Nam J Kim

Author:

Nam H. Kim

ISBN #:

0387233369

US Patent:

48517755, Jul 25, 1989

Filed:

Jul 2, 1987

Appl. No.:

7/069495

Inventors:

Nam H. Kim - Glendale CA
Timothy Hawks - Stanford CA

Assignee:

Precision Navigation, Incorporated - Menlo Park CA

International Classification:

G01R 3302

US Classification:

324247

Abstract:

A digital compass (20) has a sensing coil (60) wound on an elongated strip of high direct current permeability magnetic material. The sensing coil (60) is connected to a sensing circuit (56). The sensing coil and sensing circuit are responsive to the Earth's magnetic field to provide an oscillating signal at an output (28) of the sensing circuit (56) which varies in frequency with orientation of the at least one sensing coil (60) with respect to the Earth's magnetic field. A microprocessor (36) is connected to receive information inputs from the oscillating signal. The microprocessor converts the information inputs to an indication of orientation of the sensing coil with respect to the Earth's magnetic field based on the frequency of the oscillating signal. A display (52) receives the orientation indication from the microprocessor.