GB572285A - Improvements in or relating to electricity meters - Google Patents

Abstract

572,285. Supply meters. COMPANIA PARA LA FABRICACION DE CONTADORES Y MATERIAL INDUSTRIAL, and VITEAU, P. Feb. 18, 1944, No. 3066. [Class 37] In a direct-current ampere-hour meter comprising a permanent magnet disposed concentrically inside a soft iron cylinder and separated therefrom by a gap in which a movable element can turn around the magnet, and terminals for supplying current to the movable element, the magnet and the supply terminals are relatively displaceable in order to vary the motor couple for regulating the meter. In the mercury motor meter shown the permanent magnet 1 is in the form of a straight bar and has its magnetic circuit closed by a soft iron cylinder 2. Alternatively a cylinder magnetized transversely to its axis may be employed. In the gap between the poles of the magnet 1 and the cylinder 2 rotates a bell 3 of copper or other material of low resistance. The current to be measured is passed between terminals 4, 5 through the mercury and the bell. The magnet 1 is arranged to turn solid with a screw 6, so that it can be displaced relatively to the terminals 4, 5 for regulating the torque of the meter. The regulating device is also applicable to ampere-hour meters of the commutator type. Instead of displacing the magnet concentrically in relation to fixed current terminals, the two current terminals may be displaced concentrically in relation to a fixed magnet, or a single current terminal only may be displaced.