JP2004101106A - Control circuit for air conditioner and control method for air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control circuit for an air conditioner operable without being influenced by intrusion of noise from a valve mechanism provided on a cooling medium circuit, with enhanced reliability of a system. <P>SOLUTION: The control circuit for the air conditioner is provided with a control circuit part for controlling the whole air conditioner; a valve driving circuit for controlling the valve mechanism of a refrigerating cycle; and an insulation circuit provided between the control circuit part and the valve driving circuit and transmitting signals in an electrically insulated state, in the air conditioner provided with the refrigerating cycle having the valve mechanism for controlling a circulation flow rate and a circulation direction of the cooling medium. The control circuit part and the valve driving circuit are driven by a power source electrically insulated respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner that drives a compressor to circulate a refrigerant through a heat exchanger, and a control circuit unit that controls the entire air conditioner and a valve mechanism that controls a circulating flow rate and a circulating direction of the refrigerant. The present invention relates to a control circuit for an air conditioner having a circuit and a method for manufacturing an air conditioner.
[0002]
[Prior art]
FIG. 3 is a block diagram of a control circuit of the conventional air conditioner. In the figure, 1 is an AC power supply, 2 is a converter for converting an AC input from the AC power supply 1 to DC, 3 is an inverter for converting DC obtained from the converter 2 to an arbitrary AC, and 4 is driven by the inverter 3 Compressor, 5 is a DC power supply for various circuits, 6 is a control circuit for controlling the entire air conditioner, 7 is a driver circuit for operating a valve mechanism provided in the refrigerant circuit, and 8 is a valve driven by a driver circuit 7. is there.
[0003]
In the conventional air conditioner, as shown in FIG. 3, an AC input obtained from an AC power supply 1 is converted into a DC input by a converter 2 and is again converted into an arbitrary AC by an inverter 3 to drive the compressor 4. I do. The control circuit 6 controls the driving of the compressor 4 via the inverter 3 and at the same time controls each part of the air conditioner. A part thereof controls a valve 8 for controlling the flow direction and flow rate of the refrigerant, and the control circuit 6 drives the valve 8 via a driver circuit 7. The control circuit 6, the driver circuit 7, and the valve 8 operate by receiving power supply from the DC power supply 5, and the configuration of the DC power supply 5 is such that a circuit ground potential is applied to all parts of the control circuit 6, the driver circuit 7, and the valve 8. The power supply is the same (hereinafter referred to as a non-insulated configuration).
[0004]
[Patent Document 1]
JP-A-9-126530
[Problems to be solved by the invention]
The control circuit of the conventional air conditioner can be constructed simply and inexpensively because the DC power supply 5, which is the power supply for the control circuit 6, the driver circuit 7, and the valve 8, has a non-insulated configuration. However, when noise generated from lightning or other equipment intrudes from the valve 8, the noise eventually enters the control circuit 6 due to the non-insulated configuration, and may cause control malfunction or abnormal system stop. There has been a problem that the air conditioner falls into a state and the reliability of the entire air conditioner is impaired.
[0006]
For this reason, as shown in FIG. 4, as a countermeasure against external noise, a core 10 for reducing noise intrusion is additionally inserted between the driver circuit 7 and the valve 8 to take countermeasures. However, although the core 10 can reduce noise intrusion, it cannot electrically cut off completely, so that the effect varies widely and the suppression effect cannot be expected completely.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and the control circuit can operate without being affected by noise intrusion from a valve mechanism provided in the refrigerant circuit, and the reliability of the system can be improved. It is an object to provide a control circuit of an air conditioner and a method of manufacturing the air conditioner, which can improve the air conditioner.
[0008]
[Means for Solving the Problems]
A control circuit of an air conditioner according to the present invention includes a control circuit for controlling an entire air conditioner in an air conditioner including a refrigeration cycle having a valve mechanism for controlling a circulation flow rate and a circulation direction of a refrigerant; A valve drive circuit for controlling the valve mechanism, and an insulating circuit provided between the control circuit unit and the valve drive circuit and transmitting signals in an electrically insulated state. The driving circuits are each driven by an electrically insulated power supply.
[0009]
Further, the control circuit of the air conditioner according to the present invention is characterized in that the insulating circuit is constituted by an optical semiconductor such as a photocoupler.
[0010]
Further, the control circuit of the air conditioner according to the present invention is characterized in that the insulating circuit is constituted by a magnetic relay.
[0011]
Further, the control circuit of the air conditioner according to the present invention is characterized in that the insulation circuit is constituted by a solid state relay.
[0012]
An air conditioner control method according to the present invention is directed to an air conditioner including a refrigeration cycle having a valve mechanism for controlling a circulation flow rate and a circulation direction of a refrigerant. The signal transmission between the valve drive circuit that controls the valve mechanism and the signal transmission is performed in a state where the signal is electrically insulated by the insulating circuit, and the control circuit unit and the valve drive circuit are each connected to an electrically insulated power supply. It is characterized by being driven.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 shows the first embodiment and is a block diagram of a control circuit of the air conditioner. In the figure, 1 is an AC power supply, 2 is a converter for converting an AC input from the AC power supply 1 to DC, 3 is an inverter for converting DC obtained from the converter 2 to an arbitrary AC, and 4 is driven by the inverter 3 A compressor 5, a DC power supply for various circuits, 6 a control circuit for controlling the entire air conditioner, 7 a driver circuit for operating a valve mechanism provided in the refrigerant circuit, 8 a valve driven by the driver circuit 7, Reference numeral 9 denotes an insulating circuit that electrically insulates and transmits signals between the control circuit 6 and the driver circuit 7. The insulating circuit 9 generally uses an optical semiconductor such as a photocoupler.
[0014]
Further, the DC power supply 5 is provided with a circuit ground for each of the power supplies supplied to the control circuit 6 and the driver circuit 7, and the control circuit 6 and the driver circuit 7 have different circuit grounds.
[0015]
The AC input obtained from the AC power supply 1 is converted into a DC input by the converter 2, converted again into an arbitrary AC by the inverter 3, and the compressor 4 is driven. The control circuit 6 controls the driving of the compressor 4 via the inverter 3 and at the same time controls each part of the air conditioner. A valve 8 for controlling the flow direction and flow rate of the refrigerant is partly controlled, and in the circuit operation for driving the valve 8, a drive signal is transmitted from the control circuit 6 to the insulating circuit 9. In the insulating circuit 9, the drive signal is converted from an electric signal to an optical signal by a photocoupler, converted into an electric signal again, and then input to the driver circuit 7. The driver circuit 7 drives the valve 8 according to the input signal.
[0016]
With the above circuit configuration, the control circuit 6 and the driver circuit 7 are in an insulated state where they are not electrically connected. Even if noise enters from the valve 8, it does not enter the control circuit 6, so that the control circuit 6 is not affected by the noise and does not fall into a state such as malfunction or stop.
[0017]
In the above-described embodiment, an example in which a photocoupler is used for the insulating circuit 9 is described, but an optical semiconductor other than the photocoupler may be used.
[0018]
Embodiment 2 FIG.
FIG. 2 shows the second embodiment and is a block diagram of a control circuit of the air conditioner. In the first embodiment, the case where a photocoupler is used for the insulating circuit 9 has been described. However, the same effect can be obtained in the case where a magnetic relay is used.
[0019]
FIG. 2 shows a configuration in the case where a magnetic relay is used for the insulation circuit 9, and the other configuration is the same as that of the first embodiment shown in FIG.
[0020]
When a photocoupler is used for the insulating circuit 9, the signal transmission from the control circuit 6 to the driver circuit 7 is performed by light, but when a magnetic relay is used, the primary signal of the magnetic relay is transmitted by the signal from the control circuit 6. The current is conducted to the winding side to generate magnetism, and the secondary side contact is operated. As in the case where the photocoupler is used, the control circuit 6 and the driver circuit 7 can be electrically insulated, so that the same effect as in the first embodiment can be obtained.
[0021]
Embodiment 3 FIG.
In the above embodiment, the insulation circuit 9 uses a photocoupler and a magnetic relay. However, a solid-state relay that exchanges signals by light may be used, and the same as when a photocoupler is used. In addition, since the control circuit 6 and the driver circuit 7 can be electrically insulated, the same effect as in the first embodiment can be obtained.
[0022]
【The invention's effect】
The control circuit of the air conditioner according to the present invention includes an insulating circuit that transmits signals in a state of being electrically insulated between the control circuit unit and the valve drive circuit, and electrically connects the control circuit unit and the valve drive circuit to each other. Since the control circuit is driven by a power supply that is electrically insulated, the control circuit can operate without being affected by noise intrusion from the valve, and the effect of improving the reliability of the system can be obtained.
[0023]
In the control method of the air conditioner according to the present invention, the signal transmission between the control circuit unit that controls the entire air conditioner and the valve drive circuit that controls the valve mechanism of the refrigeration cycle is electrically insulated by the insulating circuit. The control circuit and valve drive circuit are driven by electrically insulated power supplies, respectively, so that the control circuit can be operated without being affected by noise intrusion from the valve. This has the effect of improving the reliability of the system.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a first embodiment, and is a block diagram of a control circuit of an air conditioner.
FIG. 2 shows a second embodiment, and is a block diagram of a control circuit of the air conditioner.
FIG. 3 is a block diagram of a control circuit of a conventional air conditioner.
FIG. 4 is a block diagram of a conventional measure for suppressing noise intrusion from a valve mechanism.
[Explanation of symbols]
1 AC power supply, 2 converters, 3 inverters, 4 compressors, 5 DC power supply, 6 control circuit, 7 driver circuit, 8 valves, 9 insulation circuit.

