This circuit was published in a recent magazine as a past project. It is a crystal radio from October 1986 Radio Electronics magazine. The article detailed the assembly.
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...