This circuit shows how to make an adaptation on an AM receiver to receive CW and SSB signals. The circuit is from an 80's documentation. The diode is commonly used.
This brightness control for incandescent lamps or engine speed has been found in a 1970 English...
This circuit adjusts the drained current to values up to 20 A, allowing the testing of power...
This PWM control circuit was found in an old documentation, but appears elsewhere on this site...