Development of DNA Amplification Instrument used in Disease Diagnosis

In this paper, to control the temperature of the Peltier element for DNA amplification. They are quick variation in temperature and temperature setback method required for DNA amplification. Temperature control at 95℃, 65℃ and 75℃. Peltier element was used for producing the temperature at different stage. Heating and cooling of peltier element was change the polarity of the power supply by using h-bridge. Peltier element temperature depends on current value, doesn’t voltage. Current value of the peltier element control by PWM signal. The PWM signal generated for the PIC microprocessor depends on the RTD temperature values. The PID control logic was programming by microprocessor controller.