Air conditioner

Abstract

The invention provides an air conditioner which comprises an alternating current input circuit used for outputting a power supply signal; the photoelectric coupling circuit is used for transmitting or isolating a power supply signal; the zero-cross detection circuit is used for receiving the power source signal and the preset power source signal and determining a plurality of corrected zero-cross signals according to the power source signal and the preset power source signal, errors of original zero-cross signals can be made up, the accurate zero-cross detection function of the zero-cross detection circuit is achieved, more accurate zero-cross reference is provided for the air conditioner, and the air conditioner is more accurate in zero-cross detection. It is ensured that follow-up control over loads such as a fan of the air conditioner is highly synchronous with the power cycle, and the control precision and the equipment operation stability are improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, and in particular to an air conditioner. Background Technology

[0002] In power electronic equipment such as air conditioners and motor controllers, the zero-crossing signal is a key reference signal that reflects the zero-crossing point of AC power supply voltage or current, that is, the moment when the voltage or current value is zero. Its accuracy directly affects the control precision and operational stability of the equipment.

[0003] However, the zero-crossing signals obtained in the existing technology often contain errors. For example, there is a time difference between the actual triggering time of the zero-crossing signal and the theoretical zero-crossing point, which is usually on the order of microseconds to milliseconds, causing the controller to misjudge the power supply phase. Or, when noise is mixed into the signal, a pulse similar to the zero-crossing signal may be generated at non-zero-crossing times, resulting in a false zero-crossing point. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] Therefore, one objective of this invention is to provide an air conditioner that can compensate for the error of the original zero-crossing signal, realize the accurate zero-crossing detection function of the zero-crossing detection circuit, provide a more accurate zero-crossing reference for the air conditioner, ensure that the subsequent control of the air conditioner's load, such as the fan, is highly synchronized with the power cycle, and improve control accuracy and equipment operation stability.

[0006] To achieve the above objectives, an embodiment of the first aspect of the present invention provides an air conditioner, the air conditioner comprising: an AC input circuit for outputting a power signal; an optocoupler circuit connected to the AC input circuit for transmitting or isolating the power signal; and a zero-crossing detection circuit connected to the optocoupler circuit for receiving the power signal and a preset power signal, and determining a plurality of corrected zero-crossing signals based on the power signal and the preset power signal.

[0007] The above technical solution has the following advantages or beneficial effects: According to the air conditioner of the present invention, the zero-crossing detection circuit receives the power signal output by the AC input circuit through the optocoupler circuit, and determines whether the signal crosses zero, the time of zero-crossing, the direction of deviation and the degree of deviation based on the magnitude relationship between the power signal and the preset power signal, and determines the corrected zero-crossing signal. This can make up for the error of the original zero-crossing signal, realize the accurate zero-crossing detection function of the zero-crossing detection circuit, provide a more accurate zero-crossing reference for the air conditioner, ensure that the subsequent control of the air conditioner's load, such as the fan, is highly synchronized with the power cycle, and improve the control accuracy and equipment operation stability.

[0008] In addition, an air conditioner according to an embodiment of the present invention may also have the following additional technical features: Furthermore, when multiple corrected zero-crossing signals are determined based on the power signal and the preset power signal, the zero-crossing detection circuit is configured to: determine the absolute value of the power signal; when the absolute value is equal to the preset power signal, determine a first detection time before the multiple zero-crossing signals cross zero and a second detection time after the zero-crossing; and determine multiple corrected zero-crossing signals based on the multiple first detection times and the second detection times.

[0009] The above technical solution has the following advantages or beneficial effects: it enables full-process detection of zero-crossing signals.

[0010] Furthermore, when determining multiple corrected zero-crossing signals based on multiple first detection times and multiple second detection times, the zero-crossing detection circuit is configured to: determine multiple zero-crossing signal pulse times based on multiple first detection times and multiple second detection times; and determine multiple corrected zero-crossing signals based on multiple zero-crossing signal pulse times.

[0011] The above technical solution has the following advantages or beneficial effects: it can accurately calculate the duration of multiple zero-crossing signals.

