Improvements in Electricity Meters or Motive Devices for Measuring Single and Multiphase Electric Currents.
Year: 1893

page_text: Date of Application, 23rd Mar., 1893-Accepted, 23rd Sept., 1893
COMPLETE SPECIFICATION.
Improvements in Electricity Meters or Motive Devices for Measuring
Single and Multiphase Electric Currents.
I, THOMAS DUNCAN, a citizen of the United States and residing at Fort
Wayne, in the County of Allen and State of Indiana, one of the United States of
America, Electrical Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The object of my invention is to provide a cheap, efficient and reliable meter
capable of measuring and recording with accuracy the amount of electrical energy
consumed in any given circuit or circuits of a simple or single phase alternating
or multiphase current system of distribution, without the use of brushes, coin-
mutator, mercury or rubbing contacts, or other current changing or rectifying
devices.
The principal elements employed in the construction of my improved electric
meter or motive device are, First, an armature of metal capable of rotation;
Second, an electric circuit or circuits so arranged that when traversed by simple
alternating or polyphase currents, a field of force is induced having a given polar
line or axis with reference to said armature; Third, an adjustable magnetic path
diverter of iron or other magnetizable metal so arranged with reference to said
field of force that secondary currents are induced in the armature in such a plane
that the repulsion between them and the inducing field will produce rotation of the
armature.
In the accompanying drawings
Figure 1 is a perspective view of one form of my improved meter embodying
the features above mentioned.
Figures 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13, illustrate modified forms of my
invention and various modes of adjusting and connecting the same in the circuit or
circuits.
Similar letters refer to similar parts throughout the several views.
In Fig. 1A and A represent the inducing coils or field connected in the work
circuit and through which passes the current to be measured.
C represents a cylinder or armature of silver, copper, aluminium or other electric
conducting metal placed within the field of force between or enveloped by the
energizing coils A and A, and so adjusted on the shaft or spindle M that it is free
to rotate on a jewel seated in the top of the jewel post J.
D represents a magnetic path diverter constructed of soft iron or thin sheets
of the same metal, and so adjusted at its centre within the cylinder or armature C
that it can be moved and adjusted to any desired angle by a tube to which it is
attached, but not shown, and down through which the spindle M also passes.
S and S are the clamping plates, the upper one of which is provided with
suitable recesses into which the field coils A and A snugly fit to prevent their
displacement during transportation.
This
U is a metal disc having a milled edge for raising the cylinder C and the spindle M
to which it is attached, out of the said jewel when not in use or in transit.
disc turns on a thread provided for the purpose on the tube before mentioned to
which the diverter D is secured.
F and F are aluminium fans of the retarding or power absorbing device which
is designed to regulate the speed of the armature in a well known manner.
G represents a guard adapted to prevent the fans from being injured by handling.
His the registering or recording mechanism of well known construction.
The supporting frame K is provided with an extension arm P adapted to hold

page_text: the registering train H in position. The revolutions of the armature C are
communicated to said train by means of a suitable worm on the spindle M which
meshes into a worm wheel arranged on the back of said train but not showu in the
drawings.
B and B are the connecting wires between the field coils A and A and the binding
posts E and E, these terminal binding posts are properly secured to a block of
insulating material L.
The back or main supporting frame N of the meter is provided with a flange V
cast thereon, over which the cover of the meter closely fits in such a manner as to
prevent the entrance of dust or insects.
The mode of operation of my improved recording electric meter above described
is as follows:
The armature C occupies the relation of a secondary of low resistance toward
the primary coils A and A, and is repelled from them.
If the path diverter D were absent and the axes of the coils A and A were in
line with the centre of the armature no rotation would take place, because the
repelling forces would be equal and opposite. The same result would follow if the
magnetic path diverter is placed with its axis in line with the axes of the primary
coils, those being in line with the centre of the armature. But the shifting of the
path diverter out of line with the axes of the coils as shown diagrammatically in
Figures 2, 3, 7, 9, 10, 11, 12 and 13, distorts the lines of force so that they cut
the armature obliquely and give the repelling force of the primary coils A and A
a tangential component which causes rotation of the armature.
