JP2012083089A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption at standby in an air conditioner with a remote controller.SOLUTION: This air conditioner includes: capacitors for line filters at an AC power supply; a discharge resistor for discharging electric charges accumulated in the capacitors for the line filters; and switches for supplying power to an outdoor unit. The air conditioner also includes the capacitors for the line filters by separating them at a power supply circuit at the side of an indoor unit and a rear stage of the switches. Since the static capacitance of the capacitor between lines of the AC power supply can be made variable by switching the switches to on-states and off-states, the static capacitance at an operation stop can be reduced while suppressing a noise level at operation. Accordingly, the discharge resistor can have resistance high in resistance value at the standby of the operation stop, and thereby the power consumption can be reduced.

Description

  The present invention relates to an air conditioner having a power saving mode during standby.

  These products, such as televisions, audio equipment, air conditioners, etc. are generally used in places away from the user, so they are remotely operated using a separate remote controller (hereinafter referred to as a remote controller). , Power on / off, each function on / off, and operation switching. In particular, in an indoor unit of an air conditioner, most operations are performed by a remote controller because they are often installed at high places in a room.

  In these devices operated by the remote controller, the operation to change from the operation stop state to the operation state is also performed by the remote control. Therefore, even in the operation stop state, the signal reception for receiving the carrier signal having the operation command information is received. The control circuit including the microcomputer, a microcomputer (hereinafter referred to as a microcomputer), which is an arithmetic processing unit for processing the received carrier signal, and the power supply circuit must always be energized.

  Therefore, a device operated by the remote controller has a problem that power is continuously consumed even in a signal waiting state (hereinafter referred to as a standby state) in an operation stop state. The power consumption in the standby state is very small compared to the power consumption in the operation state, but since it is always consumed, it is not an amount of power that can be ignored when accumulated in the long term. Therefore, in order to solve this problem, various methods have been proposed as means for reducing power consumption in the standby state.

  In Patent Document 1, a power saving mode in which an operation clock of the control unit is stopped by an instruction of a control unit that controls an infrared remote control receiving circuit, and the operation clock of the control unit is started by a predetermined start signal, and the operation clock Is equipped with a remote control receiver circuit that operates by switching between a normal mode that starts and operates normally, and an electronic device provided with a remote control receiver circuit that reduces power consumed by the control means by stopping the operation clock Device technology is disclosed.

  Since Patent Document 1 stops the operation clock of the control means, the carrier signal transmitted from the remote controller cannot be decoded as it is. Therefore, in order to restart the operation clock, a remote control pulse code to which a restart pulse is added, and a restart signal generation circuit that detects the restart pulse and generates a rising pulse based on the restart pulse. I have. Therefore, since a circuit for recognizing a restart pulse and a restart signal generation circuit are required in addition to a remote control receiving circuit that receives a normal carrier signal, problems such as increase in circuit scale and cost increase remain.

  In patent document 2, it is the control method of the air conditioner which is equipped with the computer which has the function which can switch the operation speed of an arithmetic unit, and controls the actuator of an air conditioner by this computer, Comprising: It is the operation speed of the arithmetic unit of the said computer. Accordingly, a control method for an air conditioner is disclosed in which the control program for the air conditioner is changed.

  Patent Document 2 relates to the operation speed of the CPU by changing the control program because there is a difference between the time required for the arithmetic processing and the time of the actuator operation to be controlled by switching the operation speed of the arithmetic device. The program execution time can be kept constant. However, if the control is relatively slow so as to control the actuator operation, it can be dealt with by turning the CPU usage rate to the processing for the actuator control, but the arithmetic processing is performed at a high speed like the decoding of the carrier signal from the remote control. In such a case, it is impossible to cope with the situation unless the operation speed is high to some extent. Further, although the CPU operating speed is switched to the stop mode, it is impossible to detect and decode the carrier signal from the remote controller even in this case.

