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.
R1 may be 10k and R2 100k. The transistor can be the BC548 and instead of the small lamp we can...
This circuit was found in the 2005 Linear Technology Linear Circuit Manual. It is a sensor with large...
This circuit uses a diode as a radiation sensor. The operational ones are old because the...