Indoor unit and air conditioner

Abstract

An indoor unit (100) is provided with: a tactile device (11) that is a device that can be touched by a user; a noise removing capacitor (13) that releases first noise mixed from an AC power supply (1) to the earth; and a noise removing capacitor (14) that releases second noise mixed from the tactile device (11) to the earth, wherein the path in which the first noise passes through the noise removing capacitor (13) and the path in which the second noise passes through the noise removing capacitor (14) are different from each other.

Description

Indoor units and air conditioners

[0001] The present disclosure relates to an indoor unit and an air conditioner into which noise can potentially enter from both a power source and a location that a user touches.

[0002] Noise from sources such as lightning can enter an air conditioner via the power supply. Furthermore, if the air conditioner is equipped with a device that can be touched by the user, static electricity or other noise can enter the unit when the user touches the device. Since this noise can cause malfunctions in the air conditioner's control circuit, it is desirable to properly dissipate it to a ground.

[0003] The television disclosed in Patent Document 1 includes a radio wave receiving wiring board and a power supply wiring board having a power supply circuit section, and a first connection point of a ground wire wired from the power supply circuit section is connected to the ground sides of the tuner section and the electronic circuit section of the receiving wiring board on the receiving wiring board. This makes it difficult for noise such as abnormal current caused by static electricity and electromagnetic waves emitted from the tuner section and the electronic circuit section to be transmitted to the electronic circuit section.

[0004] Japanese Patent Application Publication No. 10-322081

[0005] However, with the technology of Patent Document 1, if noise such as static electricity or lightning is mixed in, the noise flows through the ground pattern on the board, which has the problem that the control circuit may malfunction depending on the arrangement of the pattern.

[0006] The present disclosure has been made in consideration of the above, and aims to provide an indoor unit that can prevent a control circuit from malfunctioning even when there is a possibility of noise being introduced from both the power source and from points that the user touches.

[0007] In order to solve the above-mentioned problems and achieve the object, the indoor unit of the present disclosure includes a user-touchable device, a first noise removal capacitor that dissipates first noise mixed in from the AC power supply to the ground, and a second noise removal capacitor that dissipates second noise mixed in from the device to the ground. The path through which the first noise passes through the first noise removal capacitor and the path through which the second noise passes through the second noise removal capacitor are different paths.

[0008] The indoor unit according to the present disclosure has the advantage of being able to prevent malfunction of the control circuit even when there is a possibility of noise being mixed in from both via the power supply and from a location that the user touches.

[0009] FIG. 1 is a diagram showing the external configuration of an indoor unit provided in an air conditioner according to a first embodiment. FIG. 2 is a diagram showing the internal structure of the indoor unit when the design panel shown in FIG. 1 is opened. FIG. 3 is a diagram showing the circuit configuration of an indoor unit provided in an air conditioner according to a first embodiment. FIG. 4 is a diagram showing the configuration of an air conditioner according to a first embodiment. FIG. 5 is a diagram showing the circuit configuration of an indoor unit provided in an air conditioner of a comparative example. FIG. 6 is a diagram showing the circuit configuration of an indoor unit provided in an air conditioner according to a second embodiment.

[0010] Hereinafter, an indoor unit and an air conditioner according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1 Fig. 1 is a diagram showing the external configuration of an indoor unit provided in an air conditioner according to embodiment 1. Fig. 2 is a diagram showing the internal structure of the indoor unit when the design panel shown in Fig. 1 is opened. The air conditioner includes an indoor unit 100 and an outdoor unit (not shown).

[0012] The indoor unit 100 is equipped with a design panel (top panel) 101. The design panel 101 is attached to the main body of the indoor unit 100 so as to be able to open and close freely. Devices that can be touched by the user are arranged inside the indoor unit 100. Hereinafter, the devices that can be touched by the user are referred to as tactile devices 11.

[0013] The tactile device 11 is configured to be detachable by the user, for example. The tactile device 11 is configured using, for example, two electric wires (or a metal plate, metal-plated resin, etc.), and suppresses viruses in the air and collects dust and other particles by applying a high voltage between the two electric wires. When the tactile device 11 is touched by the user, static electricity may be input into the indoor unit 100.

[0014] 1 and 2, components constituting the refrigeration cycle of the air conditioner, such as an outdoor unit, a heat exchanger, a fan, and refrigerant piping, are general-purpose components and therefore will not be described.

