基于DSP的实时PCR仪温度控制系统研制

Research and fabrication of temperature control system of real-time PCR instrument based on DSP

为小型实时聚合酶链式反应(PCR)仪研制一种基于数字信号处理器(DSP)芯片TMS320F2812的温度控制系统。由DSP产生的脉冲宽度调制(PWM)波经功率放大电路驱动半导体加热制冷片以Pt100作为温度传感器构建一种消除非线性误差的电桥传感电路,将温度信号转换为电压信号,电压信号送入DSP的A/D转换模块,同时进行位置式PID算法,然后调节PWM波的占空比,使整个系统对温度信号达到闭环控制。实验结果表明:系统的升降温速率能达到4℃/s,精度为0.2℃。

Develop a temperature control system based on DSP chip TMS320F2812 for small real-time PCR instrument. PWM wave generated by DSP through power amplifier circuit to drive semiconductor cooler, and the Ptl00 as temperature sensor to build a bridge sensing circuit eliminating nonlinear error. Temperature signal is converted to voltage signal ,which is sent to A/D converter module of DSP and at the same time carry out position PID algorithm, then adjust the duty cycle of the PWM wave, so the temperature signal is controlled by closed-loop system. Experimental results show that heating and cooling rate of the system can reach 4 ℃/s, precision is 0.2℃.