An ultra-low energy consumption test chamber

Abstract

The present disclosure provides a kind of ultra-low energy consumption test chamber, belong to electronic equipment technical field.This kind of ultra-low energy consumption test chamber includes: including compressor, condenser, expansion valve and evaporator, the exhaust port of the compressor is communicated with the import of the condenser, the outlet of the condenser is communicated with the import of the evaporator by first pipeline, the outlet of the evaporator is communicated with the back gas port of the compressor, the expansion valve is arranged on the first pipeline, the outlet of the condenser is communicated with the back gas port of the compressor by second pipeline.The present disclosure can reduce the power consumption of entire test chamber.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electronic devices, and in particular to an ultra-low energy consumption test chamber. BACKGROUND

[0002] A constant temperature test chamber can be used to test the performance of a product under different temperature and humidity conditions, which helps to evaluate the stability and reliability of the product in the actual use environment, and provides an important basis for product research and development, quality control and material evaluation, and is an indispensable device for new product research and development.

[0003] The existing constant temperature test chamber uses a constant refrigeration system to work all the time, and controls the output of the heating system (heating wire or heating pipe) to offset the energy of the refrigeration system and the energy of the heating system to achieve the purpose of constant temperature. The above method will cause waste of energy, and the temperature control precision is poor. SUMMARY

[0004] The embodiment of the present disclosure provides an ultra-low energy consumption test chamber to solve the problems of high energy consumption and poor control precision of the existing constant temperature test chamber.

[0005] The embodiment of the present disclosure provides an ultra-low energy consumption test chamber, comprising a compressor, a condenser, an expansion valve and an evaporator,

[0006] The exhaust port of the compressor is in communication with the inlet of the condenser, the outlet of the condenser is in communication with the inlet of the evaporator through a first pipeline, the outlet of the evaporator is in communication with the return air port of the compressor, and the expansion valve is arranged on the first pipeline,

[0007] The outlet of the condenser is in communication with the return air port of the compressor through a second pipeline.

[0008] In an exemplary embodiment of the present disclosure, the ultra-low energy consumption test chamber further comprises a third pipeline, one end of the third pipeline is in communication with the exhaust port of the compressor, the other end of the third pipeline is in communication with the inlet of the evaporator, and an electromagnetic valve is arranged on the third pipeline.

[0009] In an exemplary embodiment of the present disclosure, the ultra-low energy consumption test chamber further comprises a fourth pipeline, the first pipeline and the second pipeline are both in communication with the outlet of the condenser through the fourth pipeline, and a drying filter is arranged on the fourth pipeline.

[0010] In an exemplary embodiment of the present disclosure, the ultra-low energy consumption test chamber further comprises an expansion valve control circuit, the expansion valve control circuit comprises a valve core position detection circuit, a subtraction circuit, a comparison circuit and a motor driving circuit connected in sequence,

[0011] The first terminal of the subtraction circuit is connected to the first reference voltage, the second terminal of the subtraction circuit is connected to the output terminal of the valve core position detection circuit, the output terminal of the subtraction circuit is connected to the first input terminal of the comparison circuit, the second input terminal of the comparison circuit is connected to the triangular wave generating circuit, and the output terminal of the comparison circuit is connected to the control terminal of the motor drive circuit. The motor drive circuit is used to drive the valve core of the expansion valve to move.

[0012] In one exemplary embodiment of this disclosure, a logic processing circuit is provided between the comparison circuit and the motor drive circuit. The logic processing circuit includes optocoupler U6, optocoupler U7, XOR gate U8, a first AND gate, and a second AND gate.

[0013] The first input terminal of the optocoupler U6 is connected to the output terminal of the comparator circuit, the second input terminal of the optocoupler U6 is grounded, the first output terminal of the optocoupler U6 is connected to the first power supply through a first pull-up resistor, the second output terminal of the optocoupler U6 is grounded, and the output terminal of the optocoupler U6 is connected to the first input terminal of the XOR gate U8.

[0014] The first input terminal of optocoupler U7 is connected to the second power supply, the second input terminal of optocoupler U7 is connected to the output terminal of the comparator circuit, the first output terminal of optocoupler U6 is connected to the first power supply through a second pull-up resistor, the second output terminal of optocoupler U6 is grounded, and the output terminal of optocoupler U7 is connected to the second input terminal of XOR gate U8.

