GB435397A - Improvements in or relating to electrical power measuring means for prime movers - Google Patents

Abstract

435,397. Power meters. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and DAVIES, E. C., c/o General Electric Co., Witton, Birmingham. March 16, 1934, Nos. 8346 and 15668. [Class 37] The output of a prime mover is measured by an electrical instrument responsive to the output of a constant voltage generator driven by the engine, the instrument having at least one coil the current through which depends on the setting of the field regulator. this coil being energized from a circuit of the generator. In the form shown, reduction of the excitation of the field winding 2 reduces the current in the differential coil 16 on the wattmeter 4 which also has a voltage coil 15 and a coil 5 carrying the load current of the generator 1. The position of the slider 8 on the rheostat 7 varies with that of the slider 9 on the main field resistance 10. Instead of the coil 16 being connected as shown, it may carry the field current or a current proportional thereto, whilst in a further modification it is replaced by a cumulative coil carrying a current inversely proportional to that of the generator field winding. In place of a wattmeter, an ammeter may be used, its current being party dependent on the exciting current, for example by passing the field current through a differential coil on the instrument.