Claims (5)

In an air conditioner equipped with a refrigeration cycle having a valve mechanism for controlling the circulation flow rate and the circulation direction of the refrigerant,
A control circuit for controlling the entire air conditioner;
A valve drive circuit for controlling a valve mechanism of the refrigeration cycle,
An insulation circuit that is provided between the control circuit unit and the valve drive circuit and transmits a signal in an electrically insulated state,
Wherein the control circuit section and the valve drive circuit are each driven by an electrically insulated power supply. The control circuit for an air conditioner according to claim 1, wherein the insulating circuit is formed of an optical semiconductor such as a photocoupler. The control circuit for an air conditioner according to claim 1, wherein the insulation circuit is configured by a magnetic relay. The control circuit for an air conditioner according to claim 1, wherein the insulation circuit is a solid state relay. In an air conditioner equipped with a refrigeration cycle having a valve mechanism for controlling the circulation flow rate and the circulation direction of the refrigerant,
Signal transmission between a control circuit unit that controls the entire air conditioner and a valve drive circuit that controls the valve mechanism of the refrigeration cycle, performs signal transmission in a state in which it is electrically insulated by an insulating circuit,
The control method of an air conditioner, wherein the control circuit unit and the valve drive circuit are driven by power supplies that are electrically insulated from each other.

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