Design method for driving circuit of infrared detector Stirling cryocooler
By designing a domestically produced Stirling refrigerator drive circuit for infrared detectors that includes a power supply circuit and a signal control circuit, and using domestically produced components and filtering technology, the problems of localization, large power supply ripple, and image noise interference were solved, achieving efficient refrigerator drive and improved image quality.
Patent Information
- Application Number
- CN202510847466.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2025-10-17
Smart Images
Figure CN120799795A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of infrared imaging, and particularly relates to a driving circuit design method of a Stirling cryocooler of an infrared detector. BACKGROUND
[0002] The infrared imaging refrigeration technology is a technology for cooling a detector element of a thermal imaging system to a low temperature or a deep low temperature so that the thermal imaging system can work normally. The main tasks of the technology are two: one is to form a suitable low-temperature constant-temperature environment through refrigeration to ensure that an electronic device or a system that needs to work at a low temperature can function normally or the sensitivity of the device is improved; and the other is to shield or reduce thermal noise from a filter, a baffle and an optical system of the thermal imaging system. It is urgent to develop a driving circuit of a Stirling cryocooler of an infrared detector of a national device. SUMMARY
[0003] (I) Technical problems to be solved
[0004] The technical problems to be solved by the application are: 1. a driving circuit of a Stirling cryocooler of an infrared detector is designed to be localized, so that the driving circuit becomes a system that can independently run and has complete functions; 2. the design optimization of noise interference of a circuit system is performed, especially the optimization design of interference of the cryocooler on the entire circuit after the cryocooler is started; and 3. the driving capacity of the cryocooler is improved, and the refrigeration time and the refrigeration efficiency of the cryocooler are reduced.
[0005] (II) Technical solutions
[0006] In order to solve the above technical problems, the application provides a driving circuit design method of a Stirling cryocooler of an infrared detector. The driving circuit is designed to include a power supply circuit and a signal control circuit. The power supply circuit includes a power supply module and an LDO low-dropout linear voltage stabilizer. The signal control circuit includes a single-chip microcomputer processor, a cryocooler driving chip and a temperature sensor. One way of an input voltage is raised to 28V voltage after passing through the power supply module, and the power supply module provides a power supply for the cryocooler driving chip. Another way is converted into 3.3V voltage through the LDO low-dropout linear voltage stabilizer and filtered to supply the single-chip microcomputer processor and the temperature sensor. The single-chip microcomputer processor circuit is responsible for receiving a temperature signal from the temperature sensor, and then outputs a control signal to the cryocooler driving chip according to the temperature signal, so that the cryocooler driving chip controls the cryocooler to move correspondingly and controls the temperature of the cryocooler.
[0007] The application also provides a driving circuit designed based on the method.
[0008] The application also provides an infrared imaging refrigeration system using the driving circuit.
[0009] (III) Beneficial effects
[0010] The application provides a scheme design of a Stirling cryocooler driving circuit of an infrared detector, satisfies the national production requirement of special equipment, greatly reduces the cost problem of the cryocooler driving circuit, solves the production cycle and key technology of the cryocooler driving circuit and product self-controlling, can greatly guarantee the reliability and safety of key projects, avoids the backdoor of the chip, avoids the risk of malicious tampering and leakage of sensitive information, maintains social stability and national security. In addition, the scheme solves the defects of large power supply ripple, image horizontal stripe interference, image noise point interference and cost in the cryocooler driving circuit. BRIEF DESCRIPTION OF DRAWINGS
[0011] Figure 1 It is a principle block diagram of a cryocooler driving circuit system of the application;
[0012] Figure 2 It is a principle diagram of a power supply module of the application;
[0013] Figure 3 It is a principle diagram of an LDO linear power supply circuit of the application;
[0014] Figure 4 It is a principle diagram of a single-chip microcomputer processor circuit of the application;
[0015] Figure 5 It is a principle diagram of a cryocooler driving circuit of the application;
[0016] Figure 6 It is a principle diagram of a temperature measurement sensor circuit of the application. DETAILED DESCRIPTION
[0017] In order to make the purpose, content and advantages of the application more clear, the specific embodiments of the application are further described in detail below in combination with the drawings and examples.