  In Patent Document 3, a remote operation device that outputs an operation control operation signal of an air conditioner, a reception unit that receives a signal from the remote operation device, and a signal that is captured from the reception unit are decoded, and the air conditioner In an air conditioner equipped with a computer that performs the operation of the actuator or data writing to an external memory, calculation speed switching means for switching the operation speed of the calculation device to the computer, and the operation mode and stop mode of the air conditioner Mode determining means for determining whether or not the operation speed switching means determines that the operation of the air conditioner is stopped when the mode determining means determines that the operation speed of the air conditioner is stopped. It is slow enough to enable, and when the operation mode is determined by decoding the signal from the remote control device, Control method of an air conditioner, characterized by faster when stopping the operation speed of the location is disclosed.

  In Patent Document 3, there is a case where the operation speed of the arithmetic device is decreased to such an extent that a signal from a remote control device is received and decoded. In general, an infrared signal modulated at 38 kHz is used as a signal of a home air conditioner, and communication is performed in accordance with a format defined by the Japan Home Appliances Association. Therefore, even when this signal is decoded, the detection of Hi or Lo, the determination of whether the bit is 0 or 1, the storage of bit information, the configuration of a signal code such as 8 bits, and the signal code stored in the arithmetic unit It is necessary to perform a large number of arithmetic processes such as comparisons. Therefore, an operation speed of several MHz is required for decoding as a signal. For this reason, it is not possible to obtain a great effect even if the operation speed of the arithmetic unit is lowered to the limit and power consumption is reduced.

  In Patent Document 4, a converter that converts alternating current connected to a commercial power source into direct current, an inverter that converts direct current connected to the output stage of the converter into alternating current, and a compressor driving motor connected to the inverter; An outdoor control circuit that controls the converter and the inverter; an outdoor unit that includes an outdoor control power source that supplies power to the outdoor control circuit and the indoor unit; and a motor for heat exchange and wind direction plate driving of the indoor unit. An air conditioner composed of an indoor control circuit to control and an indoor unit equipped with an indoor control power supply is equipped with a power supply circuit control IC that does not reduce power efficiency when power consumption is low, and supplies power to other than indoor and outdoor control microcomputers The technology of the air conditioner which controls a microcomputer with low electric power, without reducing power supply efficiency, even if it stopped is disclosed.

  Japanese Patent Application Laid-Open No. 2004-228561 includes a circuit that lowers the voltage supplied to an operating circuit when it is in a low power consumption state, but there is no specific mention of the means. There is no mention of a line filter capacitor or a discharge resistor between the power supply lines.

Japanese Patent Application Laid-Open No. 2007-221397 Japanese Patent No. 3483483 Japanese Patent No. 3788132 JP 2002-81712 A

  Conventionally, in a device remotely operated by a remote controller such as a television, an audio device, an air conditioner, etc., since the operation to change from the operation stop state to the operation state is often performed by the remote control, the operation is performed even in the operation stop state. The signal receiving unit for receiving the carrier signal having the command information, the control circuit including the microcomputer as the arithmetic processing unit for processing the received carrier signal, and the power supply circuit are not always energized. However, power consumption in the standby state has been a problem.

  In order to solve this problem, a method has been proposed in which the operation clock of the arithmetic processing unit can be varied at a low speed, or the power supply to a load that does not need to be stopped or energized is cut off as described above.

  However, as described above, it is necessary to ensure a sufficient clock speed to decode the carrier signal from the remote control, or to be able to recognize that the carrier signal is received by another circuit. There has been a problem that power consumption cannot be reduced in a circuit such as a signal receiving unit and a regulator that must always be energized.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an air conditioner capable of reducing power consumption in a standby state without using a complicated configuration.

  An object of the present invention is to provide an air conditioner including a line filter capacitor in an AC power source, a discharge resistor that discharges electric charges accumulated in the line filter capacitor, and a switch for supplying power to the outdoor unit. This is achieved by separately providing the line filter capacitor in the power supply circuit on the indoor unit side and the subsequent stage of the switch.

  The above object is achieved by providing a discharge resistor in parallel with the line filter capacitor provided in the subsequent stage of the switch in the subsequent stage of the switch.

