Found in a 1967 Electronics World, this oscillator changes its tone when objects move in their environment. The output is made on a low impedance phone.
This circuit can be used in decoration or to draw attention, in a “fake” assembly for example. What he...
This sophisticated alarm with traditional components was found in an ancient American...
We found this AM radio in a 1957 transistor application manual, published by Raytheon. The...