improvements in ада Connected with Electrical Distribution Dy Means of Direct or Alternating Currents, Chiefly for Lighting Purposes, and in Electric Measuring Instruments which may be Used therewith.
Year: 1887

page_text: Date of Application, 6th May, 1887
Complete Left, 6th Feb., 1888
Complete Accepted, 27th Apr., 1888
improvements in ада
Connected with Electrical Distribution Dy
Means of Direct or Alternating Currents, Chiefly for Lighting
Purposes, and in Electric Measuring Instruments which may be
Used therewith.
I, JAMES SWINBURNE, of Shona Chelmsford, in the county of Essex, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention refers to the distribution of electrical power, chiefly for lighting
purposes, by means of converters working with direct or alternating currents; and to
apparatus for measuring the electrical power so distributed, or for other measuring
purposes.
At present the usual practice with alternating current converters, or secondary
generators is to use an alternating current dynamo of very high electromotive force
at a central generating station, and to arrange converters with their primary wires in
parallel. The secondary circuits are then used for incandescent lamps; and these
lamps are arranged in parallel, or as it is sometimes called, multiple arc.
This arrangement of the converters has the drawbacks that if very high electromotive
forces come on the primary circuits the insulation is apt to give way & that when the
converters are so connected either the leads must be large & expensive or the currents
must be smaller than convenient in practice. Coupling the primary wires of the
converters in series has been attempted, but it was found that the converters would
not regulate, and when the lamps on the secondary circuit were turned out one by one
so that the secondary circuit was decreased the virtual back electromotive force in the
primary circuit of the converter increased while the virtual electromotive force on the
lamps also increased.
The arrangement of converters with their primary circuits in series has therefore
never come into use.
According to my invention the primary circuits of the converters are arranged in
series, so that what may be called a constant alternating current is used in the
primary circuit. The secondary circuit of each converter is connected to incandescent
lamps, but these are arranged in series, not in parallel. Each lamp is provided with

page_text: a short circuiting switch which is used to turn it out. Thus when all the lamps are
turned out the secondary circuit is short-circuited.. By using plenty of iron in the
construction of the converter it may be made to give a practically constant virtual
current in the secondary circuits. I prefer to use incandescent lamps taking about
5 ampères & 10 volts, so that the electromotive force in a house is not dangerous.
Thus a house wired for twenty lamps, of which ten are used, will have 100 volts on
the secondary terminals of the converter.
If it is found that the lamps burn too bright when only a few are used it may be
advisable to use some regulating device. An electromagnet with a fine iron wire core
may be arranged in parallel with the lamp circuit, so that an armature is released
which closes a small subsidiary secondary circuit thus reducing the current induced
in the secondary coil proper or preventing its increase when many lamps are
turned out.
1 may sometimes arrange little induction coils so as to be cut in or out by the
switches that turn the lamps in or out to keep the lamps of uniform brightness. A
house with a large number of lamps may have several converters. The primary wires
are of course arranged in series the secondary circuits are either separate or coupled
in series.
Each converter has an automatic cut-out which short-circuits the primary circuits
if the secondary is broken by a lamp failing or otherwise. Each lamp may have a
cut-out also or a cut-out may be placed for several.
The alternating current generator. is governed so as to give a constant effective
current by weakening its fields or otherwise. Thus a small converter may be placed
in the main circuit with its secondary circuit working a dynamometer with both coils
in series. This dynamometer then measures what may be called the virtual current
in all the secondary circuits. It works a relay which controls the excitation of the
field magnets or the speed of the engine.
For distributing by means of direct currents I use direct current converters which
resemble direct current dynamos with two armatures, or one armature wound with
two circuits. One circuit is the primary, and turns the armature, thus generating a
current in the other wire.
Distribution by direct current converters may, according to my invention, be
carried out in several ways.
a
The primary circuits of several converters may be connected up in series. I then
use a dynamo, or dynamos at the generating station wound and governed to give
constant current. I wind the field magnets and primary armature circuit of the
converters in series, so that there is constant torque on the armatures due to the
primary current; 'the machine will then run at such a speed as to give constant or
very nearly constent current in the secondary circuit. In the secondary circuit I
arrange incandescent lamps in series as in the case of alternating current converters
as already described and explained. These lamps are, preferably of low resistance,
and have shortcircuiting switches & cut outs as explained, but have no self induction
coils.
