Improvements in Distributing Electricity, and Means or Apparatus for the Purpose.
Year: 1892

page_text: Date of Application, 22nd Dec., 1892
Complete Specification Left, 2nd Sept., 1893-Accepted, 7th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Distributing Electricity, and Means or Apparatus
for the Purpose.
I, HAYDN THIES HARRISON, of 29 Dorchester Place, Blandford Square,
London, N.W., Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
The ordinary systems of electrical distribution (excluding the direct high tension,
rarely used) may be divided into two classes the direct low tension system and the
alternating high tension (transformer) system; each of these has its advantages and
disadvantages.
meters
An advantage of the low tension system lies in the fact that practically all the
energy produced during light loads is registered on the consumers'
appreciable loss in the mains occurring only during heavy loads and as the station
is ordinarily running a light load on the average probably some 16 hours out of
the 24 it becomes obvious that the system has a good day load efficiency, especially
as accumulators may be used during the day and steam be shut down altogether.
On the other hand the low tension system is only practicable over a comparatively
small area, the conductors laid down have to be capable of carrying the maximum
load, thus absorbing a large amount of capital in mains; during heavy loads much
of the energy is wasted in heating these mains; and, moreover, the large direct
current dynamos necessary for the system are costly to make and suffer considerably
from wear and tear.
The alternating high tension (transformer) system has a high plant efficiency
during medium and heavy loads, but during the day time there is more energy lost
in magnetizing the transformers than is consumed in light by the consumers at
the time; hence with this system there is high efficiency during heavy loads and
low efficiency during light loads; moreover the system has the advantage that it is
able to distribute its energy over a larger area and involves less outlay of capital in
mains and transformers than is involved in providing the mains of a corresponding
low tension system.
Now my invention has reference to a system in which the foregoing two systems
are combined and which is adapted to admit of running when a light load is on (for
example during the day) with a low tension dynamo, or accumulators direct on to
the consumers' lights, and when the load begins to increase to switch over onto a
high tension alternator, which will feed the consumers' lights through transformers
in the ordinary manner. For these purposes I provide in connection with the
primary and secondary mains, switches adapted when operated to throw the
respective transformers into circuit this being done directly the low tension current
is switched off and before the high tension alternating current is switched on, and
to cut out the transformers and connect the consumers' or secondary mains direct
switched off*
on to the service or primary mains directly the high tension current
and the low tension current switched on.
In carrying out my invention it is advantageous though not in all cases necessary
to employ automatic switches such that the automatic changes will take place as
rapidly as practicable so as to minimise the blink in the light. In order to effect
this I take advantage of the retardation of the alternating current due to self
induction, and also of the repulsion of copper rings and short circuited coils from
magnets excited by an alternating current.
According to one arrangement for carrying out my invention, each transformer
or bank of transformers either in a consumer's house or in a distributing station is
provided with an automatic switch comprising a lever on which are fixed four

page_text: copper connecting pieces or staples two on each side of the fulcrum and four pairs
of contacts for example mercury cups so arranged that there are two pairs on each
side of the fulcrum of the lever and so that each connecting piece can when
depressed connect up one pair of them.
One arm of the lever is weighted so that the two connecting pieces on that arm
will remain in the corresponding two pairs of mercury cups except when the weighted
end is attracted by an electro magnet placed above it. This electro-magnet is
wound with very fine wire the iron forming its core being carefully laminated so as
to make it a very efficient choking coil. The magnet winding is connected across
the primary or service mains.
The two pairs of mercury cups under the weighted end of the lever are so
connected that when the electro-magnet does not attract the armature the
oonnecting pieces being immersed in the mercury in the said cups will connect
the primary of the transformer to the primary or service mains and the secondary
of the transformer to the secondary or consumers' main. The other end of the
lever being raised the connecting pieces carried thereby will be out of the two
corresponding pairs of mercury cups which are insulated from each other thus
disconnecting the transformer from the mains. These two pairs of mercury cups
are connected in such a way that when the connecting pieces are down the primary
or service mains from the central station are connected direct on to the secondary
or consumers' mains, and the transformer is disconnected.
