This telephone recording circuit was found in the June 1979 issue of Radio Electronics magazine. The components are common at the time and the power is supplied by the power grid.
This 1992 circuit was designed to operate with the CB16766E circuit auto alarm. The circuit...
Found in documentation from the 1970s, this circuit employs an operational amplifier from that...
The components of this circuit are not common today, as it was obtained in the Linear Applications...