Morning all. Hope everyone is safe.
In what i believe to be SD etiquette, i have searching for an answer to this question for over a year now. I have searched online, and technical textbooks during this time, and asked some technical people. I’ve decided to ask the SD brains to see if anyone has any knowledge of this.
I understand the Hall-effect (Lorentz force in semiconductors when in presence of magnetic induction). But how do two-way hall-effect sensors work?
i have technical documentation (from Renault) that talks about a two-way Hall-effect sensor that senses crankshaft position (via a target on the flywheel). It transmits a 45 microsecond square-wave signal when the engine rotates in normal direction but then transmits a 90 microsecond signal when the engine rotates backwards (on shut down, the compression in the engine causes a natural ‘kick-back’, so this type of sensor will allow very precise determination of crankshaft position for rapid restart of the engine (Stop-Start capability)).
I want to know for sure how this works (cos i’m pig-headed).
As I said, I’ve tried to find a definitive answer. The only thing that i can think could work is an increase in current to the sensor (as i understand it, the Lorentz force is proportional to current supplied to the semiconductor so a different voltage would be produced if, on engine shutdown, the sensor was informed and the processing unit within the sensor switched to a higher/lower current supply to the semiconductor. The sensor can then monitor the number of signals at this different voltage then the sensor processing unit converts that to a longer (90 microsecond) signal which is then sent back to the engine ECU).
Any help would be great. And please correct me if i’m wrong in any of my assertions in this post.
If no-one can, i guess i haven’t lost anything by asking…
