Improvements in Alternating Current Transformers or Induction Coils.
Year: 1887

page_text: Date of Application, 10th Mar., 1887
Complete Left, 8th Dec., 1887
Complete Accepted, 3rd Feb., 1888
PROVISIONAL SPECIFICATION.
Improvements in Alternating Current Transformers or Induction
Coils.
We, ROBERT DICK, Manufacturer, and RANKIN KENNEDY, Electrical Engineer,
both of the Electric Lamp Works, 115 Woodside Road, Glasgow, Lanarkshire, do
hereby declare the nature of our Invention, to be as follows:-
In the usual forms of transformers and induction coils, for transforming alternating
currents of electric energy from low potential to high potential, and from high
potential to low potential, the magnetic iron organ portion of the transformer is
magnetised alternately in opposite directions, the flow of magnetic force is reversed in
direction with overy reversal of the direction of the alternating current: this reversal
of the magnetism which is very rapid, as often over 200 reversals are made per second,
consumes energy which is converted into beat in the iron, and this heat is a source of
trouble and often destroys the insulation of the coils of wire in the transformers.
To obviate this heating and loss of energy, according to our Invention, we construct
transformers in such a manner and operate them by currents of electric energy so
arranged that no reversals of magnetism occurs in them at all. For this purpose we
wind the transformers with two circuits a primary and secondary for the alternating
currents, in the usual manner, and by our improvements we use a third circuit for
the circulation of an independent current flowing continuously in one direction, and
this continuous current has for its object the initial magnetising of the magnetic iron
organ portion of the transformer continuously in one direction. This initial inagnetism
may be induced in the magnetic iron organ or core of a transformer by other well
known means than by a circuit or coil of wire and a continuous direction current of
electric energy; thus a permanent magnet or an electro magnet may be employed to
give the necessary initial magnetism to the magnetic iron organ or core.
In carrying our invention into practice we may apply our improvements with
great advantage to any form or construction of induction coil or transformer by using
a third wire or circuit through which flows a current of electric energy in one
direction. This third continuous direction current circuit may be wound side by side
either over, under, or between the two alternating current circuits of primary and

page_text: secondary wire provided it surrounds or is surrounded by the magnetic iron organ,
and magnetises that organ efficiently.
The effects or working of this method of winding induction coils or transformers
we explain thus:-The continuous current in the third circuit raises the iron organ
of the transformer to a high degree of magnetism in one direction, the alternating
currents in the primary wire of the transformer alternately raises and lowers the
degree of magnetism in the core or iron organ of the transformer but never reverses
that magnetisin in direction. When the current in the primary wire is in the same
direction as the continuous current, the magnetism in the iron organ rises in
intensity when the current in the primary wire is in the opposite direction to that
in the continuous current circuit the magnetism in the iron organ is reduced but not
reversed and the strength of the currents are so balanced and the number of turns
in each circuit are so proportioned that the magnetism in the iron organ falls to zero,
but not below it; and rises to a maximum with the alternating currents when full
work is being done by the transformer.
;
The continuous currents may be supplied to the third wire circuit by a shunt from
the generator which excites the field magnets of the alternating current dynamo
which supplies electric energy to the primary wire in the circuit, or from other con-
venient source where direct currents are generated.
Transformers having their iron organ portion magnetised as described may be
operated by an intermittent current in the primary circuit producing an alternating
current in the secondary circuit and this with great advantage where the primary
potential employed is low.
PML 1007

page_text: We, ROBERT DICK, Manufacturer, and RANKIN KENNEDY, Electrical Engineer,
both of the Electric Lamp Works 115 Woodside Road, Glasgow, Lanarkshire, do
hereby declare the nature of our said Invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement in writing reference being had to the accompanying two Sheets of
Drawings, and to the letters and figures marked thereon, that is to say :-
In the usual forms of transformers and induction coils for transforming alternating
currents of electric energy from low potential to high potential, and from high potential
to low potential, for lighting or heating purposes, the magnetic iron organ portion or
core of the transformer is magnetised alternately in opposite directions, the flow of
magnetic force is reversed in direction with every reversal of the direction of the
alternating current; this reversal of the magnetism which is very rapid, as often over
200 reversals are made per second, consumes energy which is converted into heat in
the iron, and this heat is a source of trouble and often destroys the insulation of the
coils of wire in the transformers.
To obviate this heating and loss of energy, according to our invention we construct
transformers in such a manner and operate them by currents of electric energy so
arranged that no reversals of magnetism occurs in them at all. For this purpose we
wind the transformers with two circuits a primary and secondary for the alternating
currents, in the usual manner, and by our improvements, we use a third circuit for
the circulation of an independent current flowing continuously in one direction, and
this continuous current has for its object the initial magnetising of the magnetic iron
organ portion of the transformer continuously in one direction. This initial magnetism
may be induced in the magnetic iron organ or core of a transformer by other well-
known means than by a circuit or coil of wire and a continuous direction current of
electric energy; thus an electro-magnet or a permanent magnet may be employed in
place of the wire circuit to give the necessary initial magnetism to the magnetic iron
organ or core.
In carrying our invention into practice we may apply our improvements with
great advantage to any form or construction of induction coil or transformer by using
a third wire or circuit through which flows a current of electric energy in one
direction. This third continuous direction current circuit may be wound side by
side either over, under, or between the two alternating current circuits of primary and
secondary wire, provided it surrounds or is surrounded by the magnetic iron organ
and magnetises that organ efficiently.
The effects or working of this method of winding induction coils or transformers,

