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.
This circuit was found in ancient American documentation. It provides a 70 Vpp signal at...
This circuit appears in various parts of this site and this section, with diverse origins. This is from...
This stage of IF to 455 kHz operates with voltages from 1.5 V. We find it in a 90s Popular...