Improvements in or relating to Apparatus for Supplying Variable Amounts of Electricity to and thus Regulating the Brilliancy of Electric Lamps.
Year: 1888

page_text: Improvements in or relating to Apparatus for Supplying Variable
Amounts of Electricity to and thus Regulating the Brilliancy
of Electric Lamps.
A communication from abroad by GEORGE WESTINGHOUSE, Junior, of Pittsburgh,
County of Alleghany, State of Pennsylvania, United States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, & 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 to apparatus employed in connection with electric currents
supplied with alternating, pulsatory, or intermittent currents, for regulating tho
brilliancy at which the laups included in the secondary circuits of induction coils or
electric converters, may be caused to burn.
The object of the invention is to provide convenient means for turning down any
desired lamps or increasing their brilliancy as required, without causing any material
wasto or useless consumption of electric current.
The invention consists generally, in connecting between two distributing conductors
leading from an electric converter or generator, a coil of insulated wire provided with
a movable core of less length than the coil, and in deriving from a portion of the coil
a secondary circuit in which the lamps to be regulated are included. By varying the
position of the core with reference to the portion of the coil included in the secondary,
the brilliancy at which the lights will be operated may be varied..
In the accompanying drawing there is shown in diagram, an organization of circuits
and apparatus for carrying out the invention.
Referring to the Figure, A represents a suitable source of alternating, intermittent,
or pulsatory electric currents, and L, L, conductors leading therefrom to a work
circuit. Between the conductors L', 1, at any desired point, there is connected a
coil P of insulated wire. Within this coil there is included a core C, formed preferably
of divided iron, in a manner well understood. This core is provided with a handle
or other convenient means for adjusting its position with reference to the coil. The
core and coil are so organized that their positions may be changed relative to each
other.

page_text: From one terminal, l, of the coil P, a conductor is derived. A second
conductor is led from an intermediate point 2 in the length of the coil P.
The conductors and are designed to constitute a secondary electric circuit,
and between them are connected translating devices d, d, which are, in this
instance, the lamps to be regulated. These are here shown as being connected in
multiple urc.
It is evident that the counter-electromotive force developed in the coil P by reason
of the passage of the current from the generator A through the coil, and the conse-
quent magnetization of the core C will he dependent upon the position of the core
within the coil. In the position shown, the counter-electromotive force will be
developed for the most part in the portion of the coil included between the points a
and y. Now as the core is moved toward the point 1. the counter electromotive force
will be developed more and more in the portion between the points 1 and 2, and less
between the point 2 and the terminal 3. Therefore when the core is between the
points 1 and 2 the lights & will burn at their highest brilliancy. When the core is
moved towards the point 3, the brightness of the lamps will be diminished, and when
the core is entirely withdrawn froin hatween the points 1 and 2 the lamps will. .be
extinguished.
The portion of the coil which is at any time out of the magnetic influence of
the core, will act as idle wire, and consequently there will be no material loss of
current. It should be observed, however. that as the core is drawn toward the
terminal 3. its secondary circuit becomes less and less perfect and consequently the
current traversing the coil will be gradually diminished, and when it is entirely with-
drawn from the section 1, 2 practically no current will pass.
This organization of apparatus is especially convenient whenever it is desired to
regulate the brilliancy of a portion of the lamps supplied from a given circuit, so as
to maintain them at any desired brilliancy, while others supplied from the same source
are kept at a different candle-power, as for instance in a theatre, the foot lights d, d,
may be lowered while other lamps D, D, included between the conductors Land L'
may be caused to burn at a constant candlepower: Other lights- may be included.
in the secondary circuits of other converters Cas indicated at 7, 7.—The
regulators may be applied independently of each other to different portions of the
same circuit; or a single regulator may be employed for controlling all the lights in
a given circuit.
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 with a source of alternating, intermittent or pulsatory electric
currents, of a single coil of insulated wire included in circuit with said source,
translating devices, a circuit including the latter in series with a portion only of said
coil, and a single core at all times entirely within the inductive influence of said coil,
but movable therein with reference to the last-named circuit, whereby the brilliancy
of the lights may be regulated.
2. The combination of a source of electric currents, a coil of insulated wire
included in its circuit, translating devices included in series with a portion of
the coil, and in multiple arc with another portion of the coil, and a core movable
within said coil.
Dated this 30th day of Tul. 1000