Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from Texas Instruments. Unusual component these days.
Suggested to power the previous circuit, this power supply was found in the December 1990 issue of...
This is a very useful autotransformer circuit on the bench. We found it in the September 1970...
This circuit was obtained in a 1960 documentation of General Electric. It is applied in the...