IMPROVE- MENTS RELATING TO THE DISTRIBUTION OF ELECTRICAL ENERGY FOR LIGHT POWER, AND OTHER PURPOSES
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
in the County of Middlesex, Patent Agent for an Invention of IMPROVE-
MENTS RELATING TO THE DISTRIBUTION OF ELECTRICAL ENERGY FOR LIGHT
POWER, AND OTHER PURPOSES Communicated to him from abroad by
Thomas Alva Edison of Menlo Park in the State of New Jersey United States
of America
PROVISIONAL SPECIFICATION left by the said Thomas John Handford
at the Office of the Commissioners of Patents on the 28th December 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent IMPROVEMENTS RELATING TO THE DISTRIBUTION OF
ELECTRICAL ENERGY FOR LIGHT POWER AND OTHER PURPOSES A communi-
cation to me from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey United States of America,
"
In multiple arc systems of lighting by electrical incandescence supplying power
for motors and the like in which complete or round metallic circuits are used, it
may sometimes be desired to employ electric currents of unusually high electro
motive force so that the size of the conductors which convey the said current may
be diminished, thus economizing in metal and allowing the conductors to be placed
overhead instead of laid underground in places where the former arrangement is
more desirable or convenient.
It is also generally desirable in such systems that the incandescing electric lamps
motors or other translating devices should be independent of each other that is to
say, that such devices shall be independently controllable so that each lamp can be
lighted and extinguished separately and without affecting any others.
Now this Invention has for its object providing a system in which currents of
high tension can be used while at the same time each translating device (lamp for
example) is entirely independent of all the others; and this object is accomplished
by employing a source of energy of high electro motive force, arranging the

page_text: translating devices in multiple series dividing the said source into as many parts
as there are translating devices in series in any circuit extending across between
the main conductors and correspondingly dividing each series of translating devices
such division being made by means of a central compensating conductor or
conductors connected between the parts or divisions of the source of energy and
also between the translating devices so that when all the devices in any multiple
arc circuit are in use current will pass through all such devices the current passing
across from the positive to the negative main conductor, but if one or more trans-
lating devices (lamps for example) are removed from any series circuit the excess
of current which would otherwise affect the other lamps in the circuit is taken by
the compensating central conductor so that the other lamps remain unchanged.
The compensating conductor is preferably a metallic wire although the earth
may be used for the purpose if it is so desired.
In carrying out the Invention the central station or source of electrical supply
for the system may contain one two or any desired number of generators according
to the number of translating devices to be supplied with current: such generators
developing a high electro-motive force. Dynamo or magneto electric machines are
by preference used as the generators but secondary batteries may be employed if
desired; and the generators may be connected in any desired manner.
If two generators placed in series are employed, the compensating conductor
is connected betwen the two to the wire connecting their armatures such compen-
sating conductor extending out between the two main conductors leading from the
generators.
The multiple are circuits which contain the lamps or other translating devices
extend across from each main conductor to the compensating conductor. When
equal numbers of lamps are in circuit on opposite sides of the compensating
conductor no current will traverse such compensating conductor the whole amount
generated passing out through the positive main conductor across both sets of
multiple arc circuits containing lamps and back by the negative main conductor
Thus the same effect is produced as though two lamps were in series in each
multiple arc circuit as the current must pass through two lamps to get from the
positive to the negative conductor. At the same time however such two lamps
are independently controllable.
In case lamps are removed from one side of the compensating conductor so that
the numbers on opposite sides become unequal a portion of current varying in
amount according to the degree of inequality will pass through the compensating
conductor the direction of such current varying according to whether the positive
or the negative side contains the greater number of translating devices in circuit.
The system should be so arranged by properly locating the lamps and conductors
that at no time can there be a very great inequality between the two sets of lamps.
Thus very little current will ever traverse the compensating conductor, almost the
whole passing out through the positive and returning by means of the negative
main conductor. The compensating conductor can therefore be of small mass when
the system is so arranged it never being required to convey much current.
When a theatre or other building using a large number of lamps is to be lighted,
two circuits one from each side of the -compensating conductor are run into the
building and the lamps are divided equally or nearly so between the said circuits
so that the turning on and off of the lamps of the building will not disturb the
balance existing in the system.
In running large motors they can be placed in cross circuits between the main
conductors without connection with the compensating conductor so that placing
such a motor in or removing it from circuit will not disturb the balance
An adjustable resistance is preferably placed in each main conductor so that in
case the drop in electro motive force is greater on one main conductor than on the
other the resistance may be adjusted to compensate for such inequality. In systems
of general distribution such resistances would be placed in the conductors of the
feeding circuits.