The action of the arrangement is as follows:-
Assuming the station to be running with accumulators or with a direct current
dynamo for a light load when the mains laid down for the high tension current are
capable of carrying the current necessary to light the lamps direct then when the
load, as shown by the ammeter at the station increases to a suitable amount the
high tension alternators are started and the load switched by a double pole two-way
switch from the direct low tension current generator to the high tension alternating
current generator. The action of the automatic switch at the distributing station
or private house or of each such switch where there are several is as follows:-
While running with a direct low tension current the electro magnet of the
automatic switch will be powerfully energized there being no retardation to the
current passing through its winding beyond the ohmic resistance, consequently
it attracts its armature and connects the primary or service mains direct onto the
secondary or consumers' main, but directly the direct low tension current is
switched off there is a momentary break in the primary or service mains, which
permits the weighted end of the lever to fall and throw the corresponding
transformer into circuit so that directly, the alternating high tension current is
switched on, the secondary or consumers' main will be served by the transformer,
the retardation of the electro-magnet with alternating current being so high
due to self induction, that it is unable to attract the weighted end of the lever which
serves as its armature or is provided with an armature. The electro-magnet can if
desired be made to repel the armature when the alternating current is on by placing
a short circuited wire around the armature.
In another arrangement in which the circuits are arranged in the same way as in
the one just described, the electro-magnet of the automatic switch is wound with
thick and thin wires the thick wire being connected in series with the primary of
the transformer on the primary or service mains and the fine wire being connected
as a shunt across the secondary or consumers' main.
In this arrangement when the direct low tension current is switched on, it passes
through the thick wire of the electro-magnet and through the primary of the
transformer. This causes the electro magnet to attract its armature and lift the
lever thereby connecting the secondary mains to the primary mains. The fine
wire is also simultaneously connected across the secondary mains thereby energizing
the electro-magnet and holding the armature up. The lever being thus raised the
primary and secondary windings of the transformer are disconnected from the
mains. When the direct low pressure current is switched off and the alternating

page_text: high tension current is switched on the armature will fall and connect the
transformer to the primary or service main the electro-magnet not being able then
to attract the armature owing to the current passing through its thick winding
being too weak, it being only the primary current of the transformer, and the
fine wire winding on the magnet not allowing sufficient current to pass.
Moreover.
by the armature with a short circuited coil it will be repelled from the electro-
magnet.
In a further arrangement there are three wires from the generating station. One
of these extending wires is provided at one end with a switch by which it can be
connected either to the high tension alternating current dynamos or to the low
tension direct current dynamos or accumulators as required.
This wire is also connected to the primary and secondary winding of the
transformer (or of each transformer where there are more than one) at the
distributing station or consumer's house and to one of the secondary or consumer's
mains. One of the other wires is connected to the other pole of the alternator or
alternators and to the other end of the primary winding of the transformer and the
third wire is connected to the other pole of the direct current dynamo or dynamos
or accumulators and through the winding of the electro-magnet in the automatic
switch of the secondary or consumers' main. The magnet is also provided with a
second winding connected across the secondary main.
The automatic switch is so arranged that when the electro magnet is energised
by switching on the direct low tension current the contact piece one only of which
is used in this case is raised out of the mercury cups of which there is only one
pair, thereby disconnecting the secondary winding of the transformer from the
secondary or consumer's main.
When the switch on the third wire is moved so as to switch on the alternating
high tension dynamos the high tension current will pass through the primary
winding of the transformer and the armature and lever will cease to be held up by the
electro magnet and in falling will connect the secondary or consumers' mains to the
secondary winding of the transformer from which they will then be supplied with
electricity.
Dated this 22nd dox of December 1802
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Distributing Electricity, and Means or Apparatus
for the Purpose.
I, HAYDN THIES HARRISON, of 29 Dorchester Place, Blandford Square,
London N.W. Electrical 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 ordinary systems of electrical distribution (excluding the direct high tension,
rarely used) may be divided into two classes, the direct low tension system, and the
alternating high tension (transformer) system; each of these has its advantages
and disadvantages.
An advantage of the low tension system lies in the fact that practically all the
energy produced during light loads is registered on the consumers' meters,
appreciable loss in the mains occurring only during heavy loads, and as the station
is ordinarily running a light load on the average probably some 16 hours out of
the 24, it becomes obvious that the system has a good day-load efficiency, especially
as accumulators may be used during the day, and steam be shut down altogether.
