Improvements in and relating to an arrangement in magnetic compasses for producing acontrol signal dependent on the angular position of the compass magnet

摘要

990, 214. Electric control systems. DANMARINE (DANAVIA A. S) A.S. April 30, 1963 [May 7, 1962], No. 16978/63. Heading G1N. An arrangement for producing an electrical signal, dependent upon the angular position of a compass magnet 1, comprises four identical coils 2, 3, 4, 5 arranged on a plurality of rectangular hysteresis loop magnetic cores 6, 7, 8, 9 outside the compass bowl, the coils being connected in a bridge circuit comprising a pair of input terminals 12, 13, fed with A.C., and a pair of output terminals 14, 15, the coils being symmetrical in pairs relative to the axis 18 of rotation of magnet 1, and the axes of the coils lying in a plane perpendicular to axis 18. The output may be applied to steering gear 17. Preferably the bridge is balanced when the axes of the coils lie at 45 degrees to the N-S direction of magnet 1: If device 17 responds to the second harmonic of the supply voltage the winding directions of the coils may be selected so that the second harmonic voltage is zero at the 0 degrees position. The coils and cores are mounted on a support which is rotatable about axis 18 through an operating member, preferably through reversing gearing. It is stated that the output at 14,15 is unaffected by tilting of the compass card due to heeling of the ship. A capacitor 20 may be used to make the output signal substantially sinusoidal.