This circuit was found in a March 1988 Radio Electronics. The voltage scale is set at R3. 19 LEDs are used in this indicator circuit.
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....