Using the LM3909 this circuit was found in the January 1992 issue of Radio Electronics magazine. Resistor R1 should be chosen according to the table given next to the diagram.
Activating a relay from pulses (from a monostable, for example) can be useful in many types of...
This project uses an unusual integrated circuit that consists of a programmed timer. The circuit was...
I found this circuit in a Popular Electronics from 1992. The circuit shows how we can receive...