establishment of the digital winkelwerte spend a resolver

摘要

971,715. Electric selective signalling systems. GENERAL PRECISION Inc. Jan. 24,1962 [Feb.10, 1961], No. 2675/62. Heading G4H. Sine and cosine voltages of an angle # produced for example by a synchro are converted into a binary representation of the angle by sequentially attenuating the larger of the two voltages until it equals the other, the sequential attenuations being equivalent to multiplying the larger voltage, say the cosine, by a sequence of values starting with 45 degrees and converging towards tan #, whereupon the attenuated cosine voltage equals the sine voltage since cos #.tan # = sin #. This process determines the angle within any one of the eight octants, the particular octant being determined by logic circuits from the signs and relative magnitudes of the two voltages. As described the sine and cosine voltages are produced by a circuit 99, Fig. 5, and are applied to a comparator 14, the larger passing via a resistive attenuating network initially set to correspond to an angle of 45 degrees. The switches in the attenuating network are then sequentially closed and each is either left closed or re-opened in dependence upon the result of each comparison. The final condition of the switches represents the angle within a range of 45 degrees. The particular octant in which the angle lies is determined by logic circuitry (Fig. 11 not shown) and provides an additional three more significant binary bits which together with the bits produced by the attenuating network specify the angle within the range 0 degrees to 36 degrees. Specification 971,716 is referred to.