[0012] Furthermore, when determining multiple corrected zero-crossing signals based on multiple zero-crossing signal pulse times, the zero-crossing detection circuit is configured to: calculate the average zero-crossing signal pulse time of the multiple zero-crossing signal pulse times; and determine multiple corrected zero-crossing signals based on multiple first detection times and the average zero-crossing signal pulse time.

[0013] The above technical solution has the following advantages or beneficial effects: taking the average value can determine a more accurate zero-crossing signal pulse time, avoiding situations where the error is large in a single acquisition. The corrected zero-crossing point is used as the zero point for the air conditioner's controller to control the fan drive.

[0014] Furthermore, the air conditioner also includes a communication circuit, and the preset power signal includes a first preset power signal. When receiving the preset power signal from the air conditioner control circuit, the zero-crossing detection circuit is configured to receive the first preset power signal output by the communication circuit.

[0015] The above technical solution has the following advantages or beneficial effects: It broadens the sources of preset power signals.

[0016] Furthermore, the communication circuit includes a first optocoupler and a first resistor. When receiving the first preset power signal output by the communication circuit, the zero-crossing detection circuit is configured to: acquire the reference voltage, conduction current of the first optocoupler, and resistance value of the first resistor; and determine the first preset power signal based on the reference voltage, conduction current, and resistance value.

[0017] The above technical solution has the following advantages or beneficial effects: ensuring the accuracy of the first preset power signal.

[0018] Furthermore, the zero-crossing detection circuit includes a first filtering module. After receiving the power signal and the preset power signal, the first filtering module is configured to: filter out high-frequency noise and fluctuation noise of the power signal to determine the filtered power signal.

[0019] The above technical solution has the following advantages or beneficial effects: by filtering out high-frequency noise, high-frequency interference can be avoided from affecting the normal operation of subsequent circuits, such as preventing control signals from being triggered falsely or loads from operating abnormally. Filtering out fluctuation noise can stabilize the voltage or current amplitude of the power supply signal, reduce irregular fluctuations in the signal, and make the determined filtered power supply signal closer to the ideal power supply waveform, thereby providing a stable and clean power input for subsequent circuits and improving the overall reliability, operating accuracy and anti-interference capability of the air conditioner.

[0020] Furthermore, the zero-crossing detection circuit includes a second filtering module. After determining multiple corrected zero-crossing signals based on the power signal and the preset power signal, the second filtering module is configured to: filter out high-frequency noise and fluctuation noise of the corrected zero-crossing signals, and determine the filtered corrected zero-crossing signals.

[0021] The above technical solution has the following advantages or beneficial effects: by filtering out high-frequency noise, it can avoid misjudgment of zero-crossing time caused by high-frequency interference, such as preventing false zero-crossing pulses from triggering control circuits. Filtering out fluctuation noise can eliminate irregular jitter of signal amplitude, making the zero-crossing edge of the filtered and corrected zero-crossing signal, i.e., the rising edge or falling edge, clearer and steeper, thereby providing a more accurate and reliable zero-crossing time reference for subsequent circuits, and improving the synchronization control accuracy, anti-interference ability and operational stability of the entire device.

[0022] Furthermore, the air conditioner also includes a controller connected to the zero-crossing detection circuit, for receiving a plurality of corrected zero-crossing signals and controlling the fan of the air conditioner according to the plurality of corrected zero-crossing signals.

[0023] The above technical solution has the following advantages or beneficial effects: it can achieve precise synchronization of the operating status of the fan, such as speed, start-stop timing and AC power cycle, improve the stability, energy efficiency and control accuracy of the fan operation, and reduce the fan operation fluctuation or energy consumption increase caused by power phase deviation.

[0024] Furthermore, the air conditioner also includes a controller connected to the zero-crossing detection circuit, used to receive the air conditioner's start-up command before the AC input circuit outputs a power signal.

