Automatic power-down for PCs

There are many programs that take of lot of precious time, even on relatively fast PC-AT computers. Examples include electronic circuit simulators, sorting routines, disk compression programs, and PCB auto-routers. Eventually, the enjoyment of the PC user sitting back and sipping coffee or tea as the machine crunches its way through masses of data turns into impatience. After a few such sessions, you have seen it all happening, and time-consuming programs are usually banned to night-time hours. Unfortunately, this means that the computer remains on long after finishing the relevant program. The circuit presented here does away with this disadvantage of off-peak, unmanned computing by enabling the computer to shut itself down.