GB1068474A - Automatic steering apparatus for ships - Google Patents

Abstract

1,068,474. Automatic steering control. DANSK AUTOMATISK ROR-KONTROL AS. May 22, 1964 [May 25, 1963], No. 21323/64. Heading G3R. In an automatic steering control system for a ship, an electrical network connected to the pick-off of a compass, arranged outside the wheelhouse, has a distribution of potential indicative of the course of the ship and adjustable pick-off means connected to a rudder controller. As shown, alternating voltage from an oscillator 33 is applied between electrodes 19, 20 carried by the float of a magnetic compass so that the relative phases of the potentials of electrodes 26-29 located in the conductive compass liquid are dependent on the heading of a ship carrying the compass. The potentials of electrodes 26-29 are applied through cathode follower stages 46-49 to a circular resistance element 34 having sliders 40, 41 which are set to correspond with a desired course. Deviations in one sense or other from the desired course then produces a voltage of one phase sense or the other which is applied through a de-modulator 42 to correct the heading by servomotor control of the rudder (not shown). Course setting resistor 34 may be located in the wheelhouse while the compass is kept in a more suitable location and viewed through a periscope. Additional shunt resistors 44 may be associated with resistor 34 to compensate for non-linearities in the compass potential distribution. Each pair of potentials applied to resistor 34 serves to energize through de-modulators 50, 51 one coil of a two-coil moving coil course indicator 52. The arrangement of compass elements and the method of supplying current to them is illustrated in Fig. 1 (not shown). Use of circular resistor or light responsive compass pick-offs instead of the conductive liquid arrangement is referred to.