(http://i1162.photobucket.com/albums/q537/0x4E4F/Simple_Voltage_Detector.gif)
ESD Detector - project shot (http://www.youtube.com/watch?v=YQ7SzAt3Vyw#)
извор
http://www.eskimo.com/~billb/emotor/chargdet.html
This simple circuit can detect the invisible fields of voltage which surround all electrified objects. It acts as an electronic "electroscope."
Regular foil-leaf electroscopes deal with electrostatic potentials in the range of many hundreds or thousands of volts. The above device can detect one volt. Its sensitivity is ridiculously high. Since "static electricity" in our environment is actually a matter of high voltage, this device can sense those high-voltage electrically charged objects at a great distance. On a low-humidity day and with a 1/2 meter antenna wire, its little LED-light will respond strongly when someone combs their hair at a distance of five meters or more. If a metal object is lifted up upon a non-conductive support and touched against the sensor wire, the sensor can detect whether that object has an electrostatic potential of as little as one volt!
Note: I use the term "electrification" rather than "charging", in order to avoid confusion between electric charge and net-charge. "Charge" is the stuff on the negative electrons and positive protons, while "net-charge" is the imbalance between positive and negative particles which appears on everyday objects. Avoid saying that everyday objects become electrically "charged." After all, their atoms are always full of charges. Instead they become "electrified" whenever their pre-existing + and - charges are not equal.