频率计设计.doc

摘要
在电子技术中,频率是最基本的参数之一,并且与许多电参量的测量方案、测量结果都有十分密切的关系,因此频率的测量就显得更为重要。测量频率的方法有多种,其中电子计数器测量频率具有精度高、使用方便、测量迅速,以及便于实现测量过程自动化等优点,是频率测量的重要手段之一。本课题主要选择以集成芯片作为核心器件,设计了一个简易数字频率计以触发器和计数器为核心,由信号输入、隔直,触发、计数、数据处理和数据显示等功能模块组成。放大整型电路:对被测信号进行预处理;闸门电路:构成一个秒信号,提取单位时间内进入计数器的脉冲个数;时基信号:产生一个秒信号;计数器译码电路:计数译码集成在一块芯片上,计单位时间内脉冲个数,把十进制计数器计数结果译成BCD码;显示:把BCD码译码在数码管显示出来。设计中采用了模块化设计方法,采用适当的放大和整形,提高了测量频率的范围。
关键词频率;集成电路;译码电路;计数电路;双稳态触发器
Abstract
Be one of the most fundamental parameter in electron technology medium frequency , parameter measurement scheme , measurement result all have very close something to do with a lot of electricity and , the frequency measurement looks like being more important therefore right away . The method measuring frequency has various , among them the electronic counter measures frequency having accuracy height , usage is convenient , measurement is prompt , easy to realize measurement process automation waits for merit and , is one of the important means that frequency measures .This subject has mainly explained that chooses integrated circuit as the key device, has designed a simple and easy digital cymometer, regard trigger and counter as core , input , separate by signal frank , touch off , count circuit , data processing , data reveal module of function make up. Enlarge the circuit of integrated type: To be carried on the preconditioning by the signal of examining; The circuit of the gate : Formed a second signal by NE556, seize the pulse number of entering the counter in unit time; The base signal of hour: Produce the signal for one second; The decipher circuit of the counter : Count deciphers and integrate on the chip together, count the pulse number in unit time, count the result of the decimal counter to translate into BCD yard; Reveal : In charge of revealing BCD one yard of deciphers in the number . Design adopt module design method, adopt appropriate enlarge and whole, have improved frequency of :
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