On the other hand the low tension system is only practicable over a comparatively

page_text: small area; the conductors laid down have to be capable of carrying the maximum
load, thus absorbing a large amount of capital in mains; during heavy loads much
of the energy is wasted in heating these mains, and moreover, the large direct-
current dynamos necessary for the system, are costly to make, and suffer considerably
from wear and tear.
The alternating high tension (transformer) system has a high plant efficiency
during medium and heavy loads, but during the day time there is more energy lost
in magnetizing the transformers than is consumed in light by the consumers at the
time; hence, with this system, there is high efficiency during heavy loads and low
efficiency during light loads. Moreover the system has the advantage that it is
able to distribute its energy over a larger area, and involves less outlay of capital
in mains and transformers, than is involved in providing the mains of a corresponding
low tension system.
Now my invention has reference to a system in which the foregoing two systems
are combined, and which is adapted to admit of running, when a light load is on
(for example during the day), with a low tension dynamo, or accumulators, direct
on to the consumers' lights; and, when the load begins to increase, of switching
over onto a high tension alternator, which will feed the consumers' lights through
transformers in the ordinary manner. For these purposes, I provide in connection
with the primary and secondary mains, switches adapted to automatically throw
the respective transformers into circuit directly the low tension current is switched
off, and before the high tension alternating current is switched on; and to cut out
the transformers, and connect the consumers' or secondary mains direct on to the
service or primary mains, directly the high tension current is switched off and the
low tension current switched on.
In carrying out my invention,. I employ automatic switches, such that
the automatic changes will take place as rapidly as practicable, so as to minimise
the blink in the light. In order to effect this I take advantage of the retardation
of the alternating current, due to self-induction, and also of the repulsion of copper
rings and short circuited coils from magnets excited by an alternating current.
In the accompanying drawings,
Fig. 1 is a diagrammatic view illustrating one arrangement for carrying out my
invention.
In this arrangement each transformer 1, or bank of transformers, either in a
consumer's house, or in a distributing station 2, is provided with an automatic
switch comprising a lever 3 with armature 3* on which are fixed four copper
connecting pieces or staples 4, 4ª, 4, 4 two on each side of the fulcrum 3º, and
four pairs of contacts 5, 5ª, 5b, 5° for example mercury cups, so arranged (as
shown), that there are two pairs on each side of the fulcrum of the lever, and so
that each connecting piece or staple can, when depressed, connect up one such
pair.
One arm of the lever 3 is loaded so that the two connecting pieces 4, 4*, on that
arm will remain in the corresponding two pairs of mercury cups 5, 5*, except when
the loaded end of the lever is attracted by an electro-magnet 6 placed above it.
This electro-magnet is wound with very fine wire 7, and the iron forming its core
is carefully laminated, so as to make it a very efficient choking coil.
The magnet
winding is connected direct across the primary or service mains 8, 8ª as
shown.
The two pairs of mercury cups 5, 5" under the loaded end of the lever, are sc
connected that when the electro-magnet 6 does not attract the armature or lever 3,
the connecting pieces 4, 4ª being immersed in the mercury in the said cups 5, 5",
will respectively connect the primary 1ª of the transformer, to the primary or
service main 8, and the secondary 1 of the transformer, to the secondary or
consumers' main 9 through the conductors shown.
The other end of the lever 3 being then raised, the connecting pieces 4, 4°
carried thereby, will be out of the two corresponding pairs of mercury cups 5b, 5°
which are insulated from each other-thus disconnecting the secondary or

page_text: consumers' mains from the primary or service mains. These two pairs of mercury
cups are connected up in such a way that when the connecting pieces 4, 4º, are
down, the primary or service mains 8, 8ª from the central station 10 are connected
direct on to the secondary or consumers' mains 9, 9, and the transformer is
disconnected.
In the example shown, this is effected by connecting one of the mercury cups 5º
with the main 8 by a conductor 11, and the other with the main 9ª by a
conductor 12 and connecting one of the mercury cups 5 with the primary 8 by a
conductor 13 and the other to the main 9 by a conductor 14.
