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.
As part of a larger project, we found this modulation meter in the August 1994 Electronics Now...
This circuit was found in an 80's Electronic Engineering. The circuit uses operatives of the time...
This circuit is an improvement of the previous one, with the use of two transistors produces a...