MICROCONTROLLER BASED TEMPERATURE INDICATOR AND CONTROLLER

摘要

Microcontroller usage in dedicated system design, has assumed an importance in process control applications. Microcontroller based systems are used in many applications in industry like measurement of temperature, flow etc. The paper presents one such application designed and developed as a laboratory model with the objective of measurement, display and control of the temperature of water bath. The R TD PT -100 is used as a temperature transducer as the temperature of interest ranges from 0 to 99 degree centigrade. The output of RID is conditioned so as to get voltage signal. Output of this circuit is given to microcontroller through ADC 0808. A program written using SPJ system software does the display of actual temperature. As one of the objectives is to control the temperature of the water bath, software is downloaded in 89C51 to compare the measured temperature with the set point entered by the user. If temperature does not reaches the set point value then accordingly the duty cycle is controlled by 89C51 and in turn power supplied to the heater gets controlled, After designing and developing this system, the designed model was tested and it was found that the system was working in satisfactory manner.