US698652A - Electric meter. - Google Patents

Description

Patente'd Apr. 29, I902.

T. DUNCAN.

ELECTRIC METER.

(Application filed Aug. 28, 1899.)

2 Sheets$heet I.

(No Model.)

Fig. 2.

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No. 698,652. Pat e nted Apr. 29, I902.

' T. DUNCAN.

ELECTRIC METER. (Application filed Aug. 28, 1899.; (No Model.) 2 Sheets-Sheet 2.

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UNITED STATES PATENT OFFICE.

THOMAS DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SIEMENS & HALSKE ELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

ELECTRIC METER.

srnomxoarro v forming part of Letters Patent No. 698,652, dated April 29, 1902.

' Application filed August 28, 1899. Serial No. 728,690. on model.)

To all whom. it may concern:

Be it known that I, THOMAS DUNCAN, of Chicago, in the. connty'of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Meters; (Case- No. 60,) of which the following is a specification.

This invention relates to improvements in.

induction motor-meters for alternating-current work, and particularly to means for Ob? taining in such meters a magnetic field in quadrature with the electromotive force which it represents.

The invention consists in the matters hereinafter described, and particularly pointed outin the appended claims, and will-be fully understood from the following detailed description of the constructions illustrated in the accompanying drawings, in which- Figures 1, 3, and 4 are diagrammatic views of meters embodying my invention. Fig. 2

. isa vector diagram of the essential current tions.

.coil between the terminals (1 and d of the.

main shunt-circuit. This resistance R is so connected as to'include more or less of the turns D of the coil or coils l) and may be said to complete a subordinate circuit in which such included turns D are in series with said resistance and with the volt field-coil 0.

As shown in Fig. 1, the impedance-coil D consists of two separate sections or coils each connected with one of theterminals c cv of the coil 0, and the resistance R isconnected' to include a portion ofthe turns of bothsec- In Fig. 3 the construction is similar, except that the'common core d of the impedance-coil is an annular ring instead of a straight bar. In this figure also an adjustable switch 1' is shown as provided between one terminal of the resistance E and the adjacent coil D to permit more or less of the turns D of the latter to be cut in or out, as desired. In Fig. 4 the impedance-coil is a single coil, which the shunted resistance It connects directly to the terminal cl of the main shunt, to which latter the terminal a.

current to the coil 0,. as it wouldnatnrally be lagged by the impedance-coil. The line E. represents the counter electromotive force set up in the-turns D'by the inductive action ofthe current Fand the line f the current which this counter electromotive tends to set upin the subordinate circuit formed by the resistance R, turns 1), and coil C. This current combines with the currentF to form the resultant current F, which by proper proportioning andadjustment maybe made to lag the exact ninety degreesdesired.

I claim as my invention-=- 1. The combination, with the armature, se-

ries and volt field-coils, and impedance-coil in series with the volt field-coil in a shuntcircuit across the line, of a resistance connected in said shunt-circuit in parallel with the field-coil and including the turns of the impedance-coiL. v 1

2. The combination, with the armature, series and volt field-coils, and-impedance-coil in series with the volt field-coil'in a shuntcircuit across the line, ofa resistance connected in said shunt-circuit in parallel with the volt field-coil and forming therewith a closed circuit including a portionof the turns of the impedance-coil.

3. The combination, with the armature, series and volt field-coils, and impedance-coil in series with the volt field-coil in ashuntcircuit across the line, ot a resistance connected in said shunt-circuit in parallel with the volt field-coil and forming therewith a closed circuit including a portion of the turns .of the impedance-coil, and means for varying the number of the included turns.

zoo

4. Ihe co mbina tioh, with the arniatur; se

in shunt of one of the windings, including turns of'the impedance-coil and formingtherewith a closed. circuit, substantially as described.

In testimony that I claim the foregoing as myinvention I afiixnry signature, inpresence of two subscribing witnesses, this 23d day of August, A. D. 18.99; v y

i THOMAS DUNCAN.

Witnesses:

'- VWILLIAM F. MEYER,.

DAYTON N. PETTIT.

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