[SCHEMATIC OF DEVICE] (The earth-ground is not required.)
(The 1-Meg resistor is not required.)

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. This 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 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 to 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 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. Realworld objects become “electrified” whenever their pre-existing + and - charges are not equal.

PARTS LIST:

* 1 - Standard 9-volt battery
* 1 - MPF-102 N-channel Field Effect Transistor (FET) Radio Shack #276-2062
* 1 - Red Light Emitting Diode (LED) Radio Shack #276-041
* MISC:
o Battery connector (#270-325)
o Alligator Clip Leads (#278-1156)
o solder, if desired
o 1-meg resistor (not required)
o plastic, fur, foil, comb, tape dispenser, plastic cup

[Drawing: FET and LED soldered to 9v connector]
(Tiny version bult atop a 9v battery connector)
Shortcuts:o 1.CONSTRUCTION HINTS
o 2. SENSE E-FIELDS
o 3. SENSE POSITIVE ELECTRIFICATION
o 4. CHARGE IS CONSERVED
o 5. PEELING CAUSES ELECTRIFICATION
o 6. JUMPING ELECTRONS, “VOICE CONTROL”
o 7. VARIABLE GAIN
o 8. FIELD DISTORTIONS
o 9. VANDEGRAAFF SENSING
o 10. HOMEMADE CAPACITORS
o 11. DIPOLE ANTENNA
o 12. THE SKY VOLTAGE
o 13. UNTESTED SUGGESTIONS
o 14. HOW IT WORKS
o 15. WHERE IT CAME FROM
o 15. FET-PANEL MUSEUM EXHIBIT