[0025] The above technical solution has the following advantages or beneficial effects: it enables the preparation work of the zero-crossing detection circuit to be started in advance, ensuring that zero-crossing detection can be performed immediately when the AC input circuit outputs a power signal, thereby achieving precise control of the air conditioner load.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a structural block diagram of an air conditioner according to an embodiment of the present invention; Figure 2 This is a hardware connection diagram of an air conditioner according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the determination of a corrected zero-crossing signal according to an embodiment of the present invention; Figure 4 This is a hardware connection diagram of an air conditioner according to another embodiment of the present invention; Figure 5 This is a hardware structure diagram of a communication circuit according to an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the determination of a corrected zero-crossing signal according to another embodiment of the present invention; Figure 7 This is a flowchart of a control method for an air conditioner according to an embodiment of the present invention.

[0028] Figure label: Air conditioner 1; AC input circuit 11; optocoupler circuit 12; zero-crossing detection circuit 13; communication circuit 14; First filtering module 131; Second filtering module 133. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0030] The following is combined Figures 1-6 Air conditioner 1, according to an embodiment of the present invention.

[0031] like Figure 1 As shown, the air conditioner 1 of this embodiment includes: an AC input circuit 11, an optocoupler circuit 12 and a zero-crossing detection circuit 13, wherein the optocoupler circuit 12 adopts an optocoupler B.

[0032] The AC input circuit 11 is used to output a power signal; the optocoupler circuit 12 is connected to the AC input circuit 11 and is used to transmit or isolate the power signal; the zero-crossing detection circuit 13 is connected to the optocoupler circuit 12 and is used to receive the power signal and the preset power signal, and determine multiple corrected zero-crossing signals based on the power signal and the preset power signal.

[0033] In this embodiment, the AC input circuit 11 outputs a power signal, and the optocoupler circuit 12 transmits or isolates the power signal. After the zero-crossing detection circuit 13 receives the power signal, it starts working. Based on the magnitude relationship between the power signal and a preset power signal, it determines whether the signal has crossed zero, the time of zero crossing, the direction of deviation, and the degree of deviation, and determines a corrected zero-crossing signal. This can compensate for errors in the original zero-crossing signal, such as zero-crossing time offset caused by noise interference, making the zero-crossing signal more closely match the actual power phase characteristics. The preset power signal can be set by the user or by the air conditioner to realize the zero-crossing detection function of the zero-crossing detection circuit 13, providing a more accurate zero-crossing reference for the air conditioner 1. This ensures that the subsequent control of the air conditioner's load, such as the fan, is highly synchronized with the power cycle, improving control accuracy and equipment operational stability.

[0034] According to an embodiment of the present invention, the zero-crossing detection circuit receives the power signal output from the AC input circuit through an optocoupler circuit. Based on the magnitude relationship between the power signal and a preset power signal, it determines whether the signal has crossed zero, the time of zero-crossing, the direction of deviation, and the degree of deviation, and determines the corrected zero-crossing signal. This can compensate for the error of the original zero-crossing signal, realize the precise zero-crossing detection function of the zero-crossing detection circuit, provide a more accurate zero-crossing reference for the air conditioner, ensure that the subsequent control of the air conditioner's load, such as the fan, is highly synchronized with the power cycle, and improve control accuracy and equipment operation stability.

[0035] Let's start with... Figure 2 For example, let's take a preset power signal as Uc.

[0036] In some embodiments, when multiple corrected zero-crossing signals are determined based on a power signal and a preset power signal, the zero-crossing detection circuit is configured to: determine the absolute value of the power signal; when the absolute value is equal to the preset power signal, determine a first detection time T2n before the zero-crossing of the multiple zero-crossing signals and a second detection time T2n+1 after the zero-crossing; determine multiple corrected zero-crossing signals based on the multiple first detection times and the second detection times, thereby achieving full-process detection of the zero-crossing signals.

[0037] In an embodiment, such as Figure 3As shown, when the AC input circuit 11 outputs a power signal, such as an AC input voltage, the zero-crossing detection circuit determines the absolute value of the power signal, i.e., the amplitude of the AC input voltage. When the amplitude of the AC input voltage is lower than Uc, the optocoupler circuit 12 is cut off, the secondary side is in the cut-off state, the first transistor V4 is in the cut-off state, the zero-crossing detection port ZERO of the chip port receives a high level, and the chip port detects a zero-crossing signal. When the power signal output by the AC input circuit 11, such as the AC transmission voltage, is in the positive and negative half-cycles and the amplitude of the AC input voltage is greater than Uc, the forward diode of the optocoupler circuit 12 is turned on, and then the secondary side is turned on. The first power supply 12V starts to supply power to the base of the first transistor V4. The collector and emitter of the first transistor V4 are turned on, the voltage at the collector is set to 0, the zero-crossing detection circuit starts to work, and the zero-crossing detection port ZERO of the chip port detects a low level.

