fuel flow sensing

[Tom Cloud]

>Larry,
>
>On Sun, 14 Sep 1997, Lawrence S. Harris III wrote:
>
>> is done on a line labeled DOL (Data output link).  The computer also has 
>> an input from the VSS (Vehicle Speed Sensor) and can thus calculate MPG.
>
>Do you know how the Vehicle Speed Sensor works? I am currently working on
>a system that uses magnets fixed onto the drive shaft, and a hall effect
>transistor. The problem i have found is that the shaft tends to move
>around quite a bit (in relation to the rest of the vehicle). As i have
>mounted the hall effect device onto the underside of the car, it
>sometimese cannot sense the magnet becaues the drive shaft is too far
>away. I haven't had a second attempt yet (with longer magnets/stronger and
>moving the hall effect device closer) but i was wondering if there is
>some other way that i should maybe try.
>
>Thanks
>
>Jason

long, long ago, in a galaxy far away, Heathkit offered a mileage
computer -- back in the days of carbs -- don't know how it worked,
how well it worked, when it was offered ..... nothing else .... but
it's a clue

Tom Cloud