We found this circuit in Mullard's 1960s transistor manual. No information about transformers is given. Transistors are germanium types of the time.
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...