透射电子显微镜透镜稳流电源的研究

The Study of Current-Invariable Lens Power Supply for TEM

本文以物镜磁透镜稳流电源为例,介绍了透射电子显微镜透镜稳流电源的结构和工作原理。透镜稳流电源由前置高精度稳压电源模块、数模转换器、低漂移电压比较放大器、高精度恒温基准电压源、电流输出前置驱动、电流输出功率模块、基准电阻、输出电流检测模块等组成。通过检测基准电阻两端的电压并将其反馈到电压比较放大器形成对输出电流的闭环控制,达到对电流稳定度的要求。透镜稳流电源受计算机的控制,能接收稳流电流参数,并将电源的工作状态发送给计算机。实验结果表明该透镜稳流电源完全达到了设计指标,可以满足透射电子显微镜各级磁透镜的要求。

The construct and operating principle of the power supply for TEM is intrudced in this paper taking example for the object lens. The lens power supply is composed of pre high precision voltage- invariable power, digital-to-analog convertor, vohage-compare amplifier, high precision voltage reference, pre current output driver, current output power amplifier, reference resistance and current check module. Due to the voltage spanning reference resistance is feedback to the voltage-compare amplifier, output current is controlled in closed loop to keep invariable. The lens power can receive current parameters from compute and can transmite all kinds of working state back to the controlling compute. The lens power supply can satisfy the needs of TEM through experiment.