Hi there I made a simmilar question some days before.
I am trying to count the gears while a tractor is moving. The counter will be an AVR which will make some calculations in order to give some details vs the machine operation time and the speed. The details will be in a graphic display as real time graphs.
There is a ground speed-geartooth-reluctance sensor with only 2 cables positioned very near the gear teeth. The vehicle's battery is a 12V. The sensor has a label in each cable (A and B). I have measured the output of the sensor using the circuit:
1. 12V DC then in series
2. Resistor 10K then in series
3. sensor's cable labeled A
4. sensor's cable labeled B to GND
Measuring the drop voltage across the resistor with an oscilloscope I see an anodic sine curve when a tooth comes, then a cross over depended on the tooth length and then a cathodic sine curve when the tooth left.
I made all these not on the tractor but on my desk. The sense of this sensor goes in a monitor that shows the ground speed of the vehicle. So does anybody knows what is the internal circuit inside the vehicle supports and read the sensor? Is there any standard? Is there any circuit I could use to read the sensor without effecting the vehicle's inside circuit. I tried the google but not a lot of things (just theory).
Thanks a lot.