Patent GB-447707-A (GB)
Title: Method of and system for determining positions by means of a rotating radio beacon
IPC: G01S1/44
Filed: 1935-04-17
Abstract: 447,707. Electric signalling systems. LORENZ AKT.-GES., C., 1, Lorenzweg, Tempelhof, Berlin. April 17, 1935, Nos. 11864, 11865, 11866, and 11867. Convention dates, April 19, 1934, Aug. 10, 1934, Nov. 28, 1934, and Nov. 30, 1934. [Class 40 (i)] [See also Group XL] Relates to systems for utilizing the beam sent out by a rotating beacon of the type in which anequi-signal line is produced between two regions in which differing and alternate signals are radiated, such as those described in Specifications 405,727 and 438,446, [both in Group XL], and is characterized in that the number of signals of each kind received between pauses in the transmission occurring after one or more complete beacon rotations is counted separately, the bearing being obtained by substituting these numbers a, b in the formula gamma=90 - b - a/2 f where gamma is the angle in degrees from the zero signal and f is the number of degrees per signal. The forms of the signals used I, II are shown in the upper part of Fig. 2, the lower part showing the resulting impulses after the signals have passed through a transformer T, Fig. 3. Thus pairs of oppositely directed impulses are produced, the direction, of the first impulse determining which kind of signal is being received and which one of a pair of counter windings is energized. The output of the transformer T is in one embodiment, Fig. 3, applied to two series-connected oppositelypolarized relays R1, R2, the first of a pair of impulses operating one of them, e.g. R1 which closes its contact r1<11> to energize the counter winding Z1 and its contact r1<1> to short-circuit the other relay R2. The second oppositely directed impulse is ineffective owing to the short-circuiting of relay R2 which is removed only after the second impulse has ceased. Thus the different signals are distributed to the counter windings Z1, Z2 and the sum of each may be separately indicated or the subtraction made automatically and the bearing indicated directly by a common indicator moved in opposite directions by the two kinds of signal. In a second embodiment a single polarized relay R, Fig. 4, causes the discharge of a condenser C through the windings Z1 or Z2 depending on whether the contact r<1> or r<11> is closed by the first of a pair of signal impulses. The second oppositely directed impulse has no effect as the condenser is not charged by the time it arrives. In a modification of this arrangement, Fig. 5 (not shown), holding windings are provided on the relay R and connected in series with the coils Z1, Z2. In a further embodiment, Fig. 6, the condenser C is discharged through one of the windings Z1, Z2 depending on which of the valves Rl, R2 is rendered conducting by the first of a pair of signal impulses. Alternatively, a pair of grid-controlled gas or vapour filled valves may be arranged in a similar circuit to be trigged by the signals. The counter or counters may be returned to zero manually or by clockwork during the pause between one set of signals and the next, or by a particular signal from the transmitter. To eliminate errors, the polarity of the input transformer and counter windings may be reversed in the pauses by similar methods.