  The object is achieved by providing the switch on the indoor unit side.

  The above object is achieved by using a relay for the switch.

  The present invention can provide an air conditioner that can reduce power consumption in a standby state.

The figure which shows the external appearance structure of the air conditioner which concerns on embodiment of this invention. The sectional side view of an indoor unit. The figure which shows schematic structure of the signal receiving part provided in the indoor unit, and its periphery. The figure which shows the system configuration | structure of an air conditioner. The figure which shows the system structural example in the power supply circuit of an air conditioner. The figure which shows another example of the system configuration example in the power supply circuit of an air conditioner. The flowchart explaining operation | movement (transition to the low speed mode from a normal mode) of a power supply interruption | blocking switch. The flowchart explaining operation | movement (transition to low speed mode from normal mode) of a power supply cutoff switch. The time chart which shows the operation example at the time of the carrier signal reception in normal mode and low speed mode. The time chart which shows the return operation example to normal mode at the time of low speed mode. The time chart which shows the operation example at the time of noise reception. The time chart which shows another example of the return operation example to normal mode at the time of low speed mode.

  Below, the air conditioner 1 which concerns on embodiment of this invention is demonstrated in detail, referring a figure.

  First, the whole structure of the air conditioner 1 which concerns on this embodiment is demonstrated using FIG. 1, FIG. FIG. 1 is a diagram showing an external configuration of an air conditioner 1 according to the present embodiment, and FIG. 2 is a side sectional view of the indoor unit 2 of the air conditioner 1.

  An air conditioner 1 shown in FIG. 1 is configured by connecting an indoor unit 2 and an outdoor unit 3 with a connection pipe 4, a power transmission cable 5, and a communication cable 6, and air-conditions the room. A signal receiving unit 8 that receives an infrared carrier signal from a separate remote controller (hereinafter referred to as “remote controller”) 7 is provided at the lower right end of the indoor unit 2 shown in the lower right of the figure.

  As shown in FIG. 2, the indoor unit 2 is provided with a heat exchanger 10 at the center of the casing base 9, and a cross flow fan having a length substantially equal to the width of the heat exchanger 10 on the downstream side of the heat exchanger 10. An indoor blower fan 11 of the type is arranged, a dew tray 12 is attached, these are covered with a decorative frame 13, and a front panel 14 is attached to the front surface of the decorative frame 13.

  In addition, the decorative frame 13 is provided with an air inlet 15 for sucking room air and an air outlet 16 for blowing air having adjusted temperature and humidity. When the indoor blower fan 11 provided downstream of the air flow of the heat exchanger 10 is rotated, the indoor air passes through the heat exchanger 10 and the indoor blower fan 11 from the air suction port 15 provided in the indoor unit 2. The left and right wind direction plates 17 arranged in the middle of the blowout air passage 11a flow in the blowout air passage 11a having a width substantially equal to the length of the indoor blower fan 11, and the right and left directions of the airflow are deflected. The vertical airflow direction plate 18 deflects the vertical direction of the airflow and blows it out into the room.

  FIG. 3 is a diagram illustrating a schematic configuration of the signal receiving unit 8 provided in the indoor unit 2 and its surroundings. The signal receiving unit 8 is provided with an infrared light receiving element 19 that receives an infrared carrier signal from a separate remote controller 7.

  In addition, the signal receiving unit 8 is provided with an integrally configured display unit 20 adjacent thereto. The display unit 20 lights up the display light emitting diodes (20a, 20b, 20c, 20d, 20e, 20f) provided in the inside thereof, and visually conveys the driving situation to the user.

  Next, a system configuration in the air conditioner 1 will be described.

  FIG. 4 is a diagram illustrating a system configuration of the air conditioner 1. The indoor unit 2 shown in FIG. 4 includes a control board 21 in an internal electrical component box (not shown). In FIG. 4, the inrush current prevention circuit 22, the power relay 46, and the power supply circuit 24 constitute a power supply unit. An indoor fan motor 26 is connected to the power supply circuit 24 via a fan motor drive circuit 25, and a two-way valve 28 is connected via a two-way valve drive circuit 27.

