Based on the MC1488 or MC1489 operational amplifiers, this circuit has a 5000V isolation driving a 2N3055 transistor for a high-power signal. The receiver is a common phototransistor.
This flip-flop or bistable was found in a publication about transistors from the 60's. The circuit...
This preamplifier circuit for magnetic cartridges was found in the March 1986 Radio Electronics magazine....
This oscillator was found in a book on transistors from 1954. The transistor is from the time, and...