[0018] The application provides a driving circuit design method of a Stirling cryocooler (referred to as a cryocooler) of an infrared detector, realizes the driving circuit design of a domestic infrared detector Stirling cryocooler, and the domestic rate of components and elements reaches 100%. The driving circuit (referred to as a cryocooler driving circuit) of the infrared detector Stirling cryocooler includes a power supply circuit and a signal control circuit, and specifically relates to the content of infrared imaging, domestic infrared detector, domestic component and element circuit design, circuit noise reduction design and the like.
[0019] As shown in Figure 1 The application provides a driving circuit design method of a Stirling cryocooler of an infrared detector. The driving circuit design includes two parts of a power supply circuit and a signal control circuit. The power supply circuit includes a power supply module and an LDO low-dropout linear regulator; and the signal control circuit includes a single-chip microcomputer processor, a cryocooler driving chip and a temperature measurement sensor.
[0020] The working principle of the present application is:
[0021] The input voltage is boosted to 28V voltage after passing through the power supply module, providing a stable and reliable power supply for the refrigerator driving chip. The other route is converted into a stable 3.3V voltage through the LDO low-dropout linear regulator and filtered to supply the single-chip microcomputer processor and temperature sensor. The single-chip microcomputer processor circuit is responsible for receiving the temperature signal from the temperature sensor, and then outputting a control signal to the refrigerator driving chip according to the temperature signal. The refrigerator driving chip controls the corresponding movement of the refrigerator to accurately control the temperature of the refrigerator.
[0022] 1) Design of power supply module and LDO low-dropout linear regulator
[0023] The power supply module uses the MT3608 module of the domestic aerospace Minxuan company. The MT3608 module has a wide dynamic input range of 2V-24V; the module can be boosted to 28V; it has a high conversion efficiency of 97% in light load mode; the maximum output current is 4A; it has an input short circuit protection mode; the MT3608 circuit diagram is as shown in Figure 2 ,
[0024] The LDO low-dropout linear regulator uses the ME6239 chip of the domestic Weiliang Electronics Company. The ME6239 chip has the characteristics of low power consumption, low voltage difference, and high power supply rejection ratio; the normal output current is 250mA, and the adjustable output voltage range is 1.5V-12V. The ME6239 circuit diagram is as shown in Figure 3 , VDD5 is input from the input end of the ME6239 chip, and the ME6239 chip outputs VDD3, which is connected to a decoupling capacitor C7, and one end of C7 is grounded.
[0025] In the driving circuit, one route of voltage VDD5 supplies the power supply module MT3608, which is boosted to 28V VDD_M through the power supply module MT3608, and then supplies the refrigerator driving chip for use; another route of voltage VDD5 is input from the input end of the LDO low-dropout linear regulator, and 3.3V voltage VDD3 is obtained through the LDO low-dropout linear regulator, which supplies the temperature sensor and the single-chip microcomputer processor.
[0026] Problems to be solved: the harm of power supply ripple.
[0027] The ripple carried in the power supply will generate harmonics on the electrical appliances, reducing the use efficiency of the power supply. High-frequency ripple noise may also produce surges, causing damage to electrical equipment and causing serious losses. In digital circuits, ripple will interfere with the logic relationship of the circuit, causing noise interference to communication, testing and measurement, affecting the normal measurement of signals, and even damaging equipment.
[0028] The influence of the power supply ripple and noise on the present application is directly reflected on the image, and the affected thermal imager or visible light image is full of stripes and black and white noise.
[0029] The solution of the present application is:
[0030] 1. Add a LDO low-dropout linear regulator after the input voltage VDD5; this is the most effective way to reduce ripple and noise, which can well control the ripple and noise. An LDO low-dropout linear regulator ME6239 is added after the input voltage.
