This receiver circuit was found in documentation from 1924. The circuit uses two batteries, the high voltage one being 90 V.
This oscillator takes advantage of the 2000 ohms headphone inductance as the oscillator circuit coil....
This circuit was found in an 80's Electronic Engineering. The circuit uses a multivibrator with...
Found in a 90s Radio Electronics, this circuit is intended to trigger a relay when the current in...