This sequential tone generator circuit was found in the July 1980 issue of Radio Electronics magazine. It uses well-known integrated circuits. The tones are generated by programming resistors.
This circuit from a Radio Electronics from December 1974 was used in color televisions of the...
This is the circuit of an economical tape recorder from the 60s. The circuit appeared in a Radio...
This circuit was found in a Popular Electronics from the 80's. The circuit can be applied to any...