Constantly Adjusted Precise Temperature Controller

This essay gives a detailed account of the design of singlechip's soft and hard wares of high-precision temperature-controlling system. In this design, the temperature-collecting system is composed of 8 bit singlechip and 16 bit A/D converter based on actual requirement. It can still improve the performance price rate of the system in comparison with using 16 bit singlechip. Using the digital PID control, the temperature can be controlled within the range of 300℃~500℃ with a precision of± 1 ℃ and uninterrupted adjustability of temperature setting is realized. In order to enhance the precision, this design proposes that temperature-measuring circuit of platinum resistors and software should be employed to carry on adjustment of measured precision; it also proposes that the interference of the grid can be reduced by the voltage front feed; and meanwhile it calls for the application of the photoelectric insulation, the over heating protection and alarm so as to enhance the security performance of the system.It is the first time to set up such a system in Chinese armed equipments. In order to build such a system, many theoretical and technological problems have to be solved in designing system, measuring and controlling temperature, installing equipments, developing software and so on. Some of them are deeply studied.Based on the practices in engineering, in this paper some key technological problems are deeply discussed in designing the whole structures and hardware, modeling and designing controlling strategy for this system. First, considering the technological requirements of the system and based on the study and absorption of relative theories and technologies for the key problems, the whole structure of this system is designed which is satisfied for the requirements of high reliability, practicality and convenience operations. In order to make the temperature been uniform distribution, the model being controlled of this system is designed based on the over-all heat transfer theory. In the process of making PID control realized, calculating precision is improved by designing software and, designing hardware improves measuring and controlling precision of the system. This strategy is of excellent accuracy and strong robustness. The adjusting results prove that the requirement of technology of the system is satisfied in essence. Next, considering the complexity of the heating process of the system, such as the characteristics of the time change and delay, the heating system has to be further studied based onadaptive control of its model. The feasibility of the method is verified by simulation. And the simulating results prove this method is of excellent prospect.