A cabinet air conditioner circuit and cabinet air conditioner

Abstract

The embodiment of the application provides a cabinet air conditioner circuit and a cabinet air conditioner, and relates to the technical field of the cabinet air conditioner. The distance between the main control MCU (101) and the sliding door power supply control circuit (102) is less than the distance between the sliding door power supply control circuit (102) and the stepping motor (105) driven by the stepping motor drive circuit (103). When the stepping motor drive circuit does not need to be connected to the stepping motor power supply, the main control MCU can send a signal to the sliding door power supply control circuit, and the sliding door power supply control circuit disconnects the connection between the stepping motor power supply and the stepping motor drive circuit, that is, the long wire is powered off, which is equivalent to the disconnection of the antenna. The long wire will not generate an electromagnetic signal and radiation interference, and the sliding door stepping motor becomes a non-charged component. In the large-current space near the wiring board, the coupled interference is greatly reduced, thereby improving EMC.

Description

Technical Field

[0001] This application relates to the field of cabinet air conditioning technology, and in particular to cabinet air conditioning circuits and cabinet air conditioners. Background Technology

[0002] Figure 1 The diagram shows the main view of the indoor unit 11 of the floor-standing air conditioner. The sliding door 12 is in the center, and there are stepper motors above and below the sliding door 12 (for heavier sliding doors or double doors, there are two stepper motors above and two below; for lighter sliding doors, there may be one above and one below). The frame indicated by 13 represents the stepper motor. The sliding door of the floor-standing air conditioner indoor unit is opened and closed by stepper motors 13. When the air conditioner is on, the sliding door is open, and air blows out from the sliding door; when the air conditioner is off, the sliding door is closed.

[0003] Figure 2 The diagram shows a side view of the air conditioner. The power cord connects to AC power from the outside, runs to terminals on the junction box 14 below the sliding door, and is then powered by the terminals on the junction box 14: one path leads to the outdoor unit 15 of the air conditioner, and the other path leads to the electronic control board 16 above the sliding door. In the diagram, 21 represents the wire from the junction box 14 to the electronic control board 16, and 22 represents the wire from the electronic control board 16 to the stepper motor 13 below.

[0004] It is particularly important to note that the control board needs to control the stepper motor below (the stepper motor of the sliding door at the bottom must be installed at the bottom of the sliding door), therefore there is a relatively long wire 22 running from the control board to the stepper motor below.

[0005] The applicant conducted research on EMC (Electromagnetic Compatibility) testing of air conditioners. EMC testing assesses the ability of air conditioning equipment to generate electromagnetic energy without interfering with or being interfered with by the electromagnetic energy of other equipment. The relevant definition of electromagnetic interference is introduced here:

[0006] ① Electromagnetic interference propagation paths are generally divided into two types. Electromagnetic interference propagation paths are generally classified into two types: conductive coupling and radiative coupling.

[0007] ② Any electromagnetic interference necessarily involves the transmission of interference energy and a transmission path (or transmission channel). Electromagnetic interference is generally considered to be transmitted in two ways: conducted transmission and radiated transmission. Therefore, from the perspective of the affected sensor, interference coupling can be divided into two main categories: conducted coupling and radiated coupling.

[0008] ③ Conductive transmissionThere must be a complete circuit connection between the interference source and the sensor. The interference signal is transmitted to the sensor along this connection circuit, causing interference. This transmission circuit may include wires, conductive components of the equipment, power supply, common impedance, grounding plate, resistors, inductors, capacitors, and mutual inductance elements, etc.

[0009] ④ Radiative transmission Radiative coupling propagates through a medium in the form of electromagnetic waves, with interference energy emitted into the surrounding space according to the laws of electromagnetic fields. Common types of radiative coupling include: 1. Electromagnetic waves emitted by antenna A are accidentally received by antenna B, known as... Antenna pair Antenna coupling 2. Spatial electromagnetic fields are coupled through induction via conductors, which is called... Field-to-line coupling 3. The high-frequency signal induction between two parallel wires is called... Line-to-line inductive coupling .

[0010] In practical engineering, interference between two devices usually involves coupling through multiple pathways. It is precisely because multiple coupling pathways exist simultaneously and repeatedly cross-couple, jointly generating interference, that electromagnetic interference becomes difficult to control.

[0011] ⑤ Radiated interference Interference refers to the coupling (interference) of signals from a source to another electrical network through space. In high-speed PCB and system design, high-frequency signal lines, integrated circuit pins, and various connectors can all become sources of radiating interference with antenna characteristics, emitting electromagnetic waves and affecting the normal operation of other systems or other subsystems within the same system.

