Meanwhile,this method also acts as a guide for some other weak signal measurement fields. System status transfer diagram and software flow diagram are listed as appendix.
For the high-gain preamplifier, the offset and drift that influence the stability of an entire circuit is obvious. According to the demand of a feeble-signal measure system, a real-time compensation system for the offset and drift was developed. It is composed of a 12-bit serial-imported A/D transfer AD7543 and a monostable trigger-action circuit built up by 4 Schmidt triggers as demoder.
For the high-gain preamplifier, the offset and drift that influence the stability of an entire circuit is obvious. According to the demand of a feeble-signal measure system, a real-time compensation system for the offset and drift was developed. It is composed of a 12-bit serial-imported A/D transfer AD7543 and a monostable trigger-action circuit built up by 4 Schmidt triggers as demoder.
Relative detecting technology of the weak signal to the process of bleaching is mostly discussed.The research shows to the high impedance signal source whose effective sigal current is Nanoam pere order of magnitude only,signal_to_noise ratio is very low and frequency band is wide.We can choice the low drift,high impedance and wide band operational amplifier,further apply relative detecting principle and design corresponding circuits,so signal_to_noise may be improved highly and effective signals can be det...
Based on the virtual instrument design platform L ab Windows/CVI5 .0 ,we develop the programme control lock- in- amplifier that has the automatic adjustment function of test parameter,using DAQ card and lock- in- amplifier module. Itcan use as the independentinstrumentand conveniently be formed to the automatic test system. This paper introduces the design methods of hardware and software.
采用自制数采卡和 L IA- MV- 15 0锁相放大模块 ,在 NI公司 L ab Windows/ CVI5 .0虚拟仪器设计平台上 ,研制了一种用于微弱信号测量的程控锁相放大器。本文介绍该仪器硬件软件设计方法
For the high-gain preamplifier, the offset and drift that influence the stability of an entire circuit is obvious. According to the demand of a feeble-signal measure system, a real-time compensation system for the offset and drift was developed. It is composed of a 12-bit serial-imported A/D transfer AD7543 and a monostable trigger-action circuit built up by 4 Schmidt triggers as demoder. This circuit has a novel construction that 12-bit data and control signal can transfer serially through one wire. The co...