility Model Application No. 57-88347 (JP, U) Japanese Utility Model Application No. 1-66535 (JP) , U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F24F 11/02 103

Claims (4)

(57) [Claims] 1. A commercial power supply voltage in a DC power supply circuit in an outdoor unit.
Forming a DC voltage from the DC voltage, a grounded conductive
A power supply voltage is supplied to the indoor unit through a connection line composed of a wire and an ungrounded electric wire, and the indoor unit modulates an information signal from the indoor control circuit and the indoor control circuit to the connection line. A first modulation / demodulation circuit for supplying, and an outdoor control circuit for the outdoor unit and a second modulation / demodulation circuit for modulating an information signal from the outdoor control circuit and supplying the modulated information signal to the connection line, respectively. Information signals from the first and second modulation / demodulation circuits are superimposed on the DC voltage of the connection line and transmitted through the connection line, and the first and second modulation / demodulation circuits are sent through the connection line. An air conditioner configured to perform communication between the indoor control circuit and the outdoor control circuit through the connection line by demodulating the information signal and supplying the demodulated information signal to the indoor control circuit and the outdoor control circuit. in, provided the outdoor power supply circuit in the outdoor unit, the the outdoor power supply circuit
From the commercial power supply voltage and formed by the DC power supply circuit.
A DC voltage having a specified value lower than the DC voltage is formed and the outdoor
A common power supply voltage for the control circuit and the second modulation / demodulation circuit;
Then , an indoor power supply circuit is provided in the indoor unit, and the indoor power supply circuit
From the DC voltage sent through the connection line.
A constant DC voltage is formed to connect the indoor control circuit to the first transformer.
A power supply voltage common to the demodulation circuit is used, and the primary side of the transformer is connected to the first and second modulation / demodulation circuits.
Connect the secondary side of the transformer to the grounding of the connection line
Connected in series to an electric wire to connect the first and second modulation / demodulation circuits.
An air conditioner characterized in that it is configured to cut off direct current and to cut off supply of high voltage from the outdoor control circuit to the indoor unit. 2. The air conditioner according to claim 1, wherein the means is a transformer, and is provided in the indoor unit and the outdoor unit. 3. The air conditioner according to claim 1, wherein the means is a transformer, and is provided only in the outdoor unit. 4. The indoor control circuit and the outdoor control circuit according to claim 1, wherein the indoor control circuit and the outdoor control circuit output the information signal intermittently at a high frequency and supply the information signals to the first and second modulation / demodulation circuits, respectively. Air conditioner.