This circuit is part of an article published in the March 1990 issue of Radio Electronics magazine. The sensor consists of a grid-shaped electrode shown in the figure.
This circuit came out in a publication called Electronics Handbook of 1993. The circuit shows how...
Found in documentation from the 1980s, this circuit makes use of general-purpose diodes and...
This circuit memorizes through an LED indicator if your phone was used during your absence. The...