  The control board 21 is provided with a microcomputer (hereinafter referred to as “microcomputer”) 29. The microcomputer 29 is connected to a reset circuit 30, an EEPROM 31, a main clock oscillation circuit 32, and a sub clock oscillation circuit 33 connected to the power supply circuit 24.

  Further, the microcomputer 29 is connected to various sensors such as the signal receiving unit 8 including the infrared light receiving element 19, the suction temperature thermistor 34, the heat exchanger thermistor 35, and the humidity sensor 36. Further, the microcomputer 29 allows the user to sensible (visually) the operating state of the air conditioner 1 in accordance with the signals from the various sensors and the carrier signal from the remote controller 7 received through the infrared light receiving element 19. The lighting of the light emitting diodes (20a, 20b, 20c, 20d, 20e, 20f) of the display unit 20 is controlled so that it can be recognized, and the sounding of the buzzer 37 is controlled.

  Further, the microcomputer 29 controls the rotation of the front panel motor 39, the up / down air direction plate motors 40a, 40b, 40c, and the left / right air direction plate motors 41a, 41b connected via the stepping motor drive circuit 38.

  Further, an emergency operation switch 66 is connected to the microcomputer 29, and control is performed so as to forcibly perform a predetermined operation by a signal from the emergency operation switch 66.

  The microcomputer 29 manages communication with the outdoor unit 3 via the indoor / outdoor communication circuit 42 and controls the indoor unit 2 in an integrated manner.

  Next, the power supply circuit 24 will be described with reference to FIGS. 5, 6, 7, and 8. FIG. 5 is a diagram illustrating a system configuration example of the power supply circuit 24. FIG. 6 is a diagram illustrating another example of a system configuration example of the power supply circuit 24. FIG. 7 is a flowchart for explaining the operation of the power supply cutoff switch (shift from the normal mode to the low speed mode). FIG. 8 is a flowchart for explaining the operation of the power supply cutoff switch (shift from the low speed mode to the normal mode).

  In FIG. 5, the power supply circuit 24 connects the power plug 44 to the outlet 43, whereby AC power is supplied from the commercial power supply 50 through the power cord 45. The power supply circuit 24 includes a power relay 46 for transmitting power from the commercial power supply 50 to the outdoor unit 3, and an across-the-line capacitor (hereinafter referred to as “X capacitor”) 47a for noise reduction. The common mode choke coil 48 is provided. In addition, a discharge resistor 49a for discharging the electric charge stored in the X capacitor 47a after the power is shut off is provided.

  As described above, in this embodiment, in order to reduce the noise that propagates through the line of the commercial power supply 50 and flows out, the X capacitor 47a is provided between both poles of the AC line. In the air conditioner 1, an inverter drive system is mainly used for an outdoor fan motor (not shown) and the indoor fan motor 26 as well as a compressor motor (not shown) provided in the outdoor unit 3. In the case of an inverter-driven motor, the carrier frequency in switching of the semiconductor switching element is mainly from several kHz to several tens of kHz, and there arises a problem that noise of higher harmonics of the carrier frequency flows out to the line of the commercial power supply 50. . Therefore, in order to reduce noise, it is necessary to configure and cope with a filter circuit or the like. In particular, increasing the capacitance of the X capacitor 47a is an effective means for suppressing a noise component having a relatively low frequency of 1 MHz or less.

  However, increasing the capacitance of the X capacitor 47a means that the charge accumulated in the X capacitor 47a increases. That is, there arises a problem that the residual voltage between the plug blades when the power plug 44 is removed from the outlet 43 is increased. This residual voltage needs to be lowered to a predetermined voltage or lower for a predetermined time so that no electric shock is generated when the user touches between both ends of the plug blade. Therefore, in order to discharge the accumulated electric charge, it is common to provide a discharge resistor 49a connected in parallel with the X capacitor 47a. However, since the discharge resistor 49a always flows while the power supply is energized, there is a problem in that power continues to be consumed even in a standby state. Therefore, in order to reduce power consumption, it is necessary to make the discharge resistor 49a have a resistance value as high as possible.

