This 1980s circuit was found in Motorola documentation. The circuit uses period components that admit of equivalents. Light feedback in a modern version can be done by optical fiber.
This small receiver uses CK722 transistors and was found in a documentation by Hugo Gernsback from...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...
This circuit generates short pulses. The transistor can be a 2N2222 or BC548 and the frequency is given by...