GB466131A - A method of and means for obtaining the sum or difference and angular relation between quantities which may be represented by coplanar vectors - Google Patents

Abstract

466,131. Electric signalling systems. ELLIOTT BROS. (LONDON), Ltd., and HAWKES, H. D. Nov. 22, 1935, No. 32398. [Class 40 (i)] [Also in Group XIX] In a system for obtaining the resul. tant of vector quantities the magnitude of the vectors are represented by alter nating currents anc the angles between the vectors by the phase relationship! of the currents, the currents being superposed in a single circuit including instruments for indicating the magnitude and direction of the resultant. As shown, a phase-shifting transformer 5, 6, 7 is supplied from a two-phase source 1 .. 4. A potentiometer 10 is connected across one phase 1, 2 and is adjusted in accordance with the magnitude of one of the vectors to be summoned. A potentiometer 9 is connected to the rotatable secondary winding 7 which is set in accordance with the angle between the vectors and the potentiometer is adjusted according to the magnitude of the second vector. The potentiometers supply the windings 11, 12 of a summation transformer 13 having a secondary circuit including a current meter 15 and the current coil of a power factor meter 14 the voltage coils of which are supplied from the mains 1 .. 4. The phase angle between the vectors is determined by measuring the phase angles of the secondary current relative to the supply mains 1 .. 4. If it is desired to measure the angle relatively to an arbitrary axis the power factor meter may be supplied from a source which is correspondingly phase displaced relatively to the supply 1 .. 4. The system may be used for determining the true velocity and direction of the wind from a moving vehicle, such as a ship. In this application, the winding 7, set in accordance with the direction of the wind, supplies one winding of an apparatus such as is described in Specification 405,043 and comprising two magnetic circuits linked by a shaped movable coil which is adapted to vary the linkage. The shaped coil is adjusted in accordance with the apparent wind velocity by current derived from an ancometer and the output from a winding or the second magnetic circuit may supply a circuit including an ammeter and a power factor meter. A current component proportional to the speed of the vehicle is also superposed by a transformer in the indicating circuit. Wind direction relative to the true north may be ascertained by interposing in the supply to the direction indicator a compass controlled phase shifting transformer. The Provisional Specification states that the scale of the direction indicator may be adjusted in order to determine direction relatively to the true north. Specification 413,804 also is referred to.