Using the CMOS IC 4046 we found this VCO in the November 1984 Radio Electronics magazine. The center frequency is given by the capacitor. The maximum frequency is around a few megahertz.
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....