This flashlight project with a blinking light that makes it easy to find was found in the January 1990 issue of Radio Electronics magazine. The light uses a common light bulb.
This is the basic configuration of a monostable TTL with the 74121. The trip is done with an NC...
This fixed source configuration with 78xx series regulators has already been explored in several...
In the figure we have a TTL logic interfacing circuit as CMOS logic using a 6N139 optocoupler...