Today at work, I came across a c=
ircuit =
for detecting electrostatic fields. Since I have need for such a thin=
g, I =
tried to build one. The only problem is that the required components =
weren't available (what else is new?). It called for an n-channel FET=
and =
all I could come up with was an n-channel MOSFET (2N7000). I got the =
pinout from Digi-Key and proceeded to build the circuit.
>
Needless to say, it didn't work.=
So =
I decided that the pinout must be wrong. I turned it 180 degrees and =
it =
started working, but not like the description said it would. The clos=
er I =
moved my hand to the 'antenna', the higher the voltage went. I put in=
an =
LED so I could watch it. It was sitting at about 530mV until my hand =
got =
about 10" away and it began to rise. At about 4 inches, it went to ab=
out =
1.3V and when I would touch it, it jumped to 4.8V (input V=3D5VDC). =
The strange thing about it: =
; The =
2N7000 is backwards! At least I think it is. The S (source?) pi=
n is =
on the negative side of the supply and the D (drain?) pin is on the positiv=
e =
side. The gate is acting as the antenna. Maybe I've got the ter=
ms =
wrong. It's still a cool thing. I was thinking it could be used=
as a =
'real' antenna for a walker or popper. It could trigger a Nu that ope=
rates =
the reverser. Something that deserves further =
investigation(IMHO).
Guardians of the sacred words: N=
ee, =
Ptang, and NeeWhon! =
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