[0015] The first output terminal of the optocoupler U6 is connected to the first input terminal of the first AND gate, the output terminal of the XOR gate U8 is connected to the second input terminal of the first AND gate, and the output terminal of the first AND gate is connected to the first control terminal of the motor drive circuit.

[0016] The first output terminal of the optocoupler U7 is connected to the first input terminal of the second AND gate, the output terminal of the XOR gate U8 is connected to the second input terminal of the second AND gate, and the output terminal of the second AND gate is connected to the second control terminal of the motor drive circuit.

[0017] In one exemplary embodiment of this disclosure, the valve core position detection circuit includes a displacement sensor, a first amplification circuit, and a second amplification circuit connected in sequence.

[0018] The displacement sensor is used to detect the displacement of the expansion valve core, and the output terminal of the second amplification circuit is the output terminal of the valve core position detection circuit.

[0019] In one exemplary embodiment of this disclosure, the ultra-low energy consumption test chamber further includes a reference position output circuit, which comprises a DAC module U2 and a voltage reference chip U1. The digital input terminal of the DAC module U2 is connected to the main control unit, and the analog input terminal of the DAC module U2 is the first reference voltage.

[0020] The input terminal of the voltage reference chip U1 is connected to the third power supply, and the output terminal of the voltage reference chip U1 is connected to the reference voltage input terminal of the DAC module U2.

[0021] The beneficial effects of the ultra-low energy consumption test chamber provided in this disclosure are as follows:

[0022] In this embodiment, when the temperature inside the test chamber reaches the set temperature, the opening of the expansion valve is controlled to adjust the cooling capacity entering the evaporator, thereby regulating the evaporator's cooling temperature and maintaining the test chamber temperature at the set temperature. The remaining refrigerant in the condenser is recovered via a second pipe into the compressor's return port, achieving refrigerant reuse.

[0023] This embodiment of the disclosure takes into account that the device (or product) under test will generate a lot of heat during operation, which will cause the temperature inside the test chamber to rise. Therefore, by controlling the cooling temperature of the cooling system and the heating temperature of the heating system according to the real-time temperature inside the test chamber, the heat generated by the device under test can be fully utilized, avoiding excessive cooling energy and heating energy from canceling each other out, thereby improving energy utilization efficiency and reducing the power consumption of the entire test chamber. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of an ultra-low energy consumption test chamber provided in an embodiment of this disclosure;

[0026] Figure 2 This is a schematic diagram of the expansion valve control circuit provided in an embodiment of this disclosure;

[0027] Figure 3 This is a schematic diagram of the logic processing circuit provided in an embodiment of this disclosure;

[0028] Figure 4 This is a schematic diagram of the valve core position detection circuit provided in an embodiment of this disclosure;

[0029] In the picture:

[0030] 1 Expansion valve, 2 First pipe, 3 Second pipe, 4 Fourth pipe, 5 Dryer filter, 6 Refrigerant capillary tube, 7 Return capillary tube, 8 Solenoid valve, 9 Third pipe. Detailed Implementation

[0031] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0032] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0033] The implementation of this disclosure will be described in detail below with reference to the specific accompanying drawings:

[0034] Figure 1 This is a structural schematic diagram of an ultra-low energy consumption test chamber provided in an embodiment of this disclosure. (Refer to...) Figure 1 The ultra-low energy consumption test chamber includes a compressor, condenser, expansion valve 1, and evaporator.

[0035] The compressor's discharge port is connected to the condenser's inlet, the condenser's outlet is connected to the evaporator's inlet via the first pipe 2, and the evaporator's outlet is connected to the compressor's return port. Expansion valve 1 is installed on the first pipe 2.

[0036] The outlet of the condenser is connected to the return port of the compressor through the second pipe 3.

[0037] In this embodiment, when the temperature inside the test chamber reaches the set temperature, the opening of the expansion valve 1 is controlled to adjust the cooling capacity entering the evaporator, thereby regulating the cooling temperature of the evaporator and maintaining the temperature inside the test chamber at the set temperature. Other refrigerant in the condenser is recovered through the second pipe 3 into the compressor's return port, achieving refrigerant reuse.

