This circuit is for old telephones with analog lines. It was found in the May 1988 Radio Electronics magazine. The circuit is powered by the line signal voltaje.
This circuit can reduce the voltage of a source by providing regulated adjustable output. The...
Found in a 1992 book, this circuit is intended for operation with audio signals. Equivalent...
This circuit was found in a 90's RF Design. The circuit employs an integrated of the time. The 56 to...