GB222725A - Improvements in or relating to electricity meters particularly induction watt-hour meters - Google Patents

Abstract

222,725. White, A. E., (Sangamo Electric Co.). Dec. 18, 1923. Induction motor meters.-An induction watthour meter has a series electromagnet 30, Figs. 3 and 6, and a shunt electromagnet 35 with a central leg 40 between the pole pieces 38, 39; phase compensating means are provided and consist of a coil 50 on the leg 40 in the air gaps and' a resistance 51 connected across the ends of the coil. These means are adjusted to ensure that the flux in the air gaps is in exact quadrature with the impressed voltage. The rotatable disc 52 passes between the two magnets 30, 35 and also between the poles of two damping permanent magnets 77, 78, Figs. 7 and 8, associated with which is a soft iron disc 83, Figs. 5 and 7, on an adjusting screw 84. The upper end of the disc spindle 55 has an elongated journal of reduced diameter in a sleeve in an adjusting screw 63 and motion is transmitted to the indicators in the usual manner. The indicator driving train is supported by plates 69, 70 held in place by means of a U-shaped plate 72 with ends turned up at right angles to the body of the plate and passed through slots in the plate 70 where they are locked by latches 74. A flat single turn coil 87 forms a light load adjustment member. It is placed in the space between the electromagnets and can be moved transverselv by a micrometer screw 88, Fig. 8. A closed conductor loop 95 may be placed on the shunt magnet.