Air conditioning device

Abstract

The utility model discloses an air conditioning device which comprises a controller and a current sensor, the current sensor collects current signals and sends the current signals to the controller, the current sensor comprises a power supply pin, a reference source pin and an output pin, the air conditioning device comprises an operational amplifier, and the operational amplifier comprises an input pin and an output pin. A reference source pin and an output pin of the current sensor are respectively connected to an input pin of the operational amplifier, and an output pin of the operational amplifier is connected to the controller. The reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the influence of the reference source on the output of the current sensor is eliminated through the operational amplifier, so that the output of the operational amplifier is not related to the reference source, and when the environment temperature changes, even if the voltage of the reference source changes along with the temperature, the output of the current sensor is not influenced. And the sampling output of the operational amplifier is not influenced by the reference source, so that the current sampling precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioners, in particular to an air conditioner for which current detection is not affected by temperature. Background Art

[0002] Air conditioners generally collect current information through current sensors. Current sensors generally have 4 pins, a Vcc (power supply), a GND (ground), a reference source (Vref), and an output (Vout). The reference source Vref of the current sensor is 1 / 2Vcc. For a 5V power supply, the reference source is generally 2.5V. However, because VCC has errors, Vref will also change with temperature, resulting in errors in the output of the current sensor.

[0003] In some harsh working conditions, for example, when the ambient temperature is 52°C, the temperature of the electrical box inside the air conditioner will exceed 60°C. For high-current air conditioners, if only the output of the current sensor is sampled, when the ambient temperature reaches 52°C, the reference source will have a large error, causing the current sensor sampling to have errors, resulting in inaccurate output current and causing system alarms.

[0004] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The utility model provides an air conditioning device, which solves the technical problem that the current sensor sampling of the existing air conditioning device is affected by temperature and causes false alarm.

[0006] In order to achieve the above-mentioned utility model purpose, the utility model adopts the following technical solutions:

[0007] An air conditioning device includes a controller and a current sensor, wherein the current sensor collects a current signal and sends it to the controller, the current sensor includes a power pin, a reference source pin and an output pin, the air conditioning device includes an operational amplifier, the operational amplifier includes an input pin and an output pin, the reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the output pin of the operational amplifier is connected to the controller.

[0008] In some embodiments of the present application, the operational amplifier includes a forward input pin and a reverse input pin, the reference source pin is connected to the reverse input pin of the operational amplifier, the output pin of the current sensor is connected to the forward input pin of the operational amplifier, and a resistor is connected between the output pin and the reverse input pin of the operational amplifier.

[0009] In some embodiments of the present application, the operational amplifier includes a forward input pin and a reverse input pin, the output pin of the current sensor is connected to the reverse input pin of the operational amplifier, the reference source pin is connected to the forward input pin of the operational amplifier, and a resistor is connected between the output pin and the reverse input pin of the operational amplifier.

[0010] In some embodiments of the present application, the air conditioning device includes an inverting circuit, the output pin of the operational amplifier is connected to the input of the inverting circuit, and the output of the inverting circuit is connected to the controller.

[0011] In some embodiments of the present application, the inverting circuit includes a second operational amplifier, the second operational amplifier includes a forward input pin, a reverse input pin and an output pin, the output pin of the operational amplifier is connected to the reverse input pin of the second operational amplifier, the output pin of the second operational amplifier is connected to the controller, and a resistor is connected between the output pin and the reverse input pin of the second operational amplifier.

[0012] In some embodiments of the present application, the output pin of the second operational amplifier is connected to the controller via a resistor R5, and the resistor R5 is grounded via a capacitor C4.

[0013] In some embodiments of the present application, the resistor R5 and the capacitor C4 enable the sampling time to be less than 1 μs.

[0014] In some embodiments of the present application, the non-inverting input pin of the second operational amplifier is grounded through a resistor.

[0015] In some embodiments of the present application, the air-conditioning device includes a third operational amplifier and a power supply, the third operational amplifier includes a positive input pin, a reverse input pin and an output pin, the reference source pin is connected to the output pin of the third operational amplifier, the positive input pin of the third operational amplifier is grounded, and the reverse input pin of the third operational amplifier is connected to the power supply.