The torque or turning moment of the armature increases from zero when the
path diverter is in line with the axes of the coils A and A to a maximum when it is
at an angle of about 40 degrees with that line.
Obviously reversing the angular position of the diverter reverses the direction
of rotation of the armature.
Figures 2, 3, 4, 6, 8, 9, 10, 11, and 12 are diagrammatic modifications of single
phase alternating current meters, while Figures 5 and 7 show the method of
measuring three or tri-phase alternating currents.
Figure 18 represents a motive device operating upon the same principle.
Figure 2 shows the manner in which the lines of magnetic flux emanating from
the primary coil or electro-magnet A are influenced by the adjustable magnetic
path diverter D and cause the armature to revolve as indicated by the arrow.
If
the diverter be moved towards A the speed of the armature will decrease until the
diverter D is in the same axial plane with the coil A, when rotation will cease
altogether as heretofore explained.
But if moved past this axial line rotation will again take place but in the opposite
direction.
If the diverter D be removed from within the armature C my meter is still
operative by altering the angle or position of the coil A. and causing it to approach
or face the armature C at a tangent or angle as shown by any of the three coils A
in Figure 4.
Figure 3 represents an energy or Watt meter for measuring on single phase
systems of distribution. The coils A and A are placed in series with the main
conductors carrying the current to be measured, the diverter D being wound with a
fiue wire coil and connected in shunt or multiple across the terminals of the system
of supply. A condenser T is shown in connection with the diverter, its use being
to eliminate or prevent the development of induction or counter electromotive
force, to insure accuracy in the volts or pressure factor, the same being one of the
three factors necessary for the computation of electrical energy, the other two being
the amperes and time.
The series coils A and A represent the amperes, so that any change taking place
in the amount of current through the coils A and A, or pressure between the
terminals of the diverter D will cause a corresponding change in the torque or
speed of the armature C.

page_text: The diverter core D when used in a Watt meter is preferably made from some
insulating material, such as moulded mica or other insulator not liable to warp
under the influence of heat; the iron not being necessary since the shunt winding
produces the necessary field.
The absence of iron from the shunt coil diverter D also insures freedom from
inductance, which is of importance when measuring the energy of alternating
currents.
This meter may also be used for measuring the energy consumed in a two phase
system of distribution by connecting each of the field coils A and A in the two
circuits of the system respectively. If used as a Coulomb meter the diverter D may
be of iron without the shunt coil, and if used as a Watt meter the shunt coil may be
disconnected at its centre, thereby making two coils and connecting their terminals
to the two circuits of the system in parallel arc. The methods of connecting are
well understood by those skilled in the art.
I have also used an iron cored diverter wound with a shunt or volt coil for
Coulomb meters, using the shunt in this instance for producing an auxiliary
field for the purpose of overcoming or balancing the friction and inertia of the
meter.
Figure 4 shows a Coulomb meter without a diverter, but when one is used, the
form shown in Figure 7 answers the purpose well. The points of said diverter
when turned or bent like the ends or poles of the coil A in Figure 6 give excellent
results; again, the space within the armature C may be filled by an iron core which
perceptibly increases its rotative power, and which may be made stationary with a
small clearance between it and the armature C, or it may be secured thereto and
be adapted to revolve therewith.
I have used an iron cylinder placed in the same manner within the armature C
with good results; I have also cut slots or holes through the surface of said
armature for the purpose of providing a more defined path for the secondary
currents to circulate, and insulating the iron cylinder therefrom. These field
coils A, A and A can be connected into the three circuits of a triphase system as
shown in Figure 7, but when such is donc another force is brought into action
which further increases the torque producing properties of the device, viz.: the
action of the revolving magnetic poles tending to drag the cylinder around after
them. Therefore in my improved meter or motive device when used with multi-
phase currents, rotation of the armature is due to two distinct forces working
together, viz.; The repulsion set up between the armature and the poles of the
field, and the action of the revolving magnetic field or poles dragging the cylinder
around with or after them thereby making the device more efficient than when the
revolving magnetism alone acts, as is the case with all other multiphase current
motors.
