恒流型测温电路的设计和非线性误差仿真

Simulated on Design and Non-Linearity Error of Temperature Measurement Circuit of Constant-Current Styles

为解决实际测温电路的设计和调试难度较大且周期较长的问题,采用计算机仿真研究方法,应用国际流行的Psp ice程序作为仿真工具,以恒流型铂电阻测温电路为研究对象,给出系统非线性误差校正电路的结构和参数。为有效控制系统非线性误差,给出分阶段测温原则。仿真结果表明,校正后非线性误差可以达到0.1%,但存在不均匀性。推导出系统输出和电路参数关系公式。调节运算放大器的电压传输特性在线性工作区内工作范围实现系统的调零。该调零方法简单且不影响系统增益。该设计方法能减少设计时间约为90%。

The designs and tests of actual temperature measurement circuit are weary and time-consuming. Using computer to simulate a temperature measurement circuit of constant-current with a platinum resistor, the article gives the configuration and the element parameter values of the non-linearity error improvement circuit with Pspice program as the analysis and design tool. In order to control the non-linearity error effectively temperature measurement should be taken in two phases. The principle of dividing the two phases is given. The non-linearity error of the system can reach 0.1%, but there is an error non-uniformity. The relation between output voltage and the circuit element parameters is given. The zero point calibration method is improved by changing the working area of the voltage transfer characteristic of the operational amplifier within the linear working area. The zero point calibration method is simple and does not affect the voltage gain of the system. Tmethndcan reduce the design time about 90%.