This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be changed. The load depends on the relay. The circuit is old, from 1988 documentation, but totally viable today.
The circuit shown in the figure is from a 1976 publication. Equivalent tunnel diodes can be used....
This 1975 circuit for automotive applications replaces the mechanical vibrator found in old cars...
This circuit is intended to switch high frequency antennas using common diodes. The circuit is from...