Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from Texas Instruments. Unusual component these days.
We found this circuit in the Electronics Experimenter Handbook 1983 edition. The circuit uses...
This little-known regulator today was found in a Radio Electronics circuit from December 1978. The...
This circuit was obtained in a 1982 Maplin magazine. The circuit can be applied to equivalent power...