Detection of Weak Signals
LI Xiangcang · Modern Electronics Technique · 2006
It is common for people to meet some weak sound,light and electricity signals in daily life.These signals may be helpful or harmful to people′s life.However,they can not be detected with ordinary meters.This paper emphasizes the method to detect these kinds of signals and specifies the operating principles of different parts of circuits by the example — ultrasonic wave detector.