Stair Lighting Timer

The objective of this project is to design and install an electronics timer circuit for staircase lighting This is a push-to-on, and auto-OFF circuit. User needs to push the button only ones: to turn the light on. The light will turn automatically OFF after some time, since the switching OFF mechanism is timer based. The "push to on" switch is used here; this should be momentarily pushed to turn the light on. When "push to on" switch is pushed, pin-2 gets a negative pulse, and the timer get...