efiguy

I'm curious to learn more about how (specifically Automotive) crankshaft encoding is done electronically speaking... What I mean is this: I know that the majority of crank position sensors are of the VRT variety which produce a varying amplitude proportional to the speed of the target wheel it is measuring. What I don't understand is: How does one convert this sine wave type signal into something digital that the controller can use to tell not only the engine speed (that part is easy) but the physical location of the crank shaft? let's say we have a tooth on the crankshaft that passes the sensor at 60 degrees before TDC and it produces 3-5 volts peak to peak at 1000 RPM's, but maybe as much as 60 or 80 volts peak to peak at 7000 RPM. I can understand how simply counting the frequency can lead to the engine RPM, but how does the A/D conversion work so that you can assign that event to an actual crank location?