Abstract: An angular position transducer which determines rotation of a shaft from zero to 360 degrees using a polarized disc with coded tracks, a light source and light detector, and various processing devices to convert an analog signal generated by polarizing light into a discrete output signal.

Abstract: A magnetic compass comprises: a gimbal mounted direct read card supported on a bearing in the equatorial plane of the compass in a compass bowl; and a housing having a base to which the compass bowl and corrector magnets are mounted; the corrector magnets being positioned above the base beside the bowl for access without moving the compass; means for supporting the corrector magnets located on three axes, one axis parallel to the lubber line and the equatorial plane of the compass in a horizontal orientation of the housing, a second normal to the lubber line and parallel to the equatorial plane and a third normal to the equatorial plane in a horizontal orientation of the housing and parallel to the lubber line and the equatorial plane in a vertical orientation of the housing; said corrector magnets mounted on two of said axes, said second axis and the one of said first and third axes parallel to said lubber line in the horizontal or vertical orientation selected for mounting said compass; the compass card ass

Abstract: A small, light magnetic compass, in which the magnetic moment of the compass card is large relative to its weight, is adjustably mounted upon a member firmly coupled to the human head so that accurate compass bearings may be obtained, or a vessel steered, through an optical system presenting a magnified image of the compass card to the eye of the wearer.