有个朋友看了我自己做的小闹钟，让我帮他做一个控制泵的定时器，就是设置好泵转多长时间然后停多长时间，让泵这样循环往复的走走停停，我就拿我的小闹钟改了一个，原来的蜂鸣器改成了继电器。-A friend saw my own small alarm clock, let me help him make a timer to control pump is set up to pump more and more time and then stopped a long time, let the pump cycle of stop-and-go this way, I Take me to a small alarm clock, the original turned into a relay buzzer.