Improved Method of and Means for Controlling or Converting Electric Currents.
Year: 1894

page_text: Date of Application, 27th Apr., 1894
Complete Specification Left, 28th Jan., 1895-Accepted, 27th Apr., 1895
PROVISIONAL SPECIFICATION.
Improved Method of and Means for Controlling or Converting
Electric Currents.
I, ANTHONY FRAZER, of 19 Percy Gardens, Tynemouth, Merchant, do hereby
declare the nature of this invention to be as follows:-
My invention relates to a novel method of and means for controlling electric
currents, (alternating, or continuous, in direction; of high, or low, potential; and,
from whatever source originating) :-in such a manner as to allow of their being
passed through either high, or low, induction transformers, and to render said
currents adaptable for any of the purposes to which electricity is applicable,
irrespective of the nature of the current primarily generated. Thus, say for.
converting continuous into alternating currents or vice-versa, or both conversions
synchronally combined.
In order that my invention may the better be understood, I will further describe
same by reference to and by the aid of the drawing hereto appended, being a front
elevational view of my rotary current (duplex) alternator. That is to say :-
Two dises A A of suitable nonconducting material and of equal and suitable
diameter and thickness are mounted towards each end of a shaft b, also preferably
of suitable nonconducting material for a single alternator, and on which is mounted
centrally a solid cylinder E of material similar to A A and of equal diameter to
form a duplex alternator. The ends of the shaft are fitted with steel spindles to
enable it to revolve freely in suitable metallic bearings inserted in the two
uprights CC (also of suitable nonconducting material) so that the discs may be
supported to clear the wood base D to which the uprights are affixed. The steel
spindle at one end of the shaft b is prolonged through the bearing, to carry a
pulley H or other suitable driving arrangement. The periphery of each of the
discs A A is deeply grooved laterally to receive suitable metallic segments, sunk
flush, in such a way as to present a series of equal alternations of metallic and
nonconducting surface, the number of such alternations being made to correspond
with the number of current alternations required to be produced at each revolution,
or they may be built up of alternate laminations of metal and nonconducting
material. The discs are so placed relatively to each other on the shaft that each
metallic segment on the one, coincides with an insulating space on the other. A
circular metallic plate equal in diameter to that of the discs, is affixed to the
surfaces a a of each of the discs A A in electrical contact with all the segments on each
disc. The central cylinder E is divided circumferentially into five divisions ggff
&n of which the two ggare grooved and segmented similarly to A A and with
an equal number of alternations, also arranged so that a metallic segment on the
one coincides with an insulating space on the other. ff are two plain metallic
bands in electrical contact with the metallic segments to which they are respectively
contiguous. n is an insulating space surrounding the cylinder. On each of the
uprights CC, is affixed a binding post m m connected with suitable springs to
press lightly against the metal covered surfaces a a of the discs A A.
upright L of suitable nonconducting material is affixed to the base D so as to be
opposite to and at a suitable distance in front of, the cylinder E. To this upright
are affixed four horizontal metallic arms or holders RW w each suitably connected
with a binding post or terminal and each insulated from the other. Of these
holders, Rr extend on each side of the upright to points opposite the discs A A,
A third

page_text: '
while Wo extend similarly to points opposite the divisions g g on the central
cylinder. At each extremity of the holders are suitable brushes 1. 1, 2. 2ª, 3. 3*, 4.4*,
in frictional contact with the segmented surfaces to which they are respectively
opposite. The upright L also carries affixed to it near the base, two brushes S S
in contact respectively with the metallic bands ffaforesaid on the cylinder E.
The brushes in the holders RW to are so placed that when 1 and 3 are in contact
with a metallic segment, 2 and 4 would be insulated. Then the brushes at the
opposite extremities of the holders 1 and 3ª would be insulated while 2* and 4*
would be on metal segments.
