Date: Wed Feb 14 10:19:50 2007

Author: Chuck Patten

Subject: Re: Science First van de Graff generator

Post:
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was the lineage all wet?

_____

From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Richard Heckathorn
Sent: Wednesday, February 14, 2007 12:07 AM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] Science First van de Graff generator



Greetings,



I purchased a stronger motor for mine. Helped some but not great.



I also mounted a heir dryer element in the base. Put an inline on-off
switch. This really helped.



Ok when this is all one has.



Dick





Helping teachers who facilitate, motivating students who learn.

Dick Heckathorn 14665 Pawnee Trail Middleburg Hts, OH 44130 440-826-0834

www.cvcaroyals.org/~rheckathorn/

Adjunct Physics Teacher - Baldwin Wallace College

Physics is learning how to communicate with ones environment so that it will
talk back.



-----Original Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Sam Sampere
Sent: Tuesday, February 13, 2007 4:03 PM
To: tap-l@lists.ncsu.edu
Subject: [tap-l]



I picked up a Science First Van de Graaff generator over the summer for loan
to HS teachers. I've used it a couple times and have been pretty
disappointed in it. I should have realized that when the front panel reads
"Van de Graff". The correct spelling is Graaff.



I also heard what sounded like arcing coming from inside the base. When I
opened it up and turned it on and looked, I could see arcs from one of the
fuse connectors to the other. Hmmm. Why would the fuse be arcing to itself??



Why is the charging current so small - barely noticeable on a 100 micro amp
meter. Turns out that the motor ground isn't connected to the chassis. Oh,
the chassis is floating! So the supplied ground terminals aren't really
ground at all because they're not connected.



A simple alligator clip connecting building ground to the base solved all
the problems. 25ish microamps, no arcing at the fuse, no shock turning off
the VdG, etc. Geesh!



As far as small VdGs go, I think I like the Winsco best. Unless you have an
old Cenco unit. Those are great, especially when you make new pulleys out of
gray PVC and acrylic as Cliff suggested eons ago.



Sam



--------------------------
Sam Sampere
Syracuse University
Department of Physics
201 Physics Building
Syracuse, NY 13244
315-443-5999
315-443-9103 (fax)




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was the lineage all =
wet?


From: tap-l-owner@lists.ncsu.edu=20
[mailto:tap-l-owner@lists.ncsu.edu] On Behalf Of Richard=20
HeckathornSent: Wednesday, February 14, 2007 12:07 =
AMTo:=20
tap-l@lists.ncsu.eduSubject: Re: [tap-l] Science First van de =
Graff=20
generator


Greetings,

I purchased a =
stronger=20
motor for mine. Helped some but not great.

I also =
mounted a heir=20
dryer element in the base. Put an inline on-off switch. This really=20
helped.

Ok when this =
is all one=20
has.

Dick



Helping=20
teachers=20
who =
facilitate,=20
motivating students=20
who=20
learn.
Dick =
Heckathorn 14665=20
Pawnee Trail Middleburg Hts, OH 44130 =20
440-826-0834
www.cvcaroyals.org/~rheckathorn/
Adjunct Physics Teacher - Baldwin =
Wallace=20
College
Physics is learning how to =
communicate with=20
ones environment so that it will talk back.

-----Original=20
Message-----From:=20
tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On Behalf Of Sam =
SampereSent: Tuesday, February 13, 2007 =
4:03=20
PMTo:=20
tap-l@lists.ncsu.eduSubject:=20
[tap-l]

I picked up a Science =
First Van de=20
Graaff generator over the summer for loan to HS teachers. I’ve =
used it a couple=20
times and have been pretty disappointed in it. I should have realized =
that when=20
the front panel reads “Van de Graff”. The correct spelling =
is Graaff.=20


I also heard what sounded =
like=20
arcing coming from inside the base. When I opened it up and turned it on =
and=20
looked, I could see arcs from one of the fuse connectors to the other. =
Hmmm. Why=20
would the fuse be arcing to itself??

Why is the charging =
current so small=20
– barely noticeable on a 100 micro amp meter. Turns out that the =
motor ground=20
isn’t connected to the chassis. Oh, the chassis is floating! So =
the supplied=20
ground terminals aren’t really ground at all because they’re =
not connected.=20


A simple alligator clip =
connecting=20
building ground to the base solved all the problems. 25ish microamps, no =
arcing=20
at the fuse, no shock turning off the VdG, etc. Geesh!

As far as small VdGs go, I =
think I=20
like the Winsco best. Unless you have an old Cenco unit. Those are =
great,=20
especially when you make new pulleys out of gray PVC and acrylic as =
Cliff=20
suggested eons ago.

Sam

--------------------------=20
Sam =
Sampere=20
Syracuse=20
University Department of=20
Physics 201 Physics=20
Building Syracuse, NY=20
13244 315-443-5999=20
315-443-9103=20
(fax)


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