This interesting sensor for RF signals was found in an article in the June 1989 Radio Electronics magazine. It is a field strength meter with an LED bargraph indicator.
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....