Re: [Phys-l] Hall effect lab experience with common materials ?

[curtis osterhoudt <flutzpah@yahoo.com>]

  Brian W: What kind of op-amp are we talking about? If we need only modest voltages as output, any of a thousand $5 op-amp chips would do it. Also, could probably up the sensitivity considerably by using AC on the "foil" side and using a lock-in amplifier (if available). 

      Don't call "pity!" yet!
               Curtis O.

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Down with categorical imperative!
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________________________________
From: Brian Whatcott <betwys1@sbcglobal.net>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Saturday, September 19, 2009 7:52:11 AM
Subject: Re: [Phys-l] Hall effect lab experience with common materials ?

CARABAJAL PEREZ, MARCIAL ROBERTO wrote:
> Hello:
>
> I am trying to design a Hall effect Lab demonstration, but using the simplest way possible, although we have the Lab instruments, the idea is to built a sensor with common life materials .  Could it be possible ?.
>
> My best regards.
> Roberto
>  
I noticed the silence after this post was deafening!    My first thought 
was this:
A graduate student had a gift put in his lap when his advisor asked him 
to check for
a transverse electromagnetic effect in current carriers. 
Which he did with eponymous effect....

    If it was that accessible, how difficult could it be to demonstrate?
After all, there are now powerful compact permanent magnets, thin 
conductive foils
and sensitive meters.   It turns out that the effect is after all a 
small one,
so that the Hall effect sensors use op amps integrated in the package to
render the effect usable.

So if I come by a little gold leaf, a pair of neodymium or whatever magnets,
a power supply, I still might need an op amp to make the effect convincing.
And that takes it away from the simple and cheap.

Pity!

Brian W
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