page_text: It is evident that more than one generator may be placed on each side of the
central conductor in series or in multiple arc if desired.
If currents are to be employed of such high tension that three or more lamps
must be placed in each cross circuit between the positive and negative sides of the
main circuit three or more generators or series of generators may be placed in series
with two or more compensating conductors extending between the main conductors
such compensating conductors being connected between the generators or series of
generators the source of energy being thus divided into as many parts as there are
lamps in series in each of such cross circuits.
By the use of this Invention lamps in different districts connected with separate
central stations may be connected in series with each other; the generators of the
two stations being connected by a conductor and compensating conductors running
from convenient parts of the district.
If desired one generator only may be placed at the central station having its
commutator provided with an extra brush or brushes placed between the main
brushes from which the compensating conductor or conductors run such conductors
being connected with the multiple arc circuits between the lamps.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas John Handford in the Great Seal Patent Office on the
28th June 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent "IMPROVEMENTS RELATING TO THE DISTRIBUTION OF
ELECTRICAL ENERGY FOR LIGHT, POWER, AND OTHER PURPOSES " A. communi-
cation to me from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey, United States of America.
In multiple are systems of lighting by electrical incandescence, supplying power
for motors, and the like, in which complete, or round metallic circuits are used,
it is sometimes desired to employ electric currents of unusually high electromotive
force, so that the size of the conductors which convey the said current may be
diminished, thus economizing in metal and allowing the conductors to be placed
overhead instead of laid underground in places where the former arrangement is
more desirable or convenient It also generally desirable in such systems that
the incandescing electric lamps, motors, or other translating devices should be
independent of each other that is to say that such devices shall be independently
controllable so that in the case of lamps each lamp can be lighted and extinguished
separately and without affecting any others.
It has previously been proposed to accomplish this result by arranging the
translating devices in multiple series, employing as many dynamo or magneto
electric machines as there are translating devices in series in any circuit which
extend across between the main conductors and correspondingly dividing each
series of translating devices such division being made by means of a central or
intermediate compensating conductor, or conductors, connected between the dynamo
or magneto electric machines, and also between the translating devices; so that
when all the devices in any multiple arc circuit are in use current will pass through
all such devices, the current passing across from the positive to the negative main
conductor, but if one or more translating devices (lamps for example) are removed
from any series circuit the excess of current which would otherwise affect the other
lamps in the circuit is taken by the compensating central conductor, so that the
other lamps remain unchanged.
Now the present Invention relates to improvements on this system whereby
important advantages are obtained.
According to one mode of carrying out the said Invention, there are employed
dynamo or magneto electric machines, main conductors, and a compensating
conductor, or conductors, with translating devices arranged in multiple series as
hereinbefore described, and in combination therewith an adjustable resistance is
provided in each main conductor so that in case the drop in electro-motive force
is greater on one main conductor than on the other the resistance may be adjusted
to compensate for such inequality.
Secondary batteries or other sources of electrical energy may also be employed
if desired in substitution for dynamo or magneto electric machines the arrangement
being otherwise similar to that herein before described.
In the case of lamps or other translating devices arranged in different districts
connected with separate central stations they are connected in series with each
other, the generators of the two stations being connected by a conductor and
compensating conductors being run from convenient parts of the district.
this case the adjustable resistances when employed are placed in the feeder
circuits.
In
According to another mode of carrying out the said Invention a single dynamo

page_text: or magneto electric machine is employed at the central station or source of electrical
supply, and the commutator of this machine is provided with an extra brush or
brushes which is or are placed between the main brushes and from which the
compensating conductor or conductors run, such conductors being connected with
the multiple arc circuits between the translating devices.
The earth may in some cases be utilized as the compensating conductor adjustable
resistances placed one in each main conductor being employed to compensate for
the inequalities in electromotive force in the two main conductors.
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the accompanying sheets of drawings
Figure 1 (Sheet. 1), Figs. 1º, and 1b (Sheet 2) of the accompanying drawings
are diagrams showing the arrangement of dynamo electric machines in series, with
a balancing adjustable resistance in each of the main conductors.
Figure 2, (Sheet 1) shows an arrangement whereby lamps in different districts
supplied from separate stations may be placed in series;
Figure 3 illustrates a mode of carrying out the said Invention with the use of
one generator;
Figure 4 illustrates the use of secondary batteries; and
Figure 4 (Sheet 2), illustrates the use of the earth as a compensating conductor.
In Figure 1, A, A, represent two dynamo or magneto electric machines, connected
in series by conductor 3, and having positive and negative main conductors P, N,
extending from them. Midway between the generators, the compensating con-
ductor 4, is attached to conductor 3. Multiple are circuits, 7, 8, extend from
the compensating conductor to each of the inain conductors, and each of such
multiple arc circuits contains a series of lamps or other translating devices those
on one side of the compensating conductor being designated by a, and those on the
other by a¹.
Assuming lamps to be the translating devices employed when, as shown, the
number of lamps a is equal to that of lamps a', any current which may tend to
return through conductor 4, will be neutralized by the current which will meet it
from wire 3, so that no current will pass in either direction in the said conductor 4.
But if a lamp or lamps a' be removed from circuit so that less current will pass
from conductor P, to conductor 4, the tendency from wire 3, to wire 4, will be
correspondingly greater than the return tendency and current due to the inequality
will flow in wire 4, which will pass through the lamps a, and return through
conductor N, whilst if a lamp or lamps a be removed so that less current will pass
from 4, to N, the difference of current will return through conductor 4. Thus the
conductor 4, compensates for differences in either side; and while the lamps are
independently controllable and any lamp can be removed from circuit without
varying the current flowing to the lamps on the opposite side yet it is evident that
currents may be employed of as a high tension, as though the lamps were arranged
in multiple series in the ordinary way.
R, R, are adjustable resistances placed one in each main conductor so that in
case the drop in electro-motive force is greater on one main conductor than on the
other, the resistance may be adjusted to compensate for such inequality; the use of
adjustable resistances in this manner and for this purpose forming the essential
feature of this part of the said Invention.
In lieu of the translating devices being placed across multiple arc circuits
derived from the main conductors and compensating conductor as shown in
figure 1, they may be arranged in multiple arc circuits 5, 6, extending across
between the main conductors and compensating conductor, as shown in figure la
(Sheet 2)
In figure 1b (Sheet 2) three generators A, A, A, are shown in series, there being
two compensating conductors 4, and 4, and three sets of lamps a, a, a³, the main
portion of the current passing entirely across from conductor P, to conductor N,

