I recently installed a new stereo head-unit in my car. One of the challenges with installing this head-unit was that a certain wire from the harness needed to be grounded, but only after the radio had ...

The main principle of this circuit is that the door lock opens only when the buttons in series are pressed at a time. We can use it to lock the doors and for other security purposes. This article ...

The following automatic battery-charger design is created with a circuit that could qualify as the simplest window comparator ever built around a single transistor (see the figure). It starts charging ...

Large scale digital logic began not with the vacuum tube but the electromechanical relay. Although vacuum tubes were available at the time – and were used on competing machines – Konrad Zuse chose to ...