Year: 1898

page_text: Date of Application, 20th Sept., 1898
Complete Specification Left, 19th June, 1899-Accepted, 29th July, 1899
I, CHARLES FELTON SCOTT, of East Pittsburg, State of Pennsylvania, United States
of America, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:
My invention relates to systems of electrical distribution in which two main supply
conductors and a neutral or balancing conductor are provided for supplying trans-
lating devices arranged in multiple series.
The object of my invention is to provide for converting a single-phase circuit of
this character into a four-wire system suitable for the operation of two-phase
alternating current motors as well as single-phase translating devices. My inven-
tion further includes the provision of means whereby a plurality of three-wire out-of-
phase circuits may be so combined and supplemented that either or both may be
utilized for the operation of polyphase motors.
My invention briefly consists in adding a fourth conductor to a three-wire single-
phase alternating current system said fourth conductor and the neutral or balancing
conductor of the three-wire system being connected to the terminals of another
alternating current system the currents flowing in which are in quadrature with
those flowing in the main conductors of the first or three-wire system. By this
means 1 obtain a four-wire system which is suitable for the operation of two-phase
motors and at the same time the operation of the single-phase translating devices is
not interferred with.
In the systems illustrated in the accompanying drawings I have indicated a two-
phase generator as the means for obtaining at once two alternating current systems
the currents flowing in one system being in quadrature with those flowing in the
other system but it is not of course essential to my invention that the currents
should be derived from the same source of energy; two entirely independent circuits
may obviously be used.
Figure 1 is a diagram illustrating one embodiment of my invention, and
Figure 2 is a diagram of the electromotive forces in the circuit represented in
Figure 1.
Figures 3 and 4 are diagrams similar to Figures 1 and 2 respectively illustrating
a modification of the system.
Referring now particularly to Figures 1 and 2 of the drawing, I is a two-phase
alternating current generator which, as shewn, supplies the primaries of two trans-
formers 2 and 3 having the same ratio of transformation. If the voltage of the
generator is suitable for transmission of current to the line directly, and its armature
is suitably wound for supplying three-wire circuits, the transformers may obviously
be omitted. The secondary of transformer 2 supplies a three-wire circuit 4, 5, 6,
the middle or compensating conductor 5 being connected to the middle of such
secondary.
The secondary of the transformer 3 may supply a similar three-wire circuit,
7. 8. 9. as shewn, or if the energy from this transformer is not desired for the opera-

page_text: Scout & improvements in Systems of Electrical Distribution.
tion of translating devices supplied through such a circuit, the conductors, 7, 8 and 9
may be omitted.
It is well understood in the art that if the two sides of a three-wire circuit are
equally loaded, there will be no transfer of energy through the compensating wire or
conductor and that the potential between this wire and each of the main or outer
wires is one-half that between the two outer wires. As indicated in Figure 1, the
two circuits which differ from each other in phase by 90°, extend in different direc-
tions to supply different sets of translating devices. In order to utilize one of these
circuits for the driving of one or more two-phase motors, according to my invention,
I run a fourth conductor 10 from one of the terminals of the secondary of trans-
former 3 and connect the middle or compensating conductor 5 of the first circuit
with the other terminal of transformer 3, then the two main conductors 4 and 6 of
the first circuit will supply current of one phase to the motors 11 and the middle
wire 5, and the fourth wire 10 will supply current of the other phase to said motors.
A brief examination of these circuits and the conditions controlling them will show
that the potential between the middle wire 5 of the first circuit, when connected as
indicated in the drawing to one of the terminals of transformer 3 and the fourth
wire 10 of the first circuit, which is connected from the other terminal of trans-
former 3 will be the same as that between conductors 4 and 6, and that the current
in circuit 5-10 is in quadrature with the current in circuit 4-6 (see Figure 2).
Referring now to Figures 3 and 4, in order to utilize the second circuit 7, 8, 9 as
well as the first circuit 4, 5, 6 for the operation of two-phase motors it becomes
necessary to employ a second secondary 12 for the transformer 2 or its equivalent,
the terminals of such secondary being respectively connected to the fourth wire 13
of the second circuit and to the neutral or compensating wire 8 of such circuit. An
analysis of the electromotive forces of this second circuit connected and supplied as
indicated will show that the potential between the fourth wire 13 and the neutral
wire 8 is the same as that between the two main wires 7 and 9 of the circuit, and
that the currents supplied will differ in phase by 90° (see Figure 4).
It will be understood as within my invention to provide either transformer with a
second secondary such as that shewn at 12 in Figure 3 and to connect the neutral
and supplemental conductors of the other circuit to its respective terminals.
The arrangement of the apparatus and circuits described is such as to permit of
the utilization of existing single-phase three-wire circuits in the most economical
and desirable manner for the operation of two-phase motors wherever such are desired,
but I do not intend to limit my invention to any specific number of circuits or
phases of currents, nor is it necessary that the voltage of the first system should be
the same as that of the system in quadrature.
Dated the 20th day of Sentember 1802
improvements in Systems of Electrical Distribution.
I, CHARLES FELTON SCOTT, of East Pittsburgh, State of Pennsylvania, United
States of America, Electrical Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
My invention relates to systems of electrical distribution in which two main supply
conductors and a neutral or balancing conductor are provided for supplying trans-
lating devices arranged in multiple series.

