GB638971A - Improvements in or relating to flux valve magnetic compasses - Google Patents

Abstract

638,971. Gyroscopic apparatus. SPERRY GYROSCOPE CO., Inc. Dec. 10, 1941, No. 15940. Convention date, Nov. 20, 1940. [Class 97 (iii)] [Also in Groups XXXVI and XXXVIII] A gyro compass is controlled by a stabilized magnetic compass of the flux-valve type. In one arrangement for aircraft, the flux valve, which may be carried by a pendulum or by the rotor bearing casing of the gyro, is connected to the rotor of a Selsyn receiver, the output of which, after amplification, controls a relay 36 polarized by a coil 37 which is fed by current of the same phase as the compass but doubled in frequency. This relay controls an induction motor structure associated with one of the horizontal trunnions so as to produce a torque for causing the gyro to precess, carrying with it the rotor 28 of the Selsyn, until it is in the magnetic meridian, the Selsyn output then being zero. During turns, the compass is disconnected from the Selsyn by a switch controlled by the rate-of-turn gyro. In another arrangement, in which the compass is part of an automatic pilot system, operation of a handle 53 for changing the course, rotates the compass 41 and the follow-up disc 56, the compass being disconnected by a centrifugal switch 50 while the handle is operated. The craft, in known manner, takes a new course by the operation of a pilot motor until the follow-up disc resumes its previous position in relation to the shaft 30<SP>1</SP> carried by the gyro. Thereafter, the gyro is kept in agreement with the compass by similar means to that previously described except that the Selsyn is omitted, the differential relay being controlled directly by the amplified compass currents. The magnetic compass may be carried by the gyro, in which case the Selsyn 23 is not mechanically coupled to the gyro rotor. Specification 599,428, [Group XXXVI], is referred to.