Air conditioner

Abstract

The utility model discloses an air conditioner, which comprises a water pan, a drainage pump; a water level detection unit; the main controller is provided with a first control port, a second control port and a detection port; the first driving unit is used for driving the drainage pump to operate and is provided with a power input end and a PWM input end; the first control unit is controlled by detection output of the water level detection unit, when the water level detection unit is normal and the detected water level does not reach a preset water level, the output end of the first control unit is grounded, and when the water level detection unit is disconnected, the first control unit outputs a control power supply; a dual diode; a second control unit; and the third control unit is controlled by detection output, the input end of the third control unit is connected with the second control port, and the output end of the third control unit is connected with the PWM input end through an optocoupler. According to the utility model, when the water level detection unit is abnormally disconnected or a program flies, the hardware drainage control circuit is adopted to control the drainage pump to drain water.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning equipment, in particular to an air conditioner. Background Art

[0002] In the related art, when the air conditioner is in the cooling mode, water vapor in the air touches the low-temperature evaporator, forming condensed water that flows into the water receiving tray of the indoor unit. The condensed water in the water receiving tray is connected to the outside of the outdoor unit through a pipe and discharged to the outside. If the drainage is not smooth, the condensed water will remain in the water receiving tray, which may cause peculiar smell, bacteria growth, or rust.

[0003] The indoor unit of the traditional split air conditioner is designed with an installation structure to drain the condensed water from high to low under the action of gravity to the outside. However, for a new type of air conditioner (such as a central air conditioner), the total amount of drained water is relatively large, and a drainage pump for forcibly discharging the drained water to the outside is usually set.

[0004] Generally, a water level detection unit is arranged in the water receiving tray, which is configured to detect the water level in the water receiving tray and output a trigger signal to start the drainage pump to drain water when the actual water level is above the set water level, and stop outputting the trigger signal and not start the drainage pump when the water level is below the set water level. In this case, the drainage will depend on the signal sent by the water level detection unit for control. Therefore, once the amount of condensed water is too large, causing the water level detection unit to malfunction and stop outputting the trigger signal, or the program malfunctions and runs away, at this time, the drainage pump is no longer controlled, and there is a risk of abnormal drainage overflow. Summary of the Utility Model

[0005] Some embodiments of the present application provide an air conditioner, which satisfies the reliable drainage of the drainage pump under normal and abnormal disconnection conditions of the float switch by designing a reliable drainage control circuit.

[0006] To achieve the above-mentioned utility model purpose, the embodiments of the present utility model adopt the following technical solutions:

[0007] Some embodiments of the present application relate to an air conditioner, including:

[0008] A water receiving tray, which is used to receive the condensed water generated when the air flow passes through the evaporator during the refrigeration operation of the air conditioner;

[0009] A drainage pump, which is installed in the water receiving tray and is used to discharge the condensed water in the water receiving tray to the outside;

[0010] A water level detection unit, which is used to detect the water level in the water receiving tray;

[0011] A main controller, which has a first control port, a second control port, and a detection port connected to the detection output end of the water level detection unit;

[0012] A first driving unit, which is used to drive the drainage pump to operate and has a power input terminal and a PWM input terminal;

[0013] A first control unit, which is controlled by the detection output of the water level detection unit. When the water level detection unit is normal and the detected water level does not reach the preset water level, the output terminal of the first control unit is grounded. When the water level detection unit is abnormally disconnected or the detected water level reaches the preset water level, the first control unit outputs a control power supply;

[0014] A double diode, which includes a first diode and a second diode connected in parallel in the same direction. The anode of the first diode is connected to the output terminal of the first control unit, and the anode of the second diode is connected to the first control port;

[0015] A second control unit, whose control terminal is connected to the common connection point of the cathode of the first diode and the cathode of the second diode, and the output terminal is connected to the power input terminal;

[0016] A third control unit, which is controlled by the detection output. The input terminal of the third control unit is connected to the second control port, and the output terminal is connected to the PWM input terminal through an optocoupler.

[0017] For the air conditioner involved in the embodiment of the present application, when the water level detection unit is normal, if the program runs away, that is, the signals output by the first control port and the second control port are not controlled. As the water level in the water receiving tray rises to the preset water level detected by the water level detection unit, at this time, the first control unit outputs a control power supply to provide a power signal for the first driving unit, and outputs a fixed high level to the PWM input terminal of the first driving unit through the optocoupler, so as to realize the drainage work of the drainage pump through the hardware drainage control circuit without program control;

[0018] Similarly, when the water level detection unit is abnormally disconnected, the drainage pump can also be forced to start draining through the hardware drainage control circuit without program control, realizing reliable drainage.

[0019] When the water level detection unit is normal, the control signal output through the first control port provides a power signal for the first driving unit, and the control signal output through the second control port provides a PWM signal for the first driving unit, realizing the drainage control of the drainage pump.

