This flip-flop circuit with general purpose transistors was found in American documentation from the 1980s. The maximum operating speed depends on the transistors. Diodes are commonly used.
In this application we use an additional input circuit to enable the logic command with keys,...
This ultra-low frequency receiver circuit was published in the August 1973 issue of Radio...
This amplifier was obtained from the CA3140 datasheet, an operational amplifier with JFET at the...