气体传感器脉宽恒温控制电路设计

Design on Pulse-Width PID Temperature Control in Gas Sensor

针对薄膜气体传感器敏感芯体的气体温度特性,设计了一种实用的脉宽恒温控制电路。采用经典PID控制模式,自适应调节加热功率,满足高温高湿的环境要求。样机器件全部采用有失效率指标的高等级质量国产元件,可靠性完全可估。样机对启动电流、最高温度等最坏情况做了特别设计,同时为了有效降低失效率,对有效工作模式做了规定以适合高可靠性、低风险的航天应用要求。实验数据表明氢气传感器控温电路精度可达0.15℃,可满足传感器精度要求。

A practical temperature control circuit is designed especially for gas sensor according to properties of the thin sensitive core films.The classical PID control mode is adapted to adjust the heating power and meet the environmental requirements of high temperature and high humidity.All domestic components have failure rate,so the reliability of the prototype can be estimated.The prototype is especially designed for the worst situations of starting current and maximum temperature.The prototype is also recommended for the normal work mode to reduce the failure rate.The experiments data show that the hydrogen sensor temperature control circuit precision can reach 0.1 5 degrees,which meets the requirement of the hydrogen sensor.