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555电路用法很多,通常输入和输出是反相的.在某些场合,为了省去倒相级就要求输出和输入同相,这时可用强复位端,接法如图1,只要将2、6端接地,从4端输入脉冲信号,输出便与输入同.对于需要定时输出的设备,如电子钟打铃仪,其输出负脉冲宽度最小为1分钟,而打铃时间一般只有十几秒,为了能定时,且省去倒相级,笔者采用了如图2所示电路.1端为输入端,R、C为定时元件.当输入为高电平时,集成电路不接地,7脚或3端输出高电平.当负脉冲过来时,相当于1端接地,集成块满中了工作条件,同时电容C通过R充电,一开始电容C两端电压为零,R上电压为
555 circuits use a lot, usually the input and output is anti-phase. In some cases, in order to eliminate the need to output phase inversion and input in-phase, then available strong reset end, connected to Figure 1, as long as 2,6 End, input pulse signal from the 4 end, the output will be the same as the input.For the need to output the device, such as electronic clock bell instrument, the minimum negative pulse width of 1 minute, and ringing time is generally only a few seconds, In order to timing, and eliminating the need for phase inversion, I used the circuit shown in Figure 2. 1 end for the input, R, C for the timing components. When the input is high, the integrated circuit is not grounded, 7 or 3 When the negative pulse over, equivalent to 1 end of the ground, the integrated block full of working conditions, while the capacitor C through the R charge, the beginning of the voltage across the capacitor C is zero, the voltage on R is