GB751137A - Improvements relating to a radar auto-follow apparatus - Google Patents

Abstract

751,137. Transformers. NAAMLOOZE VENNOOTSCHAP HOLLANDSE SIGNAALAPPARATEN. March 25, 1954 [March 26, 1953], No. 8771/54. Class 38 (2). [Also in Groups XXXVI and XL (c)] In a radar system (see Group XL (c)), the video output from the receiver is coupled sequentially to a plurality of output circuits by means of an electromechanical inductive distributer synchronized with the aerial scan. In Fig. 1 the distributer comprises a non-magnetic conductive disc 102 and two diametrically disposed transformers 103, 104, each comprising primary and secondary coils 105, 106 and 107, 108 wound on separate ferrite cores mounted perpendicularly to and on opposite sides of the disc, the two cores of each transformer being interconnected by a ferrite U-piece. The video output from the receiver 117 is applied in series through the primary coils 105, 107 and the secondaries 106, 108 are connected respectively to output circuits 110, 109. The disc 102 is mounted on the rotating aerial feed 101 and a segment of the disc is cut out or slotted so that coupling between the primary and secondary coils of each transformer is effective only once per revolution when the cut-out or slotted segment is interposed between the two cores. The disc 102 may have a plurality of symmetrically disposed cut-out segments and/or more than two angularly spaced pick-up transformers may be provided, Figs. 2a and 2b (not shown). In a modification, Fig. 4, the coupling segment of the disc comprises magnetic material 401 which passes mid-way between the cores of the primary and secondary coils. The non-coupling segment may comprise an annular segment 402 of magnetic material which just clears the primary core and the U-piece thereby providing a magnetic short circuit; in this case the conductive disc may be omitted. In a further modification, Fig. 3 (not shown), the disc is replaced by an arcuate plate mounted on a reed which is vibrated by an electromagnet and in Figs. 5a and 5b the receiver output is coupled to a coil 501 which is mounted on an arm 511 attached to a rotating shaft 510 so that the coil 501 is coupled sequentially to stator coils 502-505 connected to the output circuits. The coil 501 is coupled to the receiver by means of a rotary inductive coupling comprising a fixed coil 506 mounted on an E-shaped core 507 and a coil 509 and disc 508 mounted concentrically on shaft 510; alternatively slip rings may be employed.