[0015] 3 is a diagram showing the circuit configuration of an indoor unit included in the air conditioner according to the first embodiment. The indoor unit 100 is connected to an AC power supply 1. The indoor unit 100 includes a filter protection circuit 2, a diode bridge 3, a smoothing electrolytic capacitor 4, a transformer circuit 5, a voltage generating diode 6, a smoothing capacitor 7, a control circuit 8, a power supply feedback circuit 9, and a high-voltage power supply circuit 10. The indoor unit 100 also includes a tangible device 11, a coupling capacitor (bypass capacitor) 12, noise removal capacitors 13 and 14, and a ground terminal E1. The noise removal capacitor 13 is a first noise removal capacitor, and the noise removal capacitor 14 is a second noise removal capacitor.

[0016] In the indoor unit 100, components other than the tactile device 11 are arranged on a substrate (hereinafter referred to as a circuit board). Specifically, the indoor unit 100's circuit board includes a filter protection circuit 2, a diode bridge 3, a smoothing electrolytic capacitor 4, a transformer circuit 5, a voltage-generating diode 6, a smoothing capacitor 7, a control circuit 8, a power feedback circuit 9, a high-voltage power supply circuit 10, a coupling capacitor 12, noise-removal capacitors 13 and 14, and a ground terminal E1. Note that the components of the indoor unit 100 other than the tactile device 11 may be distributed across multiple circuit boards. The ground terminal E1 is an earth connection that connects the circuit board to an earth (such as a metal block). The earth terminal E1 and the earth are connected by a cable or the like. The earth terminal E1 is a terminal that releases noise transmitted via the noise-removal capacitors 13 and 14 to the earth. The earth may be arranged inside the indoor unit 100 or in the outdoor unit.

[0017] The filter protection circuit 2 is connected to the AC power supply 1 by two connection wires and is also connected to the diode bridge 3 by two connection wires. The diode bridge 3 is connected to the transformer circuit 5 by two connection wires and is also connected to the filter protection circuit 2 by two connection wires.

[0018] One of the connection lines connecting the diode bridge 3 and the transformer circuit 5 has a connection point P1, and the other has an upstream connection point P2 and a downstream connection point P4. The smoothing electrolytic capacitor 4 is connected to the connection points P1 and P2. The connection point P2 is also connected to ground (GND) and the connection point P4.

[0019] The transformer circuit 5 is connected to the connection point P3 via a voltage generating diode 6. The transformer circuit 5 is also connected to the connection points P1 and P4. The connection point P4 is connected to the connection point P5 via a coupling capacitor 12. The connection point P4 is connected to the connection point P2 and the coupling capacitor 12. The smoothing capacitor 7 is also connected to the connection points P3 and P5.

[0020] The connection point P3 is connected to the connection point P6, and the connection point P5 is connected to the connection point P7. A power supply feedback circuit 9 is connected to the connection points P6 and P7. The connection point P7 is connected to the connection point P8. A control circuit 8 is connected to the connection points P6 and P8 and the high-voltage power supply circuit 10.

[0021] The high-voltage power supply circuit 10 is connected to the tactile device 11. The high-voltage power supply circuit 10 is also connected to a connection point P9. The connection point P9 is connected to a connection point P8 and a noise removal capacitor 14. The noise removal capacitor 14 is connected to a connection point P10 via a connection line L1.

[0022] The noise removal capacitor 13 is connected to the connection points P5 and P10 and the earth terminal E1, which is grounded.

[0023] The filter protection circuit 2 filters out unnecessary current from the AC power supply 1 and protects downstream circuits. The filter protection circuit 2 is composed of a choke coil, an inrush current prevention resistor, an NTC (Negative Temperature Coefficient) thermistor, and other components. The choke coil is an inductor that allows direct current or current (power, signal) with a frequency lower than the desired frequency to pass and blocks current with a frequency higher than the desired frequency. The inrush current prevention resistor is a resistor that prevents inrush current when the power is turned on. The NTC thermistor is a thermistor with negative temperature characteristics (temperature compensation). The filter protection circuit 2 sends the current from the AC power supply 1 to the diode bridge 3.

[0024] The diode bridge 3 sends the current from the filter protection circuit 2 to the smoothing electrolytic capacitor 4. The diode bridge 3 and the smoothing electrolytic capacitor 4 perform full-wave rectification.

[0025] The transformer circuit 5 transforms the primary voltage on the input side, which is the voltage from the diode bridge 3, into a secondary voltage on the output side. The transformer circuit 5 is configured using an isolation transformer, snubber, power supply integrated circuit (IC), etc. The transformer circuit 5 obtains voltage fluctuation status from the secondary-side power supply feedback circuit 9 and controls the transformation operation based on the voltage fluctuation status to obtain a stable DC voltage. Note that the connection lines between the transformer circuit 5 and the power supply feedback circuit 9 are not shown in the figure.

