On Tue, 20 Dec 2011 22:10:21 -0500, "Angelo Campanella"
wrote:


wrote:

Lenny, try taking a plain NE-2 with no resistor and connecting about a
foot of insulated #22 solid insulated wire to one lead and wrapping
that around a piece of insulated wire the same size as your service
entrance wire and connecting the other lamp lead to neutral. Energise
the heavy wire with 120V and see if the NE-2 glows just from the
capacitance of the large wire to small wire. That is about as simple
as it gets and is adequately insulated from the service cable to not
need any current protection.

That looks like a reasonable monitoring action except that when you are
dealing with the incoming line that has no protection, you have to be sure
that whatever you connect across it does not short or catch on fire in the
long run... Aside from that, You only need to monitor one 115v side to
determine whether the power is gone. I suggest you try various physical
"capacitors" by connecting them in series with the NE-2. A 50' extension
cord would provide maybe 2500 pF (.00025 uF), which may be enough to dimly
light that lamp. For instance, with the 50' extension coil disconnected and
laying on the floor, using a plug pigtail, connect the common or ground
house wire to one lead of the NE-2. Connect the hot house wire to the hot
line of the 50' extension cord. the capacitance of the 50' coil should
supply enough brightness to be seen in a dark room.

Even simpler still and a lot safer, buy any extension cord that has a
neon light built into one end. Install it in your favorite house room. Plug
it in and hang the lit end anywhere in sight.

Ange
Do the math. You need 10,000pF at 220 volts, roughly double that at
120 volts to drive a NE2 lamp to full brightness. Treat it like a
parallel plate capacitor; the formula isC= K*0.2248*A/d. K is the
dialectric constant (most materials have a dielectric constant between
1 and 10), A is the area of the plates, d is the distance between the
plates.

If you wrap foil around a 000 Ga insulated wire you will be getting
roughly 1 square inch of capacitive area per linear inch of cable.
Heavy gauge extention cord has 14 Ga wire, being generous you will be
getting .06 square inches of capacitive area per linear inch of the
cord.

PlainBill