Figure 5 shows another form of triphase Watt meter measuring the energy being
consumed by the incandescent lamps W. The shunt wound diverter D is
connected in multiple arc to represent the volts while the coils A are in series in
the work circuits. The star combination is shown in the connections of the
diverter D, but a mesh combination may be substituted therefor.
Figure 6 shows the series winding or field coil A placed within the armature C,
which is also operative even if the diverters D and D be removed, since the poles
or points of A are curved, which causes the magnetic flux to cut through or
encounter the armature C at an angle or tangent, thereby repelling it.
the diverters D and D are used, the speed is regulated by their distance from the
armature C.
When
Figure 7 represents one form of a triphase Coulomb meter, the three pole diverters
being used to regulate the speed. The coils A, A, and A are preferably made so
as to entirely envelop or surround the armature to reduce the magnetic resistance
of the field. When used as a Watt meter the diverter as shown in Figure 5 is very
satisfactory, and by connecting any or all of the fields in series it will operate with
simple alternate or single phase currents. For measuring four or quarter phase

page_text: currents I employ four fields in the same manner, and for higher phases use a
corresponding number of coils.
Figure 8 shows another method of producing rotation and measuring the energy
consumed upon either single phase or two phase current systems, by using strips of
sheet iron or steel D² and D2 placed within the coils A and A tangentially to the
armature C to give direction and concentration to the lines of force.
Figures 9 and 10 represent other methods of accomplishing the same purpose, and
of increasing the efficiency of the rotative power.
Figure 11 illustrates a single phase Watt meter. The resistance R placed in
series with the shunt coil diverter D may be a non-inductive winding of German
silver wire, or one or more incandescent lamps may be used which are of a non-
inductive character. There may also be placed in shunt around the terminals of R
or shunted around the diverter D, or both, a suitable condenser as shown in
Figure 3. For measuring the energy or total output of a central station I connect
the series field coils A. and A in the primary and use a small transformer to excite
or energize the diverter D. In this manner it is possible to make Watt meters for
measuring the energy on exceedingly high voltages.
Another method I employ is to make the coils A and A part of the secondary
circuit of a transformer whose primary is connected in series in the main line or
source of supply, with the diverter excited as before described by the other small
constant potential transformer. This and the foregoing method applies also to
meters for multiphase currents.
Figure 12 shows a disc in place of a cylinder, and the diverter D may be wound
in series with the coil A, or in shunt as in a Watt meter. If the diverter D be
removed the disc will still rotate in the direction of the arrow but more feebly. A
suitable number of poles or field coils may be arranged over or under the armature C
and connected to a single or multiphase source of alternating currents and produce
rotation of the disc.
Figure 13 shows a six pole motive device embodying the same principles and
connected for triphase currents. To make it operative on single phase currents all
that is necessary is to connect all the field coils either in series or multiple arc, the
diverter being used to determine the rate of speed and direction of rotation as
before described. For operating with two phase currents I connect three alternate
poles or coils in series or multiple and join their ends or terminals to one of the
circuits, then connect the three remaining poles or coils in the same manner to the
other circuit.
Fór connecting to a six phase system the field connections already given will
answer by disconnecting the three terminals joined together at the point X thus
giving six terminals instead of three as shown, these are then connected to the six
line wires of the system in the usual manner. In like manner by having twelve
poles instead of six it becomes a motive device suitable for single phase, two phase,
three phase, four or quarter phase, six phase and twelve phase currents, and by
increasing the number of poles it can be made to operate with any increased number
of multiphase currents.
The field coils may also be wound within the space between the polar projections,
and said polar projections may face the armature at a tangent as shown in
Figures 4, 6, and 12, when rotation of the armature C will ensue even if the
diverter be removed, but with a reduction in the turning moment.
I also desire to call attention to the fact that when operating with any multiphase
current, rotation of the armature C.will continue if any of the circuits comprising
the system of distribution be cut or opened, or as long as one of said currents is in
action or being used.