[0038] The first pipe 2 is equipped with a refrigeration capillary tube 6. After the refrigerant passes through the expansion valve 1 and the capillary tube, it changes from a high-temperature, high-pressure liquid state to a low-temperature, low-pressure liquid state so that it can vaporize and absorb heat in the evaporator. The second pipe 3 is equipped with a return capillary tube 7, which can cool down the high-temperature, high-pressure liquid in the second pipe 3. The cooled liquid enters the compressor's return port to cool the compressor.

[0039] This embodiment of the disclosure takes into account that the device under test will generate a lot of heat during operation, which will cause the temperature inside the test chamber to rise. Therefore, by controlling the cooling temperature of the cooling system and the heating temperature of the heating system according to the real-time temperature inside the test chamber, the heat generated by the device under test can be fully utilized, avoiding excessive cooling energy and heating energy from canceling each other out, thereby improving energy utilization efficiency and reducing the power consumption of the entire test chamber.

[0040] In one exemplary embodiment of this disclosure, the ultra-low energy consumption test chamber further includes a third pipe 9, one end of which is connected to the exhaust port of the compressor, and the other end of which is connected to the inlet of the evaporator. A solenoid valve 8 is provided on the third pipe 9.

[0041] In this embodiment, insufficient or excessive refrigerant, reduced compressor efficiency, and decreased evaporator performance can all cause evaporator frosting. Evaporator frosting hinders heat exchange between the refrigerant and the air, which leads to a decrease in the evaporator's heat transfer efficiency, a weakening of the cooling effect, and an increase in the power consumption of the refrigeration system.

[0042] To solve the above problems, this embodiment sets up a third pipe 9. By periodically controlling the opening of the solenoid valve 8 on the third pipe 9, the high-temperature gas from the compressor exhaust port is introduced into the evaporator, and the heat of the high-temperature gas is used to melt the frost layer on the surface of the evaporator.

[0043] In one exemplary embodiment of this disclosure, the ultra-low energy consumption test chamber further includes a fourth pipe 4, and the first pipe 2 and the second pipe 3 are both connected to the outlet of the condenser through the fourth pipe 4. A drying filter 5 is provided on the fourth pipe 4.

[0044] In this embodiment, if a small amount of air enters the pipes of the refrigeration system, the moisture in the air will corrode the pipes. To avoid this problem, this embodiment provides a dryer filter 5 on the fourth pipe 4, which can filter out moisture in the air and prevent the moisture in the air from corroding the pipes.

[0045] In one exemplary embodiment of this disclosure, the ultra-low energy consumption test chamber further includes an expansion valve control circuit, which comprises a valve core position detection circuit, a subtraction circuit, a comparison circuit, and a motor drive circuit connected in sequence.

[0046] The first terminal of the subtraction circuit is connected to the first reference voltage, the second terminal of the subtraction circuit is connected to the output terminal of the valve core position detection circuit, the output terminal of the subtraction circuit is connected to the first input terminal of the comparator circuit, the second input terminal of the comparator circuit is connected to the triangular wave generating circuit, and the output terminal of the comparator circuit is connected to the control terminal of the motor drive circuit. The motor drive circuit is used to drive the valve core of the expansion valve to move.

[0047] This embodiment provides a specific method for adjusting the opening of the expansion valve. The expansion valve is an electronic expansion valve, which contains a motor. By controlling the forward and reverse rotation of the motor, the position of the valve core is moved, thereby adjusting the opening of the expansion valve.

[0048] Resistors R6 and R8, along with operational amplifier U4A, form a subtraction circuit. Comparator U5A forms a comparator circuit. The magnitude of the first reference voltage changes with the temperature of the test chamber. This first reference voltage is connected to the first input terminal of the subtraction circuit. The valve core position detection circuit detects the valve core position in real time and converts the valve core position signal into a voltage signal, which is then connected to the second input terminal of the subtraction circuit. The subtraction circuit outputs the voltage difference between the first reference voltage and the output terminal of the valve core position detection circuit. The output terminal of the subtraction circuit is connected to the first input terminal of the comparator circuit and compared with the triangular wave signal output by the triangular wave generator circuit. The comparator circuit outputs a PWM signal with the same frequency as the triangular wave signal, which is used to control the forward and reverse rotation and speed of the motor.

