This circuit was found in a publication in the 1980s. Modern equivalent components can be used. The source must be isolated. The circuit includes an oscillator.
This circuit was found in a 1995 documentation. It drives a set of sequential LEDs from the sound...
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...
The integrated circuit used is equivalent to the 555 and the transistor can be the BC558. R1 and...