This circuit for very long-time intervals was found in the March 1993 Radio Electronics magazine. Times of several days or even weeks can be achieved depending on the value of C1.
This circuit was obtained in an old magazine from the 1970s. The circuit can still be assembled with...
This circuit was found in a Popular Electronics from the 90s. Transistors are general purpose...
This biestable vox circuit was found in an old documentation. The circuit makes use of components of...