Found in Popular Electronics from the 90's, this circuit uses 555 integrated and common transistors to generate two tones determined by push buttons S1 and S2.
This circuit turns a lamp on and off with alternate touches of a switch. Modern Darlingtons can be used....
This circuit with the CK722 was found in a Raytheon publication from the 60's. The relay is of the...
This circuit was found in Radio Electronics magazine from July 1960. The components used are...