This CMOS 4001 oscillator alternately turns the relay on and off at times set by R2. The circuit is from Electronics Now magazine, June 1995.
This SCS counter circuit was found in a 1964 General Electric documentation. The circuit has a...
This simple 1-transistor reflex receiver was published in Radio Electronics magazine in September 1959....
Operational amplifiers used in this 80's circuit is not very common today, but the setting can be...