The Controlling System Of The Triple Pulse Vacuum Sterilizer In Dentistry

The triple plus vacuum sterilizer is the main sterilization equipment in dental clinic. This paper has achieved the control of temperature and pressure in the process of sterilization by the method of fuzzy control. PIC16C74 is the core components in the system, the paper also have study the thermodynamic properties of the steam.Though the decision of the hardware design, control methods and software design, the paper finished the overall design. And then design the linear temperature pressure signals collection circuit, but also for the security and anti-interference.In the way of controlling, the paper propose the steam control principles by the thermodynamic analysis of the steam characteristics and skilled operators summarized the practical experience and lessons, The controller set up for this system is a planar-input and single output one. The slow formation and the low variable velocity of the vapor in the sterilization instrument, easy change of temperature on the container's ektexine and the delay of the formation of the pressure in the container are taken into account by this fuzzy controller. And this fuzzy controller is designed for the deviation of the vapor pressure and the temperature on container's ektexine as its two inputs, its output is a time variable which controls the status of the thyristor. Compared with the usual control method, this method can prevent overshoot of the vapor pressure, the ektexine's temperature and ensuring the security of the system.The control system has accomplished the control of the enclosed containers pressure steam formation, and achieved good results to ensure the effectiveness of sterilization devices and shorten working hours. It has strong promotional practical value in the dental clinics.