[0049] When the test chamber temperature is higher than the set value, the magnitude of the first reference voltage can be increased. At this time, the first reference voltage is greater than the output voltage of the valve core position detection circuit, and the duty cycle of the PWM signal output by the comparator circuit is greater than 50%. The motor rotates forward, driving the valve core to move, increasing the opening of the expansion valve, and increasing the evaporator's cooling capacity, thereby lowering the test chamber temperature. Conversely, when the test chamber temperature is lower than the set value, the magnitude of the first reference voltage can be decreased. At this time, the first reference voltage is less than the output voltage of the valve core position detection circuit, and the duty cycle of the PWM signal output by the comparator circuit is less than 50%. The motor rotates in reverse, driving the valve core to move, decreasing the opening of the expansion valve, and decreasing the evaporator's cooling capacity, thereby raising the test chamber temperature.

[0050] In one exemplary embodiment of this disclosure, a logic processing circuit is provided between the comparison circuit and the motor drive circuit. The logic processing circuit includes optocoupler U6, optocoupler U7, XOR gate U8, a first AND gate, and a second AND gate.

[0051] The first input terminal of optocoupler U6 is connected to the output terminal of the comparator circuit, the second input terminal of optocoupler U6 is grounded, the first output terminal of optocoupler U6 is connected to the first power supply through the first pull-up resistor, the second output terminal of optocoupler U6 is grounded, and the output terminal of optocoupler U6 is connected to the first input terminal of XOR gate U8.

[0052] The first input terminal of optocoupler U7 is connected to the second power supply, and the second input terminal of optocoupler U7 is connected to the output terminal of the comparator circuit. The first output terminal of optocoupler U6 is connected to the first power supply through the second pull-up resistor, and the second output terminal of optocoupler U6 is grounded. The output terminal of optocoupler U7 is connected to the second input terminal of XOR gate U8.

[0053] The first output terminal of optocoupler U6 is connected to the first input terminal of the first AND gate, the output terminal of XOR gate U8 is connected to the second input terminal of the first AND gate, and the output terminal of the first AND gate is connected to the first control terminal of the motor drive circuit.

[0054] The first output terminal of optocoupler U7 is connected to the first input terminal of the second AND gate, the output terminal of XOR gate U8 is connected to the second input terminal of the second AND gate, and the output terminal of the second AND gate is connected to the second control terminal of the motor drive circuit.

[0055] In this embodiment, the first AND gate and the second AND gate are each implemented using two AND gate units of a 74HC08 quad AND gate chip. The motor drive circuit can adopt an H-bridge circuit, which includes two half-bridges composed of four power transistors. The upper arm of the first half-bridge and the lower arm of the second half-bridge are controlled synchronously, and the control signals of the upper and lower arms of each half-bridge are opposite. To avoid the upper and lower arms of the same half-bridge conducting simultaneously and causing a short circuit, this embodiment adds a logic processing circuit to convert the PWM signal (PWM1A) output by the comparator circuit into two mutually exclusive drive signals G1 and G2, which are respectively connected to the upper and lower arms of the same half-bridge, thus preventing the upper and lower arms of the same half-bridge from conducting simultaneously.

[0056] Specifically, when the PWM1A signal output by the comparator circuit is high, optocoupler U6 is turned on, and its first output is low. Simultaneously, optocoupler U7 is turned off, and its first output is high. The signals at the two inputs of XOR gate U8 are opposite, and XOR gate U8 outputs a high signal. The first output of optocoupler U6 and the output of XOR gate U8 are connected to the first AND gate, which outputs a low signal G1, turning off the upper bridge arm. The first output of optocoupler U7 and the output of XOR gate U8 are connected to the second AND gate, which outputs a high signal G2, turning on the lower bridge arm. Conversely, when the PWM1A signal output by the comparator circuit is low, optocoupler U6 is turned off, and its first output is high. Simultaneously, optocoupler U7 is turned on, and its first output is low. The signals at the two inputs of XOR gate U8 are opposite, and XOR gate U8 outputs a high signal. The first output terminal of optocoupler U6 and the output terminal of XOR gate U8 are connected to the first AND gate. The first AND gate outputs a high-level signal G1, and the upper bridge arm is turned on. The first output terminal of optocoupler U7 and the output terminal of XOR gate U8 are connected to the second AND gate. The second AND gate outputs a low-level signal G2, and the lower bridge arm is turned off.