[0020] The hardware drainage control circuit formed by the first control unit, the second control unit, the third control unit and the first driving unit can ensure the reliable drainage of the drainage pump regardless of whether the water level detection unit is normal, or whether the program runs away, etc.

[0021] In some embodiments of the present application, the water level detection unit is a float switch;

[0022] When the float switch is normal and the detected water level does not reach the preset water level, the float switch outputs a high level;

[0023] When the float switch is normal and the detected water level reaches the preset water level, the float switch outputs a low level;

[0024] When the float switch is abnormally disconnected, the detection output end of the float switch is pulled low to output a low level through a pull-down circuit.

[0025] The water level detection unit commonly uses a float switch. Of course, the water level detection unit can also choose to use a detection element (such as a proximity sensor) that can detect the position of the float, and the float can freely float up and down with the water level in the condensed water in the water receiving tray.

[0026] In some embodiments of the present application, the first control unit includes a switch element that conducts when a high level is applied. When the float switch outputs a high level, the switch element that conducts when a high level is applied conducts. When the float switch outputs a low level, the switch element that conducts when a high level is applied disconnects;

[0027] The third control unit includes a switch element that conducts when a high level is applied. When the float switch outputs a high level, the switch element that conducts when a high level is applied conducts. When the float switch outputs a low level, the switch element that conducts when a high level is applied disconnects.

[0028] The above-mentioned switch element that conducts when a high level is applied can be an NPN transistor.

[0029] In some embodiments of the present application, the second control unit further includes:

[0030] A first switch control element, which is a switch element that conducts when a high level is applied. The control end of the first switch control element is connected to the common connection point, the first end is connected to a pull-up resistor, and the second end is grounded;

[0031] A second switch control element, which is a switch element that conducts when a low level is applied. The control end is connected to the common connection point of the first end of the first switch control element and the pull-up resistor. The first end is connected to the power supply, and the second end is connected to a pull-down resistor. The power supply input end is connected to the common connection point of the pull-down resistor and the second end of the second switch control element.

[0032] In some embodiments of the present application, a filtering unit is provided on the input side of the power supply input end.

[0033] The filtering unit is used to filter out the clutter signals entering the power supply input end to ensure stable power supply for the first driving unit.

[0034] In some embodiments of the present application, the air conditioner further includes:

[0035] A current protection unit is arranged on the line between the output end of the second control unit and the power input end, and is used to automatically cut off the power supply to the first driving unit when the current on the line reaches a specified value.

[0036] By arranging the current protection unit, the first driving unit and the drain pump are protected.

[0037] In some embodiments of the present application, the current protection unit is a PTC thermistor.

[0038] The temperature of the PTC thermistor will increase when the current increases. After reaching its Curie temperature, it enters the protection state and automatically switches the first driving unit. When the temperature drops below the Curie temperature, it exits the protection state and automatically conducts the first driving unit.

[0039] Some embodiments of the present application further relate to an air conditioner, including:

[0040] A water receiving tray, which is used to receive the condensed water generated when the air flow passes through the low-temperature evaporator during the refrigeration operation of the air conditioner;

[0041] A first drain pump and a second drain pump, which are respectively installed in the water receiving tray and are used to drain the condensed water in the water receiving tray to the outside;

[0042] A water level detection unit, which is used to detect the water level in the water receiving tray;

[0043] A main controller, which has a first control port, a second control port and a detection port connected to the detection output end of the water level detection unit;

[0044] A first driving unit, which is used to drive the first drain pump to operate and has a power input end and a PWM input end;

[0045] A second driving unit. When the water level detection unit is normal and the detected water level does not reach the preset water level, the second driving unit drives the coil of the relay to be energized or de-energized. When the water level detection unit is abnormally disconnected or the detected water level reaches the preset water level, the coil is de-energized, and the normally closed switch of the relay is connected to the power supply line of the second drain pump;

[0046] A first control unit, which is controlled by the detection output of the water level detection unit. When the water level detection unit is normal and the detected water level does not reach the preset water level, the output end of the first control unit is grounded. When the water level detection unit is abnormal or the detected water level reaches the preset water level, the first control unit outputs a control power supply;

[0047] A double diode, which includes a first diode and a second diode connected in parallel in the same direction. The anode of the first diode is connected to the output terminal of the first control unit, and the anode of the second diode is connected to the first control port;

[0048] A second control unit, whose control terminal is connected to the common connection point of the cathodes of the first diode and the second diode, and the output terminal is connected to the power input terminal;

[0049] A third control unit, which is controlled by the detection output. The input terminal of the third control unit is connected to the second control port, and the output terminal is connected to the PWM input terminal through an optocoupler.

[0050] The air conditioner involved in the embodiments of the present application controls the double water pumps to drain water by using the hardware drainage control circuit when the water level detection unit is abnormal or the program runs away, improving the drainage efficiency while achieving reliable drainage.