As the converter may otherwise tend to give slightly less than the normal current
at the higher speeds, I sometimes wind an additional wire of high resistance round the
field magnets, & connect it up in shunt to the secondary circuit, so as to strengthen
the fields enough to overcome the extra bearing and commutator friction. For series
work' I prefer to wind both primary and secondary coils on one armature. There is then
no appreciable lead of the brushes on either commutator. I use few commutator
sections, and so design the armatures that there is little or no self induction. The
sparking then gives no trouble, and as there is little load on the bearings the machines
need little or no attention.
To measure the electrical energy supplied a house by such a converter I attach a
revolution counter to the spindle of the converter.
If it is needed to preserve constant or approximately constant electromotive force on
the secondary circuit with a constant current in the primary I may make the converter
in' the form of a double machine, with two armatures, and two sets of field magnets

page_text: with the axles coupled together, or joined. I arrange the field magnets in such a
manner that when there is a heavy load on the secondary circuit the field of the primary
magnets are more strongly magnetised. Thus, for instance, the primary fields may
be partly magnetised by the primary current, and partly by coils in series with the
secondary circuit. The primary magnets may thus have just enough turns of primary
wire to excite them enough to start the machine with no load; the secondary magnets
being excited in shunt to the secondary circuit. The rest of the coils on the primary
fields may then consist of wire in series with the secondary circuit. The secondary
magnets may be wound with some backward turns in series with the secondary
circuit.
If it is needed to drive several converters with their primary coils in parallel on a
circuit with approximately constant electromotive force I use a few turns of primary
round the primary magnets to start them, but excite mainly in shunt to the secondary
circuit. The secondary magnets are also excited mainly in shunt to the secondary.
circuit, but are partly excited in series with it so as to give constant electromotive.
force in spite of the slackening of speed due to increased load. I prefer for such work
generally to drive each converter from its own dynamo at the central station, and
to make the dynamo give a higher electromotive force on the terminals of the converter
when a large current is used. I then use an armature wound with two circuits in the
converter and one set of field magnets. The field magnets are then excited in shunt
to the secondary circuit, and the dynamo & motor and leads are so calculated as to
give constant electromotive force on the secondary circuit. If the variation of load is
not excessive I prefer a series generator in this case. A converter wound as last
described has its brushes always in the same position as there is no lead or very little
lead required. The commutator sections are few in number, and the wires, carefully
insulated, are so arranged that there is no self induction when the sections are
commutated.
Other methods of controlling converters by winding the magnets with wires in
series with or in shunt to the primary or secondary circuits may be used. The
brushes may also be given a backward or forward lead, arrangements being applied
to prevent excessive sparking.
My invention also has reference to measuring instruments, and has for its object the
measurement of the electricity passed through a given part of a circuit during a given
period or of the electrical energy spent during a given period or the measure of the
product of the average E.M.F. & the time through a certain period or in
mathematical language the apparatus is for taking certain electrical & other time
integrals.
This part of my invention may be best understood by explaining the simplest case
first. If a house is supplied with electrical energy at a constant potential as is
commonly the case but takes different currents at different times what is wanted, is to
determine the quantity of electricity used. To do this I place a suitable ammeter in
the main circuit & I place a little copper deposition or other voltameter with a high
resistance in series with it in shunt to the whole of the lamps so as to have a
constant E.M.F. on its terminals. This high resistance is more or less cut out by the
ammeter so that the greater the current through the ammeter the greater the current
through the voltameter. The ammeter may for example consist of a coil of wire or
solenoid with a soft iron core & this core may be sucked into different positions against
a spring. As the current varies it works a small rubbing contact made with as little
friction as possible which regulates the high resistance in series with the volt-
ameter.
The solenoid is calibrated & the resistances are calculated accordingly. The metal
deposited in the voltameter is then proportionate to the quantity of electricity passed
through the main circuit.
