Found in General Electric's 1969 documentation, this circuit uses two Foto Darlingtons to control the SCRs driving phases. SCRs can be equivalent current types.
This window comparator circuit was found in a Popular Electronics from the 90s. The circuit has a...
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This circuit with automatic gain control was found in the July 1988 issue of Radio Electronics magazine....