[0051] In some embodiments of the present application, the second driving unit includes:

[0052] A driving chip, whose input pin is connected to an output terminal of the main controller. The output pin corresponding to the input pin is connected to the common connection point of one end of the coil and the anode of the freewheeling diode. The common connection point of the other end of the coil and the cathode of the freewheeling diode is connected to the detection output terminal.

[0053] In some embodiments of the present application, the air conditioner further includes:

[0054] A pull-down circuit, which is arranged between the detection output terminal and the detection port, and is used to pull down the signal output by the detection output terminal when the signal output by the detection output terminal is uncertain.

[0055] The provided pull-down circuit is used to output a definite low level when the water level detection unit is abnormally disconnected.

[0056] After reading the specific embodiments of the present utility model in conjunction with the accompanying drawings, other features and advantages of the present utility model will become clearer. Description of the Drawings

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0058] Figure 1 It is a principle block diagram of an existing air conditioner;

[0059] Figure 2 Structural diagram of the first drainage pump arranged in the water receiving tray in the air conditioner embodiment proposed according to the present application;

[0060] Figure 3 Principle block diagram of the air conditioner embodiment proposed according to the present application Figure 1 ;

[0061] Figure 4 Hardware circuit for controlling the first drainage pump in the air conditioner embodiment proposed according to the present application Figure 1 ;

[0062] Figure 5 Schematic diagram of driving the first driving unit under different float switch states in the air conditioner embodiment proposed according to the present application;

[0063] Figure 6 Hardware circuit for controlling the first drainage pump in the air conditioner embodiment proposed according to the present application Figure 2 ;

[0064] Figure 7 Structural diagram of the first drainage pump and the second drainage pump arranged in the water receiving tray in the air conditioner embodiment proposed according to the present application;

[0065] Figure 8 Principle block diagram of the air conditioner embodiment proposed according to the present application Figure 2 ;

[0066] Figure 9 Hardware circuit diagram for controlling the second drainage pump in the air conditioner embodiment proposed according to the present application;

[0067] Figure 10 Schematic diagram of driving the second driving unit under different float switch states in the air conditioner embodiment proposed according to the present application.

[0068] Reference numerals:

[0069] 100, water receiving tray; 210, first drainage pump; 220, second drainage pump; 300, water level detection unit; 400, main controller; 510, first control unit; 520, second control unit; 530, third control unit; 540, first driving unit; 550, second driving unit; 560, filtering unit; 570, pull-down circuit; 580, PTC thermistor. Detailed implementation manners

[0070] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0071] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0072] The terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0073] In the description of the present application, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0074] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on the top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is lower than that of the second feature.

[0075] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0076] <Basic working principle of an air conditioner>

[0077] See Figure 1 , which shows a block diagram of an air conditioner.

[0078] The air conditioner performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0079] The low-temperature and low-pressure refrigerant enters the compressor, and the compressor compresses the refrigerant into a high-temperature and high-pressure state of refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0080] The expansion valve expands the high-temperature and high-pressure liquid-phase refrigerant formed by condensation in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by using the latent heat of evaporation of the refrigerant for heat exchange with the material to be cooled. During the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0081] The outdoor unit of the air conditioner refers to the part of the refrigeration cycle including the compressor and the outdoor heat exchanger. The indoor unit of the air conditioner includes the indoor heat exchanger, and the expansion valve can be provided in the indoor unit or the outdoor unit.

[0082] The indoor heat exchanger and the outdoor heat exchanger are used as condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner serves as a heater in the heating mode. When the indoor heat exchanger is used as an evaporator, the air conditioner serves as a cooler in the cooling mode.

[0083] The drain pump is a component of the indoor unit of an air conditioner. When the air conditioner is in the cooling mode, when the air flow passes through the surface of the indoor heat exchanger acting as an evaporator, condensate will be generated on its surface. Generally, a water receiving tray 100 for receiving this condensate will be arranged below the indoor heat exchanger. See Figure 2 .

[0084] The first drain pump 210 is installed in the water receiving tray 100 and is used to drain the condensate in the water receiving tray 100 through the drain pipe L1 along the Figure 2 arrow direction shown in the figure to the outside of the indoor unit of the air conditioner.

[0085] Generally, a water level detection unit 300 will be arranged in the water receiving tray 100 to detect the water level in the water receiving tray 100.

[0086] The water level detection unit 300 can be a float switch or a detection element (such as a proximity sensor) that can detect the position of the float. The float floats up and down freely with the water level of the condensate in the water receiving tray 100.

[0087] In some embodiments of the present application, see Figure 3 , the water level detection unit 300 is selected as a float switch.

[0088] A preset water level is preset inside the float switch, and this preset water level is the maximum water receiving level in the water receiving tray 100.

[0089] When the water level of the float switch does not reach the preset water level, it is in a short-circuit normally closed state, and the detection port MCU1 of the main controller 400 receives a high-level detection signal. When the float switch is disconnected due to the water level reaching the preset water level (this situation is recorded as normal disconnection), the detection port MCU1 of the main controller 400 receives a low-level detection signal.

