Precision Temperature Control System Based on PID Algorithm

A precision temperature control system that uses ATmega128 as the main control microcomputer is built. The temperature is sensed by a Pt100 thermistor, and then converted into the voltage signal by a temperature transmitter to the microcomputer. Two kinds of digital PID (Proportional-Integral-Differential) algorithms are adopted to control the output power of the thermo-electric cooler (TEC) automatically. The test results of the improved temperature control system show that the set-up time of this system is about 340s and the temperature control accuracy is up to±0.1°C.