[0016] In some embodiments of the present application, the inverting input pin of the third operational amplifier is connected to a power supply via a resistor, and the inverting input pin of the third operational amplifier is connected to an output pin of the third operational amplifier via a resistor.

[0017] Compared with the prior art, the advantages and positive effects of the utility model are as follows: an air conditioning device includes a controller and a current sensor, the current sensor collects a current signal and sends it to the controller, the current sensor includes a power pin, a reference source pin and an output pin, the air conditioning device includes an operational amplifier, the operational amplifier includes an input pin and an output pin, the reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the output pin of the operational amplifier is connected to the controller. The reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the influence of the reference source on the output of the current sensor is eliminated by the operational amplifier, so that the output of the operational amplifier is not related to the reference source. When the ambient temperature changes, even if the voltage of the reference source changes with the temperature, the sampling output of the operational amplifier is not affected by the reference source, thereby improving the current sampling accuracy.

[0018] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of a current sensor sampling circuit of an existing device;

[0021] Figure 2 A schematic diagram of a waveform of a current sensor converting an alternating current into a current sampling current;

[0022] Figure 3 This is a schematic diagram of the internal architecture of the current sensor;

[0023] Figure 4 It is a schematic diagram of the corresponding relationship between the output voltage of the current sensor and the actual current;

[0024] Figure 5 is the actual current waveform of the current sensor;

[0025] Figure 6 is a schematic diagram of a current sensor sampling circuit of an air conditioner according to an embodiment;

[0026] Figure 7 for Figure 6 Waveform diagram of ;

[0027] Figure 8is a schematic diagram of another current sensor sampling circuit of an air conditioning device according to an embodiment;

[0028] Fig. 9 for Figure 8 Waveform diagram of ;

[0029] Fig.10 A schematic diagram of another current sensor sampling circuit of an air conditioning device according to an embodiment;

[0030] Fig.11 for Fig.10 Schematic diagram of the waveform. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0034] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such 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 utility model provides various specific examples of 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.

[0037] The air conditioning device provided in the present application performs a refrigeration cycle of the air conditioning device by using a compressor, a condenser, a throttling device and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation to cool or heat the indoor space.

[0038] The low-temperature and low-pressure refrigerant enters the compressor, which compresses it into high-temperature and high-pressure 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 the heat is released to the surrounding environment through the condensation process.

[0039] The throttling device expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the throttling device and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioning device can adjust the temperature of the indoor space.

[0040] The outdoor unit of the air conditioner refers to a part of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and a throttling device may be provided in the indoor unit and / or the outdoor unit.

[0041] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner functions as a heater in a heating state, and when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in a cooling state.

[0042] When the air-conditioning device is running, it is necessary to detect the operating current of the air-conditioning device, and to perform an alarm or protection operation when the current does not meet the requirements to ensure the safe operation of the air-conditioning device.

[0043] exist Figure 1 In the example, the current sensor detects the current information of the three-phase AC input, and outputs it to the MCU controller after amplification through the operational amplifier. The MCU controller determines whether the current information of the three-phase AC input meets the requirements based on the received signal. If it meets the requirements, the air-conditioning device operates normally. If it does not meet the requirements, an alarm or protection operation is performed.

[0044] The function of the current sensor is to convert the floating AC high current signal into a DC voltage signal that can be sampled by the MCU, such as Figure 2 shown.

[0045] exist Figure 3 In the example, this is the architecture of the current sensor: VC is the power supply voltage of the current sensor, for example, the power supply voltage of the current sensor is DC5V, GND is the power supply ground of the current sensor (the same power supply system as DC5V), Vout is the output of the current sensor, Vref is the reference of the current sensor, generally Vref=1 / 2VC, for example: VC=5V, Vref=2.5V.

[0046] Figure 4 It is the corresponding relationship between the output voltage of the current sensor and the actual current. If the center point of the signal sampled by the current sensor is offset by 2.5V, the actual current is Figure 5 , the current waveform is distorted, and the currents are asymmetric at the center point, which shows that it deviates from the center point, causing a large error. The root cause of the above problem is that the reference voltage Vref changes with temperature, which leads to inaccurate sampling.