page_text: and an amount due to differences in the number of translating devices will return
through the central conductors.
The number of lamps a² being greater than a', a portion of current due to the
difference will return through conductor 4°, the remainder passing through lamps a¹
to conductor 4.
The number of lamps a being greater than a current will flow from the
generators through conductor 4 to supply lamps a which current will return
through main conductor N.
R, R, (Figs 1 and 1b) represent the adjustable resistances as before
64
In figure 2 C, and C, each represents a district to be supplied with electric
energy a central station or source of supply being provided for each district. At
one central station generators B, B are placed in multiple arc, and at the other
central station generators B¹, B₁, are similarly arranged. It is desired to connect
lamps in district C, in series with lamps in district C. In order to accomplish
this, a conductor D, is run from one station to the other, connecting one pole of
cach battery of generators together. From the other poles run the feeding
circuits P, N1, and P2, N2, such feeding circuits being connected with the main
conductors of the system. Compensating conductors 4, are connected at convenient
points to the said main conductors, all such compensating conductors being con-
nected at the same point to the wire D, between the stations, so that a divided
source of electric energy is formed as in the previous cases.
Current flows through feeding conductors P1, P2, to main conductors p, p, then
through cross circuits containing translating devices to main conductors n, n,
thence by a conductor o, to district C¹, through translating devices to main
conductors p, and back to the generators by feeders N¹ N°.
It is evident that each translating device in district C, is in series with one in
district C', although all such devices are independently controllable; the con-
ductors 4 acting to compensate for the removal of any device on either side.
It is obvious that any desired number of districts may be connected in this
manner by proportionately dividing the source of energy, so that currents of very
high electromotive force may be employed.
Figure 3, illustrates the application of the Invention to a single generator A of
high electromotive force.
The main current is taken from the machine by the commutator brushes C, C,
to which are connected the main conductors P, N; and an extra brush C¹
is provided between the main brushes, from which runs the compensating
conductor 4. Lamps, motors or other translating devices a, a¹ are arranged across
between the main conductors.
The current taken by the extra brush neutralizes the tendency for current to
return on the compensating wire, so that no current traverses that wire so long
as the number of translating devices remains the same on each side of the said
compensating wire, whilst as the numbers vary, current traverses such conductor
in one or the other direction as previously explained.
It is evident that the generator may be still further divided by the use of a
greater number of extra brushes and compensating conductors.
In figure 4. D, D, are secondary batteries; P, N being the main conductors
and 4, the central conductor. R, R, are the adjustable resistances for the purpose
before described.
Figure 4 (Sheet. 2) illustrates the use of the earth as a compensating conductor,
which arrangement may be convenient in some cases though it is preferred to use a
metallic conductor.
The generators A, A, are connected by wire 3, in series, and conductors P, N,
extend from them. Translating devices a¹, are connected with conductor P, and
also to earth E; and translating devices a, connected to conductor N are also
connected to earth. Between the generators A, A, wire 3, is connected to earth as
sbown. It will readily be seen that current will pass through the earth from P,
to N, and thus through both sets of translating devices in multiple series. An

page_text: amount of current due to any inequality between the devices a, and a¹ will it. is
evident pass between wire 3, and the translating devices through the earth in the
same manner as explained with reference to the metallic conductor 4, figure 1.
R, R, are the adjustable resistances as before.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is :-
First The use of separate adjustable resistances in the main conductors, in a
compensating system having dynamo or magneto-electric machines, secondary
batteries, or other sources of electrical energy in series, and one or more com-
pensating conductors running back to the divided source, substantially as
herein before described.
Second. The arrangement substantially as herein before described with reference
to figure 2, of the accompanying drawings
Third The employment in a system of electrical distribution, of main conductors
extending from the main commutator brushes of a dynamo or magneto-electric
machine, a compensating conductor, or conductors extending from an intermediate
extra brush or brushes, and translating devices arranged in multiple series,
substantially as herein before described with reference to figure 3, of the accom-
panying drawings.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this twenty eighth day of June in the year of our Lord,
one thousand eight hundred and eighty three.
TH³ J HANDFORD (L.S.)