An improved apparatus for the measurement of the power factor in electric circuits

摘要

422,169. Power-factor measurements. LANDIS & GYR AKT.-GES., 1, Hofstrasse, Zug, Switzerland. July 14, 1934, No. 20683. Convention date, Aug. 31, 1933. [Class 37] Apparatus for power-factor measurements comprises a Ferraris instrument energized by currents proportional to the voltage and current of the circuit these currents being maintained constant by known means. The instrument may be a motor meter effecting impulse transmission or a wattmeter giving direct indication. The secondary 3 of a current transformer shunted by a resistance 11 is in series circuit with a resistor 4 driven by a synchronous motor 17, current coils 6 of an I2-hour meter 7 and current coils 8 of the Ferraris instrument. The ohmic resistance of the current circuit is large compared with the inductance resistance in order to maintain the current phase relationship. An iron-hydrogen resistor 15 is employed to keep the pressure constant.