如图所示电路,光电耦合器4N 25 起到耦合脉冲信号和隔离单片机89C 51 系统与输出部分的作用,使两部分电流相互独立
输出部分的地线接机壳或大地,而 89C 51 系统的电源地线浮空,不与交流电源的地线相接,这样可以避免输出部分电源变化对单片机电源的影响,减小系统所受的干扰,提高系统可靠性
CNY17 Optocoupler
+---+--+---+ A |1 +--+ 6| B K |2 CNY17 5| C |3 4| E +----------+ HDSP-L101, HDSP-L201, HDSP-5401, TC07-11 Common row anode 5x7 dot matrix LED display
+---+--+---+ Col1 |1 +--+ 12| Row1 Row3 |2 11| Row2 Col2 |3 5x7 10| Col3 Row5 |4 LED 9| Row4 Row6 |5 8| Col5 Row7 |6 7| Col4 +----------+ HDSP-L103, HDSP-L203, HDSP-5403 Common row cathode 5x7 dot matrix LED display
+---+--+---+ Row1 |1 +--+ 12| Col5 Row2 |2 11| Row3 Col2 |3 5x7 10| Row4 Col1 |4 LED 9| Col4 Row6 |5 8| Row5 Row7 |6 7| Col3 +----------+ TIL111, TIL112, TIL116, TIL117, TIL118, TIL124, TIL125, TIL126 Optocoupler
+---+--+---+ A |1 +--+ 6| B K |2 5| C |3 4| E +---