page_text: The object of my invention is to provide for converting a single-phase circuit of this
character into a four-wire system suitable for the operation of two-phase alternating
current motors as well as single-phase translating devices. My invention further
includes the provision of means whereby a plurality of three-wire out of phase circuits
may be so combined and supplemented that either or both may be utilised for the
operation of polyphase motors.
My invention briefly consists in adding a fourth conductor to a three-wire single-
phase alternating current system, said fourth conductor and the neutral or balancing
conductor of the three-wire system being connected to the terminals of another
alternating current system, the currents flowing in which are in quadrature with those
flowing in the main conductors of the first or three-wire system. By this means I
obtain a four-wire system, which is suitable for the operation of two-phase motors,
and at the same time the operation of the single-phase translating devices is not
interfered with.
In the systems illustrated in the drawings filed with my Provisional Specification I
have indicated a two-phase generator as the means for obtaining at once two
alternating current systems, the currents flowing in one system being in quadrature
with those flowing in the other system, but it is not, of course, essential to my
invention that the currents should be derived from the same source of energy; two
entirely independent circuits may obviously be used.
Figure 1 is a diagram illustrating one embodiment of my invention, and
Figure 2 is a diagram of the electro-motor forces in the circuit represented in
Figure 1.
Figures 3 and 4 are diagrams similar to Figures 1 and 2 respectively illustrating a
modification of the system.
Referring now particularly to Figures 1 and 2 of the drawing, 1 is a two-phase
alternating current generator, which, as shewn, supplies the primaries of two trans-
formers 2 and 3 having the same ratio of transformation. If the voltage of the
generator is suitable for transmission of current to the line directly, and its armature
is suitably wound for supplying three-wire circuits, the transformers may obviously be
omitted. The secondary of transformer 2 supplies a three-wire circuit 4, 5, 6 the
middle or compensating conductor 5 being connected to the middle of such
secondary.
The secondary of the transformer 3 may supply a similar three-wire circuit 7, 8, 9,
as shewn, or if the energy from this transformer is not desired for the operation of
translating devices supplied through such a circuit, the conductors 7, 8, and 9 may be
omitted.
It is well understood in the art that if the two sides of a three-wire circuit are
equally loaded there will be no transfer of energy through the compensating wire or
conductor and that the potential between this wire and each of the main or outer
wires is one-half that between the two outer wires. As indicated in Figure 1, the
two circuits which differ from each other in phase by 90°, extend in different directions
to supply different sets of translating devices. In order to utilize one of these circuits
for the driving of one or more two-phase motors, according to my invention, I run a
fourth conductor 10 from one of the terminals of the secondary of transformer 3 and
connect the middle or compensating conductor of the first circuit with the other
terminal of transformer 3, then the two main conductors 4 and 6 of the first circuit
will supply current of one phase to the motors 11, and the middle wire 5 and the
fourth wire 10 will supply current of the other phase to said motors. A. brief examina-
tion of these circuits and the conditions controlling them will shew that the potential
between the middle wire 5 of the first circuit, when connected as indicated in the
drawing to one of the terminals of transformer 3, and the fourth wire 10 of the first
circuit, which is connected from the other terminal of transformer 3, will be the
same as that between conductors 4 and 6, and that the current in circuit 5-10 is in
quadrature with the current in circuit 4-6 (see Figure 2).
Referring now to Figures 3 and 4, in order to utilise the second circuit 7, 8, 9 as
well as the first circuit 4, 5, 6, for the operation of two-phase motors it becomes

page_text: necessary to employ a second secondary 12 for the transformer 2 or its equivalent, the
terminals of such secondary being respectively connected to the fourth wire 13 of the
second circuit and to the neutral or compensating wire 8 of such circuit. An analysis
of the electro-motive forces of this second circuit connected and supplied as indicated
will shew that the potential between the fourth wire 13 and the neutral wire 8 is the
same as that between the two main wires 7 and 9 of the circuit, and that the currents
supplied will differ in phase by 90° (see Figure 4).
It will be understood as within my invention to provide either transformer with a
second secondary such as that shewn at 12 in Figure 3 and to connect the neutral and
supplemental conductors of the other circuit to its respective terminals.
The arrangement of the apparatus and circuits described is such as to permit of the
utilisation of existing single phase three-wire circuits in the most economical and
desirable manner for the operation of two-phase motors wherever such are desired,
but I do not intend to limit my invention to any specific number of circuits or phases
of currents, nor is it necessary that the voltage of the first system should be the same
as that of the system in quadrature.
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. Converting a multiple wire single-phase alternating current system feeding
translating devices in multiple series into a four wire two-phase system by connecting
the neutral or middle conductor and a fourth wire respectively to the terminals of a
circuit carrying currents in quadrature with those in the multiple wire system.
2. The modification of the invention in which the middle or neutral conductor of
the multiple wire system and the fourth conductor are respectively connected to the
terminals of the secondary coil of a transformer the current in the primary coil of
which is in quadrature with the current in the outer or main conductors of the
multiple wire system.
3. Systems of electrical distribution arranged substantially as hereinbefore
described.
Dated 4 10 d...
T
1000