T
When the two terminals m m² are connected respectively with the positive and
negative wires conveying a continuous or direct current, and terminals on Rr
connected, it will be seen that the circuit would be completed and a current would
flow from m (positive) through the brush 1 on one end of holder R, through the
circuit connecting the terminals on R. and 2, and so through the brush 2* to
négative terminal m¹; the brushes 2 and 1* being at this time inoperative. A
revolution of the disc sufficient to change the respective contacts of the brushes 1, 2,
1, 2, to insulating space, metal segment, metal segment, insulating space, would
cause the current to flow from 2 (positive) to 1a (negative) in an opposite direction
through the circuit connecting the holders Rr, the brushes 1 and 2 being now
inactive, and so on throughout the revolution of the discs, resulting in an alternation
of direction in the circuit between R 1, for every alternation of metal and
iusulation on the discs. A suitable transformer may be interposed in the circuit Rr
either to induce low potential from high potential currents or vice versa, according
as the primary current may be of high, or low, E. M.F. If it be now required to
reconvert the resulting alternations of induced current into one of continuous
direction, the wires conveying them are attached to the brushes S S, (the terminal
screws being indicated throughout the drawing by the letter t) whereupon the
currents will flow through the brushes on to the metallic' bands ff of the
cylinder E, and be collected synchronally as a direct current from the segmented
divisions 9 9 of the cylinder E by the brushes 3, 4, 3" 4" on the holders W to (the
terminals of which are connected by the external circuit) in a manner substantially
the same as that already above described.
When the original current is continuous in direction, either of high, or low, E.M.F.
the alternator may be driven (at a speed depending on the number of alternations
on the discs and the mumber of current alternations required to be produced per
minute) either directly from the engine or dynamo, or by a small suitable electro
motor actuated by a shunt from the main circuit; and, when convenient, a portion.
only of the total current may be dealt with by the alternator, which in this case
would be placed in a shunt with a suitable resistance. When it is desired, however,
to transmit currents of high potential to distant stations, there to be used as low
potential currents, it will be necessary, if they are originally low potential
continuous, to convert them by a duplex alternator and a suitable transformer into
high potential continuous before leaving the generating station, and after trans-
mission to the distant station, to use a second alternator driven by a small motor,
and transformer; the alternator in this latter case being either single, or duplex,
according as the current distributed is desired to assume an alternating, or
continuous, form.
a
When the original current is generated by an alternating dynamo at the central
station, a single alternator should be used at the station, specially constructed with
a large number of segments, and so geared up (with a view to ensure perfect
synchronism of action) that when driven from a supplementary pulley on the shaft of the
dynamo, the number of alternations produced per minute shall be exactly equivalent
to the known number of current alternations per minute generated by the dynamo;
the resulting current being continuous in direction for transmission, and if required
for a distant circuit and originally of low potential, would be sent through a
transformer prior to being rendered continuous in direction by the alternator.
From the foregoing. particulars descriptive of the device according to my
เ

page_text: invention, it will be seen that it is distinguished markedly by the following amongst
other special and advantageous features. That is to say:-the alternating
conducting and nonconducting surfaces of the rotary discs herein referred to, being
acted upon as described, by the quadrupled set of brushes, so as to ensure that two
are always electrically active while the remaining two are insulated, thus producing
the alternations without entailing loss in conversion. Again, under the arrangement
which I adopt of the duplex type of alternator herein described and shewn, the
adoption of a second set of discs and quadrupled brushes fixed on same shaft
ensures absolutely synchronal action in the re-alternation or re-rendering continuous,
of a current which has already been made alternating in direction by the first set of
discs through which it has passed.
Amongst the various uses to which the device according to my invention is
applicable I may mention that of its adaptability to form the commutator of any
suitable direct current electro-motor, enabling it to be driven by an alternating
current, and thus obviating the necessity of employing complicated multiphase
motors for use with such alternating currents.
JAMES
STEVENSON,
1, Furnival Street, Holborn, London, E.C., Agent for Applicant.
Improved Method of and Means for Controlling or Converting
Electric Currents.