[0047] In order to avoid the adverse effects of temperature on current sampling, existing air-conditioning devices generally adopt a shutdown method, read the reference source data when shut down, and then restart for detection. However, this method requires the air-conditioning device to be shut down, resulting in a poor user experience.

[0048] Therefore, the present application proposes a current sampling circuit for an air-conditioning device, which can avoid the influence of temperature on the voltage of a reference source. There is no need to control the air-conditioning device to shut down. The current sampling circuit can automatically compensate with temperature changes, and the current sensor can accurately sample and work reliably.

[0049] An air conditioning device includes a controller and a current sensor. The current sensor collects a current signal and sends it to the controller. The current sensor includes a power pin, a reference source pin and an output pin. The air conditioning device includes an operational amplifier. The operational amplifier includes an input pin and an output pin. The reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the output pin of the operational amplifier is connected to the controller.

[0050] The reference source pin and output pin of the current sensor are respectively connected to the input pin of the operational amplifier. The influence of the reference source on the output of the current sensor is eliminated through the operational amplifier, so that the output of the operational amplifier is independent of the reference source. When the ambient temperature changes, even if the reference source voltage changes with the temperature, the sampling output of the operational amplifier is not affected by the reference source voltage, thereby improving the current sampling accuracy.

[0051] Among them, the current sensor is used to collect the AC current of the AC power supply.

[0052] The power pin of the current sensor is connected to VCC (power supply) and GND (ground), and the reference source pin of the current sensor is connected to the reference source Vref.

[0053] In order to automatically achieve temperature compensation, the Vout output of the current sensor needs to be differentiated from Vref. Because the Vout output of the current sensor is differential with Vref, even if Vref is not 1 / 2VCC, the Vout output will not be affected.

[0054] The Vout of the current sensor = Vref + Gth × Ip.

[0055] Gth: Theoretical sensitivity, the unit is mV / A. Generally, the specification sheet has the corresponding value. For example, a LEM CKSR-75 has a specification sheet Gth=6.25mV / A.

[0056] Ip: Peak current.

[0057] Vref: The reference value of the current sensor, generally 1 / 2VCC, will be affected by temperature.

[0058] When Vout and Vref are differential, V=Vout-Vref=Gth×Ip.

[0059] Therefore, the output V obtained after differentiation has nothing to do with Vref.

[0060] The output of the current sensor must be differentiated through operational amplifier operation and finally output to the MCU sampling pin.

[0061] In some embodiments, the operational amplifier includes a positive input pin and a negative input pin, the reference source pin of the current sensor is connected to the negative input pin of the operational amplifier, the output pin of the current sensor is connected to the positive input pin of the operational amplifier, and a resistor is connected between the output pin of the operational amplifier and the negative input pin of the operational amplifier.

[0062] exist Figure 6 In the example of FIG. 1 , the operational amplifier U1 includes a positive input pin, a reverse input pin, and an output pin.

[0063] The reference source pin Vref of the current sensor is connected to the inverting input pin of the operational amplifier U1.

[0064] The reference source pin Vref of the current sensor is connected to the inverting input pin of the operational amplifier U1 through the resistor R10 and the resistor R8.

[0065] The output pin Vout of the current sensor is connected to the positive input pin of the operational amplifier U1.

[0066] The output pin Vout of the current sensor is connected to the positive input pin of the operational amplifier U1 through the resistor R8.

[0067] Resistor R8 and the non-inverting input pin of operational amplifier U1 are connected to ground via resistor R1.

[0068] A feedback resistor R4 is connected between an output pin V of the operational amplifier U1 and an inverting input pin of the operational amplifier U1.

[0069] Figure 7 : is a waveform diagram of the output voltage Vout of the output pin Vout of the current sensor, the reference voltage Vref of the reference source pin and the output voltage V of the operational amplifier U1. Among them, the output voltage V of the operational amplifier U1 is in phase with the waveform of the output voltage Vout of the output pin of the current sensor.

[0070] In some embodiments, the operational amplifier includes a positive input pin and a negative input pin, the output pin of the current sensor is connected to the negative input pin of the operational amplifier, the reference source pin of the current sensor is connected to the positive input pin of the operational amplifier, and a resistor is connected between the output pin of the operational amplifier and the negative input pin of the operational amplifier.

