Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from Texas Instruments. Unusual component these days.
This circuit is from an Italian publication from 1988, but it can be assembled today because the...
The circuit, shown in the figure, produces a good power audio tone, whose frequency is adjusted by the...
This circuit was found in a Maxim documentation from the 90s. It is valid for the lower income types...