火炬点火装置
选题： C题 锁定放大器的设计
参赛队编号： NJ290
学生姓名： 田原 惠琦 李一博
摘要
载重车本系统是基于相敏检波(PSD)技术的锁定放大器(LIA)，用于实现强干扰背景下uV级微弱信号的有效检测。本文给出一种基于TI器件的解决方案。系统由信号通道、参考通道、相敏检波器三部分组成。其中信号通道由加法器、分压网络组成，实现信号与干扰的叠加并将大信号衰减为微弱信号，参考通道包括移相电路、触发整形电路，生成用于驱动模拟开关实现PSD的方波信号。相敏检波器为核心，检波后经低通滤波输出直流信号供AD采样处理。经单片机简单计算，在液晶屏上显示微弱信号幅值。经测试，本系统较好完成了微弱信号的检测。 刮刀研磨机
关键词：微弱信号检测 锁定放大 相敏检波
Abstract
The system is a lock-in amplifier (LIA) designed with phase sensitive detection (PSD) technique . The amplitude of low-level signal (uV ) added with high noise can be detected correctly. The article describes a solution using TI devices.
铸铁锅炉柴草热水器The device consists of three modules . The signal channel achieves the superposition of noise and signal . A voltage divider built with pure resistor network is also included in signal channel to produce the low-level signal. The reference channel moves the phase of reference input and generate a square wave sequence to drive the analog switch CD4053 which is responsible for the phase-sensitive detection. A low-pass filter is used to extract the DC component of PSD signal which is linear related to the amplitude of the detected low-level signal. The system works well in test.
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