If it is desired to measure the energy when the E.M.F. on the circuit varies if
the E.M.F. depends on the current alone the resistance can sometimes be proportioned
so as to make the deposited metal proportionate to the energy. If however the E.M.F.
is independent of the current instead of an ammeter a power-meter or wattmeter is

page_text: used to work the resistance & the voltameter circuit has constant E.M.F. kept upon
it by means of a volt-meter which puts more or less resistance in circuit with it or by
having a separate set of cells independent of the circuits which thus supply the current
for the voltameter.
If alternating currents are used the method last described is applicable the resistance
being controlled by an alternating watt-meter.
If a house is supplied with alternating currents at a constant E.M.F. the watt-meter
may be used as before or the following method may be used.
The main current is passed through the small induction coil which is preferably made
without iron the secondary coil of this then gives an E.M.F. which depends on the
current in the main circuit. A small vibrating arrangement is connected up so as to
commutate the secondary circuit or to intermit it so as to get a series of impulses in
one direction. The voltameter is then put in series with a high resistance which is
made without self induction in the secondary circuit. This intermitting arrangement
may be used when taking any other alternating current measurements. For instance
it may be used to take readings of the E.M.F. or of the currents by means of volt
meters, or ammeters.
My invention is applicable to very many purposes, such for instance as measuring
the output of secondary batteries. When a voltmeter is used to work the resistance
I prefer one on the principle of Cardew's well known instrument as it is not much
interfered with by the friction of the little contacts. In some cases where it is
difficult to make a watt-meter that can work in spite of the friction the resistances
can be worked by two separate instruments one being a volt meter & the other an
ainmeter.
My method of integrating may be applied to various purposes, for instance a steam
engine may have a little cylinder like that of an ordinary indicator & instead of taking
a diagram the index may be made to work the resistance contacts.
A source of constant E.M.F. is then put in series & from the volt-ameter reading
can then be got the number of H.P. hours given by the engine.
If the engine varies much in speed a little magneto-electric generator driven by it
can be used to give the current for the voltameter so that the speed error is eliminated.
This arrangement is applicable for instance to locomotives. In short the system can
be applied in any case where apparatus can be arranged to alter the resistance. Instead
of resistances in some cases a sliding arrangement may put in more or less cells
so as to alter the E.M.F.
Dated this 5th day of May 1887

page_text: I JAMES SWINBURNE of Shona, Chelmsford, Electrical Engineer do hereby declare
the nature of this invention and in what manner the saine is to be performed,
to be particularly described and ascertained in and by the following statement :-
My invention refers to the distribution of electrical power, chiefly for lighting
purposes by means of converters working with direct or alternating currents; and to
apparatus for measuring the electrical power or electrical energy so distributed, or for
other measuring purposes.
In direct current work one of the following arrangements may be used. It may be
desired to preserve constant pressure on the secondary circuit with constant pressure
on the primary.
The pressure on the secondary circuit may be wanted to increase a little with the
load so that lamps at a little distance from the converter will get constant pressure in
spite of the resistance of the leads. In addition to this the pressure on the primary
may fall with an increased load, owing to the loss in the primary leads. This fall may
take place only when the converter is loaded, or it may be due to other converters
connected in parallel. Again constant current might be wanted in the secondary
circuit with constant or varying pressure on the primary. Or constant pressure or
constant current may be wanted in the secondary with constant current in the primary.
To obtain something approaching constant pressure in the secondary circuit with
approximately constant primary pressure a converter is sometimes used made as is well
known, like a dynamo with two armature circuits and two commutators. This has
several drawbacks. As it cannot be run at very high speeds the resistances of the two
armature circuits reduce the full load secondary pressure considerably, & this cannot
be corrected by any method of winding the field magnets. So that if there is a
five per cent loss in each armature circuit the secondary pressure at full load falls
about 10 per cent. When the loss by primary & secondary is added it is obvious that
the variation with small converters of this type is too great to admit of their working
incandescent lamps successfully. In addition there is danger of contact between the
primary and secondary circuits which is an objection in house lighting. To overcome
this I use a converter with two armatures each armature having its own magnets so
that the machine is really a dynamo and motor coupled together as far as mechanical
construction goes. The field magnets are then wound so as to give constant pressure
on the secondary circuit. If the primary circuit has constant pressure the primary
and secondary magnets may be wound in shunt to the secondary circuit and the
secondary field magnet strengthened or the primary field weakened by some turns of
the main primary or main secondary circuit.
