We found this circuit in documentation from the 90s. The circuit uses components that are still common today, turning off a load after the programmed time. The time is given by the capacitor.
This simple expandable circuit was obtained from a Popular Electronics from the 80's. The supply...
This traditional configuration found in a Radio Shack document can use 2N2646. More keys can be...
This circuit was obtained in an Argentine publication in 1976. It consists of a series voltage...