This circuit with 117 V output was found in a 1969 Electronic Design. Drive transistors admit equivalents and information about transformers is not given.
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...