An Improved Method of and Apparatus for Compensating for Variation of Current due to Variation of Resistance Arising from Changes of Temperature in Windings such as Field Windings of Dynamo-electric Machinery, Solenoids and the like.

摘要

22,159. Stansfield, W., and Hatt, J. J. Oct. 20. Dynamos, regulating; field magnets; motors, controlling; electro-magnets.-Variation of resistance arising from changes of temperature in magnet windings is compensated for by arranging two opposing windings A, B, Fig. 1, on the magnets F, one B being connected directly across a substantially constant source of potential, and the other A being connected across a substantially constant source of potential in series with a resistance C the temperature coefficient of which is markedly different from that of the windings A, B. The winding A has a larger number of ampereturns than the winding B. The ampere-turns are preferably inversely proportional to the normal voltages across the windings. The winding B may be connected across the resistance C and in series with the winding A. A resistance D, Fig. 3, with a higher temperature-coefficient than the winding A may be connected in parallel with the winding A. Regulating -resistances R, Ra, Rb may be connected in series with the armature M and windings A, B respectively. The Provisional Specification also states that the resistance D may have a temperaturecoefficient equal to or less than that of the winding A.