This simple circuit was found in a Japanese magazine in 1967. The circuit is listening on a headset and the coil is 50 + 50 turns of wire 28 or thinner on a ferrite rod.
This circuit is from Mullard documentation from 1969. Transistors support current equivalents. Output...
This circuit or practical idea comes from a time when cheap solar cells were not available (1992). What is...
From an input signal, and using an unusual current source, this circuit generates a ramp, that is, a...