This circuit was found in a Popular Electronics from the 90's. Its purpose is to detect the ionization of the air. The meter can be replaced by the current scale of an ordinary multimeter.
This circuit has a start and reset switches and can generate signals at long intervals determined by the...
We found this circuit in English documentation for PCs from 1996. The ZN448 is a very uncommon...
This circuit produces a sequence of steps controlled by P1 and applied to a 12V stepper motor with...