In the figure we have the configuration of a voltage regulator with 3 transistors. The components depend on the desired voltage and current as well as on the characteristics of the transistors.
This circuit was found in an Electronic Design from 1967. The circuit uses two triacs being T2...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This shield from the 60's uses a germanium transistor of the time and a common type of relay of...