page_text: we explain thus :-The continuous current in the third circuit raises the iron organ
of the transformer to a high degree of magnetism in one direction, the alternating
current in the primary wire of the transformer alternately raises and lowers the
degree of magnetism in the core or iron organ of the transformer, but never reverses
that inagnetism in direction. When the current in the primary wire is in the same
direction as the continuous current, the magnetism in the iron organ rises in
intensity; when the current in the primary wire is in the opposite direction to that
in the continuous current circuit the magnetism in the iron organ is reduced but not
reversed and the strengths of the currents are so balanced and the number of turns
in each circuit are so proportioned that the magnetism in the iron organ falls to zero,
but not below it, and rises to a maximum with the alternating currents when full
work is being done by the transformer.
The continuous currents may be supplied to the third wire circuit by a continuous
dynamo electric machine or by a shunt from the generator which excites the field
magnets of the alternating current dynamo which supplies electric energy to the
primary wire in the circuit, or from other convenient source where direct currents aro
generated. Transformers having their iron organ portions magnetised as described
may be operated by an intermittent current in the primary circuit producing an
alternating current in the secondary circuit and this with great advantage where the
primary potential employed is low.
And in order to enable others skilled in the art to which our invention relates, to
construct transformers or induction coils and put them into practice in accordance
with our improvements, we have hereunto appended two explanatory Sheets of
Drawings, in which the same reference letters are used to indicate corresponding parts
in the several Figures where shown. Figure 1 is a front sectional elevation in
perspective of a completo transformer or induction coil constructed in accordance
with our improvements. a, b, is the primary wire which is supplied with alternating
currents of electric energy from a dynamo electric machine or generator; c, d, our
new arrangement of wire for supplying a continuous current of electric energy, and
ef, the secondary wires or circuit of the transformer. Figure 2 shows a longitudinal
elevation of the magnetic iron organ portion or core A, of a transformer, having
coiled round it the primary wire a, b, which may be supplied with an alternating or
intermittent current of electric energy; c, d, our new arrangement of wire through
which a continuous current is transmitted; and ef the secondary wire or circuit
in which an alternating current is induced. Figure 3 shows an elevation of the
magnetic iron organ or core A, of a transformer, having coiled round it the primary
wire a, b, and secondary wire or circuit ef, and our new arrangement of third
wire c, d, coiled round the pole pieces B B', to form an electro-magnet, for the
purpose of acting as a conductor to prevent the reversal of the magnetism in the
core A of the transformer, as in the former figures. Figure 4 shows an elevation of
the transformer iron core A and primary and secondary conductors a, b, and e, f, as
in Figure 3, but in which a permanent magnet CC, is used as the conductor for
preventing the reversal of the magnetism in the transformer core A. Figure 5 on
Sheet 2 is a general view showing our improvements applied to a practical system of
distribution of electric energy in which a main transforiner is used.
In this arrange-
ment D is an alternating dynamo, E a continuous current dynamo, and a small
separate continuous current dynamo, which excites the field magnets of both the
dynamos D and E, through the wire D'. A is a main transformer round which is
coiled a primary wire circuit a, b, from the commutator brushes of the alternating
dynamo D; e f is a secondary wire circuit which supplies alternating currents of
electric energy, induced by the primary wire a, b, to the secondary generators and
translating devices or glow lamps grouped in parallel arc at G between its con-
ductors. c, d, is our improved third wire circuit wound round the main transformer A,
and through which passes a continuous current of electric energy from the commutator
brushes of the dynamo E, and this circuit c, d, prevents any reversal of the magnetism
in the main transformer A. The dotted lines D2 in Figure 5 indicate how the field
magnets of the alternating dynamo D, can be excited by a current from the continuous
3.

page_text: dynamo E, and our new third wire circuit ed supplied with a continuous current of
electric energy as a shunt from the commutator-brushes of the dynamo E, the
dynamo F being not required under this arrangement.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
First. In a system of distribution of electric energy in the form of alternating or
intermittent currents by means of transformers or induction coils, the herein described
method of preventing any reversal of the magnetism in the magnetic iron portion or
cores of the transformers, substantially as set forth.
Second. In a system of distribution of electric energy in the form of alternating or
intermittent currents, the combination of a transformer or transformers with primary
and secondary conductors of alternating or intermittent currents, and a third con-
ductor of continuous currents, substantially as and for the purposes set forth.
Third. In a system of distribution of electric energy in the form of alternating or
intermittent currents, the combination of a main transformer, with alternating and
continuous dynamos, primary and secondary alternating or intermittent current
circuits, and a third continuous current circuit, substantially as and for the purposes
set forth.