The circuit in the figure uses two of the 4001's four gates to trigger a relay in a timed manner. The time interval obtained depends on the capacitor C1 whose value can be between 10uF and 1 000uF. With 10uF the time interval obtained is in the order of 10 seconds. Very large capacitor values can make the circuit unstable, especially if they leak. The relay is of the type that has a maximum coil current of 50 mA and voltage equal to that used in the supply.