  However, as described above, the discharge resistor 49a needs to be reduced to a resistance value determined by a time constant with the capacitance of the X capacitor 47a because the residual voltage needs to be lowered to a predetermined voltage or lower during a predetermined time. For this reason, the resistance value cannot be simply increased. To increase the resistance value of the discharge resistor 49a, the capacitance of the X capacitor 47a must be reduced.

  However, during the standby state, the inverter-driven motor is not operating, so the noise level is low, and there is no problem even if the capacitance of the X capacitor 47a is small. However, during the operation in which the inverter-driven motor operates. Since the noise level increases, the capacitance of the X capacitor 47a cannot simply be reduced. Therefore, in order to solve this problem, an X capacitor 47b and a discharge resistor 49b are provided in the subsequent stage of the power relay 46 (on the outdoor unit 3 side with the power relay 46 interposed). Thus, when the air conditioner 1 performs an operation such as cooling, heating, or dehumidification, that is, when the power relay 46 is turned on, the indoor unit 2 and the outdoor unit 3 are operated, and the noise level is high, the X capacitor 47a Since the X capacitor 47b is connected, a sufficient electrostatic capacity can be ensured. Further, in the standby state when the operation is stopped, in which the noise level is low, the capacitance of only the X capacitor 47a is obtained by disconnecting the power relay 46, so that the resistance value of the discharge resistor 49a is increased. Can do. Therefore, the power consumption in the standby state can be reduced without impairing the noise performance, and further, the electric shock due to the plug blade residual voltage of the power plug 44 can be prevented. 5 shows an example in which the X capacitor 47b and the discharge resistor 49b are mounted on the same board on the outdoor unit 3 side with the power relay 46 interposed therebetween. However, the X capacitor 47b and the discharge resistor 49b are mounted on different boards or connected to the terminal block 67. The mounting means is not limited.

  Further, even when the operation is performed only by the indoor unit 2 such as the air blowing operation, the noise level may be high depending on the number of rotations of the indoor air blowing fan 11. Therefore, although the outdoor unit 3 is not operated, the power relay 46 is intentionally turned on. It is configured to do.

  Furthermore, the power supply circuit 24 includes a rectifier circuit 53 including a diode bridge 52, a smoothing capacitor 51, a switching power supply IC 54, and a switching transformer 55 that convert electric power from the commercial power supply 50 into an AC voltage to a DC voltage. A switching power supply circuit 56, a main control power supply regulator 57 and a sub control power supply regulator 58 provided on the secondary side of the switching transformer 55 are provided.

  The switching power supply circuit 56 has a multi-output configuration such as an 18.5V power supply 59, a 12V power supply 60, and an 8.5V power supply 61 by a switching transformer 55 formed of divided windings. The 8.5V power source 61 is connected to a main control power source regulator 57 and a sub control power source regulator 58. The 5.3V power source 62 stepped down by the main control power source regulator 57, It is divided into a 3.3 V power source 63 that has been stepped down by a regulator 58 for control power source.

  The 18.5V power supply 59, the 12V power supply 60, and the front stage of the main control power supply regulator 57 are provided with power supply cut-off switches (64a, 64b, 64c), and all the power supplies connected to the respective power supplies are provided. When the load becomes a condition that does not require the supply of power, that is, when the condition for entering the standby state is met, the power supply cut-off switches (64a, 64b, 64c) are turned off to supply power to each load. The power supply is cut off and unnecessary power consumption is suppressed. The power supply cutoff switch (64a, 64b, 64c) can be configured by using a relay, transistor, or MOS-FET. However, in the case of a relay and a transistor, a drive current for turning on the switch is required. Therefore, in the present embodiment, a MOS-FET that requires almost no drive current is used to reduce power consumption during operation.