[0090] When the float switch is abnormally disconnected (for example, the float switch is damaged, or the float switch and other structures interfere and are abnormally stuck, etc.), the detection port MCU1 of the main controller 400 may receive an uncertain level signal, and the detection output terminal may be floating.

[0091] In some embodiments of the present application, see Figure 4 , in order to be able to output a definite level at the detection output terminal when the float switch is abnormally disconnected, a pull-down circuit 570 can be arranged between the detection output terminal and the detection port MCU1 to realize pulling down the detection output terminal to a low level.

[0092] In some embodiments of the present application, the pull-down circuit 570 can be an RC circuit formed by a parallel connection of a pull-down capacitor and a pull-down resistor, etc.

[0093] In some embodiments of the present application, other water level detection units 300 may also be selected. When the detected actual water level does not reach the preset water level, the detection terminal MCU1 port of the main controller 400 receives a low-level detection signal, and when the actual water level reaches the preset water level and disconnects, the detection port of the main controller 400 receives a high-level detection signal. No specific limitation is made here.

[0094] In the prior art, when the water level detection unit 300 is normal and the detected water level does not reach the preset water level, the first drain pump 210 does not work; when the water level detection unit 300 is normal and the detected water level reaches the preset water level, the first drain pump 210 works, and when the water level detection unit 300 is abnormally disconnected, the first drain pump 210 cannot work either.

[0095] In the case where the first drain pump 210 works as described above, the main controller 400 mainly controls drainage by means of a program. However, when the program runs wild, it may occur that normal drainage cannot be achieved.

[0096] Therefore, in some embodiments of the present application, a reliable hardware drainage control circuit is designed. Even when the program runs wild or the water level detection unit 300 is abnormally disconnected, drainage can be achieved by relying on the hardware drainage control circuit, ensuring reliable drainage and avoiding water overflow.

[0097] See Figure 3 , in some embodiments of the present application, the hardware drainage control circuit includes a first control unit 510, a double diode, a second control unit 520, a third control unit 530, and a first drive unit 540.

[0098] In some embodiments of the present application, the water level detection unit 300 is taken as an example of a float switch for introduction.

[0099] See Figure 4 , the detection port of the float switch for outputting the detection signal is connected to the detection port MCU1 of the main controller 400.

[0100] The control end of the first control unit 510 receives the detection signal and is controlled by the detection signal.

[0101] When the float switch is normal and the detected water level does not reach the preset water level, the output end of the first control unit 510 is connected to the ground; when the float switch is normally disconnected or abnormally disconnected, the first control unit 510 outputs a control power supply.

[0102] The double diode D13 includes a first diode and a second diode arranged in parallel, and the cathodes of the first diode and the second diode are commonly connected.

[0103] The anode of the first diode is connected to the output end of the first control unit 510.

[0104] The anode of the second diode is connected to the first control port MCU3 of the main controller 400, where the first control port MCU3 is the control port for supplying power to the first driving unit 540 and is used to control the electrical energy supplied to the power input terminal VCC of the first driving unit 540 when the program is not running wild.

[0105] As described above, when the float switch is normal and the detected water level does not reach the preset water level, the output terminal of the first control unit 510 is connected to the ground. At this time, the power supply to the power input terminal VCC depends on the control signal output by the first control port MCU3.

[0106] When the float switch is normally open or abnormally open, the first control unit 510 outputs a control power supply.

[0107] The control terminal of the second control unit 520 is connected to the common connection point of the cathode of the first diode and the cathode of the second diode, and the output terminal is connected to the power input terminal VCC.

[0108] When the output terminal of the first control unit 510 is connected to the ground, the second control unit 520 controls the electrical energy of the power input terminal VCC according to the control signal output by the first control port MCU3; when the first control unit 510 outputs a control power supply, the second control unit 520 is controlled by this control power supply and outputs a fixed level to the power input terminal VCC.

[0109] That is, when the program runs wild, a fixed level is used to supply electrical energy to the first driving unit 540, and when the program does not run wild, the first drainage pump 210 can supply electrical energy to the first driving unit 540 by relying on both the internal program and the hardware control circuit.

[0110] In some embodiments of the present application, due to the use of a float switch, when it is normal and the detected water level does not reach the preset water level, the detection output terminal outputs a high level, and when it is normally open or abnormally open, the detection output terminal outputs a low level.

[0111] Therefore, the first control unit 510 may include a switching element that conducts when a high level is applied, that is, it conducts when a high level is received at the control terminal of the first control unit 510 and cuts off when a low level is received.

[0112] The switching element that conducts when a high level is applied may select an NPN transistor Q20.

[0113] See Figure 4 , in some embodiments of the present application, the base of the NPN transistor Q20 is connected to the detection output terminal, the collector is connected to the power supply Vcc through a pull-up resistor R63, and the emitter is grounded.

[0114] The position where the pull-up resistor R63 is connected to the collector serves as the output terminal of the first control unit 510.

