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 circuit causes an LED to flash if the monitored voltage exceeds the value set in the pot. The...
Found in an Electronics World of 1966 this circuit can be made with current power transistors. It causes...
Found in a 1970 documentation, this SCR bistable can be implemented with modern equivalent SCRs. Observe...