I have also used the herein described device for indicating the electromotive force
or as a volt meter, also as an Ampere meter.
By winding the field coils with fine wire for the volt meter, and the Ampere meter
with thick wire depending upon the proposed indicating capacity, then by attaching
a suitable spiral spring or its equivalent. to the armature C which is further

page_text: provided with a pointer placed over an index or dial, the deflections can be taken as
representing the volts or amperes as the case may be. Again by using the series or
Ampere coils and the shunt or volt diverter coil in combination therewith as shown
in the several Watt meter figures, and by using a pointer, index and spring as afore-
mentioned, the instrument will answer for a direct reading Watt meter, its indications
representing the instantaneous energy in watts.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In an electric meter or motive device for single and multiphase electric
currents; the combination of a primary coil or coils traversed by the current
or currents to be measured and approaching or facing the armature at an angle
or tangent, and a closed revolving metallic secondary as herein set forth and
described.
+
2. In an electric transformer motor meter for single and multiphase electric
currents, the combination of a primary coil or coils located in the circuit or
circuits of the system of distribution, the closed revolving secondary or armature,
and an iron magnetic path diverter all substantially as herein before set forth and
described.
3. In an electric motor meter for single and multiphase electric currents the
combination of a primary coil, coils or electromagnets, a closed secondary in the
form of a cylinder and capable of rotation, and a shunt wound diverter, all substan-
tially as described.
4. In an electric meter for measuring the energy consumed in single or
multiphase current systems of distribution, the combination of a primary field
or fields located in the circuit or circuits of the supply system, a revolving
secondary, a magnetic path diverter and a condenser, all substantially as set forth
and described.
5. In an electric meter and motive device, the combination of a primary or
energizing coil or coils located in the circuit or circuits of the system of supply a
secondary or armature, and an adjustable diverter, all substantially as herein set
forth and described.
6. In an electric meter the combination of a primary coil or coils located in the
circuit or circuits of the system of supply, and traversed by the current or currents
to be measured, a cylindrical armature or revolving secondary, an indicating or
registering train, and the retarding or power absorbing fans, all substantially as
described.
7. In an electric meter for single and multiphase electric currents, the combination
of a coil or coils for energizing the armature, a revolving secondary, a path diverter,
a counting, indicating or registering train, and a set of fans or vanes all substan-
tially as set forth and described.
8. In an electricity meter for measuring single and multiphase electric currents,
the combination of an energizing field coil, coils or electro-magnets, a cylindrical
armature or revoluble secondary, an adjustable magnetic diverter, a registering or
integrating mechanism, a winged retarding fan, and the upper clamping plate S for
holding the fields in position, all substantially as described.
9. In an electricity meter for measuring single and multiphase currents, the
combination of an energizing field coil or coils located in the circuit or circuits of
the system of supply, a revoluble armature or secondary, a magnetic diverter, a
registering mechanism a retarding winged fan, and the safety device U, all substan-
tially as described.
10. In an electricity meter for single and multiphase currents consisting of one
or more open or solenoid coils located respectively in the one or more circuits of
the system, in combination with a rotating closed circuit or secondary in the form
of a cylinder, the said coils being arranged around the cylinder with their axes
substantially radial thereto and enclosing the edges thereof without overlapping

page_text: each other, and a magnetic diverter mounted concentrically with said cylinder and.
adjustable to determine the direction of the magnetic flux established by the coils,
all substantially as set forth and described.
11. The combination in an electricity meter capable of measuring single or multi-
phase alternating currents, of the energizing coil or coils located in or representing
the current to be measured in the circuit or circuits of the system of supply, the
cylindrical armature or closed secondary C, the diverter D, the retarding fans F,
the registering train H, the spindle M and the upper clamping plate S, all
substantially as set forth and described.
Dated this First day of March 1893.
THOMAS DUNCAN.
J. C. Chapman,
70, Chancery Lane, London, W.C., Chartered Patent Agent.