[0115] When the NPN transistor Q20 receives a high level, it conducts, and at this time, the output terminal of the first control unit 510 is grounded; when the NPN transistor Q20 receives a low level, it is turned off, and at this time, the output terminal of the first control unit 510 is connected to the power supply Vcc through the pull-up resistor R63.

[0116] When the float switch is abnormally disconnected, the NPN transistor Q20 is also turned off. Therefore, the output terminal of the first control unit 510 is also connected to the power supply Vcc through the pull-up resistor R63.

[0117] In some embodiments of the present application, the second control unit 520 includes a first switch control element and a second switch control element.

[0118] The first switch control element is a switch element that conducts when receiving a high level. In some embodiments of the present application, referring to Figure 4 , this switch element that conducts when receiving a high level is the NPN transistor Q19.

[0119] The control terminal of the NPN transistor Q19 is connected to the common connection point of the cathodes of the first diode and the second diode. The collector is connected to the power supply Vcc through the pull-up resistor R62, and the emitter is grounded.

[0120] The second switch control element is a switch element that conducts when receiving a low level. In some embodiments of the present application, referring to Figure 4 , this switch element that conducts when receiving a low level is the PNP transistor Q18.

[0121] The base of the PNP transistor Q18 is connected to the common connection point of the collector of the NPN transistor Q19 and the pull-up resistor R62 through the current-limiting resistor R61, and the base of the PNP transistor Q18 is also connected to the common connection point of the emitter and the power supply Vcc through the base pull-up resistor R60. The collector is grounded through the pull-down resistor R59.

[0122] The common connection point of the collector of the PNP transistor Q18 and the pull-down resistor R59 is connected to the power input terminal VCC.

[0123] As follows, referring to Figure 4 and Figure 5 , describe the power supply situation for the power input terminal VCC in different cases.

[0124] (1) When the float switch is normal and the detected water level does not reach the preset water level, the detection output terminal outputs a high level. At this time, the NPN transistor Q20 is turned on, the anode of the first diode is grounded, and at this time, the NPN transistor Q19 is controlled to conduct or cut off by the control signal output from the first control port MCU3.

[0125] When controlling the NPN transistor Q19 to conduct, the PNP transistor Q18 conducts. In this way, the level Vcc is provided to the power input terminal VCC (that is, the first driving unit 540 operates); when the NPN transistor Q19 is cut off and disconnected, the PNP transistor Q18 is cut off and disconnected. In this way, the ground level is provided to the power input terminal VCC (that is, the first driving unit 540 stops operating).

[0126] That is, the power input terminal VCC is controlled by the control signal output by the first control port MCU3.

[0127] During the normal water level detection process of the float switch, if the program runs wild, the water level will continue to rise until it reaches the preset water level. At this time, the float switch is normally disconnected, the detection output terminal outputs a low level. At this time, the NPN transistor Q20 is cut off and disconnected. The anode of the first diode is connected to Vcc through the resistor R63. That is, the first control unit 510 provides control power to the second control unit 520.

[0128] After that, both the NPN transistor Q19 and the PNP transistor Q18 are conducting, providing the level Vcc to the power input terminal VCC (that is, the first driving unit 540 operates).

[0129] (2) When the float switch is normally disconnected, the detection output terminal outputs a low level. At this time, the NPN transistor Q20 is disconnected. The anode of the first diode is connected to Vcc through the resistor R63. At this time, regardless of whether the control signal output by the first control port MCU3 runs wild, both the NPN transistor Q19 and the PNP transistor Q18 are conducting, providing the level Vcc to the power input terminal VCC (that is, the first driving unit 540 operates).

[0130] (3) When the float switch is abnormally disconnected, the detection output terminal of the float switch is pulled down to a low level through the pull-down circuit 570.

[0131] At this time, the NPN transistor Q20 is disconnected. The anode of the first diode is connected to Vcc through the resistor R63. At this time, regardless of whether the control signal output by the first control port MCU3 runs wild, both the NPN transistor Q19 and the PNP transistor Q18 are conducting, providing the level Vcc to the power input terminal VCC (that is, the first driving unit 540 operates).

[0132] In some embodiments of the present application, refer to Figure 4 , a filtering unit 560 is further provided between the output terminal of the second control unit 520 and the power input terminal VCC.

[0133] The filtering unit 560 is used to filter out the clutter entering the power input terminal VCC.

[0134] The filtering unit 560 may be a grounded capacitor C83.

[0135] In some embodiments of the present application, in order to prevent current backflow, a diode D12 is further provided at the power input terminal VCC. The anode of the diode D12 is grounded, and the cathode is connected to the power input terminal VCC.

[0136] In order to protect the first driving unit 540, a current protection unit is further provided between the output terminal of the second control unit 520 and the power input terminal VCC.

[0137] The current protection unit is used to cut off the power supply to the first driving unit 540 when the current supplied to the power input terminal VCC exceeds a specified value.

