[Phys-L] Re: Looking for electricity demo apparatus

[Bernard Cleyet <anngeorg@PACBELL.NET>]

They are either spark coils or Tesla Coils.  they are often easily
repaired  (I've repaired for others and myself.)  Check the Chem.  dept.
or other vacuum people   They are (gross) leak detectors.

Did you feel a shock or a burn?  The Tesla coils are rather high
frequency oscillators, so the skin effect prevents shock.  If one holds
a metal object to receive the "spark" one feels nothing, but a direct
discharge to the skin results in first warmth and then a burn.  If you
feel a (definite) shock then the device is a spark coil similar to one
used for the ignition in early auto's.  The main obvious difference is
the spark coil has a ferromagnetic core  (bundle of iron wires for dc
use), while the Tesla or Oudin coil has no core (air).  You can use
spark timer (used w/ Behr free fall and other waxed tape uses, e.g.
Atwood machine and air track carts). Especially if it has a variable
frequency adjustment. (Set it at max.).. Also both Wimshurst and Van de
Graaf generators will "lite" gas tubes.

You can make your own.  Tesla instructions abound on the webb and an
auto ignition coil may be driven by a distributor substitute.
(oscillator driving a switching transistor.)

BTW, that knob (button) adjusts the spark gap if a Tesla coil, or the
tension of the interrupter (exactly the same as a buzzer or electric
bell) if a spark coil.

Finally, mail them to me (contact me off list) and I'll be pleased to
attempt a repair.

bc

p.s. if all else fails purchase one for $213 from KIMBLE glass co.

http://www.kimble-kontes.com/html/pg-691550.html

That's cheating tho.



Gonzalez-Espada, Wilson wrote:

> Hello all:
>
> Here at Tech we had two 14" handheld "sparkers" (dated 1963) that we used for electricity demos. They were brown, with a 3" metal tip and a variable button resistor to adjust the size of the sparks. They produced a spark that lit a fluorescent lamp. The current was low enough that we used it to "shock" ourselves painlessly (kind of; it left tiny red marks that dissapear in 24 hours).
>
> The "sparkers" are dead now. They sound as if they are working but no sparks are produced. We need to replace them ASAP.
>
> Question
> 1. What is the correct name for this apparatus?
> 2. Where could I find a replacement?
>
> I have search the Internet, but without the proper name I have been unable to find a replacement.
>
> Thanks in advance,
>
> Wilson J. Gonzalez-Espada, Ph.D.
> Asst Professor of Physical Science/Science Education
> School of Physical and Life Sciences
> Arkansas Tech University
> 1701 N. Boulder Ave. (McEver Hall)
> Russellville, AR  72801
> (479) 968-0293
> (479) 964-0837 fax
>
>
>
>
>
>
> ________________________________________________________________
> Sent via the WebMail system at mail.atu.edu
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