[0026] The voltage generating diode 6 and smoothing capacitor 7 generate a desired DC voltage (e.g., 12 V) from the voltage transformed by the transformer circuit 5. The coupling capacitor 12 passes only the signal current and blocks the DC current. That is, the coupling capacitor 12 utilizes the capacitor's ability to block the DC component to extract and pass only the AC component from the DC and AC components. The coupling capacitor 12 removes switching noise generated on the primary side.

[0027] The power supply feedback circuit 9 detects the voltage on the secondary side of the transformer circuit 5 and outputs a feedback signal to the transformer circuit 5 to control the input on the primary side of the transformer circuit 5. The control circuit 8 operates using the voltage transformed by the transformer circuit 5.

[0028] The control circuit 8 is configured using a DC (Direct Current) converter, a microcomputer, a thermistor, a stepping motor, etc. The control circuit 8 generates a low voltage (e.g., 5 V) required in a stage subsequent to the control circuit 8, controls a fan motor (not shown), a refrigerant circuit (not shown), etc., detects temperature using a thermistor (not shown), controls air direction using a stepping motor (not shown), and controls the high-voltage power supply circuit 10. The high-voltage power supply circuit 10 generates a low voltage of about 10 V to a high voltage of about 6000 V. The high-voltage power supply circuit 10 drives the tactile device 11 with the generated high voltage.

[0029] The noise removal capacitors 13, 14 release noise components that are generated on the circuit of the indoor unit 100 and pass through the circuit, and noise components that are mixed in from the outside and pass through the circuit, to the ground via the ground terminal E1.

[0030] For example, the noise removal capacitor 13 dissipates noise (noise components) 150 transmitted via the AC power supply 1, the filter protection circuit 2, the diode bridge 3, the connection point P1, the transformer circuit 5, the connection point P4, the coupling capacitor 12, and the connection point P5 to the ground via the connection point P10 and the ground terminal E1.

[0031] Furthermore, the noise removal capacitor 14 dissipates noise (noise components) 160 transmitted via the tactile device 11, the high-voltage power supply circuit 10, and the connection point P9 to the ground via the connection line L1, the connection point P10, and the ground terminal E1. In this way, the ground terminal E1 in the first embodiment is a ground terminal common to the noise removal capacitors 13 and 14.

[0032] In the indoor unit 100, after the AC power supply 1 is turned on, the current from the AC power supply 1 is sent to the diode bridge 3 via the filter protection circuit 2. This current is full-wave rectified by the diode bridge 3 and the smoothing electrolytic capacitor 4.

[0033] The current from the AC power supply 1 is full-wave rectified, then voltage converted by a transformer circuit 5, and converted to a desired DC voltage by a voltage generating diode 6 and a smoothing capacitor 7, and sent to a high-voltage power supply circuit 10. The high-voltage power supply circuit 10 generates a high voltage from the low voltage converted by the voltage generating diode 6 and the smoothing capacitor 7, and drives a tactile device 11 with the generated high voltage.

[0034] The indoor unit 100 dissipates both noise 150 introduced from the AC power supply 1, such as lightning, and noise 160 introduced from a location (touchable device 11) that the user touches, such as static electricity, to the earth via separate paths so as not to affect the control circuit 8. This makes the indoor unit 100 an air conditioner that is robust against external disturbances such as noise 150 and 160. Noise 150 introduced from the AC power supply 1, such as lightning, is the first noise, and noise 160 introduced from the touchable device 11 that the user touches, such as static electricity, is the second noise.

[0035] 4 is a diagram showing the configuration of an air conditioner according to the first embodiment. The air conditioner 500 includes an indoor unit 100 and an outdoor unit 400. In the air conditioner 500, the indoor unit 100 and the outdoor unit 400 are connected via a signal line or the like. Note that if the outdoor unit 400 is earthed, the indoor unit 100 and the outdoor unit 400 are connected via an earth cable or the like.

[0036] Here, the circuit configuration of an air conditioner of the comparative example will be described. Fig. 5 is a diagram showing the circuit configuration of an indoor unit provided in the air conditioner of the comparative example. Compared to indoor unit 100, indoor unit 300 provided in the air conditioner of the comparative example does not have connection points P9, P10 or noise removal capacitor 14. Furthermore, indoor unit 300 does not have a connection line connecting connection point P9 and noise removal capacitor 14, nor does it have connection line L1 connecting connection point P10 and noise removal capacitor 14.

