GB880227A - Means for coupling between the rotating and fixed parts for an electric signal transmission system - Google Patents

Abstract

880,227. Capacitors. NIPPON ELECTRIC CO. Ltd. Aug. 21, 1959 [Aug. 27, 1958], No. 28648/59. Class 37. [Also in Group XL (c)] In a rotary coupling of capacitive type in which a capacity value of near infinity is achieved by means of a negative impedance converter compensation for slight variations in capacity during rotation is also provided (see Group XL (c)). For this purpose it is necessary to arrange for each coupling to include three separate coupling capacitors whose construction is such that any variation of capacity during rotation is as nearly as possible the same in each. Fig. 5 shows a construction for three coupling capacitors 3, 6 and 7 in which cylindrical electrodes 3b, 6b, 7b rotate with a common shaft and fixed cylindrical electrodes 3a, 6a and 7a surround them. In another construction the electrodes are of annular form, each set arranged concentrically on a common disc. Fixed and rotatable discs are arranged parallel and in alignment to form the coupling (Figs. 6a and 66, not shown). This latter construction may be elaborated by dividing the annular electrodes into radial bands on the moving disc as shown in Fig. 6c. If the fixed disc has a single similar band switching from a plurality of circuits on the moving part to a single one on the fixed part can be effected. For more complex switching the fixed disc may be the same as the moving one.