[0057] As can be seen from the above analysis, the settings of optocoupler U6, optocoupler U7, XOR gate U8, first AND gate and second AND gate in this embodiment convert one PWM signal output by the comparison circuit into two mutually exclusive drive signals G1 and G2, which are respectively connected to the upper and lower arms of the same half-bridge, thus avoiding the simultaneous conduction of the upper and lower arms of the same half-bridge.

[0058] In one exemplary embodiment of this disclosure, the valve core position detection circuit includes a displacement sensor, a first amplification circuit, and a second amplification circuit connected in sequence.

[0059] The displacement sensor is used to detect the displacement of the expansion valve core, and the output of the second amplifier circuit is the output of the core position detection circuit.

[0060] In this embodiment, the displacement sensor can be a potentiometer, photoelectric encoder, magnetic sensor, etc. These sensors can measure the displacement of the valve core and convert the displacement signal of the valve core into a voltage signal output. Resistors R16 and R11 and operational amplifier U3A constitute the first amplification circuit, and resistors R3 and R1 and operational amplifier U3B constitute the second amplification circuit. The voltage signal output by the displacement sensor is amplified sequentially by the first and second amplification circuits and then converted to a set voltage level for use in the subsequent comparison circuit.

[0061] In one exemplary embodiment of this disclosure, the ultra-low energy consumption test chamber further includes a reference position output circuit, which includes a DAC module U2 and a voltage reference chip U1. The digital input terminal of the DAC module U2 is connected to the main control unit, and the analog input terminal of the DAC module U2 is a first reference voltage.

[0062] The input terminal of the voltage reference chip U1 is connected to the third power supply, and the output terminal of the voltage reference chip U1 is connected to the reference voltage input terminal of the DAC module U2.

[0063] In this embodiment, the main control unit can be selected from general-purpose microcontroller chips such as single-chip microcomputers, DSPs, and ARMs. The main control unit is the control center of the entire ultra-low power consumption test chamber. The main control unit can output different digital signals to the DAC module U2 according to the real-time temperature of the test chamber. The DAC module U2 converts the digital signals output by the main control unit into analog signals, that is, the first reference voltage, so that the magnitude of the first reference voltage changes with the temperature of the test chamber.

[0064] The voltage reference chip U1 is used to convert the 3.3V voltage of the third power supply to 2.5V voltage, providing a stable reference voltage for the DAC module U2, which is beneficial to the accurate conversion of the DAC module U2.

