GB1306792A - Apparatus including displacement-responsive inductive-transducers - Google Patents

Abstract

1306792 Measuring angular displacement electrically SMITHS INDUSTRIES Ltd 24 Jan 1972 [27 Jan 1971] 3310/71 Heading G1N A rate gyro 10, Fig. 1, rotating about a spindle 11 is supported in a gimbal structure 1 for rotation about a perpendicular axis 3, whereby an angular velocity of the assembly about a mutually perpendicular axis 13 produces an angular displacement of the gimbal structure about axis 3, which is measured by a variable coupling inductive transducer 7 incorporating a temperature compensation network. The gimbal structure 1 is supported by bearings 4, 5 and a torsion bar 6. The transducer 7 comprises a 12-pole stator 8, Fig. 2, fixed to the main housing 2 and a 6- pole rotor 9 mounted on the gimbal structure 1. The stator is wound with a primary winding 21, embracing the poles in pairs with adjacent pole pairs wound in opposite directions, and a secondary winding 22 wound,similarly to the primary winding 21 but displaced by one stator pole pitch. Hence displacement of the rotor 9 through 60 degrees produces one complete amplitude cycle of induced voltage in the secondary winding 22 as the poles or rotor 9 vary the coupling between the primary and secondary windings. To compensate for errors produced by variations in temperature, a further secondary winding 29 is wound with the primary winding 21 and its constant voltage is combined with that of the secondary winding 22 in a circuit, Figs. 3 and 4, (not shown), which includes a thermistor, and is arranged to compensate for changes in the output with zero angular velocity input about axis 13 and for changes in the output scale factor.