论文部分内容阅读
前言在大地电磁测深仪中,以往的滤波器均采用波段开关换挡。仪器在野外工作时,开关经常因接触不良而发生故障。当同时使用多道时,开关不能实现同步换挡,更不能用微机来控制。本设计采用微机控制模拟开关自动换挡,巧妙地解决了上述困难。众所周知,模拟开关不同于机械开关,它在接通时仍有电阻R_S,R_S对滤波器的特性有何影响?能否满足仪器的技术要求?计算结果表明,滤波器的幅频特性、相频特性,与R_S=0(模拟开关导通时电阻为230Ω左右)时的特性相比较,完全能够满足仪器的技术要求。实践证明性能良好。下面分别介绍电路的设计,滤波器特性的理论计算及其实测结果。
Preface In the earth electromagnetic sounder, the previous filters are used band switch shift. When the instrument is working in the field, the switch often fails due to poor contact. When using multiple channels at the same time, the switch can not be synchronized shift, but can not be controlled by the computer. The design uses computer controlled analog switch automatic shift, cleverly solved the above difficulties. As we all know, the analog switch is different from the mechanical switch, it is still connected when the resistance R_S, R_S on the characteristics of the filter? Can meet the technical requirements of the instrument? Calculation results show that the filter amplitude-frequency characteristics, phase frequency Characteristics, and R_S = 0 (analog switch turn-on resistance of about 230Ω) compared to the characteristics, fully able to meet the technical requirements of the instrument. Practice has proved that good performance. The following describes the circuit design, the theoretical calculation of the filter characteristics and the measured results.