If the primary pressure varies with the load its winding may be arranged to com-
pensate for it & also to compensate for loss in the secondary leads. If the primary

page_text: pressure varies independently of the load I prefer to wind the primary fields in shunt
to the primary circuit so that they are not saturated so that the armature runs at
approximately constant speed when the primary pressure varies. The principle here
applied is that the secondary field is comparatively stronger than the primary at full
load than at half or no load. This demands separate armatures and field magnets.
To prevent sparking with change of load I use what I call reversing pole peices.
These are fully described in my specification 17120 of /85 and 6409 /87 so that they
need not be described here. As the secondary and primary circuits are separate in
the apparatus just described, there is no danger. Instead of the arrangement just
described I generally prefer to use a converter in which the arinature is a stationary
ring with a small field magnet rotating inside it. As dynamos on this principle are
fully described in the specification 17120 of 186 it is only necessary to describe the
modification needed when they are used as converters. The stationary armature is
wound with two circuits, but as the armature is stationary there is no difficulty
in insulating them thoroughly. The field magnet being small can be rotated very
rapidly, and the armature can be made of very low resistance as there is plenty of
room.
It is therefore hardly necessary to use separate armatures and field magnets, as the
fall of potential at full load is small. This difficulty is also obviated to some extent
by making the dynamo at the central station give higher pressure at full load. Thus
if the converters lose four per cent at full load the dynamo may give two per cent
more so that the actual drop is only two per cent.
Any consumer who has only one or two lamps on will then get two per cent too
much so that the variation is generally two per cent each way. In cases in which the
armature is wound with two circuits which always have approximately the same ampere
turns I use very few sections. For instance I use six coils on each circuit with three
part commutators, or eight or twelve coils with four or six part commutators.
When constant pressure is wanted in the secondary with constant current in the
primary I arrange separate armatures and field magnets. The field magnets of the
secondary are wound shunt & series as in an ordinary compound machine. The
primary field magnets are wound in series with the secondary circuit, with a few
turns of the primary in addition to start the machine. The primary field magnets and
armature are designed so that the iron is far from saturation. This arrangement does
not work very well through long ranges so it should only be calculated say from half to
full load. Sparking is prevented by reversing pole peices.
For constant current in both circuits a single armature may be used. The field
magnet is excited in series with one circuit preferably the primary, and the speed
varies with the pressure on the secondary circuit. A revolution counter is attached
to the spindle to measure the work done, thus serving as a meter.
When a direct current is wanted in the secondary circuit for use with secondary
batteries, and there is an alternating current in the primary I use a combination of
the alternating current motor and a direct current dynamo. Two machines may be
combined, the fields of both being excited by the secondary. To start the machine
the batteries are connected with the secondary circuit, a resistance being put
in the field so that it runs at the right speed. The primary circuit is then connected
with the central station through resistance which is gradually removed.
My invention also has reference to instruments for measuring the electricity or the
electrical energy spent during a given period or in mathematical language for taking
certain time integrals.
For instance, if a house is supplied with electricity at constant potential as
is commonly the case, what is wanted is to determine the quantity of electricity
used.
To do this I place a suitable ammeter in the main circuit. I place a little copper
deposition or other voltameter with a high resistance in series with it in shunt to the
house lamps, so as to have constant pressure on the terminals.
This high resistance is more or less cut out by the ammeter so that the greater
the current is through the ammeter the greater the current through the voltameter.

page_text: The ammeter may for instance consist of a solenoid with a soft iron core the suction
being resisted by the spring. The movements of the core work a small rubbing
contact made with as little friction as possible, which regulates the high resistance in
series with the voltameter.
The solenoid is calibrated & the resistances are made accordingly. The metal
deposited is then proportional to the electricity passed. If the electrical pressure
varies the weight of metal is proportional to the energy. Instead of the metal
voltameter I sometimes use a gas voltameter & measure the volume of gas produced
preferably by means of a little gas meter.
For alternating currents the same arrangements may be used the resistance
being wound noninductively and a suitable animeter being used.
The gas voltameter should also be used, as metal is not deposited by alternating
currents.