  Further, the power supply cutoff switch (64a, 64b, 64c) is turned off, and when the load is light as viewed from the switching power supply circuit 56, thinning control is performed such that the switching operation of the switching power supply IC 54 is partially stopped. Thus, the number of times of switching per unit time is reduced, that is, the sum of switching losses per unit time is reduced to reduce power consumption.

  Further, the output side of the main control power source regulator 57, that is, the 5.3V power source 62, and the output side of the sub control power source regulator 58, that is, the 3.3V power source 63 are connected by a diode or to supply power. When the cutoff switch 64c is ON, power is supplied from the main control power supply regulator 57 having a high output voltage. When the power supply cutoff switch 64c is OFF, power is supplied from the sub control power supply regulator 58. The configuration is supplied.

  Each of the backflow prevention diodes (65a, 65b) is a Schottky diode having a small voltage drop of VF of 0.3V. Therefore, the voltage on the cathode side of each backflow prevention diode (65a, 65b) is 5V when the power supply cutoff switch 64c is ON, and 3V when it is OFF. The on / off switching of the power supply cut-off switch 64c is executed after the microcomputer 29 calculates whether or not a predetermined condition is met, as shown in FIGS.

  The microcomputer 29, the main clock oscillation circuit 32, the arithmetic processing unit 68 including the sub clock oscillation circuit 33, the signal receiving unit 8 including the infrared light receiving element 19, the emergency operation switch 66, and the operation command from the outside are detected. Then, the minimum circuit and load necessary for shifting from the standby state to the operation state are connected to the cathode side of each backflow prevention diode (65a, 65b), and the standby of the EEPROM 31, the display unit 20, the indoor / outdoor communication circuit 42, etc. A circuit and a load that are unnecessary in the state are connected to the anode side of the backflow prevention diode 65a on the main control power supply regulator 57 side.

  The microcomputer 29 and the infrared light receiving element 19 use elements having a minimum operating voltage of 2.7 V and a normal operating voltage of 5 V. Therefore, since power is supplied only to limited circuits and loads in the standby state, power consumption can be reduced, and the power supply voltage of the arithmetic processing unit 68 and the signal receiving unit 8 is linearly reduced from 5 V to 3 V. Since it is driven, power consumption can be further reduced while maintaining a stable operation.

  Note that, as described above, the power supply voltage of the arithmetic processing unit 68 and the power supply voltage of the circuit unnecessary for the standby state and the load are separately connected to both ends of the backflow prevention diode 65a. A potential difference corresponding to the drop occurs. However, as described above, by using a Schottky diode with a small voltage drop for the backflow prevention diode 65a, the potential difference within the maximum rated voltage of the microcomputer 29 can be suppressed.

  Further, as described above, the power supplied from the sub-control power regulator 58 is power that covers only a limited load in the standby state, and therefore, compared with the power supplied from the main control power regulator 57 during operation. , Very little power. That is, since the sub-control power supply regulator 58 has a small amount of power to be supplied, a regulator having a low output current discharge capability can be used. In general, when the load current is large, the regulator requires a large amount of drive power in order to ensure current amplification. In addition, since the design point must be designed in consideration of the maximum load, the circuit efficiency at the time of low load tends to decrease, and the ratio of the drive current to the output current increases at the time of low load. On the other hand, a regulator with a low output current discharging capability can be used near the maximum efficiency point of the regulator if the element itself is small and a light load such as a limited load in a standby state. Therefore, the power consumption in the standby state can be further reduced by making the sub-control power supply regulator 58 a regulator having a low output current discharge capability.

  As described above, in this embodiment, the drive power source is divided by the diode or, but the following may be considered as another method.

  As shown in FIG. 6, even when the microcomputer 29, the signal receiving unit 8 including the infrared light receiving element 19, the emergency operation switch 66, and the like are in a standby state, the minimum necessary power to the circuit and load is always supplied. Supplyed from a step-down circuit composed of a sub-control power supply regulator 58, EEPROM 31 (writeable / readable external storage medium), suction temperature thermistor 34, heat exchanger thermistor 35, humidity sensor 36, indoor / outdoor communication circuit 42, display In a circuit or load that is driven at the same potential as or lower than that of the microcomputer 29 such as the unit 20 but does not need to be energized in a standby state, power is supplied from a step-down circuit composed of a main control power regulator 57. In this way, the power supply is completely divided.