15 is a direct low tension current dynamo at the central station 10; or this
dynamo may be replaced by accumulators. 16 is a high tension alternator. 17 is
a double pole two-way switch by which either the dynamo 15, or the alternator 16,
can be connected with the mains 8, 8. 9* are lamps or other translating devices
on the secondary mains.
The action of the arrangement is as follows:-
Assuming the central station 10 to be running with the direct current dynamo 15
for a light load, and that the mains 8, 8, laid down for the high tension current,
are capable of carrying the current necessary to light the lamps direct, then, when
the load, as shown by the ammeter at the station, increases to a suitable amount,
the high tension alternator 16 is started, and the load switched by the switch 17
from the direct low tension current generator 15 to the high tension alternating
current generator 16, the switch 17 then assuming the position shown. The action
of the automatic switch at the distributing station or private house 2, or of each
such switch where there are several, is as follows:--While running with a direct
low tension current, the electro-magnet 6 of the automatic switch will be powerfully
energized, there being no retardation to the direct current passing through its
winding, beyond the ohmic resistance, consequently it will attract its armature or
lever 3 and connect the primary or service mains 8 8" direct onto the secondary or
consumers main 9 9 by way of the connecting pieces 4° 4°, pairs of mercury
cups 5 5, and the conductors herein before mentioned, but immediately the direct
low tension from the dynamo 15 is switched off, there is a momentary break in the
primary or service mains 8, 8" which permits the weighted end of the lever to fall,
and throw the corresponding transformer into circuit, through the connecting
pieces 4, 4ª, pairs of mercury cups, 5, 5ª and conductors shown, so that directly the
alternating high tension current is switched on, the secondary or consumers'
main 9, 9" will be served by the transformer, the retardation of the electro-magnet 6
with alternating current being then so high, due to self induction, that it is unable
to attract the loaded end of the lever 3, which serves as its armature, or which is
provided with an armature. The electro-magnet 6 can, if desired, be even made to
repel the armature when the alternating current is on, by placing a short-circuited
wire around the armature, in a manner that will be readily understood without
further description.
The arrangement herein before described, may be modified by winding the core
of the electro-magnet 6 of the automatic switch with a second winding 7" as shown
in Fig. 1. In this case the winding 7 is made of thick wire and is connected in
series with the primary 1 of the transformer on the primary or service main 8
by the conductor shown. The other winding 7 is made of thin wire, and is
connected as a shunt across the secondary or consumers' main 9, 9" as shewn.
In this modified arrangement, when the direct low tension current is switched on,
it passes through the thick wire 7, of the electro-magnet, and through the primary 1*
of the transformer. This causes the electro-magnet to attract its armature or
lever 3 and lift the loaded end thereof below it, thereby connecting the secondary
mains to the primary mains in the manner hereinbefore described. The fine wire 7ª
being connected across the secondary mains through which the direct low tension
current will then be passing, the electro-magnet will be energized by such current
and will hold the armature up. The weighted end of the lever 3 being thus raised,

page_text: the primary and secondary windings 1 and 1 of the transformer will be discon-
nected from the mains 8, and 9ª respectively. When the direct low pressure
current is switched off, and the alternating high tension current is switched on, the
armature or lever 3 will fall and connect the primary winding of the transformer
to the primary or service main 8, the electro-magnet not being then able to attract
the armature or lever owing to the current passing through its thick winding being
too weak it being only the primary current of the transformer, whilst that passing
through the fine wire winding on the magnet will then be an alternating current
and unable to attract the loaded end of the lever for the reason hereinbefore
stated. Moreover by providing the armature or lever with a short-circuited coil,
it will be then repelled from the said electro-magnet.
Fig. 2 is a diagrammatic view illustrating a further arrangement in which there
are three primary wires 8, 8, 8b, from the generating station. The wire 8b is
provided at one end with a switch 17 by which it can be connected either to one
pole of the high tension alternating current dynamos 25, or to one pole of the low
tension direct current dynamos 24, or accumulators, as required.
