GB190922922A - Improvements in Electrical Energy Meters. - Google Patents

Abstract

22,922. Siemens & Halske Akt.-Ges. Oct. 8, 1908, [Convention date]. Commutator motor meters power meters.-An energy or power meter has two or more armatures k<1>, k<2> connected together so that their turning moments are opposed to each other; permanent magnets m are arranged to act on the fields of electro-magnets s<1>, s<2> so as to strengthen one field and weaken the other. The magnet coils are connected between the mains, and the armature coils may be connected across the terminals of a resistance in the main circuit, either in series or parallel with each other. An air-gap r in one of the soft-iron yokes i reduces the errors due to hysteresis. To compensate for the effect of varying permeability, the field-strengths of the magnets s<1>, s<2>, when without current, are made different by making them of different forms or materials, or with different airgaps, or by using magnetic shunts, which latter may be adjustable; or the currents in the armature coils may be made different by means of shunts. Accordiog to the Specification in the original form, as open to inspection under Section 91 (3) (a), the magnets may be excited by the main current, and the armature coils connected between the mains ; this subject-matter does not appear in the Complete Specification as accepted.