[0038] Taking the first zero-crossing signal t0 as an example, the absolute value of Uc from the rising edge of the zero-crossing signal t0 is detected and the corresponding time is determined as T2n. The absolute value of U2 from the falling edge of the zero-crossing signal t0 is detected and the corresponding time is recorded as T2n+1.

[0039] In some embodiments, when multiple corrected zero-crossing signals are determined based on multiple first detection times and second detection times, the zero-crossing detection circuit is configured to: determine multiple zero-crossing signal pulse times tn based on multiple first detection times and second detection times; and determine multiple corrected zero-crossing signals based on the multiple zero-crossing signal pulse times.

[0040] In this embodiment, the time difference between the falling edge time T2n+1 and the rising edge time T2n of the zero-crossing signal t0 is calculated, and the time difference is determined as the zero-crossing signal pulse time, i.e., tn = T2n+1 - T2n. Similarly, the pulse times of multiple zero-crossing signals are calculated to accurately calculate the duration of multiple zero-crossing signals.

[0041] In some embodiments, when multiple corrected zero-crossing signals are determined based on multiple zero-crossing signal pulse times, the zero-crossing detection circuit is configured to: calculate the average zero-crossing signal pulse time t of the multiple zero-crossing signal pulse times; and determine multiple corrected zero-crossing signals based on multiple first detection times T2n and the average zero-crossing signal pulse time.

[0042] In this embodiment, the average zero-crossing signal pulse time t of multiple zero-crossing signal pulse times is calculated. For example, the average zero-crossing signal pulse time t = (tn + tn-1 + ... + tn-10) / 10 of every 10 zero-crossing signal pulse times is calculated. Taking the average value can determine a more accurate zero-crossing signal pulse time and avoid the situation where the error of a single acquisition is large.

[0043] Based on multiple first detection times T2n and the average zero-crossing signal pulse time t, multiple corrected zero-crossing signals are determined. For example, the first corrected zero-crossing point ZREO1 = T2n + t / 2 is used as the zero point for the air conditioner's controller to control the fan drive. Similarly, multiple subsequent corrected zero-crossing points are calculated.

[0044] In addition to being set by the user, the preset power signal can also be set by the communication circuit.

[0045] In some embodiments, such as Figure 4 As shown, the air conditioner 1 also includes a communication circuit 14. The preset power signal includes a first preset power signal. When receiving the preset power signal from the air conditioner control circuit, the zero-crossing detection circuit is configured to receive the first preset power signal output by the communication circuit, thereby broadening the sources of the preset power signal.

[0046] In some embodiments, such as Figure 5 As shown, the air conditioner 1 includes: an AC input circuit 11, an optocoupler circuit 12, a zero-crossing detection circuit 13, and a communication circuit 14. The optocoupler circuit 12 adopts a bidirectional thyristor transistor optocoupler, for example, denoted as B1, which is composed of a light-emitting diode at the input end and a bidirectional thyristor or a transistor at the output end for auxiliary control, realizing electro-optical-electric conversion and control, and realizing the dual functions of electrical isolation and signal transmission.

[0047] For example, the bidirectional thyristor optocoupler B1 uses an optical signal as an intermediate medium to completely isolate the input side of the optocoupler circuit 12 (i.e., the AC input circuit 11) from the output side (i.e., the zero-crossing detection circuit 13 and / or the communication circuit 14), avoiding direct electrical connection between the two circuits. For instance, it can block the direct current path between high and low voltage, preventing high voltage from entering the low voltage side and damaging precision components such as CPUs and sensors, while ensuring operator safety. Alternatively, it can isolate different ground potentials. In complex electronic systems such as automotive electronics and industrial control systems, different modules may have ground potential differences, i.e., common-mode voltages. Direct connection will generate common-mode interference, such as noise and surges. The bidirectional thyristor optocoupler B1 cuts off the common-mode current path and suppresses interference through electro-optical-electro-electrical conversion, ensuring the accuracy of signal transmission.

