Method of calibrating and zeroing stepper motor gauges
US5665897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1996 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Aug 9, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R7/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rotary gauge driven by a stepper motor has a stop near the zero point of the gauge graphics. A factory calibration procedure rotates the gauge field in reverse direction to move the gauge pointer against the stop and continues field rotation until the rotor becomes unstable and flips back in the forward direction, and then moved to a rotor rest position. The angle of flip back, the rest position and the number of steps to the zero position are stored in non-volatile memory. In the vehicle, when the ignition is off, the microprocessor or the stepper motor wakes periodically and exercises the gauge, using the stored values to reset the gauge to the stable position. When ignition is turned on, the microprocessor moves the gauge directly to the zero position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.