Improvements in the Method of Distributing Electricity by Means of Alternating Currents.
Year: 1889

page_text: Date of Application, 11th May, 1889
Complete Specification Left, 11th Feb., 1890-Accepted, 10th May, 1890
Improvements in the Method of Distributing Electricity by Means
of Alternating Currents.
LLEWELYN BIRCHALL ATKINSON % W. J. Goolden & Co. Woodfield Road
Harrow Road London W. Civil Engineer do hereby declare the nature of this inven
tion to be as follows:-
This invention relates to the combination with a source of supply of alternating
currents with or without intermediate transformers of a motor-generator with
secondary batteries.
The motor-generator consists of two field magnet systems with two armatures on
one shaft, or of one field magnet system with one armature having two windings,
the one armature or winding with a field magnet forming a system suitable for
receiving or generating alternating currents, the other armature or winding and
field magnet, forming a system suitable for receiving or generating a continuous
current.
The secondary batteries are used, either as a means of starting the motor-generator,
by connecting them to the continuous current system used as a motor, until it runs
up to the proper speed to enable the alternating current system to run as a
synchronous motor, the source of alternating current supplying the power, when
the continuous current system becomes a generator and is used to excite the field
magnetism and to recharge the batteries, or, the continuous current system having
been used as a starting motor by means of the secondary batteries, the motor
generator when running supplied with power from the alternating source may be
used to charge batteries or to run lamps direct or for any purpose whore a
continuous current is desired.
This method of transforming the current is advantageous to maintain a constant
potential on the lamps, irrespective of the potential of the supply, for the alternate
motor if of sufficient size runs at a speed depending on the number of alternations
per second and not on the pressure of the supply, and this number is constant,
and the generator may be compound wound to give a constant potential at a
constant speed.
The current supplied is continuous, in the sense that the current supplied by any
continuous. current dynamo is continuous, and is not merely an alternating current
rectified to a variable unidirectional current, thus making it most suitable for electro
magnetic apparatus.
Any of the usual constructions of magnets, and armatures may be used, but it is
preferable to use a form of magnets which acting on one armature with two windings
is adapted either. for continuous or alternating currents.
1000
j
COMPLETE SPECIFICATION.
Improvements in the Method of Distributing Electricity by Means
of Alternating Currents.
ILLEWELYN BIRCHALL ATKINSON % W. J. Goolden & Co., Harrow Road in the
County of Middlesex, Civil 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 :-
This Invention relates to the combination with a source of supply of alternating

page_text: currents with or without intermediate transformers of a motor generator with
secondary batteries.
The motor generator consists of two field magnetic systems with two armatures on
one shaft or of one field magnetic system with one armature having two windings,
one armature or winding with a field magnet forming a system suitable for receiving
or generating a continuous current.
And in order that my invention may be the better understood I now proceed to
describe the same in relation to the drawings hereunto annexed reference being had
to the letters and figures marked thereon. Like letters refer to like parts through-
out the drawings.
Fig. 1. is an end elevation of an alternator and a continuous current dynamo forming
an improved generator.
Fig. 2. shows the two armatures and diagramatically their connections to the source.
of supply of alternating current and to the field magnet windings m, m with secondary
batteries and lamps in parallel.
Fig. 3. shows the general method of distribution with motor generators as described
working in series.
In Fig. 1. a &b are the field magnets of the alternating and continuous current
machines respectively. c is the armature of the continuous current machine with
the usual commutator & brushes c', and with accumulators as generally adapted.
d is the armature of the alternating current machine with collecting rings d¹ of usual
construction.
These two armatures are mounted on the same shaft, or in place of these two
separate armatures a single armature and field magnetic system may be used as
described in Specification No. 789589 where the alternating and continuous coils
are placed alternately upon the same armature with a commutator & collecting
rings.
In Fig. 2 the mains e. are connected to the source of alternating current supplied
by a generator maintaining a constant speed of alternation.
The secondary mains ff are connected to the terminals of the field magnets of
both continuous and alternating machines, these magnet coils being represented
diagramatically at m in Fig. 2.
They are also connected to the lamps or other device n to which the continuous
current is to be supplied, and to them may also be connected with or without the
resistance 9, the accumulators h.
The secondary battery h. is used as a means of starting the motor generator by
connecting it to the continuous current armature and magnet, which, acting as a
motor, when receiving an external current revolves both the continuous and alter-
nating armatures, until they reach such a speed that on passing the alternating
current from the main e. through the alternating armature, the alternating machine
runs as a synchronous motor. When this condition is reached, by strengthening the
field magnets of the continuous current machine, which becomes a generator, and is
used to excite the field magnets of both machines, it may be also used to charge the
battery and to feed the lamps.
This method of transforming alternating currents into continuous currents is
advantageous for the purpose of maintaining a constant potential on the lamps or
other device in the secondary system, within certain limits depending upon the alternate
motor being of sufficient power and irrespective of the potential or current, which is
supplied to the alternating armature, provided that the number of alternations per
second of the main generator is kept constant. This system is thus fitted for use in
the case of parallel distribution, where there are feeders of great length, over which
there is a large fall of potential; or more particularly in the case of distribution with
motor generators in series as shown in Figure 3 where k. is the main generator
and 1. 1. are the motor generators.
With a constant current in the primary alternating circuit a constant potential is
maintained in the secondary circuits irrespective of the load on them. The current
supplied is continuous in the sense that a current of any continuous current dynamo

page_text: is continuous, and is not merely an alternating current rectified to a variable uni-
directional current, thus making it most suitable for electro-magnetic apparatus.
Any of the usual constructions of magnets and armatures may be used, but it is
preferable to use a form of magnets which acting on one armature with two windings
is adapted either for continuous or alternating currents as described and illustrated in
Specification No. 7895 as applied for by me on May 11th 1889.
Having now particularly described the nature of my said invention and in
what manner the same is to be performed, I declare that what I claim is.
1st. The method of electric distribution from a source of alternating current, the
speed of alternation being maintained constant by synchronous motors or motor
generators supplying continuous current at constant potential independant of the
potential of the supply circuit substantially as described.
2nd. In such a method of electric distribution the combination of a main
alternating generator with motor generators having their alternate armature
connections in series supplied at constant current, the secondary continuous
current armature of said motor generators supplying continuous current at
constant potential.
Dated the 11th day of February 1890.
FELL & WILDING,
1, Queen Victoria Street, E.C., Agents for the Applicant.