This circuit was found in a 1967 Electronic Design. The FET is from that time. Capacitor C is determined by the frequency of the signal worked.
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...