This circuit uses two diodes in a doubling configuration to receive medium-wave range signals. The phone is crystal. We found it in a 1968 American documentation.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....