Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then disconnect the charger. The transistor may be a general purpose type.
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...