[0071] exist Figure 8 In the example of FIG. 1 , the operational amplifier U1 includes a positive input pin, a reverse input pin, and an output pin.

[0072] The reference source pin Vref of the current sensor is connected to the positive input pin of the operational amplifier U1.

[0073] The reference source pin Vref of the current sensor is connected to the positive input pin of the operational amplifier U1 through the resistor R10 and the resistor R2.

[0074] Resistor R2 is connected to the positive input pin of operational amplifier U1 through resistor R1 to ground.

[0075] The output pin Vout of the current sensor is connected to the inverting input pin of the operational amplifier U1.

[0076] The output pin Vout of the current sensor is connected to the inverting input pin of the operational amplifier U1 through the resistor R8.

[0077] A feedback resistor R4 is connected between an output pin V of the operational amplifier U1 and an inverting input pin of the operational amplifier U1.

[0078] Fig. 9 : is a waveform diagram of the output voltage Vout of the output pin Vout of the current sensor, the reference voltage Vref of the reference source pin and the output voltage V of the operational amplifier U1. Among them, the output voltage V of the operational amplifier U1 is inversely proportional to the waveform of the output voltage Vout of the output pin of the current sensor.

[0079] In some embodiments, the operational amplifier includes a positive input pin and a negative input pin, the output pin of the current sensor is connected to the negative input pin of the operational amplifier, the reference source pin of the current sensor is connected to the positive input pin of the operational amplifier, and a resistor is connected between the output pin of the operational amplifier and the negative input pin of the operational amplifier. The air conditioning device includes an inverting circuit, the output pin of the operational amplifier is connected to the input of the inverting circuit, and the output of the inverting circuit is connected to the controller.

[0080] The inverting circuit includes a second operational amplifier, which includes a forward input pin, a reverse input pin and an output pin. The output pin of the operational amplifier is connected to the reverse input pin of the second operational amplifier, the output pin of the second operational amplifier is connected to the controller, and a resistor is connected between the output pin and the reverse input pin of the second operational amplifier.

[0081] exist Fig.10 In the example of FIG. 1 , the operational amplifier U1 includes a positive input pin, a reverse input pin, and an output pin.

[0082] The reference source pin Vref of the current sensor is connected to the positive input pin of the operational amplifier U1.

[0083] The reference source pin Vref of the current sensor is connected to the positive input pin of the operational amplifier U1 through the resistor R10 and the resistor R2.

[0084] The output pin Vout of the current sensor is connected to the inverting input pin of the operational amplifier U1.

[0085] The output pin Vout of the current sensor is connected to the inverting input pin of the operational amplifier U1 through the resistor R1.

[0086] A feedback resistor R4 is connected between the output pin of the operational amplifier U1 and the inverting input pin of the operational amplifier U1.

[0087] The second operational amplifier U2 includes a positive input pin, a negative input pin and an output pin.

[0088] The output pin of the operational amplifier U1 is connected to the inverting input pin of the second operational amplifier U2.

[0089] The output pin of the operational amplifier U1 is connected to the inverting input pin of the second operational amplifier U2 through a resistor R3 .

[0090] The output pin of the second operational amplifier U2 is connected to the controller.

[0091] The output pin of the second operational amplifier U2 is connected to the controller via a resistor R5 , and the resistor R5 is grounded via a capacitor C4 .

[0092] The output pin of the second operational amplifier U2 outputs a voltage V. The output pin of the second operational amplifier U2 outputs a voltage V through a resistor R5, and the resistor R5 is grounded through a capacitor C4.

[0093] The resistor R5 and the capacitor C4 make the sampling time less than 1 μs to meet the sampling requirement.

[0094] A resistor R7 is connected between the output pin and the inverting input pin of the second operational amplifier U2.

[0095] The non-inverting input pin of the second operational amplifier U2 is connected to ground through a resistor.

[0096] A non-inverting input pin of the second operational amplifier U2 is grounded via a resistor R6.

[0097] Fig.11 : is a waveform diagram of the output voltage Vout of the output pin Vout of the current sensor and the output voltage V of the second operational amplifier U2. The waveforms of the output voltage Vout of the output pin of the current sensor and the output voltage Vout of the operational amplifier are in phase and have the same waveform.