[0012] The applicant's research revealed that Problems :like Figure 1 , Figure 2 The terminal block contains the main power cord, especially the one connected to the outdoor unit, which carries a large current and generates a strong magnetic field. The terminal block is very close to the stepper motor below, and the long wire 22 is easily coupled by the magnetic field generated by this large current. In addition, the stepper motor below also has a coil inside, similar to a current transformer. Multiple coupling paths exist simultaneously and repeatedly cross-couple, jointly generating interference, making electromagnetic interference difficult to control, negatively affecting the normal operation of the air conditioner, and causing it to fail the EMC test.

[0013] Therefore, the applicant proposed that the following technical issues need to be addressed: the sliding door stepper motor drive circuit needs to be optimized to suppress radiated interference and conducted interference. Summary of the Invention

[0014] The purpose of this application is to provide a cabinet air conditioner circuit and a cabinet air conditioner to solve the technical problem that the sliding door stepper motor drive circuit in the prior art needs to be optimized to suppress radiation interference and conduction interference.

[0015] To achieve the above objectives, the embodiments of this application adopt the following technical solutions.

[0016] In a first aspect, embodiments of this application provide a cabinet air conditioner circuit, including a main control MCU, a sliding door power control circuit, and a stepper motor drive circuit;

[0017] The main control MCU is connected to the control terminal of the sliding door power control circuit. The first terminal of the sliding door power control circuit is connected to the stepper motor power supply, and the second terminal of the sliding door power control circuit is connected to the stepper motor drive circuit.

[0018] The stepper motor drive circuit is used to drive the stepper motor to open or close the sliding door of the cabinet air conditioner; the distance between the main control MCU and the sliding door power control circuit is less than the distance between the sliding door power control circuit and the stepper motor driven by the stepper motor drive circuit.

[0019] The main control MCU is used for:

[0020] (1) Upon receiving the power-on command, control the sliding door power control circuit to be turned on, and then control the sliding door power control circuit to be turned off after a preset first time.

[0021] (2) When a power-off command is received, the power control circuit of the sliding door is turned on, and then after a preset second time, the power control circuit of the sliding door is turned off.

[0022] Optionally, the sliding door power control circuit includes a switching transistor module. The control terminal of the switching transistor module is connected to the sliding door power control terminal of the main control MCU. The first terminal of the switching transistor module is connected to the stepper motor power supply. The second terminal of the switching transistor module is connected to the stepper motor drive circuit. The ground terminal of the switching transistor module is grounded.

[0023] Optionally, the switching module includes a first switching transistor, a second switching transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor;

[0024] The control terminal of the first switching transistor is connected to the main control MCU through the first resistor. The first terminal of the first switching transistor is grounded, and the second resistor is connected between the first terminal of the first switching transistor and the control terminal of the first switching transistor.

[0025] The second terminal of the first switching transistor is connected to the control terminal of the second switching transistor through the third resistor. The first terminal of the second switching transistor is connected to the stepper motor power supply. The fourth resistor is connected between the first terminal of the second switching transistor and the control terminal of the second switching transistor. The second terminal of the second switching transistor is connected to the stepper motor drive circuit.

[0026] Optionally, the switching module further includes a diode;

[0027] The cathode of the diode is connected to the first terminal of the second switching transistor, and the anode of the diode is connected to the second terminal of the second switching transistor.

[0028] Optionally, the cabinet air conditioner circuit also includes an I / O port expansion circuit;

[0029] The main control MCU is connected to the stepper motor drive circuit through the IO port expansion circuit.

[0030] Optionally, the cabinet air conditioner circuit further includes a current-limiting resistor; the main control MCU is connected to the IO port expansion circuit through the current-limiting resistor.

[0031] Optionally, the I / O port expansion circuit includes a shift register chip with serial data input, parallel data output, and data latching functions.

[0032] Optionally, the stepper motor drive circuit includes a power switch array chip.

[0033] Optionally, the power switch array chip includes multiple ULN2003 chips, and the output terminals of the multiple ULN2003 chips are respectively connected to the up-and-down swing fan motor, the left-and-right swing fan motor, the fresh air internal circulation motor, the fresh air external circulation motor, and the sliding door stepper motor.

[0034] Secondly, embodiments of this application provide a cabinet air conditioner, which includes the cabinet air conditioner circuit described in the first aspect.