[0138] In some embodiments of the present application, referring to Figure 6 , the current protection unit may select a PTC thermistor 580.

[0139] One end of the PTC thermistor 580 is connected to the common connection point of the collector of the PNP transistor Q18 and the pull-down resistor R59, and the other end is connected to the power input terminal VCC.

[0140] When the current supplied to the power input terminal VCC is above the specified value, the temperature of the PTC thermistor 580 is higher than the Curie temperature of the PTC thermistor 580, enters the protection state, and automatically cuts off the power supply to the first driving unit 540. When the temperature drops below the Curie temperature of the PTC thermistor 580, it exits the protection state and automatically conducts the power supply to the first driving unit 540.

[0141] In some embodiments of the present application, referring to Figure 4 and Figure 5 , the third control unit 530 is also controlled by the detection output of the detection output terminal of the water level detection unit 300.

[0142] The input terminal of the third control unit 530 is connected to the second control port MCU2, and the output terminal is connected to the PWM input terminal of the first driving unit 540 through an optocoupler PC2.

[0143] The PWM signal input at the PWM input terminal is used to control the rotation speed of the first drain pump 210.

[0144] When the third control unit 530 is turned on, the PWM input terminal of the first driving unit 540 is controlled by the control signal at the second control port MCU2. For example, a PWM signal can be output or not output at the second control port MCU2 according to the working mode requirements.

[0145] The output PWM signal is isolated and sent to the PWM input terminal through the optocoupler PC2 to control whether the first drain pump 210 operates.

[0146] When the third control unit 530 is disconnected, a high-level PWM signal is provided to the PWM input terminal through the optocoupler PC2, thus ensuring the operation of the first drain pump 210 as well.

[0147] In some embodiments of the present application, the third control unit 530 may include a switching element that conducts when a high level is applied, that is, the control terminal of the third control unit 530 conducts when receiving a high level and cuts off when receiving a low level.

[0148] See Figure 4 , and the switching element that conducts when a high level is applied may be an NPN transistor Q21.

[0149] In some embodiments of the present application, the base of the NPN transistor Q21 is connected to the detection output terminal, the collector is connected to the second control port MCU2, and the emitter is connected to the optocoupler PC2 through a current-limiting resistor R29.

[0150] In some embodiments of the present application, the optocoupler PC2 contains a reverse-parallel diode. The emitter of the NPN transistor Q21 is connected to one end of the reverse-parallel diode through a current-limiting resistor R29, and the other end is grounded. The emitter of the optocoupler PC2 is grounded, the collector of the optocoupler PC2 is connected to the power supply Vcc2 through a pull-up resistor R30, and the common connection point of the collector of the optocoupler PC2 and the pull-up resistor R30 is connected to the PWM input terminal.

[0151] When the NPN transistor Q21 receives a high level, it conducts. At this time, the output terminal of the third control unit 530 is connected to the second control port MCU2, and then the control signal output by the second control port MCU2 is transmitted to the PWM input terminal through the optocoupler PC2; when the NPN transistor Q21 receives a low level, it disconnects. At this time, the optocoupler PC2 does not work, and only the power supply Vcc2 is transmitted to the PWM input terminal through the pull-up resistor R30.

[0152] When the float switch is abnormally disconnected, the detection output terminal also pulls down the level of the detection output terminal to a low level through the pull-down circuit 570. At this time, the NPN transistor Q21 is also disconnected. Therefore, the power supply Vcc2 is also transmitted to the PWM input terminal through the pull-up resistor R30.

[0153] As follows, see Figure 4 and Figure 5 , and different situations of the PWM signal input to the PWM input terminal are described.

[0154] (1') When the float switch is normal and the detected water level does not reach the preset water level, the detection output terminal outputs a high level. At this time, the NPN transistor Q21 is turned on, and the control signal output by the second control port MCU2 is output to the optocoupler PC2 and transmitted to the PWM input terminal through the optocoupler PC2.

[0155] At this time, the PWM signal of the first driving unit 540 is controlled by the control signal output from the second control port MCU2.

[0156] If the program runs away during the normal water level detection of the float switch, the power supply Vcc2 will also be transmitted to the PWM input terminal through the pull-up resistor R30.

[0157] (2') When the float switch is normally disconnected, the detection output terminal outputs a low level. At this time, the NPN transistor Q21 is disconnected, and the optocoupler PC2 does not work. At this time, only the power supply Vcc2 is transmitted to the PWM input terminal through the pull-up resistor R30.

[0158] (3') When the float switch is abnormally disconnected, the NPN transistor Q21 is disconnected, and the optocoupler PC2 does not work. At this time, only the power supply Vcc2 is transmitted to the PWM input terminal through the pull-up resistor R30.

[0159] As described above in (1), (2), (1'), and (2'), when the float switch is normal, the power input terminal VCC of the first driving unit 540 is controlled through the first control port MCU3, and the PWM input terminal of the first driving unit 540 is controlled through the second control port MCU2, so as to realize the program-controlled drainage of the first drainage pump 210.

