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 circuit generates a rectangular signal whose frequency depends on the electrolytic...
This circuit was found in an old publicatio n from the year 1958. The circuit controls an external load by...
This circuit that converts very low currents into voltage was obtained in the 80's used component...