在输出数据时,必须外接上拉电阻的是P0 口。C51单片机的P3口的引脚,还具有外中断、串行通信等第二功能。
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Nowlisten to the recording for a third time. Match each city to its problem.
Now listen to the recording for a third time. Match each city to its problem and a solution.
2、晶闸管对触发脉冲的要求是要有足够的_________、 触发脉冲前沿要陡幅值要________和 __________电压同步
3、 多个晶闸管相并联时必须________的问题,解决的方法是 串专用均流电抗器。