[0160] During the normal operation of the float switch, if the program runs away, the hardware drainage control circuit is used to make the power input terminal of the first driving unit 540 be Vcc and the PWM input terminal be connected to the power supply Vcc2 through the pull-up resistor R30, that is, to realize the drainage of the first drainage pump 210 without relying on the program control.

[0161] As described above in (3) and (3'), when the float switch is abnormally disconnected, regardless of whether the program runs away or not, the first drainage pump 210 does not rely on the program control for drainage.

[0162] Therefore, regardless of the state of the float switch or whether the program runs away, it can ensure the reliable drainage of the first drainage pump 210 and avoid the risk of water overflow.

[0163] In some embodiments of the present application, in order to improve the drainage efficiency, see Figure 7 , two drainage pumps can be arranged in the water receiving tray 100.

[0164] The drainage pump described above is denoted as the first drainage pump 210, and the first drainage pump 210 can be a DC water pump, and the other drainage pump is denoted as the second drainage pump 220.

[0165] In some embodiments of the present application, the second drainage pump 220 is also installed in the water receiving tray 100 and is used to drain the condensed water in the water receiving tray 100 to the outside.

[0166] See Figure 8 ., in addition to having the control part of the first drain pump described above Figures 1 to 6 the air conditioner also has a second drain pump 220 and a second drive unit 550, wherein the second drain pump 220 is driven to work by the second drive unit 550.

[0167] In some embodiments of the present application, see Figure 9 . The second drive unit 550 includes a drive chip (not shown) and a relay YH1.

[0168] The normally closed switch of the relay YH1 is connected to the power supply line of the second drain pump 220, that is, when the coil of the relay YH1 is energized, the second drain pump 220 stops working, and when the coil of the relay YH1 is de-energized, the second drain pump 220 works.

[0169] The drive chip controls whether the coil of the relay YH1 is energized based on the detection signal output by the water level detection unit 300.

[0170] In some embodiments of the present application, the input pin of the drive chip is connected to an output terminal of the main controller 400, and the output pin is connected to the common point of one end of the coil and the anode of the freewheeling diode D1. The common point of the other end of the coil and the cathode of the freewheeling diode D1 is connected to the detection output terminal of the water level detection unit 300.

[0171] In some embodiments of the present application, the water level detection unit 300 is selected to use a float switch.

[0172] When the float switch is normal and the detected water level does not reach the preset water level, the detection output of the float switch is high level. At this time, the start or stop of the second drain pump 220 is controlled based on the signal output by the output pin of the drive chip.

[0173] When the float switch is normally open, the detection output of the float switch is low level. At this time, the drive chip cannot drive the coil of the relay YH1, and the normally closed switch closes, and the second drain pump 220 works.

[0174] When the float switch is abnormally open, the detection output of the float switch is pulled down to low level through the pull-down circuit 570. At this time, the drive chip cannot drive the coil of the relay YH1, and the normally closed switch closes, and the second drain pump 220 works.

[0175] As follows, see Figure 9 and Figure 10 to describe different situations of coil driving.

[0176] (a)When the float switch is normal and the detected water level does not reach the preset water level, the second driving unit 550 drives the coil of the relay YH1 to be energized or not energized. That is, whether the coil is energized at this time depends on (is controlled by) the driving signal output by the second driving unit 550 (which is controlled by the main controller 400 to output a control signal).

[0177] If the program runs wild during the normal water level detection process of the float switch, the second driving unit 550 cannot drive the coil, and the coil is not energized. At this time, the second drain pump 220 is forced to start.

[0178] (b)When the float switch is normally disconnected, the second driving unit 550 cannot drive the coil. At this time, whether the program runs wild or not, the coil is not energized. At this time, the second drain pump 220 is forced to start.

[0179] (c)When the float switch is abnormally disconnected, the second driving unit 550 cannot drive the coil. At this time, whether the program runs wild or not, the coil is not energized. At this time, the second drain pump 220 is forced to start.

[0180] Therefore, as described above, regardless of the state of the float switch or whether the program runs wild, it can ensure the reliable drainage of the second drain pump 220 and avoid the risk of water overflow.

[0181] In some embodiments of the present application, regardless of the state of the float switch or whether the program runs wild, it can use the drainage hardware control circuit to ensure the reliable drainage of the first drain pump 210 and the second drain pump 220, avoid the risk of water overflow; and the dual-pump drainage improves the drainage efficiency.

[0182] In some embodiments of the present application, the second drain pump 220 is an AC water pump.

