Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by triggering different points.
This circuit, from a documentation of the 90s, uses unusual operations today, but the...
This circuit is from a Radio Electronics from May 1994. In it we have the way to connect three 4017...
This circuit is from the 70's by A. Fanzeres. We kept the original text. It has already been said...