[0065] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An ultra-low energy consumption test chamber, characterized in that, The system includes a compressor, a condenser, an expansion valve, and an evaporator. The compressor's exhaust port is connected to the condenser's inlet, the condenser's outlet is connected to the evaporator's inlet via a first pipe, and the evaporator's outlet is connected to the compressor's return port. The expansion valve is located on the first pipe. The outlet of the condenser is connected to the return port of the compressor through a second pipe; a refrigeration capillary tube is also provided on the first pipe; It also includes a third pipe, one end of which is connected to the exhaust port of the compressor, and the other end of which is connected to the inlet of the evaporator. A solenoid valve is installed on the third pipe. It also includes an expansion valve control circuit, which comprises a valve core position detection circuit, a subtraction circuit, a comparison circuit, and a motor drive circuit connected in sequence. The valve core position detection circuit is used to detect the valve core position in real time. The first terminal of the subtraction circuit is connected to the first reference voltage, the second terminal of the subtraction circuit is connected to the output terminal of the valve core position detection circuit, the output terminal of the subtraction circuit is connected to the first input terminal of the comparison circuit, the second input terminal of the comparison circuit is connected to the triangular wave generating circuit, and the output terminal of the comparison circuit is connected to the control terminal of the motor drive circuit. The motor drive circuit is used to drive the valve core of the expansion valve to move. The magnitude of the first reference voltage changes with the temperature of the test chamber. The subtraction circuit includes a first resistor, a second resistor, and a first operational amplifier. The first end of the first resistor is the second input terminal of the subtraction circuit. The second end of the first resistor is connected to the first input terminal of the first operational amplifier. The output terminal of the first operational amplifier is fed back to the first input terminal of the first operational amplifier through the second resistor. The second input terminal of the first operational amplifier is the first input terminal of the subtraction circuit. The output terminal of the first operational amplifier is the output terminal of the subtraction circuit. The comparison circuit includes a comparator, the first input terminal of the comparator is the first input terminal of the comparison circuit, the second input terminal of the comparator is the second input terminal of the comparison circuit, and the output terminal of the comparator is the output terminal of the comparison circuit; The subtraction circuit is used to output the voltage difference between the first reference voltage and the output of the valve core position detection circuit. The output of the subtraction circuit is connected to the first input of the comparator circuit and compared with the triangular wave signal output by the triangular wave generator circuit. The output of the comparator circuit outputs a PWM signal with the same frequency as the triangular wave signal. This PWM signal is used to control the forward and reverse rotation and speed of the motor. It also includes a reference position output circuit, which includes a DAC module and a voltage reference chip. The digital input terminal of the DAC module is connected to the main control unit, and the analog input terminal of the DAC module is the first reference voltage. The input terminal of the voltage reference chip is connected to a third power supply, and the output terminal of the voltage reference chip is connected to the reference voltage input terminal of the DAC module. The main control unit outputs different digital signals to the DAC module based on the real-time temperature of the test chamber. When the temperature of the test chamber is higher than the set value, the magnitude of the first reference voltage is increased. At this time, the first reference voltage is greater than the output voltage of the valve core position detection circuit, and the duty cycle of the PWM signal output by the comparator circuit is greater than 50%. The motor rotates forward, driving the valve core to move, increasing the opening of the expansion valve, and increasing the cooling capacity of the evaporator, thereby reducing the temperature of the test chamber. Conversely, when the temperature of the test chamber is lower than the set value, the magnitude of the first reference voltage is decreased. At this time, the first reference voltage is less than the output voltage of the valve core position detection circuit, and the duty cycle of the PWM signal output by the comparator circuit is less than 50%. The motor rotates in reverse, driving the valve core to move, decreasing the opening of the expansion valve, and decreasing the cooling capacity of the evaporator, thereby increasing the temperature of the test chamber.

2. The ultra-low energy consumption test chamber as described in claim 1, characterized in that, It also includes a fourth pipe, through which both the first pipe and the second pipe are connected to the outlet of the condenser, and a dryer filter is provided on the fourth pipe.

3. The ultra-low energy consumption test chamber as described in claim 1, characterized in that, A logic processing circuit is provided between the comparison circuit and the motor drive circuit. The logic processing circuit includes a first optocoupler, a second optocoupler, an XOR gate, a first AND gate, and a second AND gate. The first input terminal of the first optocoupler is connected to the output terminal of the comparator circuit, the second input terminal of the first optocoupler is grounded, the first output terminal of the first optocoupler is connected to the first power supply through a first pull-up resistor, the second output terminal of the first optocoupler is grounded, and the output terminal of the first optocoupler is connected to the first input terminal of the XOR gate. The first input terminal of the second optocoupler is connected to the second power supply, and the second input terminal of the second optocoupler is connected to the output terminal of the comparator circuit. The first output terminal of the first optocoupler is connected to the first power supply through a second pull-up resistor, and the second output terminal of the first optocoupler is grounded. The output terminal of the second optocoupler is connected to the second input terminal of the XOR gate. The first output terminal of the first optocoupler is connected to the first input terminal of the first AND gate, the output terminal of the XOR gate is connected to the second input terminal of the first AND gate, and the output terminal of the first AND gate is connected to the first control terminal of the motor drive circuit. The first output terminal of the second optocoupler is connected to the first input terminal of the second AND gate, the output terminal of the XOR gate is connected to the second input terminal of the second AND gate, and the output terminal of the second AND gate is connected to the second control terminal of the motor drive circuit.

4. The ultra-low energy consumption test chamber as described in claim 1, characterized in that, The valve core position detection circuit includes a displacement sensor, a first amplifier circuit, and a second amplifier circuit connected in sequence. The displacement sensor is used to detect the displacement of the expansion valve core, and the output terminal of the second amplification circuit is the output terminal of the valve core position detection circuit.

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