[0035] Compared with the prior art, this application has the following advantages:

[0036] When the stepper motor drive circuit does not need to be connected to the stepper motor power supply, the main control MCU sends a signal to the sliding door power control circuit. The sliding door power control circuit disconnects the stepper motor power supply from the stepper motor drive circuit, that is, the long wire is de-energized, which is equivalent to the antenna being disconnected. This long wire will not generate electromagnetic signals or radiated interference, and the sliding door stepper motor also becomes a non-energized component. In the high current space near the terminal block, the coupling interference is greatly reduced, thereby improving EMC. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the main view of the indoor unit of a cabinet air conditioner;

[0039] Figure 2 This is a side view diagram of a cabinet air conditioner.

[0040] Figure 3 A schematic diagram of a cabinet air conditioner circuit is provided for an embodiment of this application;

[0041] Figure 4 A schematic diagram showing the connection of 8 stepper motors when the main control MCU has not expanded its I / O ports;

[0042] Figure 5 A circuit diagram of a cabinet air conditioner with an I / O port expansion circuit is provided for an embodiment of this application;

[0043] Figure 6 A circuit diagram of a cabinet air conditioner using a 74HC595 chip and a ULN2003 chip is provided for an embodiment of this application.

[0044] Explanation of reference numerals in the attached figures:

[0045] 11-Floor-standing air conditioner indoor unit

[0046] 12- Sliding Door

[0047] 13-Stepper Motor

[0048] 14-Connector

[0049] 15-Air conditioner outdoor unit

[0050] 16-Electrical Control Board

[0051] 21-Wires from the terminal block to the control board

[0052] 22-Wires from the control board to the stepper motor below

[0053] 101-Main Control MCU

[0054] 102-Sliding door power control circuit

[0055] 1021-Switch Module

[0056] 103-Stepper Motor Drive Circuit

[0057] 104-Stepper Motor Power Supply

[0058] 105-Stepper Motor

[0059] 106-IO port expansion circuit Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described in the accompanying drawings can generally be arranged and designed in various different configurations.

[0061] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0062] In the description of this application, it should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The term "connection" should be interpreted broadly, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0063] The cabinet air conditioner in this application is as follows: Figure 1 , 2 Sliding doors have stepper motors installed at the bottom, which are close to the wiring board and unavoidable. The stepper motor's long connecting wires act like antennas, easily becoming sources of radiated interference and susceptible to inductive coupling from other antennas, thus affecting the air conditioner's EMC (Electronic Compatibility) performance. The stepper motor's internal windings, similar to mutual inductors, can also transmit interference signals to the controller via conduction, causing EMC tests to fail. Therefore, the sliding door stepper motor drive circuit requires optimized design to suppress both radiated and conducted interference.

[0064] To suppress radiated and conducted interference, please refer to [reference needed]. Figure 3 This application provides a cabinet air conditioner circuit, including a main control MCU 101, a sliding door power control circuit 102, and a stepper motor drive circuit 103. The stepper motor drive circuit 103 is used to drive a stepper motor 105, which can refer to the stepper motor below the sliding door, or the stepper motors above and below the sliding door.

[0065] Figure 3 In the diagram, the left end of the sliding door power control circuit 102 is defined as the control end, the top end as the first end, and the right end as the second end. The connection relationship is described as follows:

[0066] The main control MCU 101 is connected to the control terminal of the sliding door power control circuit 102. The first terminal of the sliding door power control circuit 102 is connected to the stepper motor power supply 104, and the second terminal of the sliding door power control circuit 102 is connected to the stepper motor drive circuit 103.

[0067] The distance between the main control MCU 101 and the sliding door power control circuit 102 is less than the distance between the sliding door power control circuit 102 and the stepper motor 105 driven by the stepper motor drive circuit 103. Thus, when the stepper motor drive circuit 103 does not need to be connected to the stepper motor power supply 104, the main control MCU 101 sends a signal to the sliding door power control circuit 102, and the sliding door power control circuit 102 disconnects the stepper motor power supply 104 from the stepper motor drive circuit 103. Figure 2 When the longer wire 22 is de-energized, it is equivalent to the antenna being disconnected. This longer wire will no longer generate electromagnetic signals or radiated interference. The sliding door stepper motor also becomes a non-energized component. In the high-current space near the terminal block, the coupling interference is greatly reduced, thereby improving EMC.