[0031] 2. Increase the output capacitor for filtering, which is a direct and reliable filtering means, because increasing the output capacitor value can increase the charging and discharging time, increase the power regulation time, and thus achieve the purpose of reducing the ripple; therefore, the present application designs the decoupling capacitor C7 in the LDO low-dropout linear regulator to have a capacitance value of 10uF, as shown in Figure 3 The main function of C7 is to provide stable voltage and reduce noise of the element coupled to the power supply end, thereby reducing interference.
[0032] Experiments show that after taking the above two measures, the stripes and black and white noise of the affected thermal imager or visible light image disappear.
[0033] 2) Single-chip microcomputer processor and crystal oscillator and related module circuit design
[0034] The single-chip microcomputer processor uses the 32-bit microcontroller GD32F150G8U6 chip produced by the domestic Megui Innovation Company. It is based on Cortex-M3 core and is a powerful microcontroller, whose resource analysis is shown in the following table, and the circuit is shown in Figure 4 .
[0035]
[0036] 3) Module circuit design related to refrigeration machine driving chip
[0037] The refrigeration machine driving chip uses the MS8829 produced by the domestic Ruimeng Technology Company. The MS8829 is a three-phase brushless refrigeration machine driving chip, which has a wide dynamic input range of 8V-35V; double output, and the maximum output current of each way is 1.5A; built-in micro-step phase sequence table, low conduction resistance; has internal under-voltage lock, over-current protection, over-temperature shutdown circuit and other modes; the refrigeration machine driving chip MS8829 circuit diagram is shown in Figure 5 .
[0038] Problems to be solved:
[0039] The PWM control signal to the refrigerator has overshoot phenomenon, which will increase the energy consumption of the refrigerator, waste part of the energy; There will also be a risk of losing control of the refrigerator, causing the control accuracy error to increase.
[0040] Solving measures:
[0041] 1. In the first output end OUT1 of the refrigerator driving chip U7, a filter capacitor C60 is connected through a resistor R52, the second output end OUT2 is connected through a resistor R50 and a filter capacitor C62, and the third output end OUT3 is connected through a resistor R51 and a filter capacitor C61, as shown in the figure, one end of the capacitors C60-C62 is grounded, and the capacitors are electrolytic capacitors or ceramic capacitors. Thus, by connecting appropriate electrolytic capacitors or ceramic capacitors in parallel at the output end of the refrigerator driving chip, the high-frequency decoupling and filtering elements can reduce the influence of sharp pulses. Figure 5
[0042] 2. Use RC filter, design reasonable RC low-pass filter circuit to attenuate high-frequency components and retain the integrity of low-frequency signals, thereby eliminating overshoot. In this embodiment, resistors R50-R52 are connected to capacitors C60-C62 at the output end of the refrigerator driving chip, as shown in the figure, and the resistors R50-R52 and the capacitors C60-C62 form an RC filter circuit, which can eliminate overshoot. Figure 5
[0043] The working principle of the above circuit is: the PWM wave signal is input to the refrigerator driving chip U7, U7 outputs current according to the PWM wave signal, the output current passes through the RC filter circuit composed of R50-R52 and C60-C62 to reach the motor end of the refrigerator, and drives the motor to work.
[0044] 4) Module circuit design related to temperature sensor
[0045] The temperature sensor uses CS1237 chip produced by Chipsea Technology Co., Ltd. The chip is a high-precision, low-power analog-to-digital conversion chip with one differential input channel, built-in temperature sensor and high-precision oscillator, 24-bit lossless, and output rate selectable. The CS1237 circuit diagram is shown in the figure. Figure 6
[0046] It can be seen that the circuit design of the present application has the following characteristics:
[0047] 1. High integration principle of the circuit. The present application reasonably evaluates the resources of the processor, power module and refrigerator driving chip, and according to the number of control signal lines of the detector refrigerator and the code resource amount of the control strategy, the IP pin number and the calculation resource and storage resource amount of the corresponding processor are matched and selected. In this way, a small volume package processor is selected under the premise of ensuring sufficient resources.
