An Improved Meter or Apparatus for Registering the Consumption of Alternating Electric Ourrent.
Year: 1896

page_text: Date of Application, 17th Aug., 1896-Accented, 19th June, 1897
COMPLETE SPECIFICATION.
An Improved Meter or Apparatus for Registering the Consumption
of Alternating Electric Ourrent.
I, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicate: to me from abroad hiv Messrs. Hartmann and Braun of Frankfort-on-
the-Main, in the Gorman Empire) and in what manner the same is to be perforined
to be particularly described and ascertained in and by the following statement:-
This improved moter or registering apparatus is based upon the principlo, laid
down by Ferraris, that a short-circuited rotatable armature rotates under the
influence of intersecting fields due to alternating electric currents, whenever such
fields are displaced in relation to each other in the phaso.
Referring to the accompanying drawings
.
Figuro 1'shews in cross section ono arrangement of apparatus according to this
invention,
Figure 2 is a general elevation of the apparatus and Figure 3 shows in and elevation
a modification thereof.
An electro-magnet M, with a core consisting of iron plates or laminations, is
almost closed, magnetically, by an armature A, also constructed of iron plates or
laminations, there being only left a sufficient space for a drum, barrel or cylinder C,
nade of good conducting material, such as copper or aluminium, for example, and
mounted on centres so that it can rotate between the ends of the magnet M and
of the armature A. The main current field is generated by solenoid coil S, the
lines of force of which cross those of the electro-magnet M at right anglos, and
encounter a proportionately great magnetic resistance in the iron plates extending
at right angles to thein.
By this arrangement two fields-approximately at right angles to each othor-
are generated, one of which is formed by the electro-magnet M, and the other
by the solenoid S; both being considerably displaced in relation to oach other in the
phase in consequence of the very powerful self-induction in M, and of the slight
self-induction-in S-and adapted to impart continuous rotary motion to the drum O
which motion is transferred to a rogistering apparatus by means of a worm and
worm-wheel as indicated in Fig. 3.
To improve the action two copper frames R, surrounding the revolving drum C,
as shewn in Figure 1, may be so arranged as to be capable of a certain displacement,
both rotary and sliding, relatively to such drum. Both the druin O and the magnet
system M induce currents in the same, and the field, which is yielded by the said
frames R as a result of such induction, and which is displaced in relation to the
field of S far beyond 90°, combines its direct action npon the drum with the action
of M, thereby producing a general effect such as would correspond to a field showing
a phase-displacement more marked than that which is actually displayed by M.
Besides, by turning and sliding the frames R, the values of the components of
efficiency which the said frames are capable of yielding may readily be varied in
such a manner that the aggregate effect produced by Maud R is the same as that
which would be produced by a single field displaced to the extent of 90° in relation
to the field of S.
The same object may be accomplished without the copper frames R by the employ-
ment of a small sized transformer T, as shewn in ond elevation in Figure 2, which

page_text: should be so connected with the windings of M that a portion of the latter may
communicate with the primary winding and the remaining part with the secondary
winding of the said transformer. Then the current which is branched off to the
lamps or the like in "parallel" will proceed from the pole through part of the
magnet-convolutions; next through the primary winding of T; and thence to
the opposite pole; while the remaining convolutions of M, on either side will join
the secondary coil of T. In this case the very marked displaced secondary current
in T jointly with the currents branching off from the poles direct, form a field
within the gap of the magnet M; which field-by adequately determining the
numbers of the respective convolutions-may readily be caused to be displaced with
regard to the main current field at an angle of 90° or upwards.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A meter or apparatus for registering the consumption of alternating electric
current based on the principle of Ferraris wherein, in order to bring about great
phase-displacement of the magnetic fields produced on a rotatable armature respec-
tively by the main current winding and the tension winding in relation to each
other, the latter field is generated by an electro-magnet consisting of thin plates, and
nearly closed magnetically by an armature while the first mentioned field is crented
by a solenoid coil substantially as hereiubefore described.
(2.) A meter or apparatus for registering the consumption of alternating electric
current, based upon the principle of Ferraris and arranged in accordance with the
preceding claim wherein there are combined with the rotatable armature, frames
such as R the position of which can be altered or adjusted the induction currents
of the said frames having a direct action upon the said armature and bringing about
phase-displacement of more than ninety degrees between the field of the armature
and that of the main current solenoid coil.
(3.) A meter or apparatus for registering the consumption of alternating electric
current, based upon the principle of Ferraris and arranged in accordance with the
preceding first claim wherein, with a view to producing a phase-displacement of
exceptional magnitude between the two operative fields, the winding of the laminated
electro-magnets is connected in series partly with the primary coil and partly with
the secondary coil of a transformer substantially as hereinbefore described.
Dated this 17th day of August 1806
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.