This 2002 circuit uses many more electrical components than electronics. The keys are common, and the alarm is a common clock that has this feature.
The circuit presented, from 2006, serves to control loads at a distance, robots, etc. It can be...
This circuit is given in two versions, having been found in a publication from the 90s. The second...
I found this circuit in a documentation for radio amateurs from 1975. The FET could be the BF245....