[0048] The bidirectional thyristor optocoupler B1 achieves isolation while transmitting electrical signals proportionally or in a switching manner, supporting the transmission of various signal types, such as switching signal transmission and analog signal transmission.

[0049] The communication circuit includes a first optocoupler B2 and a first resistor R7. When receiving the first preset power signal output by the communication circuit, the zero-crossing detection circuit is configured to: acquire the reference voltage, conduction current and resistance value of the first optocoupler; determine the first preset power signal based on the reference voltage, conduction current and resistance value, and ensure the accuracy of the first preset power signal.

[0050] In an embodiment, such as Figure 6 As shown, because the third capacitor C3 in the communication circuit 14 is a small electrolytic capacitor, the presence of the third capacitor C3 and the first Zener diode V6 keeps the voltage at the fourth terminal of the first optocoupler B2, i.e. the reference voltage, around U1V. The voltage at point B of the communication circuit 14, i.e. the first preset power signal, is always higher than U2=U1+I×R7, where I is the conduction current of the first optocoupler B2.

[0051] When the AC input circuit 11 outputs a power signal, such as an AC input voltage, the zero-crossing detection circuit determines the absolute value of the power signal, i.e., the amplitude of the AC input voltage. When the amplitude of the AC input voltage is lower than Uc, the secondary side of the optocoupler circuit 12, i.e., the bidirectional thyristor optocoupler B1, is in the off state, the first transistor V4 is in the off state, the zero-crossing detection port ZERO of the chip port receives a high level, and the chip port detects a zero-crossing signal. When the power signal output by the AC input circuit 11, such as the AC transmission voltage, is in the positive and negative half-cycles and the amplitude of the AC input voltage is greater than Uc, the forward diode of the optocoupler circuit 12 conducts, and then the secondary side conducts. The first power supply 12V begins to supply power to the base of the first transistor V4, the collector and emitter of the first transistor V4 conduct, the voltage at the collector is set to 0, the zero-crossing detection circuit starts to work, and the zero-crossing detection port ZERO of the chip port detects a low level.

[0052] Taking the first zero-crossing signal t0 as an example, the absolute value of the time from the rising edge of the zero-crossing signal t0 to U2 is detected, and the corresponding time is determined as T2n. The absolute value of the time from the falling edge of the zero-crossing signal t0 to U2 is detected and the corresponding time is recorded as T2n+1. The time difference between the time T2n+1 corresponding to the falling edge of the zero-crossing signal t0 and the time T2n corresponding to the rising edge of the zero-crossing signal t0 is calculated. The time difference is determined as the zero-crossing signal pulse time, i.e., tn = T2n+1 - T2n. Similarly, the pulse times of multiple zero-crossing signals are calculated, and the average zero-crossing signal pulse time t of multiple zero-crossing signal pulse times is calculated. For example, the average zero-crossing signal pulse time t of every 10 zero-crossing signal pulse times is calculated as t = (tn + tn-1 + ... + tn-10) / 10. Taking the average value can determine a more accurate zero-crossing signal pulse time and avoid the situation where the error of a single acquisition is large.

[0053] Based on multiple first detection times T2n and the average zero-crossing signal pulse time t, multiple corrected zero-crossing signals are determined, for example, the first corrected zero-crossing point ZREO1=T2n+t / 2, which is used as the zero point for the air conditioner's controller to control the fan drive.

[0054] When the power signal output by the AC input circuit 11, such as the AC transmission voltage, is in the positive and negative half-cycles and the amplitude is greater than U2, the forward diode of the optocoupler circuit 12, i.e., the bidirectional thyristor optocoupler B1, is turned on, and then the secondary side is turned on. The first power supply 12V starts to supply power to the base of the first transistor V4. The collector and emitter of the first transistor V4 are turned on, the voltage at the collector is set to 0, and the zero-crossing detection port ZERO of the chip port detects a low level.