[0037] The operation of the indoor unit 300 of the comparative example when noise 150, 161 is mixed into the indoor unit 300 from outside the indoor unit 300 will be described. Noise 150 mixed into the AC power supply 1 from lightning, other equipment, etc. flows toward the ground. That is, in the indoor unit 300 provided in the air conditioner, as in the indoor unit 100, noise 150 transmitted via the AC power supply 1, filter protection circuit 2, diode bridge 3, connection point P1, transformer circuit 5, connection point P4, coupling capacitor 12, and connection point P5 is released to the ground by the noise removal capacitor 13 via connection point P10 and ground terminal E1.

[0038] Meanwhile, in the indoor unit 300, noise 161 such as static electricity mixed in from the tactile device 11 also flows to the ground via the noise removal capacitor 13. Specifically, in the indoor unit 300, the noise 161 transmitted via the high-voltage power supply circuit 10, connection point P8, connection point P7, and connection point P5 is released by the noise removal capacitor 13 to the ground via connection point P10 and ground terminal E1.

[0039] 5, noise 161 introduced from the tactile device 11 passes near the control circuit 8 before flowing to the ground. For this reason, in the indoor unit 300, low-voltage devices such as a microcomputer (not shown) included in the control circuit 8 may malfunction or even fail due to the influence of noise 161.

[0040] Furthermore, in the indoor unit 300, if the noise removal capacitor 13 is positioned closer to the high-voltage power supply circuit 10, noise 150 mixed in from lightning coming from the AC power supply 1 or from other devices will affect the control circuit 8. In this case, in the indoor unit 300, low-voltage devices such as a microcomputer provided in the control circuit 8 may malfunction or, in some cases, break down due to the influence of the noise 150.

[0041] Furthermore, the frequency components of noise 150 mixed in from lightning, other equipment, etc. are low-frequency, ranging from several hundred Hz to 1 MHz, whereas the static electricity mixed in from tactile device 11 via the human body is high-frequency, ranging from several hundred MHz. Therefore, if only one noise-removal capacitor, noise-removal capacitor 13, is placed in indoor unit 300, it is difficult to select a noise-removal capacitor 13 with a capacity that can adequately remove noise 150, 161 mixed in from both via the power supply and from locations that the user touches, regardless of where noise-removal capacitor 13 is placed, and malfunctions and failures cannot be avoided.

[0042] As described above, when noise 150 is introduced into the indoor unit 100 from lightning or other equipment, the introduced noise 150 flows from the AC power supply 1 through the noise removal capacitor 13 toward the ground. Furthermore, in the indoor unit 100, noise 160, such as static electricity, introduced from the tangible device 11 flows toward the ground through the noise removal capacitor 14. By making the capacitance of the noise removal capacitor 13 larger than that of the noise removal capacitor 14, low-frequency noise components, such as those from lightning, do not pass through the noise removal capacitor 13 and flow to subsequent stages. Furthermore, high-frequency noise components, such as static electricity, pass through the noise removal capacitor 14 and do not affect the control circuit 8, etc.

[0043] In this way, the indoor unit 100 of embodiment 1 is provided with noise removal capacitors 13, 14, and is therefore able to dissipate both noise 150, such as lightning noise, that is mixed in from the AC power supply 1, and noise 160, such as static electricity, that is mixed in from the tangible device 11, to the earth so as not to adversely affect the control circuit 8. As a result, the indoor unit 100 can operate stably even in the event of disturbances such as noise 150 and 160, as the control circuit 8 will not malfunction or fail.

[0044] In other words, in the indoor unit 100, the path through which noise 150 mixed in from the AC power supply 1 passes through the noise removal capacitor 13 is different from the path through which noise 160 mixed in from the tactile device 11 passes through the noise removal capacitor 14. Therefore, even if there is a possibility that noise 150, 160 may be mixed in from both via the AC power supply 1 and from a location that the user touches (tactile device 11), the control circuit 8 can be prevented from malfunctioning.

[0045] Second Embodiment Next, a second embodiment will be described with reference to Fig. 6. In the second embodiment, the noise removal capacitor 13 and the noise removal capacitor 14 are connected to separate earths.

[0046] Fig. 6 is a diagram showing the circuit configuration of an indoor unit provided in an air conditioner according to embodiment 2. Of the components in Fig. 6, components that achieve the same functions as those in the indoor unit 100 according to embodiment 1 shown in Fig. 3 are assigned the same reference numerals, and duplicated explanations will be omitted.

