This project is my pride and joy. Ford was charging an incredible amount for the sensor. It was a troubled design from Infineon made with old technology. I knew that Allegro Microsystems had a new Hall Effect IC that would tune itself for the in situ air gap, making design a snap. We were projecting a savings of 1.3 million dollars in a year from industrializing this sensor, so time became very costly - every day not selling the aftermarket part would be worth a great deal.
The first task was to get a truck and try out the new sensor as fast as possible.. We picked up a used one for $17K in Raleigh. Images 1 and 2 are of the first "down and dirty" prototype. A machined hull similar to the lower half of the OEM part was made with a hole for the Allegro. The IC was wired up and soldered to the connector cut from a failed OEM part. The screw terminal made a way to take data from the sensor. We put in the rough sensor and hte truck fired up immediately and appeared to run just fine. Next we tried a bit harder to locate the IC as we would put it in the redesigned part (image 5). Meanwhile a tester was built to acquire date from a set of OEM parts for a baseline, and the new prototype compared in that way. It was also placed on the truck and driven for a couple hundred miles. |