Year: 1887

page_text: Date of Application, 12th July, 1887.
Specification Accepted, 26th Aug., 1887.
[Communicated from abroad by GEORGE WESTINGHOUSE, Junior, of Pittsburg,
County of Alleghany, State of Pennsylvania, United States of America,
Engineer.]
I WILLIAM PHILLIPS THOMPSON F.C.S. .M.I.M.E. of the Agency for Foreign
Patent Solicitors 6 Lord Street Liverpool and 6 Bank Street Manchester both in the
County of Lancaster, and 323 High Holborn in the County of Middlesex Civil
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 invention relates especially to the class of circuits and apparatus employed for
utilizing alternating or periodically varying electric currents for operating translating
devices, such for instance, as incandescent electric lights.
The object of the invention is primarily to secure convenient and effective means
for regulating the amount of current delivered to the translating devices, and for
rendering it possible to easily modify the amount of current delivered to different
translating devices or groups of the same, independently of each other.
It has become customary to supply alternating currents from a generator of suitable
character, and conduct them through one or more main line conductors to points near
where they are to be utilized. At these points the current is converted into currents
of similar character but having a potential better adapted to the work to be performed.
This last current is then delivered to the translating devices which are to be operated
thereby. Such change in the potential is secured by means of converters or induction
coils having their primary and secondary coils suitably proportioned to each other for
that purpose. Thus if the primary current is of higher potential than is required for
operating the translating devices, the secondary coil of the converter is constructed
with fewer convolutions than the primary coil. The current obtained thus from the
secondary coil is dependent upon its length and conductivity, relative to the length
and conductivity of the primary coil. Now it is evident that by leading the conductors
from different points in the length of the secondary coil, currents of different potential
may be obtained.

page_text: This invention consists in general terms, in employing in an electric lighting system
of the character described, a converter having its secondary coil formed in sections
from which independent conductors lead to corresponding switch-points. The
translating devices or groups of the same may be connected in circuit between one
terminal of the secondary coil and any one of these switch-points at will, and thus the
potential of the current_yielded to the translating devices may be diminished or
decreased as required. By the use of this means of regulation, the reduction of
current in the lamps is accomplished by a saving of power, whereas in the usual
method, in which resistance is introduced in series with the lamp, a certain amount of
energy must be wasted in the resistance.
The invention involves further details which will be described in connection with
the drawings, in which Figure 1 is a diagram illustrating the application of the
invention to a system of electric lighting, and Figure 2 illustrates an extension of the
system.
Referring to the figures, L', L', represents a main line of an electric lighting
system which is designed to be supplied with an alternating electric current in any
well known manner. The primary coil P of a converter Cis included in this line.
The secondary coil S of this converter is constructed in sections s¹³, s³. A
conductor leads from one terminal of the secondary coil, and a series of con-
ductors 1, 12, 13, lead from the respective sections. It is evident that the potential of
the induced currents in the secondary coil will depend upon the length of the active
wire, so that the difference of potential between the conductors 1, and will be less
than that between the conductors and 13 and greater than between 7 and 1. The
conductors P, 12, 13, are led parallel with each other and are provided with suitable
means whereby certain of the translating devices connected with the conductor / may
be placed in multiple are between this last named conductor and either of the other
three. A convenient construction consists in leading the conductors 1213, to contact
points a¹, a², a³, respectively and in providing these points with a switch A connected
with a conductor c. The lights d to be regulated, are included between the conductor c
and a conductor f leading from the conductor l. By means of the switch A, therefore,
the potential between the conductors fand c may be readily modified.
In some instances it may not be necessary to employ more than two sections of the
secondary, as illustrated at the switch A¹ which is provided with points a¹ and a³
connected respectively with conductors and omitting the conductor. In other
instances it may be desired to maintain the lights at all times in circuit between the
conductors of highest potential 7 and 12 as indicated at d', d¹; in still other instances
the lowest potential will be sufficient at all times, and this is obtained as indicated
at d³.
In Figure 2 the same invention is illustrated as applied to an extended system in
which more than one conversion of the current is made. In this instance the main
line L' which is supplied from an alternate current generator B, includes the primaries
of two converters and C2, and the secondaries of these converters are included in
multiple arc between two secondary mains L³ and L* which they supply. Adjustable
resistances R1, R2, may be employed for regulating the current supplied to these
converters. Translating devices d', d, may be operated directly from the secondary
mains L³ and L' in the usual manner. A converter C has its primary coils included
in multiple arc between the secondary mains, L³, LA. The connections from the
secondary coil S of this converter are of the same character as described with reference
to Figure 1, like letters referring to the similar parts. The object of this arrange-
ment is to overcome the necessity of introducing the primary current, which is usually
of comparatively high electro-motive force into places accessible to the user of the
light, and at the same time permit control of the current for each lamp as desired.
The converter employed for this arrangement is used simply as a regulator, and
need not produce any change in the electromotive force other than that obtained by
using the regulating switch; that is, the ratio of conversion is unity under normal
conditions. It may, however, be used to effect a general reduction of electromotive
force and at the same time act as a regulator if so proportioned.

page_text: There is shown in this instance still another translating device d' provided with an
independent switch A³. This serves to illustrate the method of operating different
lights deriving their currents from a single conductor f2 independently of each other
and at different potentials.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed as communicated to me by my
foreign correspondent, I declare that what I claim is :-
1. The combination, substantially as hereinbefore set forth, of a main line, a converter
having its primary coil included in the main line, conductors leading from different
points in the length of the secondary coil, translating devices or groups of the same,
and a circuit controller for including said translating devices or groups of the same
between different conductors leading from the secondary coil, at will.
2. The combination with the primary coil of a converter, of a secondary coil, con-
ductors leading from the different points in the length of the latter, switch-points to
which said conductors lead; switches applied to said points and translating devices
connected in multiple are between one of said conductors, and one of said switches.
3. The combination, in a system of electrical distribution, of a source of alterna-
ting currents, a converter having its primary coil supplied from said source, a second
converter supplied from the secondary circuit of the first named converter, conductors
leading from different points in the length of the secondary coil of the second con-
verter, translating devices and means for including any or all of said devices between
the different conductors, substantially as described.
4. The combination, in a system of electrical distribution, of a source of alternating.
currents, a converter supplied from said source, distributing conductors supplied from
the secondary of said converter, translating devices supplied from said distributing
conductors, a second converter having its primary coil also supplied from said distri-
buting conductors, other translating devices or groups of the same, and means,
substantially such as described, for including the last named translating devices in
circuit with more or less of the secondary coil of the second converter.
5. The combination with a source of electricity, of a converter having its primary
coil in circuit therewith, contact-points connected with different points in the length
of said secondary coil, a conductor permanently connected with one of said points, a
second conductor adapted to be placed in connection with any of said points, a third
conductor leading from the terminal of the secondary coil, and translating devices,
certain of which are connected in circuit between the last and first named conductors,
and other translating devices included between said last-named and the remaining
conductor.
WM. P. THOMPSON & Co.,
Agents for the Applicant.