学习利用集成逻辑门、555定时器设计脉冲信号产生电路；掌握影响脉冲波形参数的定时元件参数的计算方法；学习脉冲波形整形和分频方法

-Learning to use the integrated logic gate, 555 timer pulse signal generation circuit design　control parameters affect the timing pulse device parameters is calculated　study pulse shaping and frequency methods