speed sensor output

Have you considered that the reed closure rate might depend on the specific vehicle make and model? And that some vehicles may not use a reed at all, opting instead for an inductive or a hall-effect sensor?

For specific closure rates, I'd contact the vehicle manufacturer directly or, if you have the vehicle, tools and expertise, try making the measurements yourself.

My two cents' worth.

-e

More info please?

motorcycle, car, boat?

installation location, wheel, transmission ?

The easiest way to do this is:

1. Measure the circumference of the wheel that the speed sensor is reading.

2. Count the teeth.

This will tell you how many pulses per revolution, and how far the wheel travels in one revolution. Then:

Lets say there are 100 teeth and the circ is 1m

At 80km/h the wheel is turning 80000/60 m/min = 1333m/min

and 1333 rev/min or 100x1333 pulses per min

100x1333/60 gives 2221.6 pulses/sec - or cycles per second - so this is the frequency.

I am a bit rusty on this - so can anyone find a problem with the logic??

Regards

John