This wire is also connected to one end of the primary and secondary winding 1, 1*
respectively of the transformer (or of each transformer where there are more than
one) at the distributing station or consumer's house 2, by a conductor 18, and to
one (9) of the secondary or consumers' mains 9, 9 by a conductor 18. The
wire 8 is connected, or as in the example shown, is adapted to be connected by a
switch 17 to the other pole of the alternator 16, or alternators when several are
used, and, by a conductor 19 is connected to the other end of the primary
winding 1 of the transformer. The third wire 8ª is connected, or as in the
example shown, is adapted to be connected by a switch 17° to the other pole of
the direct current dynamo 15, or dynamos or accumulators, and, through the
conductors 20, the winding 7 of the electro-magnet in the automatic switch, and
the conductor 21, is connected to the secondary or consumers' main 9.
switches 17 and 17° are used, they may advantageously be coupled to the
switch 17 as shown so that they can be all operated simultaneously. The electro-
magnet in this arrangement is also provided with a second winding 7 of fine wire,
as in the last described arrangement, connected across the secondary mains 9, 9.
When
22 and 23 are conductors by which the other end of the secondary winding 1
can be connected to the secondary main 9 through the contact 4 carried by the
switch lever 1, and the pair of mercury cups 5. 24 is a meter in circuit with the
conductor 18*.
The automatic switch lever 3 in this construction is so arranged, as shewn, that
when the electro-magnet 6 is energized by switching on the direct low tension
current through the wires 8b, 8ª, by means of the switch 17, or 17-17° the
contact piece 4, one only of which need be used in this case, is raised out of the
mercury cups 5, of which there is only one pair, thereby disconnecting the secondary
winding 1 of the transformer from the secondary or consumers' main.
When the switch 17, or 17-17 is moved so as to switch on the alternating
high tension dynamo, the high tension current will pass through the wires 8, 85,
conductors 18 and 19, and primary winding 1 of the transformer, and the armature
and lever 3 will cease to be held up by the electro-magnet, and in falling will
connect the secondary or consumers' mains 9, 9º, to the secondary winding 1° of the
transformer, from which they will then be supplied with electricity, the alternating
current then passing through the magnet winding 7 failing, as before, to energise
the magnet and attract the switch lever.
Should it not be considered advisable that one end of the primary and secondary
windings of the transformer be connected together, as shewn, when the high
tension current is on, an extra pair of mercury cups and a connecting piece may
be introduced into the automatic switch at the opposite end of the lever 3 to the
pair shown in Fig. 2 and which lever is then extended to the other side of its
fulcrum, these additional mercury cups and contact piece serving only to make the

page_text: connection when the direct low-tension current is on and to break the connection
when the high-tension alternating current is on.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that I do not claim
broadly and generally the combination of a direct low-tension system of distributing
electricity with an alternating high-tension (transformer) system of distributing
electricity, but what I do claim is :-
1. In a combined direct low-tension and alternating high-tension (transformer)
system of distributing electricity, the employment in connection with the primary
and secondary mains and transformers, of switches adapted to automatically throw
the respective transformers into circuit directly the low-tension current is switched
off, and before the high-tension alternating current is switched on, and to cut out
the transformers and connect the consumers or secondary mains direct on to the
service or primary mains, directly the high-tension current is switched off and the
low-tension current switched on, as hereinabove set forth.
2. In the combined system of distributing electricity referred to in the preceding
claim, the employment as set forth, of an automatic switch comprising a loaded
switch lever controlling circuit connections, and an electro-magnet provided with a
winding having large self induction and connected across the primary or secondary
mains, the arrangement being such that when the said mains are connected with a
continuous current generator, the electro-magnet will operate the switch lever to
cut the corresponding transformer out of circuit, but when the said mains are
carrying an alternating current, the electro-magnet will cease to attract the switch
lever which will then act to place the said transformer in circuit, substantially as
herein described, whether or not the switch lever be provided with a metal ring or
closed coil for the purpose set forth.
3. In the combined system of distributing electricity referred to in Claim 1, the
combination and arrangement of parts constituting the improved automatic switch
and circuit connections arranged as described with reference to and illustrated in
Fig. 1 of the drawings for the purpose specified, or modified according to Fig. 14.
4. In the combined system of distributing electricity referred to in Claim 1, the
combination and arrangement of parts constituting the improved automatic switch
and circuit connections arranged as described with reference to and illustrated in
Fig. 2 of the drawings for the purpose specified.
Dated this Second day of September 1893.
W. Lloyd Wise,
H. T. HARRISON.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.