Design and Analysis of Monostable Control Circuit

The working principle of the device application circuit is shown in Figure 8. It can be used in corridors and stairways as a delayed energy-saving lighting lamp. Before going upstairs, press any button from AN1 to ANn downstairs. Pin 2 of the time-based integrated circuit IC NE555 is triggered by a low level and set. Its output pin 3 immediately becomes high level, causing the controller DM to be high level, so the lighting lamp H is on at this moment. Release the button. Since IC NE555 works in monostable mode, its pin 3 will continue to output a high level for a period of time. At the same time, the power supply charges C2 through R2. When the voltage across C2 reaches 2/3 of the power supply voltage, NE555 automatically resets, and its pin 3 returns to a low level. Pin 4 of the controller DM becomes low level, which causes the internal circuit to shut down and the lighting lamp H automatically turns off.

In this way, when going upstairs, you can press any button from AN1 to ANn to light up the lamp; when going downstairs, you can press any button from AN1 to ANn to light up the lamp. AN1 to ANn can be set according to specific needs. The continuous working time of the monostable state can be determined by the values ​​of R2 and C2.