The ammeter may be dispensed with in the case of alternating currents supplied at
constant potential. A small transformer with a closed iron circuit is used the main
house circuit being the primary and having few turns & thus giving a small secondary
current which varies as the large one. The voltameter is in this circuit.
By this means I avoid the difficulty of bringing a large current through the
voltameter and thus wasting power. Though it may not be necessary I prefer to put
a vibrating contact maker with a permanent magnet armature in the secondary circuit.
This short circuits the secondary coils for half each period so that the current through
the voltameter is only in one direction. A metal voltameter is then available and the
gas arrangement is also more accurate then. The voltameter and vibrator arrange-
ment may be put in the primary circuit without a transformer. The voltameter may
be put in the primary circuit of a direct current transformer with constant pressure on
the primary, as the current is small and can so be measured without loss of power or
other inconvenience.
DESCRIPTION OF THE DRAWINGS.
In sheet 1 of the accompanying drawings fifteen diagrams are shewn to explain the
coupling of direct current converters. The primary armatures are shewn as squares
marked p and the secondary armatures as squares marked s. Rectangles above them
represent the field magnets. In all the figures the fine lines on the rectangles represent
shunt magnet winding, & the thick lines series magnet winding. When the winding
is shewn as a right handed screw it means that it tends to magnetise the field; when
shewn as a left handed screw it means that it tends to demagnetise the field.
Fig. 1 to 10 shew direct current converters for constant potential in the secondary
with approximately constant potential in the primary.
Fig. 1 shews a direct current converter in which the primary field is excited in shant
to the primary armature and the secondary field is wound partly in shunt to the
secondary armature & partly in series with it.
In Fig. 2 the primary field is excited in shunt to the primary armature & is partly
demagnetised by the secondary main. The secondary fields are excited partly in shunt
to the secondary armature and partly in series with it.
In fig. 3 both fields are excited chiefly in shunt to the primary armature. The
primary field is weakened by the primary main & the secondary is strengthened by the
secondary main.
In Fig. 4 both fields are excited mainly by a shunt to the primary armature. The
primary is weakened by the secondary main and strengthened by the secondary
main.
In fig. 5 each field is in shunt with its own armature.
In fig. 1 to 5 the shunts are shewn and the primary field is excited in shunt to the
primary armature. This is for cases in which the primary electromotive force varies
independently of the current taken by the converter.
In fig. 6 the shunts are not shewn, but both fields are in shunt to the secondary
armature. The primary field is also partly demagnetised by the secondary main.
In fig. 7 both fields are excited mainly in shunt to the secondary armature, The

page_text: primary field is excited partly also by the primary main, & is partly demagnetised by
the secondary main.
In fig. 8 the primary is excited in shunt to the secondary armature. The secondary
is excited partly in shunt to the secondary and partly in series with it.
In fig. 9 the primary and secondary are excited in shunt to the secondary armature.
The secondary field is also partly excited by the primary main.
In fig. 10 the fields are excited in shunt to the secondary & the primary field is
partly excited by the primary main & weakened by the secondary main, & the
secondary field is partly magnetised by the secondary main.
The primary main assisting the shunt on the primary field is chiefly for starting the
apparatus. It may be short circuited out when the machine is started. A resistance
in the armature circuit may also be used when the primary field is in shunt to the primary
armature.
If there are secondary batteries in connection with the secondary circuit they can be
used for starting the machine.
Figs. 11 & 12 refer to converters for constant primary current & constant potential
in the secondary. In fig. 11 the primary field has no shunt. It is excited partly by
the primary but chiefly by the secondary main. The primary main is just enough to
start the converter; & the strength of the field varies, roughly, with the secondary
current. The secondary field is partly demagnetised by the secondary main. This is
chiefly advisable with large variations of load. The fields are wound so that at small
loads the primary field & armature are far from saturation while the secondary field
or armature is nearly saturated by its shunt. At full load the primary field is strong
& the secondary is as weak as it can be without instability.
Fig. 12 is the same except that the primary field is excited entirely by the secondary
main. This arrangement does not allow such large variations.
When the fields are both excited by a shunt or main a former that embraces both
may be used to save wire.