  In this method, the minimum circuit and load power supply voltage required for shifting to the operation state such as the microcomputer 29, the signal receiving unit 8 including the infrared light receiving element 19, and the emergency operation switch 66 are set to a low voltage in the standby state. Although it cannot be switched, the power loss is reduced due to the difference between the input voltage (8.5 V) and the output voltage (5 V) in the sub-control power supply regulator 58 and the backflow prevention diodes (65a, 65b). Since the loss is eliminated, the circuit configuration can be simplified without greatly inferior in the power consumption performance in the standby state as compared with the diode or method.

  Even in this configuration, the sub-control power supply regulator 58 remains configured to supply power only to a limited load such as the microcomputer 29, so that it has an output current discharge capability capable of being driven with high efficiency at a low current. It is possible to reduce power consumption in a standby state using a small regulator.

  In this embodiment, the step-down circuit has been described using a regulator. However, the step-down circuit does not limit the circuit system such as a switching regulator, a dropper regulator, a DC / DC converter, etc., and depends on cost, mounting space, and circuit efficiency. What is necessary is just to select suitably.

  Next, operation examples in the normal mode and the low speed mode will be described with reference to FIGS. 9, 10, 11, and 12. FIG.

  FIG. 9 is a time chart showing an operation example when receiving a carrier signal in the normal mode and the low speed mode. FIG. 10 is a time chart showing an example of the return operation to the normal mode in the low speed mode. FIG. 11 is a time chart showing an operation example at the time of noise reception. FIG. 12 is a time chart showing another example of the return operation example to the normal mode in the low speed mode.

  In this configuration, the oscillation circuit used for the operation clock of the microcomputer 29 is provided with two oscillation circuits having different clock frequencies such as the main clock oscillation circuit 32 and the sub clock oscillation circuit 33. When the air conditioner 1 is in operation, the microcomputer 29 needs high-speed arithmetic processing to control communication with the outdoor unit 3 and each load, and the operation clock must also be a high clock frequency. . However, increasing the clock frequency has a problem that the power consumed by the microcomputer 29 increases. Therefore, in order to reduce this power consumption, when high-speed arithmetic processing is indispensable, such as during operation, the operation is performed in the normal mode using the main clock oscillation circuit 32 having a high clock frequency, and high-speed arithmetic processing is performed. In the standby state where it is not necessary to perform the above, the sub clock oscillation circuit 33 having a low clock frequency is switched to the low speed mode to reduce the power consumption of the microcomputer 29 in the standby state.

  Conventionally, the clock frequency is related to the CPU load factor, such as the detection of the carrier signal input to the infrared light receiving element 19, the detection of the signal input by the emergency operation switch 66, and the arithmetic processing related to other controls. In order to read a carrier signal from the remote controller 7 in particular, detection of Hi or Lo, arithmetic processing of whether the bit is 0 or 1, storage of bit information, signal code of 8 bits, etc. In addition, it is necessary to perform a large number of arithmetic processes such as comparison with a code stored in an arithmetic unit, and a clock frequency of at least several MHz is required. However, as described above, increasing the operation clock leads to an increase in power consumption. Therefore, the sub-clock oscillation circuit 33 in the present configuration has an infrared signal carrier frequency of 38.768 kHz, which is slower than 38 kHz. The oscillator was used. Therefore, although it is possible to reduce power consumption, as shown in FIG. 9, since the sampling period becomes longer as the clock frequency decreases, the carrier signal from the remote controller 7 cannot be read as it is.