I, ANTHONY FRAZER, of 19, Percy Gardens, Tynemouth, Ships' Store
Merchant, 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: -
My invention relates to a novel method of and means for controlling electric
currents, (alternating or continuous in direction, of high, or low, potential; and
from whatever source originating) in such a manner as to allow of the currents
being passed through either high, or low induction transformers, and to render
said currents adaptable and available for any of the purposes to which electricity
is applicable, irrespective of the nature of the current primarily generated. Thus,
say for instance, for converting continuous into alternating currents, or vice versa,
or both conversions synchronously combined.
In order that my invention may the better be understood, I will proceed to
describe same in reference to and by the aid of the sheet of drawings filed with the
Provisional Specification of this my said invention; which sheet of drawings,
(Sheet 1) shews a front elevational view of the device in accordance with my
invention. I have also appended hereto another sheet of drawings, (Sheet 2).
being an isometrical perspective plan view of my device.
Referring to the drawings, two discs A, A of suitable, non-conducting material,
preferably hard wood, and of equal and of the requisite diameter and thickness,
are mounted towards each end of a shaft b of steel or other suitable material, for
a single alternator, intended to impart alternations to a primarily continuous
current of any volume or electro motive force. On the shaft bis mounted,
centrally, a solid cylinder E, of material similar to that of which the discs A, A
are made, and of equal diameter thereto, to form a duplex alternator; ie, when
it is required to reconvert into continuous current, the current which has already
been alternated by the single alternator, and transformed into lower or higher
E.M.F.; the ends of the shaft b are turned down' to form spindles to enable it to
revolve freely in suitable bearings in the two standards C, C, so that the discs
may be supported to clear the wooden or metal base D to which the uprights or

page_text: standards C, C are affixed. The spindle at one end of the shaft 6 is continued
through the bearing to carry a pulley H or other suitable means for driving the
apparatus; or it may be extended to form the armature spindle of a suitable
motor. The periphery of each of the discs A, A, is deeply grooved laterally to
receive suitable metallic segments sunk in flush, or the discs may be fitted with
the metallic rings laterally divided and alternately insulated and non-insulated
so as to present a series of alternations of metallic and non-conducting surface, or
a series of metallic segments of which those corresponding to the non-conducting
segments would be insulated from the others, the number of such alternations being
made to correspond with the number of current alternations, and so far as the pair
of discs for alternating a continuous current, and above described as a
"single
alternator," is concerned, the insulating segments being slightly broader than the
conducting segments; or, otherwise, they may be built up of alternate laminations
of metal and non-conducting material in accordance with the above. The discs
are so placed relatively to each other on the shaft b, that each metallic segment on
the one, coincides with an insulating space on the other. For the single alternator
for continuous current, circular metallic plates a a (equal in diameter to that
of the discs A A each plate having at half its radius a projecting rectangular
flange ) are affixed to each of the discs A, A in electrical contact with all the
alternate narrower segments on each disc. The smaller cylinders formed by
the flanges are slotted so as to present a series of metallic bars, equidistant from
each other and equal in number to the divisions between segments. The centrally
disposed solid cylinder E herein before referred to, is divided circumferentially into
five divisions g, g; ff; and n, of which, the two g, g are grooved and segmented
similarly to the discs A, A, but here the alternate surfaces are equal in width, and
with an equal number of alternations, so arranged that a conducting segment on
the one, coincides with an insulating segment on the other. The two divisious fit,
assume the form of plain metallic bands and are in electrical contact with alternate
segments on the discs to which they are respectively contiguous; and, the division n
serves as an insulating space surrounding the cylinder E; or a group of similarly
arranged separate discs may be used in place of a solid cylinder, a space between
them in this case representing division n. On each of the uprights or standards C, C,
or elsewhere, is suitably affixed a binding post m, m¹ respectively, seen only in
Sheet 1, connected with suitable springs so as to press lightly against the plain
metal surfaces a, a of the flanged discs A, A.
