. Electrical world. in power factor values. The principles on whichMr. Carcano, electrical engineer in charge of the Milan EdisonCompanys testing department, has designed his method, are as fol-lows : In an apparatus like the one shown in Fig. i, consisting of a discwhich can rotate under the influence of a revolving field due to asystem of coils, the n;otion will cease the moment all the currentsflowing through the different coils have the same phase; therefore, ifa number of coils are connected in series in the circuit, and anothernumber of them in shunt, the motion will cease when the curre
. Electrical world. in power factor values. The principles on whichMr. Carcano, electrical engineer in charge of the Milan EdisonCompanys testing department, has designed his method, are as fol-lows : In an apparatus like the one shown in Fig. i, consisting of a discwhich can rotate under the influence of a revolving field due to asystem of coils, the n;otion will cease the moment all the currentsflowing through the different coils have the same phase; therefore, ifa number of coils are connected in series in the circuit, and anothernumber of them in shunt, the motion will cease when the current, i,which flows through the coils connected in shunt, are in phase withthe current, /, of the principal circuit. Now, for a given shunt coilhaving such a ratio between reactance and resistance as to cause thecurrent, j, to lag by an angle 9 behind the applied to its ends,such condition will be realized when the principal current, /, lagsbehind the acting in the circuit, by an angle 0^9. (SeeFig. 2.). FIG. I.—DI.\CR.\M OK .\rPAR.\ BOOKS RECEIVED. Manuale Practico PER LOperaio Elettrotecnico. By G. : Ulrico Hoepli. 337 pages. 189 illustrations. Price, lire. It follows that if we have at our disposition a coil or a numberof coils in shimt, in which the ratio between reactance and resistance,or the angle 9, can be varied, it is quite possible to balance any value 632 ELECTRICAL WORLD and ENGINEER. Vol. XLIII. No. i8. ol fi. We can, therefore, for any value of the power factor, obtaina zero position of the disc by altering the value of 6. If the methodof altering the angle 6 enables us to know at any moment its value,we can at once read the angle O, corresponding to the angle fi. Itis possible to obtain for any value of 0 the current / in phase with /,without making an alteration in the shunt coils by applying to them,for every value of fi, a voltage taken from the opposite points ofthe circuit, in such a manner that the displacement between su
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
