GB824101A - Artificial horizon repeater - Google Patents

Abstract

824,101. Electric indicating systems. SUD-AVIATION SOC. NATIONALE DE CONSTRUCTIONS AERONAUTIQUES. Jan. 13, 1956 [Jan. 21, 1955], No. 1200/56. Class 40 (1). The altitude of an aircraft is indicated at a remote point which may be on the ground or in another aircraft by roll and pitch signals derived from a gyroscopic pick-off and used to produce a line trace on a cathode-ray tube, the inclination of the trace indicating roll and the vertical deflection, pitch. As shown, air driven gyroscope 1 mounted in gimbals 3 and stirrup 5 is provided with a conventional erecting mechanism to maintain its axis vertical. Signals corresponding to roll and pitch of the aircraft are derived from potentiometers 14, 9 over which wipers are moved by the gyroscope. The potentiometers are fed from batteries 16, 17 and the output signals are taken from between a centre lip of the battery and the wiper in each case. The indicator comprises a cathode-ray tube 18 between the horizontal deflection plates 22 of which an alternating voltage is applied to generate a line trace. The same voltage is fed to potentiometer 27 the wiper of which is moved by the coil of instrument 30. The vertical deflection plates are fed from this wiper and the potentiometer centre tap and the trace is thus tilted to an extent dependent on the roll of the aircraft. The pitch signal is applied to coil 24 which displaces the entire trace vertically in accordance with the pitch of the aircraft. Variable potentiometer 27 may be replaced by a transformer with a movable primary or a pair of variable condensers the plates of which are moved by moving-coil device 30. In a modification (Fig. 3, not shown) an inductance in circuit with the vertical deflection plates produces a phase shift which makes the trace elliptical. In addition a pulse generator in synchronism with the applied A.C. brightens the trace at two spots.