This flasher circuit consists of an astable multivibrator with the frequencies given by the capacitors. The circuit is from 1965 using light bulbs, but LEDs can be used. Power comes from 4 batteries.
We found this VU circuit with special effects in an LED array in a 1991 documentation. The circuit...
This game with digital logic circuits was found in the December 1976 issue of Radio Electronics magazine....
This 2009 circuit is a bilateral call warning. Easy to build, using light communication between two...