How does it work? How does a cam sensor work with it? Thanks.

 

You can start with this Hall Effect sensor page on Wiki. You could always search for more materials if you feel you need more information.

 

Oh, now I understand.
You don´t mean Hall efect as a type of echo, but Hall sensor...

 

An Hall Effect sensor simply generates a voltage in response to a magnetic field. There are three pins on the device. The two outside pins go to +5V and ground respectively while the middle pin is the output. An application for it would be to use it in a circuit to control the speed of a DC motor with a magnet.

 

I really want more info. in lesson form about how, and why it works, applications, etc. Just like the lessons here. Is there a really good web page?

 

http://mems.caltech.edu/courses/EE40%20Web...tDerivation.pdf

http://content.honeywell.com/sensing/prodi...al/hallbook.pdf