A third upright or standard 'L, of suitable non-conducting material, is affixed to
the base D, so as to be opposite to and at a suitable distance in front of, the
cylinder E. To this upright or standard L are affixed four horizontal metallic
arms or holders R, r; W, w, each suitably connected with a binding post or terminal
and each insulated from the other. The two arms or holders R r, extend on each
side of L to points opposite the discs A, A; and the two arms or holders W, 0,
extend similarly to points opposite the divisions 9, 9 aforesaid of the central
cylinder E, or opposite the segmental discs when a group is used in place of
solid cylinders. At each extremity of the above referred to arms or
holders R, r, W, w, are suitable brushes, 1, 1; 2, 2*: 3, 3, 4, 4*, in contact with
the segmental surfaces to which they are respectively opposite. For this purpose
in order to avoid frictional wear of the discs, I prefer to use brushes having at
their contact extremities, small metallic rollers which may revolve freely against
the peripheries of the segmented discs, and the metallic contact being thereby
limited to the line of touch between the respective circumferences of the disc and
roller, I may use to increase conduction when dealing with large currents two such
rollers on each brush suitably adjusted to act in unison. There are also two
metal strips or brushes S, S, conveniently placed, affixed to the base D in contact
with the metallic bands f,f aforesaid on the cylinder E. The brushes 1, 1; 2, 2;
3, 34, 4; on the arms or holders R, r; W, w are so disposed that when
brushes 1 and 3 are in contact, each with a conducting segment, brushes 2 and 4.
are insulated. Then, the brushes at the opposite extremities of the holders, 1

page_text: and 3 would be insulated, whilst brushes 2ª and 4* would be on a conducting
segment. Now, when the two terminals m, m' are connected respectively with
the positive and negative wires conveying a continuous or direct current, and the
terminals on R, r connected, it will be seen that the circuit would be completed and
a current would flow from the positive terminal m through the brush 1 on one end
of the holder R, through the circuit connecting the terminals on R and r, (the
terminal screws throughout the drawing being indicated by the letter t,) and so
through the brush 2 to the negative terminal m; the brushes 1 and 2ª being
at this time in operation, but on revolving the discs, owing to the slight difference
in width between the conducting and non-conducting segments on the discs A, A
the brushes 1 and 2ª would leave the conducting segments before brushes 1 and 2
had left their respective non-conducting, segments, a momentary cut off of current
being thereby made in the circuit joining R r. A revolution of the disc sufficient
to change the respective contacts of the brushes 1, 2, 1", 2", to insulating space,
metal segment, metal segment, insulating space, would cause the current to flow
from brush 2 (positive) to brush 1" (negative) in an opposite direction through
the circuit connecting the holders R, r, the brushes 1 and 2 being now inactive,
and so on throughout the revolution of the discs, resulting in an alternation of
direction in the circuit between R, r, for every alternation of conductor and
non-conductor on the discs. The metal bars formed by the slotted flanges on
the plates affixed to discs A, A are made to coincide with the small interrupting
periods produced by the inequality in size between the conducting and insulated
segments on the discs A, A and supplementary suitable brushes 5, 5* are affixed
to the base in such a manner as to make contact with one of the bars during the
period of interruption of each brush, thus taking the current during each momentary
cut off of the brushes on discs A, A, and providing a relief circuit between the
supplemental brushes 5, 5ª which will prevent "sparking" at the main brushes..
The small relief current may be used to actuate the motor when a motor is used
to drive the apparatus, or it may be otherwise employed to feed a local lamp.
circuit or to charge accumulators, or disposed of in any other suitable manner.
"
A suitable transformer may be interposed in the circuit Rr, either to induce
low potential from high potential currents or vice-versa, according as the primary
current may be of high or low E.M.F. If it be now required to reconvert the
resulting alternations of induced current into one of continuous direction, the
conveying wires are attached to the two brushes S, S, herein before referred to.
as being in contact with the metallic bands f, f, on the cylinder E, whereupon
the currents will flow through these brushes on to the metallic bands f, f, and be
collected synchronously as a direct current from the segmental divisions g, g of
the cylinder E by the brushes 3, 4, 3, 4 on the holders W, wo (the terminals.
of which are connected by the external circuit) in a manner substantially the same-
as that already above described. Usually, a relief circuit in connection with this:
part of my device would be unnecessary, but I may use an arrangement similar to
that already described for the purpose in such cases where its use might be
advisable.
