Magnetic compass assembly with direct digital read=out - comprises hall effect sensors maintained in Cardan mount in orthogonal axes driving digital resolver

摘要

The arrangement has three Hall effect sensors mounted in orthogonal axes on a Cardan mount system. The forward axis is aligned with the vehicle axis. Each cell (6) is subjected to the field having a component perpendicular to the plane of the cell and is powered from an oscillator providing a supply current (I). The output voltage (V) is applied to a differential input amplifier (7) driving two windings (8,9) in series with a resistor (10). One input on the amplifier is driven from the common point between one coil (9) and the resistor. These coils produce a magnetic field perpendicular to the cell plane to annul the perpendicular component of the magnetic field at the cell. A digital resolver is connected to the resistors enabling the angle to be determined.