Magnetic Switch?

Is there such a thing as a magnetic switch or sensor that would sense a magnet in the range of 12"-6" away?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Technology Guy wrote:

There are devices called magnetometers for all kinds of magnetic sensing. Try a google search ....
http://www.trifield.com/gaussmeters.htm
They may or may not be suitable for your needs.
Jim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dotnet_vb snipped-for-privacy@programmer.net (Technology Guy) wrote:

It depends on the strength of the magnetic field you want to detect. The simplest detector is a magnetic compass.
Al
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Depends on the power of the field your are trying to discover!
-Scott
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dotnet_vb snipped-for-privacy@programmer.net (Technology Guy) wrote in message

Magnetic field decreases at a rate of inverse cube of the distance (1/d^3). In other words the field strength knocks off pretty darn quick (of course this is dependent upon geometry and type of magnetic field). Here is an example calculation template you can use to see how the field of a permanent magnet degreades with distance. http://www.arnoldmagnetics.com/mtc/calc_gauss_cyl.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.