I'm doing work to an electrical engineer graduation subject about the transducer. I'm studying the magnetic transducer just to understand how it works and I had a little doubt.
Let's look at the image first to be more clear:
As you can see the image shows a Hall effect sensor that measures the crankshaft angular speed.
I understood that when there's a significant magnetic field or flux sensed by the Hall sensor its output, in the case of a digital sensor, will be high, otherwise, it will be low voltage.
I reflected on the Hall voltage formula: $$ V_H= R_H \cdot(\frac{B.I}{t}) $$
VH is the Hall voltage in volts, RH is the Hall effect coefficient, I is the current flowing through the sensor in amps, t is the thickness of the sensor in mm, and B is the magnetic flux density in Teslas.
In my point of view, only the magnetic flux is varying somehow in accordance with the crankshaft spinning, but I don't know how to explain it.
Could someone help me with this question?