This circuit was found in a 1980s American documentation. The data circuit has a low speed, according to the components used. Transistors support modern equivalents.
This circuit was found in General Electric documentation from 1964. It makes use of a PUT, called the...
This mid-frequency amplifier circuit was found in an American publication from the 1950's. The...
The circuit with a common operational amplifier uses a zener as a reference. The circuit is from...