[0068] This application utilizes the following characteristics of cabinet air conditioners: the sliding door only opens and closes when the unit is turned on and off; the sliding door opens when the unit is turned on and closes when the unit is turned off; the sliding door stepper motor does not operate when the air conditioner is running in normal cooling, heating, or other normal operating modes.

[0069] Therefore, embodiments of the present invention also provide a readable storage medium, which includes a computer program. When the computer program runs, it enables the main control MCU 101 to execute the following cabinet air conditioner circuit control method:

[0070] (1) When the power-on command is received, the sliding door power control circuit 102 is turned on, and then after a preset first time (e.g., 40 seconds), the sliding door power control circuit 102 is turned off.

[0071] (2) When a power-off command is received, the power control circuit 102 of the sliding door is turned on, and then after a preset second time, the power control circuit 102 of the sliding door is turned off.

[0072] Specifically:

[0073] (1) In order to open the sliding door when the power is turned on, the sliding door power control circuit 102 can be turned on immediately upon receiving the power-on command, so that the sliding door stepper motor is powered on. Then, the sliding door is opened according to the command to open the sliding door by pressing the main chip. After the preset first time, the sliding door has been opened and there is no need to continuously supply power to the stepper motor drive circuit. The sliding door power control circuit 102 can then be turned off.

[0074] (2) To close the sliding door when the machine is turned off, the sliding door power control circuit 102 can be turned on immediately upon receiving the power off command, so that the sliding door stepper motor is powered on. Then, the sliding door closing command is issued after 1 second, and the sliding door closes. After a preset second time, the sliding door has closed, and the sliding door power control circuit 102 can be turned off.

[0075] On the other hand, regarding the I / O ports of the main control MCU, such as Figure 4 (The power control circuit for the sliding door has been omitted.) Figure 4 The fresh air cabinet air conditioner has eight stepper motors in total: a vertical swing fan motor, a horizontal swing fan motor, a fresh air internal circulation motor, a fresh air external circulation motor, and four sliding door stepper motors (the eight on the right side of the diagram are the terminals for connecting the motors; these terminals can be set on the main control board where the main control MCU is located). Driving these stepper motors requires a large number of I / O ports (20 I / O ports are needed), therefore a main control MCU chip with a large number of pins needs to be selected.

[0076] In order to accommodate smaller main control MCU chips with fewer pins and reduce costs, such as Figure 5 This application embodiment also provides a cabinet air conditioner circuit with IO port expansion circuit, wherein the main control MCU 101 is connected to the stepper motor drive circuit 103 through the IO port expansion circuit 106.

[0077] One implementation method is as follows Figure 6 , Figure 6 The circuitry can be integrated onto a single main control board. The eight block-shaped motor terminals shown in the diagram can be configured as pin headers, through which the stepper motor drive circuit 103 connects to the stepper motor. The I / O port expansion circuit 106 can use a shift register chip with latching function, or a chip with serial data input, data latching, and parallel data output functions, such as the 74HC595 chip.

[0078] Figure 6 In the process, connect pin 10 (MR) and pin 16 (VDD) of the 74HC595 chip to +5V, and connect pin 13 (OE) and pin 8 (GND) to GND. C1 and C2 can be 104 surface mount capacitors, which serve as filters to ensure the stable operation of the 74HC595 chip.

[0079] Current-limiting resistors R1 to R6 can also be set. The main control MCU is connected to the 74HC595 chip through current-limiting resistors R1 to R6 to further ensure the stable operation of the 74HC595 chip. R1 to R6 can be 100Ω resistors.

[0080] When SH_CP (shift register clock input) is rising, DS (serial data input) is shifted high into the shift register; the 8 data are shifted into the shift register in sequence and appear on the parallel data output (Q0~Q7); when ST_CP (store register clock input) is rising, the parallel data output (Q0~Q7) is output simultaneously.

[0081] The 74HC595 chip outputs to the stepper motor driver circuit 103, which may include a power switch array chip, such as the ULN2003 chip. C3, C4, C5, and C6 filter the ULN2003 chip.

[0082] Figure 6 Two 74HC595 chips and two ULN2003 chips were used, connected to eight stepper motors respectively. The two 74HC595 chips expanded the main control MCU's six I / O ports to 16 I / O ports, allowing the main chip to drive eight stepper motors with only six I / O ports.

[0083] Figure 6 The following shows an implementation of a sliding door power control circuit 102. The part referred to as 1021 is a switching transistor module. The control terminal of the switching transistor module 1021 is connected to the sliding door power control terminal of the main control MCU 101. The first terminal of the switching transistor module 1021 is connected to the stepper motor power supply 104. The second terminal of the switching transistor module 1021 is connected to the stepper motor drive circuit 103. The ground terminal of the switching transistor module 1021 is grounded.

