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.
In the figure we have a configuration that allows to test NPN transistors and with the addition of a...
This circuit can be designed with ease today, as its components are common. We found it in old...
This siren produces an intermitent sound given by the characteristics of the two oscillators using the...