[0048] The advantages of high integration circuit include: small size, light weight, convenient to use and install in complex environment. The number of lead wire and soldering point is greatly reduced, the possibility of false soldering is reduced, and the reliability of circuit operation is improved. Good performance, low cost, reduce the parasitic capacitance effect, the running speed of high integration circuit is higher, and the production cost of circuit board is reduced.
[0049] 2. Nationalization of circuit design, on the one hand, in response to the requirement of product localization proposed by the state; on the other hand, the production cycle and key technology of the device can be self-controllable.
[0050] 3. Improve the driving ability of the refrigeration machine, reduce the refrigeration time, the refrigeration efficiency of the refrigeration machine, the length of the refrigeration time, which plays a crucial role in practical application.
[0051] 4. The noise level and integration of domestic devices have a certain gap compared with foreign devices, the design optimization of noise interference of circuit system is needed, especially the optimization design of the interference of the refrigeration machine after starting to the whole circuit.
[0052] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.
Claims
1. A method for designing a driving circuit for an infrared detector Stirling refrigerator, characterized in that: The drive circuit is designed to include two parts: a power supply circuit and a signal control circuit; The power supply circuit includes: a power supply module and an LDO low-dropout linear regulator; the signal control circuit includes: a single-chip microcomputer processor, a refrigerator driver chip and a temperature sensor; the input voltage is boosted to 28V after passing through the power supply module to provide power to the refrigerator driver chip, and the input voltage is converted to 3.3V by the LDO low-dropout linear regulator and supplied to the single-chip microcomputer processor and the temperature sensor after filtering; the single-chip microcomputer processor circuit is responsible for receiving the temperature signal from the temperature sensor, and then outputting a control signal to the refrigerator driver chip based on the temperature signal. The refrigerator driver chip controls the refrigerator to perform corresponding movements and control the temperature of the refrigerator.
2. The method according to claim 1, wherein The power supply module adopts the MT3608 chip. In the drive circuit, one voltage VDD5 is supplied to the power supply module MT3608, which is boosted to 28V VDD_M by the power supply module MT3608 and then supplied to the refrigerator driver chip for use; another voltage VDD5 is input from the input end of the LDO low-voltage difference linear regulator, and is stepped down by the LDO low-voltage difference linear regulator to obtain a 3.3V voltage VDD3. The voltage VDD3 is supplied to the temperature sensor and the single-chip processor for use.
3. The method according to claim 2, wherein The LDO low-voltage difference linear regulator adopts ME6239 chip, VDD5 is input from the input end of ME6239 chip, ME6239 chip outputs VDD3, VDD3 is connected to a decoupling capacitor C7, one end of C7 is grounded, and the capacitance value of decoupling capacitor C7 is designed to be 10uF.
4. The method according to claim 3, wherein The single-chip processor uses the GD32F150G8U6 chip.
5. The method according to claim 3, wherein The refrigerator driver chip uses the MS8829 chip. The first output terminal OUT1 of the MS8829 chip is connected to a filter capacitor C60 through a resistor R52, the second output terminal OUT2 is connected to a filter capacitor C62 through a resistor R50, and the third output terminal OUT3 is connected to a filter capacitor C61 through a resistor R51. One end of the capacitors C60~C62 is grounded, and the resistors R50~R52 and the capacitors C60~C62 form an RC filter circuit; the PWM wave signal is input to the refrigerator driver chip, and U7 outputs current according to the PWM wave signal. The output current reaches the motor end of the refrigerator through the RC filter circuit composed of R50~R52 and C60~C62, driving the motor to work.
6. The method according to claim 5, wherein Capacitors C60 to C62 are electrolytic capacitors or ceramic capacitors.
7. The method according to claim 3, wherein The temperature sensor adopts CS1237 chip.
8. The method according to any one of claims 1 to 7, characterized in that The method is applied in the field of infrared imaging technology.
9. A driving circuit designed based on the method according to any one of claims 1 to 8.
10. An infrared imaging refrigeration system using the driving circuit according to claim 9.