Development of a Temperature Control System Based on DSP for a Real-Time PCR Instrument

Abstract

In this paper, we develop a temperature control system based on DSP chip TMS320F28335 for a small real-time PCR instrument. In the system, PWM waves generated by the DSP passes through power amplifier circuit to drive the peltier, and a pt100 is used as a temperature sensor to build a Wheatstone bridge sensing circuit. The temperature signal from the pt100 is converted into voltage signal. Then the voltage signal goes through the A/D converted module and the Position PID algorithm to adjust the duty cycle of the PWM waves. Experimental results show that the system's rising and cooling rate can reach 4°C/s with an accuracy of 0.2°C.

Thermal sensing in fluid at the micro-nano-scales

“…115 Commercial available Pt 100 sensors with large diameters are fixed near the heaters for precise temperature control in PCR systems and a temperature accuracy within 60.1 K can be achieved. [116][117][118][119] With micro-nano processing technology, RTDs have been designed into two kinds of structures: the two-wire serpentine traces and the four-lead electrodes, with thicknesses of a few hundred nanometers and widths of a few tens of microns. With good biological compatibility, gold serpentine trace RTDs can be prepared on flexible substrates to monitor the temperature in biological tissues, such as myocardial tissue 109,110 and brain.…”