A couple of years ago I wrote up the neon glower as one of the make &
take lab activities for the NSF sponsored RECET program at the
University of Virginia. Leaving out the educational padding, this might
be useful. I will try to post the diagrams, etc. when I clean up class
website these next two weeks.
Equipment and materials:
Fuji clear film canister (free upon request at most photography
stores or film development centers)
We have had success at Sprint Photo, Wal-Mart, and
several local photography stores.
Neon glower (Radio Shack #272-1102 or 272-1101 $0.35)
(Try Mouser part 606 A1A or 606 A1B)
Aluminum foil
Super glue
Static electricity source (Silk and Teflon rod, Fur and Ebonite,
etc)
Construction of Neon firefly
Using a pencil or any sharp point object, drill two small holes
in the film canister. One hole should be in the center of the lid and
the other in the center of the bottom. Take the Neon glower and place
it in the film canister so that one lead extends approximately 1 cm
through the bottom hole. Thread the other lead through the lid and
close the film canister. Cut two rectangular pieces of aluminum foil
which are 3 cm by 6 cm. Place one piece on the top so that the lead
pokes through one half of the foil. Glue the aluminum foil to the lid of
the canister. Bend the lead down so that it touches the aluminum foil
and fold the aluminum foil over so that the foil covers the lead and the
lid. Glue the foil in place. Trim the excess foil from the lid so that
a double layer of aluminum foil covers the top. Place the other piece on
the bottom so that the lead pokes through one half of the foil. Glue the
aluminum foil to the bottom of the canister. Bend the lead down so that
it touches the aluminum foil and fold the aluminum foil over so that the
foil covers the lead and the bottom. Glue the foil in place. Trim the
excess foil from the bottom so that a double layer of aluminum foil
covers it.
Activities:
1) Using Teflon and silk, strike the silk with the Teflon rod.
Place the silk on one end of the firefly and the Teflon rod on the other
end. You should see a quick discharge of the firefly.
2) Walking across a carpet on a dry day, extend the firefly
towards metal object such as doorknob or faucet. The firefly will give
a rapid flash.
3) Using a static electricity generator such as a Wimshurst
machine (or a Van de Graaff generator), place the firefly between, but
not touching the electrodes. The firefly should exhibit a steady glow.
4) Using a static electricity generator such as a Wimshurst
machine (or a Van de Graaff generator), place the firefly between the
electrodes while touching one electrode. The firefly should exhibit a
series of flashes, as there is a discharge from electrode to electrode.
5) Make a series of fireflies and see whether all of them will
glow or flash in the setups as in #3 and #4.
THO
Thomas O'Neill
o'neill@csvrgs.k12.va.us
Physics
oneill@csvrgs.k12.va.us
C Shenandoah Valley R Governor's School
-----Original Message-----
From: Robert Morse [SMTP:Robert_Morse@CATHEDRAL.ORG]
Sent: Wednesday, May 31, 2000 2:12 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Electrostatics demo from AS&S
I did not find the item in a quick look through the latest
catalog, but this
sounds like a simple neon bulb such as an NE2 - you can buy them
in
quantities for as little as 15 cents each from suppliers such as
Mouser
Electronics- hold one wire in the hand and bring the other near
the charged
object- See The Physics Teacher- Neon Lamps and Static
Electricity- Layman
& Rutledge- 10(1) Jan 1972 p 49.
You may also show the direction of charge transfer with the neon
bulb- snap
together 8 or 9 9V batteries in series. Connect a 1000 ohm or
more resistor
in series with the battery and bulb- This establishes that the
bulb glows
at the negative electrode. Now you can look carefully at static
flashes and
deterimine which is the more negative electrode.
Bob Morse, St. Albans School, Washington, DC
> ----------
> From: Jennifer Groppe
> Reply To: phys-l@lists.nau.edu: Forum for Physics
Educators
> Sent: Thursday, May 25, 2000 10:13 AM
> To: PHYS-L@lists.nau.edu
> Subject: Electrostatics Demo from AS & S
>
> I also have a recommended purchase from American Science and
Surplus. I
>
> have purchased their "Human-Powered Light" (#89928 @ $3.25
each) for
> static electricity demos. When the students hold one of the
two leads
> and approach the Van de Graaf generator, the lights will glow.
Also, we
>
> use them to convincingly illustrate the difference between a
conductor
> and an insulator. If the kids rub a balloon in their hair and
use the
> light to pick up the electrons from the balloon, it is clear
that they
> must pick them up in clumps---ie that you cannot "ground" an
insulator,
> that even the extra electrons are tightly bound. Then, they
charge an
> electroscope and make contact with one lead to the
electroscope, and
> they get a brighter, one-time flash of light. I do not know
if you can
> get a similar type of light anywhere else. The kids really
enjoy the
> demos.
>
> Jennifer Groppe
> Maret School
> Washington, DC
>
>