[0055] In some embodiments, such as Figure 4 As shown, the zero-crossing detection circuit 13 includes a first filtering module 131. After receiving the power signal and a preset power signal, the first filtering module is configured to filter out high-frequency noise and fluctuation noise in the power signal to determine the filtered power signal. Filtering out high-frequency noise can prevent high-frequency interference from affecting the normal operation of subsequent circuits, such as preventing false triggering of control signals and abnormal load operation. Filtering out fluctuation noise can stabilize the voltage or current amplitude of the power signal, reduce irregular fluctuations in the signal, and make the determined filtered power signal closer to the ideal power waveform, thereby providing a stable and clean power input for subsequent circuits and improving the overall reliability, operating accuracy, and anti-interference capability of the air conditioner.

[0056] In some embodiments, such as Figure 4 As shown, the zero-crossing detection circuit 13 includes a second filtering module 133. After determining multiple corrected zero-crossing signals based on the power supply signal and a preset power supply signal, the second filtering module is configured to: filter out high-frequency noise and fluctuation noise from the corrected zero-crossing signals, and determine the filtered corrected zero-crossing signal. By filtering out high-frequency noise, misjudgment of the zero-crossing time caused by high-frequency interference can be avoided, for example, preventing false zero-crossing pulses from triggering the control circuit. Filtering out fluctuation noise can eliminate irregular jitter in the signal amplitude, making the zero-crossing edge (rising or falling edge) of the filtered corrected zero-crossing signal clearer and steeper, thereby providing a more accurate and reliable zero-crossing time reference for subsequent circuits, and improving the synchronization control accuracy, anti-interference capability, and operational stability of the entire device.

[0057] In some embodiments, the air conditioner further includes a controller connected to a zero-crossing detection circuit, for receiving multiple corrected zero-crossing signals and controlling the air conditioner's fan according to the multiple corrected zero-crossing signals. This achieves precise synchronization of the fan's operating status, such as speed, start-stop timing, and AC power cycle, improving the stability, energy efficiency, and control accuracy of the fan operation, and reducing fan operation fluctuations or increased energy consumption caused by power phase deviation.

[0058] In some embodiments, the air conditioner further includes a controller connected to a zero-crossing detection circuit, used to receive a start-up command from the air conditioner before the AC input circuit outputs a power signal. This allows the zero-crossing detection circuit to be prepared in advance, ensuring that zero-crossing detection can be performed immediately when the AC input circuit outputs a power signal, thereby achieving precise control of the air conditioner load.

[0059] The following is combined with Figure 7 This invention describes a control method for an air conditioner according to an embodiment of the present invention.

[0060] like Figure 7 As shown, the air conditioner control method of this embodiment includes at least steps S11-S19.

[0061] Step S11: The controller receives the start command from the air conditioner.

[0062] In step S12, the AC input circuit outputs a power signal; the optocoupler circuit transmits or isolates the power signal; and the zero-crossing detection circuit is used to receive the power signal and the preset power signal.

[0063] Step S13: The first filtering module of the zero-crossing detection circuit filters out high-frequency noise and fluctuation noise in the power supply signal to determine the filtered power supply signal.

[0064] Step S14: The zero-crossing detection circuit determines the absolute value of the power signal; when the absolute value is equal to the preset power signal, it determines the first detection time before the zero-crossing of multiple zero-crossing signals and the second detection time after the zero-crossing.

[0065] Step S15: Determine multiple zero-crossing signal pulse times based on multiple first detection times and second detection times.

[0066] Step S16: Calculate the average zero-crossing signal pulse time of multiple zero-crossing signal pulse times; determine multiple corrected zero-crossing signals based on multiple first detection times and the average zero-crossing signal pulse time.

[0067] Step S17: The second filtering module of the zero-crossing detection circuit filters out high-frequency noise and fluctuation noise of the corrected zero-crossing signal to determine the filtered corrected zero-crossing signal.

[0068] In step S18, the controller receives multiple zero-crossing correction signals and controls the air conditioner's fan according to the multiple zero-crossing correction signals.

