This circuit can be used as a shield for touch control. The circuit can use any common FET like the BF245 and should never be powered by a source without a transformer.
This circuit was obtained in an Electronics World of 1969. It is a crystal oscillator with a 100...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...
This circuit was found in the July 1992 Radio Electronics magazine. Sensitivity adjustment is made...