1、 通信工程学院 毕业论文（设计） 外文翻译 题目 单闭环温度控制系统 外 文 题 目 Single-chip temperature control system 专业： 自动化 学号： 52090523 学生姓名： 李文鹏 指导教师姓名： 指导教师职称： 教授 日期： 2013 年 3 月 16 日 Single-chip temperature control system 1 temperature sensor The temperature sensor in the electric incubator control system is one of the very impor
2、tant components, will be responsible for the acquisition of the temperature of the incubator, that is, from time to time to acquisition the temperature of the incubator. It is to preach the collected temperature control section, and then the need for heating or stop heating a series of actions by th
3、e control section temperature sensor is a temperature probe of the electric incubator, so for the temperature sensors performance, including its The technical indicators of job stability, reliability and sensitivity must ensure that, because it directly affects the operation of the entire control sy
4、stem. The temperature is closely related to the physical quantity of a peoples living environment is also a need to control the important physical quantities in scientific experiments and production activities. Therefore, in a variety of sensors, the temperature sensor is the most widely used. The t
5、emperature sensor is a temperature change is converted to electrical changes in the device, used to detect the temperature and heat, also called thermoelectric sensor. Which temperature changes into the main components of the resistance change thermal resistance, thermistor and polymer NTC, PTC ther
6、mistor resistance, temperature thermocouple and the PN junction sensor for potential sensor, the thermal radiation conversion device for the electrical volume of pyroelectric detectors, infrared detectors, in addition to the integrated temperature sensor, fiber optic temperature sensors, liquid crys
7、tal temperature sensor, and intelligent temperature sensor, etc., more and more types of applications has become increasingly extensive. Temperature materials, the measured temperature into the temperature measurement system for measuring resistance, the main metal heat resistive and semiconductor t
8、hermal resistance of two categories, the former is referred to as thermal resistance, which referred to the thermistor. Their resistance with increasing temperature, and some increase in a positive temperature coefficient thermistor, and some reduce that belong to the negative temperature coefficien
9、t thermistor. Used to measure temperature of -200 500 C within the temperature range of 500 1200 C, also have good enough features. 2 thermal resistance characteristics of Most of the metal resistance of the conductor varies with temperature characteristics, its characteristic equation is as follows
10、: Rt = Ro 1 + a (t-to) where Rt, said resistance value of the metal in any absolute temperature at time t； of Ro said that the baseline state to when the resistance value； a temperature coefficient thermistor (1 / C) . For the vast majority of the metal conductor, a is not a constant, but the functi
11、on of temperature, but within a certain temperature range, can be approximated as a constant. Metal conductor, a constant corresponding to the temperature range. The general election for the temperature resistance of the material must meet the following requirements: (1) temperature coefficient of r
12、esistance a higher, so that under the same conditions can speed up the thermal response rate and improve the sensitivity. Usually the temperature coefficient of pure metal alloy generally are made of pure metal material. (2) within the temperature range of chemical, physical properties, in order to
13、ensure the accuracy of temperature measurement of thermal resistance. (3) has a good output characteristics in the temperature range between resistance and temperature must have a linear or nearly linear relationship. (4) has a high resistivity in order to reduce the thermal resistance of the volume
14、 and weight. (5) has a good processability, and cheap. Suitable material such as platinum, copper, iron and nickel. Their resistance increases with increasing temperature, with a positive temperature coefficient. 3 system hardware design Microcomputer application system hardware circuit design is ba
15、sed single-chip temperature control system to configure peripheral devices, the optimal system configuration, in accordance with the system functional requirements, design the appropriate interface such as keyboard, monitor, printer, A / D converter, circuit. The system design should be based on the
16、 following principles: (1) If possible, choose a typical circuit, and in line with conventional single-chip usage. The design uses a typical display circuit, the A / D conversion circuit, for the standardization of hardware systems, modular lay a good foundation. (2) hardware architecture should be
17、combined with application software programs to be considered. Software to achieve the functionality as much as possible by the software, to simplify the hardware structure. By the software implementation of hardware features, the general response time than the hardware to achieve long, and CPU time.
18、 Reaction time is not due to the design, so there are some features you can use the software programming, such as a keyboard to the jitter problem. (3) in the device as possible the performance to match. All the chips in the system should be as far as possible choose low-power products. The hardware
19、 circuit including analog and digital sections, up from functional modules divided into the host circuit, data acquisition circuitry, keyboard and display circuit, control the implementation of the circuit. The system hardware includes: temperature sensors, signal conditioning circuits, A / D conver
20、sion device, the MCS-51 microcontroller, keyboard input, LED temperature display, temperature control circuit. 4 chip select The microcontroller is integrated on a silicon micro-computer microprocessors, memory and various input and output interface circuit, referred to the microcontroller. Microcon
21、troller with its high performance and low cost by the peoples attention and concern. Its advantage is small size, light weight, strong anti-jamming capability, less demanding on the environment, low-cost, high reliability, good flexibility, easier to develop. The microcontroller according to the med
22、ian of its basic operation of the processing can be divided into 4, 8, 16, 32-bit microcontroller, the most widely used is eight single-chip. According to the actual circumstances and requirements of this design, the design AT89C51 as the system controller chip. The AT89C51 is a low-power, high performance CMOS 8-bit microcontroller with 4K system programmable Flash memory. Use Atmels high density nonvolatile memory technology is fully compatible with industrial 80C51 Products Directive and pin.
