Found in a 1924 book by Gernsback, this circuit uses a double variable capacitor, a component not very common at the time. Listening was done on a loudspeaker at the time.
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...