【摘要】 在固体目标缓慢移动的激光多普勒监测中,要求数据采集系统能够精确检测出弱电流信号,同时具有较大的动态范围和一定的响应速度。为满足这些要求,设计了弱电流直接数字化数据采集系统。该系统采用DSP作为主控芯片,CPLD实现相关的逻辑控制,并通过USB2.0接口实现数据的高速上传、下载。实验表明,系统单、双极性电流信号的测量范围分别是0～6.45和-3.25～3.23,电荷测量精度约为0.05pC,采样率12.9KHz。该系统适用于弱电流和电压信号的检测,具有较强的实用性。更多还原

【Abstract】 In the research of monitoring the slow movement of solid object by using the laser Doppler measurement technology,the data acquisition system is required to have some major features,e.g.precise measurement of small current,relatively wide measurement range and high response speed.To meet the requirements,we design a set of data acquisition system of direct weak current digitization,which consists of main control chip DSP,CPLD that is used to implement logic control,and USB2.0 interface that aims to upload and download data in a high speed.The experiments indicate that the measurement range of unipolar current and bipolar current are 0 ～6.45 and-3.25 ～3.23 respectively,the measure precision of charge is about 0.05pC,and the sampling rate is 12.9KHz.The system has great practicability,which is very appropriate for detecting both weak current and voltage.更多还原