Found in the May 1975 issue of Radio Electronics magazine, this circuit turns on after a certain amount of time. This gives the owner of the premises time to leave before the alarm is activated.
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
With this circuit the visually impaired can easily locate important places inside the house, such...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...