555单稳态电路实验中出现的问题分析  

Analysis of problems in 555 monostable circuit experiments

作　　者：张学文 司佑全 ZHANG Xue-wen;SI You-quan(College of Physics and Electronic Science,Hubei Normal University,Huangshi 435002,China)

机构地区：[1]湖北师范大学物理与电子科学学院,湖北黄石435002

出　　处：《湖北师范大学学报（自然科学版）》2018年第2期78-83,共6页Journal of Hubei Normal University：Natural Science

基　　金：湖北师范学院校级教研项目JH201129;ZD201121

摘　　要：在由555定时器构成的单稳态触发器实验中,经常发生输出波形异常、暂稳态时间测量值与理论计算值偏差较大的问题。分别将信号源输出脉冲直接加到低电平触发端和将脉冲信号经过微分电路再加到低电平触发端,进行实验对比得知:发生波形畸变是由于在低电平触发端引入了负脉冲。进一步得到:对于单稳态触发器电路中的定时电容的选取,用薄膜电容代替陶瓷电容可以有效地减小测量值与理论计算值之间的偏差。In the monostable flip-flop experiment composed of the 555 timer,it often occur that the waveform output abnormally and there exists the greater deviation between the measured value of the transient steady-state time and the theoretically calculated value. In this paper,the authors through the signal source output pulse directly into the low-level trigger end and the pulse signal through the differential circuit to join the low-level trigger end,for comparison experiments,the waveform distortion is caused by the low-level trigger side introduces a negative pulse caused. In a monostable flip-flop circuit,the use of a thin film capacitor instead of a ceramic capacitor in the timing capacitor can effectively reduce the deviation between the measured value and the theoretical value.

关 键 词：555定时器 单稳态触发器 微分电路 薄膜电容 陶瓷电容 

分 类 号：TN791[电子电信—电路与系统]