  In order to solve this problem, as shown in FIG. 10, an output without bit information is provided at the beginning of the carrier signal from the remote controller 7 for a period of a predetermined multiple of the sampling period depending on the clock frequency in the standby state. A signal is provided, and then a carrier signal having bit information is transmitted. As a result, even in a low-speed mode with a slow clock frequency, even a signal having information cannot be recognized, but it can be detected only that an output signal without this bit information is received. Therefore, when it is detected that an output signal without bit information is received, the operation clock is switched to the main clock oscillation circuit 32 again, and the sampling cycle is returned to the normal cycle, so that the transmission is continued. A carrier signal having bit information can be recognized.

  As described above, by changing only the carrier signal from the remote controller 7, the signal receiving unit 8 can be used as it is, so that an inexpensive system configuration can be achieved.

  In this configuration, as described above, the standby state is restored by an output signal without bit information. For this reason, when noise or other infrared signals are received, it is not possible to determine whether the output signal has no bit information transmitted from the remote controller 7, and there is a possibility of returning from the standby state. Therefore, as shown in FIG. 11, the carrier signal returned from the standby state and transmitted thereafter is the carrier signal from the remote controller 7 paired with the indoor unit 2 in accordance with the format of the Japan Home Appliances Association. If it is different, the control immediately returns to the standby state. In addition, as shown in FIG. 12, a signal without bit information is detected by combining a Hi period and a Lo period, for example, detecting three consecutive His and then detecting two consecutive Los. It is also possible to adopt a configuration that makes it difficult to recover due to noise.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Indoor unit 3 Outdoor unit 4 Connection piping 5 Power transmission cable 6 Communication cable 7 Remote control 8 Signal receiving part 9 Case base 10 Heat exchanger 11 Indoor ventilation fan 11a Blowing air path 12 Dew tray 13 Cosmetic frame 14 Front panel 15 Air inlet 16 Air outlet 17 Left and right wind direction plate 18 Vertical wind direction plate 19 Infrared light receiving element 20 Display unit 21 Control board 22 Inrush current prevention circuit 24 Power supply circuit 25 Fan motor drive circuit 26 Indoor fan motor 27 Two-way valve drive circuit 28 Two-way valve 29 Microcomputer 30 Reset circuit 31 EEPROM
32 Main clock oscillation circuit 33 Sub clock oscillation circuit 34 Suction temperature thermistor 35 Heat exchanger thermistor 36 Humidity sensor 37 Buzzer 38 Stepping motor drive circuit 39 Front panel motors 40a, 40b, 40c Vertical wind direction plate motors 41a, 41b Left and right wind direction plates Motor 42 indoor / outdoor communication circuit 43 outlet 44 power plug 45 power cord 46 power relay 47a, 47b X capacitor 48 common mode choke coils 49a, 49b discharge resistor 50 commercial power supply 51 smoothing capacitor 52 diode bridge 53 rectifier circuit 54 switching power supply IC
55 Switching transformer 56 Switching power supply circuit 57 Main control power supply regulator 58 Sub control power supply regulator 59 18.5V power supply 60 12V power supply 61 8.5V power supply 62 5.3V power supply 63 3.3V power supply 64a, 64b, 64c Power supply cutoff Switches 65a, 65b Backflow prevention diode 66 Emergency operation switch

Claims (6)

An air conditioner including a line filter capacitor in an AC power source, a discharge resistor that discharges charges accumulated in the line filter capacitor, and a switch for supplying power to the outdoor unit,
An air conditioner characterized in that the line filter capacitor is provided separately for a power circuit on the indoor unit side and a subsequent stage of the switch.   The air conditioner according to claim 1, wherein a discharge resistor is provided in a stage subsequent to the switch in parallel with a line filter capacitor provided in a stage subsequent to the switch.   The air conditioner according to claim 1 or 2, wherein the switch is provided on an indoor unit side.   The air conditioner according to any one of claims 1 to 3, wherein a relay is used for the switch.   The air conditioner according to any one of claims 1 to 4, wherein the switch is turned on when the indoor fan motor operates.   The air conditioner according to any one of claims 1 to 5, wherein the switch is turned on except during standby.

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