This simple clock can be used to generate signals up to 100 kHz, depending on the crystal. We found it in a 1967 documentation. Note the high supply voltage.
This 2004 circuit is based on the ionization effect that occurs in old incandescent lamps with...
This bidirectional current sensing circuit was found in a 2005 Linear Technology application manual....
This circuit can be used in decoration or to draw attention, in a “fake” assembly for example. What he...