Electronic analogue compass
US6141881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1998 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Nov 3, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C17/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An compass having an electronic magnetic field sensor and an analog directional display is disclosed wherein a signal from the field sensor proportional to one component of the earth's magnetic field is alternated in polarity and integrated to produce a triangular waveform the frequency of which is proportional to the strength of that field component and wherein a triangular waveform having a frequency proportional to the second component of the earth's magnetic field is produced in the same manner. These values are used by a microcontroller to control an air-core gauge such that a disk with reference markings attached to the gauge remains positioned with one of the reference markings facing either magnetic or true north. A resistor ladder network is also connected in parallel to the inputs of the integrators and controlled by the microprocessor through a shift register in order keep the integrators out of saturation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.