1、 数字电子技术基础简明教程数字电子技术基础简明教程 摘摘 要要 本次设计所制作的是一块简易电子琴， 主要通过 NE555 定时器芯片构成多谐 振荡电路，这个电子琴主要有 8 个音符，通过 8 个电位器及琴键开关构成音符控 制电路，改变电位器阻值来改变个音符频率，从而达到所要音符频率要求，最后 通过小喇叭发出不同频率的声音。 NE555 是属于 555 系列的计时 IC 的其中的一种型号，555 系列 IC 的接脚功 能及运用都是相容的，只是型号不同的因其价格不同其稳定度、省电、可产生的 振荡频率也不大相同，但它总体上计时精确度高、温度稳定度佳，且价格便宜； 而 555 是一个用途很广且相当普遍
2、的计时 IC，只需少数的电阻和电容，便可产 生数位电路所需的各种不同频率之脉冲信号。其延时范围极广，可由几微秒至几 小时之久。555 的操作电源电压范围极大，可与 TTL，CMOS 等逻辑电路配合，也 就是它的输出准位及输入触发准位，均能与这些逻辑系列的高、低态组合。 关键词：电子琴；NE555 定时器；多谐振荡器；电位器；8 个音符频率阻值 AbstractAbstract This practice is a simple made NE555 timer, mainly through electronic circuit chip resonance swings, the keybo
3、ard mainly eight notes, through eight potentiometer and keys switch constitute notes control circuit, resistance to change a potentiator change notes, thus achieved the frequency to note, through the small frequency of different frequencies of the speaker. NE555 belongs to the timing of the IC 555 s
4、eries model, one of the series IC 555 feet function and application are compatible, just because the price of the different types of different its stability, save electricity, can produce the oscillation frequency is the same, but it also overall accuracy is high temperature, time, and the stability of cheap price, And a wide use 555 timing and quite common, just a few of the IC resistance and capacitance, can produce all kinds of digital circuit of different frequency pulse signal.
