In my University Physics II class (Electricity and magnetism) we are studying magnetism currently, and the instructor started to go over the "hall effect." I know that mercedes have a hall effect sensor on the back of the spedometer to regulate the cruise control. So I asked him after class if he knew how it worked or anything and he didnt. I was wondering if anyone here thats Electrically inclined knows how it works. He said if I bring in a spedometer he can figure it out, but I want to know, then I can share to the class that we are studying things that actually relate to real everyday life and maybe I can get some bonus points.

I have a spedometer from a w123 1982 300d that I took apart, so I can post pictures or anything anyone needs to help me explain. Thanks, Austin

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Current Stable:
1994 S500 v140, 210k miles, white with grey.

Former Mercedes in the Stable:
1983 300CD Turbo diesel 515k mi sold (rumor has it, that it has 750k miles on it now)
1984 300CD Turbo Diesel 150 k mi sold
1982 300D Turbo Diesel 225 sold
1987 300D Turbo Diesel 255k mi sold
1988 300 CE AMG Hammer 15k mi sold
1986 "300E" Amg Hammer 88k mi sold (it was really a 200, not even an E (124.020)
1992 500E 156k mi sold
etc.