Improvements relating to the Connection of Constant Current Dynamos to Electric Lamp Circuits.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Comptroller General of the 11th day of October 1897.
Date of Application, 7th Sept., 1896-Accepted, 31st Oct., 1896
COMPLETE SPECIFICATION (AMENDED).
[Communicated from abroad by CHARLES NEWBOLD BLACK, of New Haven,
County of New Haven, State of Connecticut, United States of America,
Electrician.]
Improvements relating to the Connection of Constant Current
Dynamos to Electric Lamp Circuits.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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:-
My invention relates to an improved method of connecting constant current
dynamos for operating arc-lamps, the object being to secure the economy of labor,
power, room and attendance resulting from the construction and use of machines
capable of operating a large number of lamps, and still maintaining the voltage or
pressure at a point so low as not to be dangerous to the insulation of the machine
or the circuits.
With these ends in view, my invention consists in a method of connecting a
constant current dynamo having two or more independent armature-circuits, with
two or more lamp circuits, by arranging the connections so that one or more of the
independent armature circuits of the dynamo shall be interposed between the lamp
circuits and the voltage kept within safe working limits. My invention further
consists in certain arrangements of connections as will be hereinafter described, and
pointed out in the claims.
Here I may call attention to the fact that as heretofore constructed the capacity
of constant-current dynamos has been limited to the voltage or pressure that the
insulation of the machine and lines would stand, and as only one line of lamps
could be operated by one dynaino, the units have been small as compared with
dynamos for incandescent lighting or power purposes.
Thus it is commercially
impossible, at the present stage of the art, to build lines and lamps to withstand a
pressure or voltage of much over 7000 volts, and as each lamp requires approxi-
mately 50 volts, it is evident that about one hundred and forty lamps is the
maximum number that can be operated from one dynamo.
In carrying out my invention I may employ any constant current dynamo with
two or more independent armature circuits, and having two or more commutators
that admit of being connected in series, and therefore hold myself at liberty to use
any constant current dynamo of the character specified, but without regard to its
particular description.
For the purpose of illustrating my invention, however, I have chosen to

page_text: represent in the diagram accompanying this specification the connection of an
open-coil arc-dynamo having eight bobbins, and a two-ring commutator with two
independent lamp-circuits. But this diagram, it will be understood, is chosen
simply to illustrate my invention, which is not limited to the construction and
arrangement which it shows.
In the diagram, the letters A, B, C, D, E, F, G, and H respectively represent
the bobbins of the armature of the dynamo. The said bobbins form features or
members of the armature, which is not further shown. The opposite bobbins are
connected together, as A to E, B to F, and so on. These connections, however,
are not shown in the diagram, which they would complicate. The commutator I
is what is called a two-ring commutator, and may be of any approved construction.
The negative brushes N and N1, and the positive brushes P and P may also be of
any approved construction. The field magnets are designated by X and Y, and
the lamp circuits by L and L¹. As shown, each of these circuits contains five
lamps, but the number of lamps may be varied as desired, and the two circuits
may have the same or different numbers of lamps.
With the independent circuits of the machine and the lamp-circuits connected
as described, the course of the current will be as follows. Starting at the positive
brush P, it will pass in the direction of the arrows through the line of lamps L to
the field magnet X, thence to the field magnet Y, thence to the negative brush N¹,
thence, according to the position of the armatures, through the bobbins which are
connected to the commutator ring on which the said brush N bears, to the brush P¹,
thence through the line of lamps L to the negative brush N, thence to the bobbins
on which the negative brush N at the time bears, to the positive brush P.
I may
here remark that the arrangement shown by the diagram may be varied if desired.
Thus, the field circuit can be connected in series with the line I instead of with
the line L, as shown. Again, one field magnet can be placed in each circuit
without changing the result. Under my invention the machine will automatically
accommodate itself to the number of lamps on the various circuits, whether their
number is uniform or not, as well as though all of the lamps were on the same
circuit.
The economy from almost every point of view of employing a large machine
in place of several small machines, is believed to be too patent to require extended
remark.
Having now particularly described and ascertained the nature of the said inven-
tion 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. A method of connecting a constant current dynamo having two or more
independent armature-circuits, with two or more lamp-circuits, consisting in
arranging all of the lamp-circuits in series, with the armature-circuits so distributed
as to bring one or more of the independent armature-circuits between the lamp-
circuits.
2. A method of connecting a constant current dynamo having two or more
independent armature circuits with two or more lamp circuits, consisting in
arranging the connections so that one or more of the independent armature circuits
of the dynamo shall be interposed between the lamp-circuits and the voltage kept
within safe working limits.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.