Fig. 13 is a converter for constant current in both circuits. The primary &
Becondary armature circuits are on one armature. One field excited by the secondary is
shewn. To start, the brushes are moved. To secure better insulation two armatures
may be used.
Fig. 14 is the same except that the primary field is partly excited by the primary
main. There is no shunt in figs. 13 or 14. The magnets may also be excited entirely
by the primary main.
Fig. 15 shews a converter for charging secondary batteries with constant primary
and secondary current. The magnets are excited in shunt to the secondary armature.
Fig. 16 sheet 2 is a diagram of a meter according to the present invention. a is
the main lead. It is in circuit with the coil b. When there is a current the core c is
pulled down against the force of the spring d so that the position of the core depends
on the current. A shunt circuit is led from h by way of the spring & core to e. e
makes contact with one or two of the plates ff so the circuit goes on through the
resistance g to the voltameter i & to the other main lead j. The amount of resistance
in the coils in circuit thus depends on the position of e & thus on the current in
the main a. Light spring contacts may be used instead of the wheel arrangement shewn.
Fig. 17 shews a set of contacts oo for connection with resistances in a voltameter
circuit, the resistances being controlled by the arm m moved by the fine wire k which
is expanded by the heating due to a current in it. The wire is kept taut by the spring p.
This form is specially useful for insertion in the primary circuit.
Fig. 18 shews the arrangement of meter and vibrator for alternating currents q is
a little transformer with a few turns of the main circuit as primary. The little
secondary circuit passes through the voltameter t & coil . The coil makes the
little magnets N. S oscillate thus making & breaking the contact u so that the
voltameter is short circuited when the current passes in one direction. The magnet n s
is on an arm with a spring v fixed to w. The little transformer q is not always used,
sometimes the voltameter & coil x are simply inserted in the primary circuit of the
converter that feeds the house.

page_text: In fig. 19 a gas meter voltameter is shewn in the primary circuit, z being the main
converter, not a little auxiliary for the meter. The vibrator arrangement may be used
with y.
In fig. 8 sheet 1 a voltameter is shewn in the primary of a direct current converter
A motor meter is also very suitable for this arrangement as a small current can easily
be led into the armature. A motor meter is also very suitable for alternating current
work arranged in the primary of a converter circuit.
Having now fully described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A direct current transformer with primary & secondary armatures and field
magnets wound to give approximately constant electromotive force on the secondary
circuit with approximately constant, or with varying electromotive force on the primary
circuit.
2. A direct current transformer with primary and secondary armatures and field
magnets wound to give approximately constant electromotive force on the secondary
circuit with approximately constant current in the primary circuit.
3. A direct current transformer wound to give approximately constant current
in the secondary circuit with approximately constant current in the primary
circuit.
In a direct current transformer with separate primary & secondary armatures &
field
magnets
:-
4. The field magnets wound in shunt to the secondary external circuit, the primary
field being weakened by backward turns of primary or secondary main at full load, or
by armature back induction.
5. The field magnets wound in shunt to the primary armature circuit the primary
field being weakened by backward turns of primary or secondary main at full load or
by armature back induction.
6. The field magnets wound in shunt to either or partly to each circuit with the
secondary fields strengthened at full load by forward turns of primary or secondary
main.
7. The primary fields wound so that the iron of the armature and fields is far from
saturation substantially as described & for the purposes set forth.
8. The primary field magnets wound in series with the secondary main circuit
substantially as described & for the purposes set forth.
9. In a direct current transformer with a double wound armature, winding the field
in series with the primary or secondary circuit for the purpose set forth.
10. In combination with a direct constant current transformer a meter consisting of
a revolution counter.
11. A transformer with direct secondary and alternating primary circuit substan-
tially as described and for the purpose set forth.
12. A meter for use in connection with alternating or direct currents con-
sisting of a voltameter whose current is controlled by an ammeter or wattmeter,
substantially as described.
13. A meter for use in connection with alternating currents operated by the
secondary circuit of a transformer whose primary is in the main circuit.
14. In a meter for use in connection with alternating current distribution a
vibrator to commutate the current or render it intermittent, but constant in direction.
15. An electric meter inserted in the primary circuit of a direct or alternating
current transformer.
Dated this Sixth day of February 1888.