[0098] exist Fig.10 In the example, the air conditioning device includes a third operational amplifier U3 and a power supply VREF-C.

[0099] The third operational amplifier U3 includes a non-inverting input pin, an inverting input pin and an output pin.

[0100] The reference source pin Vref of the current sensor is connected to the output pin of the third operational amplifier U3, the positive input pin of the third operational amplifier U3 is grounded, and the reverse input pin of the third operational amplifier U3 is connected to the power supply VREF-C.

[0101] The inverting input pin of the third operational amplifier U3 is connected to the power supply VREF-C via a resistor R650 , and the inverting input pin of the third operational amplifier U3 is connected to the output pin of the third operational amplifier U3 via a resistor R651 .

[0102] An impedance matching is performed through the third operational amplifier U3 to provide a loop with high input impedance and low output impedance.

[0103] exist Fig.10 In the example, the circuit design is simple, the op amp can be powered by a single power supply, and the input and output can be in phase.

[0104] Therefore, the controller of the air-conditioning device can directly collect the output voltage V, and the output voltage V is not affected by the reference voltage Vref. Therefore, the output voltage can accurately reflect the actual situation of the AC power supply current and is not affected by temperature. The air-conditioning device can directly determine whether the AC power supply current is normal based on the output voltage V, and make an alarm or protective measures when the AC power supply current is abnormal. The air-conditioning device can run all the time without controlling the air-conditioning device to shut down.

[0105] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0106] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited to this. Any changes or substitutions that can be easily thought of by technicians familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An air conditioning device, comprising a controller and a current sensor, wherein the current sensor collects a current signal and sends it to the controller, wherein the current sensor comprises a power supply pin, a reference source pin and an output pin, and wherein: The air conditioning device includes an operational amplifier, which includes an input pin and an output pin. The reference source pin and the output pin of the current sensor are respectively connected to the input pin of the operational amplifier, and the output pin of the operational amplifier is connected to the controller.

2. The air conditioning device according to claim 1, characterized in that: The operational amplifier includes a positive input pin and a negative input pin, the reference source pin is connected to the negative input pin of the operational amplifier, the output pin of the current sensor is connected to the positive input pin of the operational amplifier, and a resistor is connected between the output pin and the negative input pin of the operational amplifier.

3. The air conditioning device according to claim 1, characterized in that: The operational amplifier includes a forward input pin and a reverse input pin, the output pin of the current sensor is connected to the reverse input pin of the operational amplifier, the reference source pin is connected to the forward input pin of the operational amplifier, and a resistor is connected between the output pin and the reverse input pin of the operational amplifier.

4. The air conditioning device according to claim 3, characterized in that: The air conditioning device includes an inverter circuit, the output pin of the operational amplifier is connected to the input of the inverter circuit, and the output of the inverter circuit is connected to the controller.

5. The air conditioning device according to claim 4, characterized in that: The inverting circuit includes a second operational amplifier, which includes a forward input pin, a reverse input pin and an output pin. The output pin of the operational amplifier is connected to the reverse input pin of the second operational amplifier, and the output pin of the second operational amplifier is connected to the controller. A resistor is connected between the output pin and the reverse input pin of the second operational amplifier.

6. The air conditioning device according to claim 5, characterized in that: The output pin of the second operational amplifier is connected to the controller via a resistor R5 , and the resistor R5 is grounded via a capacitor C4 .

7. The air conditioning device according to claim 6, characterized in that: The resistor R5 and the capacitor C4 enable the sampling time to be less than 1 μs.

8. The air conditioning device according to claim 5, characterized in that: A non-inverting input pin of the second operational amplifier is grounded through a resistor.

9. The air conditioning device according to claim 8, characterized in that: The air conditioning device includes a third operational amplifier and a power supply, the third operational amplifier includes a non-inverting input pin, a reverse input pin and an output pin, the reference source pin is connected to the output pin of the third operational amplifier, the positive input pin of the third operational amplifier is grounded, and the reverse input pin of the third operational amplifier is connected to the power supply.

10. The air conditioning device according to claim 9, characterized in that: The inverting input pin of the third operational amplifier is connected to a power supply through a resistor, and the inverting input pin of the third operational amplifier is connected to an output pin of the third operational amplifier through a resistor.

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