This circuit was found in Maxim's documentation from the 90's. The configuration uses components from the time but can be adapted to use modern equivalents.
This circuit has an input impedance of 10 M ohms. We found it in the October 1993 Electronics Now...
Found in a 90s documentation, this switch that is also sensitive enough to operate capacitively uses...
This circuit changes the wave shape of a square signal according the values of C1 and R1. Other...