[0084] The switching module may specifically include a first switching transistor Q1, a second switching transistor Q2, a first resistor R7, a second resistor R8, a third resistor R9, and a fourth resistor R10. The connection relationship is described below:

[0085] The control terminal of the first switch Q1 is connected to the main control MCU 101 through the first resistor R7. The first terminal of the first switch Q1 is grounded. The second resistor R8 is connected between the first terminal of the first switch Q1 and the control terminal of the first switch Q1. The second terminal of the first switch Q1 is connected to the control terminal of the second switch Q2 through the third resistor R9. The first terminal of the second switch Q2 is connected to the stepper motor power supply 104. The fourth resistor R10 is connected between the first terminal of the second switch Q2 and the control terminal of the second switch Q2. The second terminal of the second switch Q2 is connected to the stepper motor drive circuit 103. That is, the power supply terminals of the motors PANEL-S-M1, M2, M3, and M4 in the figure are all connected to the collector of the transistor Q2.

[0086] When the sliding door power control terminal of the main control MCU 101 outputs a high level +5V, R7 and R8 divide the voltage, and the switching transistors Q1 and Q2 are turned on, supplying power to the sliding door stepper motor with 12V. When the sliding door power control terminal of the main control MCU 101 outputs a low level 0V, the switching transistors Q1 and Q2 are not turned on, and the 12V stepper motor power supply is not supplied to the sliding door stepper motor.

[0087] Figure 6 In the circuit, on the right side of the switching transistor module 1021, a diode D1 is also provided. The cathode of diode D1 is connected to the first terminal of the second switching transistor Q2, and the anode of diode D1 is connected to the second terminal of the second switching transistor Q2. In the figure, D1 is connected across the emitter and collector of transistor Q2, which can ensure that transistor Q2 is not damaged due to excessive stepper motor induced voltage. This circuit is simple and reliable.

[0088] Based on the above embodiments, this application also provides a cabinet air conditioner, including the aforementioned cabinet air conditioner circuit, wherein the main control MCU executes the aforementioned cabinet air conditioner circuit control method. A terminal block can be located at the bottom of the air conditioner, below the sliding door. A sliding door stepper motor is also located below the sliding door and near the terminal block. A main control board is located on the upper part of the air conditioner, above the sliding door. The main control board integrates a main control MCU, a sliding door power control circuit, and a stepper motor drive circuit. The terminals of the stepper motor drive circuit are connected to the sliding door stepper motors above and below the sliding door. When the sliding door stepper motor is not in use, the main control MCU controls the sliding door power control circuit to disconnect, and the long wire between the stepper motor drive circuit and the sliding door stepper motor below the sliding door is not energized, and the stepper motor is also not energized. In the high-current space near the terminal block, coupling interference is significantly reduced, thereby improving EMC.

[0089] In a test of a certain model of cabinet air conditioner, terminal voltage tests were conducted using continuous interference ranging from 148.5 kHz to 30 MHz, and interference power tests were conducted using continuous interference ranging from 30 MHz to 300 MHz, according to the methods and procedures specified in GB4343.1-2018. The terminal voltage test conditions were as follows:

[0090] Ambient temperature: 26.0°C; Relative humidity: 47.3%RH;

[0091] Rated voltage: 220V; Rated frequency: 50Hz;

[0092] Test voltage: 242V; Test frequency: 50Hz;

[0093] Environmental disturbance: ≤20dBμV;

[0094] Operating status of the tested device: cooling (set temperature: 16 degrees; fan speed: high).

[0095] The interference power test conditions are as follows:

[0096] Ambient temperature: 27.4°C; Relative humidity: 54.3%RH;

[0097] Rated voltage: 220V; Rated frequency: 50Hz;

[0098] Test voltage: 242V; Test frequency: 50Hz;

[0099] Electromagnetic environment: ≤20dBpW;

[0100] Operating status of the tested device: cooling (set temperature: 16 degrees; fan speed: high).

[0101] contrast In the case of not adopting the scheme of this application The experimental data curves, and Under the scheme of this application The test data curves show that the solution proposed in this application reduces the peak value of the terminal voltage and the peak value of the interference power by 2-3 dBμV or 2-3 dBμW, which can enable the originally qualified products to meet more stringent standards.