When the original current is continuous in direction, either of high or
low E.M.F., the alternator may be driven at a speed depending on the number
of alternations on the discs and the number of current alternations required to be:
produced per minute-either direct or by a belt from the engine or dynamo, or by
a small suitable electro-motor actuated by a shunt from the main circuit; and,
when convenient, a portion only of the total current may be dealt with by the
alternator, which in such case would be placed in a shunt with a suitable resistance.
When it is desired, however, to transmit currents of high potential to distant.
stations, there to be used as low potential currents, it will be necessary, if they are
originally low potential continuous, to convert them by a duplex alternator and a
suitable transformer into high potential continuous, before leaving the generating
station; or, they may be transmitted as high potential alternating currents; and,
after transmission to the distant station, to use a second alternator-driven by a

page_text: small motor and transformer; the alternator in this latter case being either
single, or duplex, which will depend upon whether it is desired the current
distributed shall assume an alternating or a continuous form.
When the original current is generated by an alternating dynamo at the central
station, a single alternator is used at the station, and is specially constructed with
a large number of segments, and so geared up, (with a view to secure perfect
synchronism of action) that when driven from a supplementary pulley on the shaft
of the dynamo, the number of alternations produced per minute shall be exactly
equivalent to the known number of current alternations per minute generated by
the dynamo, or may be fixed on the dynamo shaft direct, or actuated by a suitable
synchronous motor, the resulting current being continuous in direction for trans-
mission; and, if required for a distant circuit and originally of low potential, would
be sent through a transformer for conversion into high potential, prior to being
rendered continuous in direction by the alternator.
Referring to the herein before described discs A. A, I might in certain cases,
as a mode of construction alternative to that already set forth: make or build up
said discs in the form of crown wheels the projecting parallel teeth of the two discs
"meshing or taking into each other, thus forming the alternate segments.
"
Amongst the various uses to which the device according to my invention is
applicable, I may mention by way of illustration, that of its special adaptability to
form the commutator of any suitable direct current electro-motor so as to allow of
its being driven by an alternating current, and thus obviating the necessity of
employing complicated multiphase motors for use with such alternating currents,
or to form the commutator on an alternating dynamo so that continuous currents
may be taken off.
Having now particularly 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 :-
First. The improved method of, and means for, controlling or converting electric
currents (alternating, or continuous, in direction, of high, or low, potential, and
from whatever source originating) in such a manner as to enable them to be passed
through high, or low, induction transformers, as herein set forth.
Second. In the apparatus referred to in the preceding claim, the employment of
the alternating conducting and non-conducting surfaces of the discs A, A 9, 9:
herein referred to, acted upon by the quadrupled set of brushes 1, 1; 2, 2;
3, 33; 4, 4; so as to ensure that two are always electrically active while the
remaining two are insulated, thus producing the alternations without entailing loss
in conversion all as herein set forth.
Third. In the duplex type of alternator herein described, the adoption of a
second set of discs fixed on same shaft, and quadrupled brushes so as to ensure
absolutely synchronous action in the re-alternation of, or re-rendering continuous
a current which has already been made alternating in direction, by the first set of
discs through which it has passed, as herein set forth.
Fourth. The adoption of coincident relief bars in contact with separate brushes
to form a path by which the current may pass during the periods of interruption
when the main brushes are passing from conducting to insulated segments on the
respective discs as herein set forth.
Fifth. The use of brushes with dual branched extremities to make contac
simultaneously with two conducting segments and thus to increase contact surfac
as herein set forth.
Dad thin noth dox of Conury 1805
V. LAZARUS,
1, Furnival Street, Holborn, E.C., Agent for Applicant.