[0047] Unlike the indoor unit 100 of the first embodiment, the indoor unit 200 of the second embodiment does not have the connection line L1 and the connection point P10. Furthermore, in the indoor unit 200, the noise removal capacitor 14 is connected to the ground via a ground terminal E2 that is different from the ground terminal E1 to which the noise removal capacitor 13 is connected. That is, in the indoor unit 200, the noise removal capacitor 13 is connected to the ground terminal E1, which is the first ground terminal (first ground connection portion), and the noise removal capacitor 14 is connected to the ground terminal E2, which is the second ground terminal (second ground connection portion). The ground terminal E2 is a terminal that releases noise 170, such as static electricity, that is introduced from the tactile device 11 to the ground. The ground terminal E1 of the second embodiment is a terminal that releases noise 150, such as lightning noise, that is introduced from the AC power supply 1 to the ground.

[0048] The noise elimination capacitor 13 and the noise elimination capacitor 14 are connected to different earths via different earth terminals. The noise elimination capacitors 13 and 14 may also be connected to the same earth via different earth terminals. The earth (earth metal part) is a metal plate, a metal block, or the like. Specifically, the earth is a housing (sheet metal case) that surrounds the power supply board and is made of a metal plate, or a heat exchanger that is made of a metal block. When the noise elimination capacitors 13 and 14 are connected to earths via different earth terminals, one of the noise elimination capacitors 13 and 14 is connected to the housing that surrounds the power supply board, and the other is connected to the heat exchanger of the indoor unit.

[0049] In this way, in the second embodiment, the noise removal capacitors 13 and 14 are connected to different earths via different earth terminals. In other words, the indoor unit 200 may be configured so that the noise removal capacitors 13 and 14 are connected to earths at different locations on the earth, not on the circuit, but by separate cables or the like.

[0050] 6, on the circuit board on which the circuit of the indoor unit 200 is arranged, the earth terminal E1 connected to the noise removal capacitor 13 and the earth terminal E2 connected to the noise removal capacitor 14 are arranged in different positions. Then, the earth terminal E1 and the earth terminal E2 are each separately connected to an earth metal part (such as a heat exchanger in the case of an air conditioner) that is connected to the earth terminal of the AC power supply 1. In other words, the wiring for dissipating noises 150, 170 from the noise removal capacitors 13, 14 is connected to the earth metal part with separate wiring, not on the circuit board of the indoor unit 200.

[0051] In this way, in the indoor unit 200 of embodiment 2, the earth terminal E1 connected to the noise removal capacitor 13 and the earth terminal E2 connected to the noise removal capacitor 14 are located in different positions and are connected to the earth metal part by separate wiring, so that noise can be prevented from being mixed in from the earth metal part more effectively than in the indoor unit 100 of embodiment 1.

[0052] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0053] 1 AC power supply, 2 filter protection circuit, 3 diode bridge, 4 smoothing electrolytic capacitor, 5 transformer circuit, 6 voltage generation diode, 7 smoothing capacitor, 8 control circuit, 9 power supply feedback circuit, 10 high-voltage power supply circuit, 11 tangible device, 12 coupling capacitor, 13, 14 noise removal capacitor, 100, 200, 300 indoor unit, 101 design panel, 150, 160, 161, 170 noise, 400 outdoor unit, 500 air conditioner, E1, E2 earth terminal, L1 connection wire, P1 to P10 connection points.

Claims

1. A user-touchable device; a first noise removing capacitor for discharging a first noise mixed in from the AC power supply to a ground; a second noise removing capacitor for discharging a second noise input from the device to the ground; Equipped with a path through which the first noise passes through the first noise removing capacitor and a path through which the second noise passes through the second noise removing capacitor are different paths; Indoor unit.

2. the first noise removal capacitor and the second noise removal capacitor are connected to a common ground terminal; The indoor unit according to claim 1.

3. the first noise removal capacitor is connected to a first ground terminal, and the second noise removal capacitor is connected to a second ground terminal; The indoor unit according to claim 1.

4. The capacitance of the first noise removal capacitor is greater than the capacitance of the second noise removal capacitor. The indoor unit according to claim 1.

5. the first ground terminal and the second ground terminal are connected by separate wiring to a ground metal part that is disposed at a position different from a circuit board on which the first ground terminal and the second ground terminal are disposed; The indoor unit according to claim 3.

6. An indoor unit according to any one of claims 1 to 5; The outdoor unit, With Air conditioner.