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 sh

这次设计的抢答器主要四部分组成，由优先编码器，寄存器和译码器组成的抢答电路，十进制计数器组成的倒计时电路，555定时器组成的秒脉冲发生器，十六进制计数器组成的计数器。-The design of the Responder mainly of four parts, by the priority encoder, register, and the composition of the answer in the decoder circuit, consisting of decimal c