[0183] In the description of the above embodiments, the specific features, structures, materials or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0184] The above is only the specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. An air conditioner, characterized in that: include: A water receiving tray, which is used to receive condensed water generated by airflow passing through the evaporator during cooling operation of the air conditioner; A drainage pump is installed in the water receiving tray and is used to discharge the condensed water in the water receiving tray to the outside; A water level detection unit, used to detect the water level in the water receiving tray; A main controller having a first control port, a second control port and a detection port connected to the detection output end of the water level detection unit; A first driving unit, which is used to drive the drainage pump to operate and has a power input terminal and a PWM input terminal; A first control unit, which is controlled by the detection output of the water level detection unit. When the water level detection unit is normal and the detected water level does not reach the preset water level, the output end of the first control unit is connected to the ground. When the water level detection unit is abnormally disconnected or the detected water level reaches the preset water level, the first control unit outputs a control power supply. A double diode, comprising a first diode and a second diode connected in parallel in the same direction, wherein an anode of the first diode is connected to an output end of the first control unit, and an anode of the second diode is connected to the first control port; A second control unit, a control end of which is connected to a common point of the cathode of the first diode and the cathode of the second diode, and an output end of which is connected to the power input end; A third control unit is controlled by the detection output, wherein an input end of the third control unit is connected to the second control port and an output end of the third control unit is connected to the PWM input end through an optical coupler.

2. The air conditioner according to claim 1, characterized in that: The water level detection unit is a float switch; When the float switch is normal and the detected water level does not reach the preset water level, the float switch outputs a high level; When the float switch is normal and the detected water level reaches a preset water level, the float switch outputs a low level; When the float switch is abnormally disconnected, the detection output end of the float switch is pulled down to an output low level through a pull-down circuit.

3. The air conditioner according to claim 2, characterized in that: The first control unit includes a first high-level conductive switch element, when the float switch outputs a high level, the first high-level conductive switch element is turned on, when the float switch outputs a low level, the first high-level conductive switch element is turned off; The third control unit includes a third high-level conductive switch element. When the float switch outputs a high level, the third high-level conductive switch element is turned on. When the float switch outputs a low level, the third high-level conductive switch element is turned off.

4. The air conditioner according to claim 2, characterized in that: The second control unit also includes: A first switch control element, which is a switch element that is turned on at a high level, wherein a control end of the first switch control element is connected to the common point, a first end is connected to a pull-up resistor, and a second end is grounded; The second switch control element is a switch element that is turned on at a low level, wherein the control end is connected to the common point of the first end of the first switch control element and the pull-up resistor, the first end is connected to the power supply, the second end is connected to the pull-down resistor, and the power input end is connected to the common point of the pull-down resistor and the second end of the second switch control element.

5. The air conditioner according to claim 1, characterized in that: The second control unit also includes: The filter unit is arranged at the input side of the power input terminal.

6. The air conditioner according to claim 1, characterized in that: The air conditioner also includes: A current protection unit is arranged on the line between the output end of the second control unit and the power input end, and is used for automatically cutting off the power supply to the first driving unit when the current on the line reaches a specified value.

7. The air conditioner according to claim 6, characterized in that: The current protection unit is a PTC thermistor.

8. An air conditioner, characterized in that include: A water receiving tray, which is used to receive condensed water generated when the air flow passes through the low-temperature evaporator during the cooling operation of the air conditioner; A first drain pump and a second drain pump, which are respectively installed in the water receiving tray and are used to discharge condensed water in the water receiving tray to the outside; A water level detection unit, used to detect the water level in the water receiving tray; A main controller having a first control port, a second control port and a detection port connected to the detection output end of the water level detection unit; A first driving unit, which is used to drive the first drainage pump to operate and has a power input terminal and a PWM input terminal; a second driving unit, wherein when the water level detection unit is normal and the detected water level does not reach the preset water level, the second driving unit drives the coil of the relay to be energized or not energized, and when the water level detection unit is abnormally disconnected or the detected water level reaches the preset water level, the coil is not energized, and the normally closed switch of the relay is connected to the power supply line of the second drainage pump; A first control unit, which is controlled by the detection output of the water level detection unit. When the water level detection unit is normal and the detected water level does not reach the preset water level, the output end of the first control unit is connected to the ground. When the water level detection unit is abnormally disconnected or the detected water level reaches the preset water level, the first control unit outputs a control power supply. A double diode, comprising a first diode and a second diode connected in parallel in the same direction, wherein an anode of the first diode is connected to an output end of the first control unit, and an anode of the second diode is connected to the first control port; A second control unit, a control end of which is connected to a common point of the cathode of the first diode and the cathode of the second diode, and an output end of which is connected to the power input end; A third control unit is controlled by the detection output, wherein an input end of the third control unit is connected to the second control port and an output end of the third control unit is connected to the PWM input end through an optical coupler.

9. The air conditioner according to claim 8, characterized in that: The second driving unit comprises: A driving chip, wherein an input pin is connected to an output end of the main controller, an output pin corresponding to the input pin is connected to a common point between one end of the coil and the anode of the freewheeling diode, and a common point between the other end of the coil and the cathode of the freewheeling diode is connected to the detection output end.

10. The air conditioner according to claim 8, characterized in that: The air conditioner also includes: The pull-down circuit is arranged between the detection output terminal and the detection port.

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