This circuit was found in a 1967 US documentation. It shows how to build a gain control by digital signals. The circuit can be used as a shield. FET can be a modern equivalent.
The integrated circuit used is uncommon today. The numbering in parentheses is for the second...
This circuit uses two relays to reverse the direction of rotation of a direct current motor. It...
This circuit activates the horn if the door is opened with the headlights on. The circuit is for...