Motion Sensor that is.<br><br>I am a graphic
designer. I have an invention which I think is going to
catch like wildfire. <br><br>My family believes I have
lost my mind, but I am determined to create this
thing, which can be constructed in one day. Now the hard
work begins.<br><br>For as good as my invention is, it
would be ten times better if I could incorporate an
extremely sensitive motion sensor. Nothing different than a
security light that comes on when you walk in front of it.
Essentially, it would be the same as a security light that
would work on a much smaller scale. It would have to
monitor a circlular space about 2 inches in diameter, and
cut on a light once motion (light change) was
detected.<br><br>It would preferably be battery operated or require
little electricity. Does such a component exist? Is it
expensive? I don't have a science or engineering background,
so could you break this down for me?<br><br>Thanks
gals and guys.<br><br>Joey