[0069] Step S19: The zero-crossing detection circuit acquires the reference voltage, conduction current and resistance value of the first optocoupler; and determines the first preset power signal based on the reference voltage, conduction current and resistance value.

[0070] According to an embodiment of the present invention, the zero-crossing detection circuit receives the power signal output from the AC input circuit through an optocoupler circuit. Based on the magnitude relationship between the power signal and a preset power signal, it determines whether the signal has crossed zero, the time of zero-crossing, the direction of deviation, and the degree of deviation, and determines the corrected zero-crossing signal. This can compensate for the error of the original zero-crossing signal, realize the precise zero-crossing detection function of the zero-crossing detection circuit, provide a more accurate zero-crossing reference for the air conditioner, ensure that the subsequent control of the air conditioner's load, such as the fan, is highly synchronized with the power cycle, and improve control accuracy and equipment operation stability.

[0071] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0072] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that, include: AC input circuit, used to output power signal; An optocoupler circuit, which is connected to the AC input circuit, is used to transmit or isolate the power signal; A zero-crossing detection circuit, connected to the optocoupler circuit, is used to receive the power signal and a preset power signal, and to determine multiple corrected zero-crossing signals based on the power signal and the preset power signal.

2. The air conditioner according to claim 1, characterized in that, When multiple corrected zero-crossing signals are determined based on the power signal and the preset power signal, the zero-crossing detection circuit is configured as follows: Determine the absolute value of the power signal; When the absolute value is equal to the preset power signal, determine the first detection time before the zero crossing of multiple zero-crossing signals and the second detection time after the zero crossing. Multiple corrected zero-crossing signals are determined based on multiple first detection times and multiple second detection times.

3. The air conditioner according to claim 2, characterized in that, When multiple corrected zero-crossing signals are determined based on multiple first detection times and second detection times, the zero-crossing detection circuit is configured as follows: Multiple zero-crossing signal pulse times are determined based on multiple first and second detection times; The plurality of corrected zero-crossing signals are determined based on the pulse times of the plurality of zero-crossing signals.

4. The air conditioner according to claim 3, characterized in that, When determining multiple corrected zero-crossing signals based on the pulse times of the multiple zero-crossing signals, the zero-crossing detection circuit is configured as follows: Calculate the average zero-crossing signal pulse time of multiple zero-crossing signal pulse times; Multiple corrected zero-crossing signals are determined based on multiple first detection times and the average zero-crossing signal pulse time.

5. The air conditioner according to claim 1, characterized in that, The air conditioner also includes a communication circuit, and the preset power signal includes a first preset power signal. When receiving the preset power signal from the air conditioner control circuit, the zero-crossing detection circuit is configured as follows: Receive the first preset power signal output by the communication circuit.

6. The air conditioner according to claim 5, characterized in that, The communication circuit includes a first optocoupler and a first resistor. When receiving the first preset power signal output by the communication circuit, the zero-crossing detection circuit is configured as follows: Obtain the reference voltage, conduction current, and resistance value of the first optocoupler; The first preset power signal is determined based on the reference voltage, the conduction current, and the resistance value.

7. The air conditioner according to claim 1, characterized in that, The zero-crossing detection circuit includes a first filtering module. After receiving the power signal and a preset power signal, the first filtering module is configured to: High-frequency noise and fluctuation noise of the power supply signal are filtered out to determine the filtered power supply signal.

8. The air conditioner according to claim 1, characterized in that, The zero-crossing detection circuit includes a second filtering module. After determining multiple corrected zero-crossing signals based on the power supply signal and the preset power supply signal, the second filtering module is configured as follows: High-frequency noise and fluctuation noise of the corrected zero-crossing signal are filtered out to determine the filtered corrected zero-crossing signal.

9. The air conditioner according to claim 1, characterized in that, The air conditioner also includes: The controller, connected to the zero-crossing detection circuit, is used to receive multiple corrected zero-crossing signals and control the fan of the air conditioner according to the multiple corrected zero-crossing signals.

10. The air conditioner according to claim 1, characterized in that, The air conditioner also includes: The controller, connected to the zero-crossing detection circuit, is used to receive the start-up command of the air conditioner before the AC input circuit outputs a power signal.

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