[0102] In summary, this application proposes a cabinet air conditioner circuit and cabinet air conditioner with improved EMC. This circuit not only provides stable and reliable drive signals, but also effectively improves EMC, greatly increases the pass rate of EMC testing of air conditioners, and significantly reduces the number of drive I / O ports required. Miniaturized chips can be used to reduce costs.

[0103] The apparatus and system embodiments described above are merely illustrative. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement these embodiments without any creative effort.

[0104] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cabinet air conditioner circuit, characterized by comprising: The application relates to a sliding door power supply control circuit and a step motor drive circuit. The main control MCU (101) is connected to the control end of the sliding door power supply control circuit (102), the first end of the sliding door power supply control circuit (102) is connected to the step motor power supply (104), and the second end of the sliding door power supply control circuit (102) is connected to the step motor drive circuit (103). The step motor drive circuit (103) is used for driving a step motor to open or close the sliding door of a cabinet air conditioner. The main control MCU is used for controlling the sliding door power supply control circuit (102) to be turned on when a start-up instruction is received, and then controlling the sliding door power supply control circuit (102) to be turned off after a preset first time. The main control MCU is also used for controlling the sliding door power supply control circuit (102) to be turned on when a shutdown instruction is received, and then controlling the sliding door power supply control circuit (102) to be turned off after a preset second time.

2. The cabinet air conditioner circuit according to claim 1, wherein The sliding door power supply control circuit (102) comprises a switch tube module (1021), the control end of the switch tube module (1021) is connected to the sliding door power supply control end of the main control MCU (101), the first end of the switch tube module (1021) is connected to the step motor power supply (104), the second end of the switch tube module (1021) is connected to the step motor drive circuit (103), and the ground end of the switch tube module (1021) is grounded.

3. The cabinet air conditioner circuit according to claim 2, wherein The switch tube module (1021) comprises a first switch tube (Q1), a second switch tube (Q2), a first resistor (R7), a second resistor (R8), a third resistor (R9) and a fourth resistor (R10). The control end of the first switch tube (Q1) is connected to the main control MCU (101) through the first resistor (R7), the first end of the first switch tube (Q1) is grounded, and the second resistor (R8) is connected between the first end of the first switch tube (Q1) and the control end of the first switch tube (Q1). The second end of the first switch tube (Q1) is connected to the control end of the second switch tube (Q2) through the third resistor (R9), the first end of the second switch tube (Q2) is connected to the step motor power supply (104), the fourth resistor (R10) is connected between the first end of the second switch tube (Q2) and the control end of the second switch tube (Q2), and the second end of the second switch tube (Q2) is connected to the step motor drive circuit (103).

4. The cabinet air conditioner circuit according to claim 3, wherein The switch tube module further comprises a diode (D1). The cathode of the diode (D1) is connected to the first end of the second switch tube (Q2), and the anode of the diode (D1) is connected to the second end of the second switch tube (Q2).

5. The closet air conditioner circuit according to claim 1, wherein, The cabinet air conditioner circuit further comprises an IO port expansion circuit (106); The main control MCU (101) is connected with the step motor drive circuit (103) through the IO port expansion circuit (106).

6. The cabinet air conditioner circuit according to claim 5, wherein The cabinet air conditioner circuit further comprises a current limiting resistor; the main control MCU (101) is connected with the IO port expansion circuit (106) through the current limiting resistor.

7. The cabinet air conditioner circuit according to claim 5, wherein The IO port expansion circuit (106) comprises a shift register chip with data serial input, data output parallel output and data latch function.

8. The cabinet air conditioner circuit according to claim 1, wherein, The step motor drive circuit (103) comprises a power switch array chip.

9. The cabinet air conditioner circuit according to claim 8, wherein, The power switch array chip comprises a plurality of ULN2003 chips, and the output ends of the plurality of ULN2003 chips are respectively connected with the up-down air swinging motor, the left-right air swinging motor, the fresh air internal circulation motor, the fresh air external circulation motor and the sliding door step motor.

10. A cabinet air conditioner, characterized in that, The cabinet air conditioner comprises the cabinet air conditioner circuit according to any one of claims 1-9, wherein the main control MCU is used to execute the following cabinet air conditioner circuit control method: When receiving a start-up instruction, the sliding door power supply control circuit (102) is turned on, and then after a preset first time, the sliding door power supply control circuit (102) is turned off; When receiving a shutdown instruction, the sliding door power supply control circuit (102) is turned on, and then after a preset second time, the sliding door power supply control circuit (102) is turned off.

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