Improvements in Apparatus for Regulating Dynamo Electric Machines.
Year: 1888

page_text: COMPLETE SPECIFICATION. ›
Improvements in Apparatus for Regulating Dynamo Electric
Machines.
A communication from ADDISON G. WATERHOUSE, of the City of Hartford, State of
Connecticut, United States of America, Electrical Engineer.
I, ARTHUR SHIPPEY of 13 and 14 King Street, in the City of London, Electrical
Engineer, do hereby declare the nature of the said Invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
The present Invention relates to improved mechanism adapted to regulate the
current producing capacity of dynamo electric machines. The improved mechanism
is applicable to dynamo machines of constant electromotive force with a variable
current such as used for incandescent lighting and is represented diagrammatically
in Fig. 1. of the accompanying drawings as applied to such a machine, and is also
applicable to dynamo machines of constant current with variable electromotive force
such as used for are lighting and is represented diagrammatically in Fig. 2. as applied
to such a machine.
Referring firstly to Fig. 1, E, represents the armature of the dynamo, and C, its
commutator with main wires, .m, leading from brushes, A, and, B, to the lamps, L.
F, represents the field magnet coils which are run in a circuit (herein termed the
"field circuit") leading from the commutator brush, B, around the field magnets to an
external resistance, F, and F", then around what is herein termed a working
magnet, w, and back to the armature on brush, A.
Another circuit (herein termed the "regulating shunt"), begins at brush, A, passes
out on line, s, then around a regulating magnet, R, and back on wire, s', to the
brush, B. This circuit is composed of fine wire of a high resistance, and is used
to actuate the magnet, R. Both of the magnets, w, and, R, are supposed to be what
are known as suck magnets, having stationary coils and moveable armatures
The object to be obtained, is to maintain a constant electromotive force in the
current of the main circuit, m. This is accomplished by regulating the strength of
the field magnet circuit. If a dynamo is properly proportioned and constructed
it will be self regulating, so far as its electro motive force is concerned, independent

page_text: .
number of lamps, providing the speed of the armature is constant.
as this is not practically possible it is found necessary to regulate the strengt
Bu
of the field magnetism, so as to compensate for changes in the speed of the armature
This is accomplished according to the present improvements firstly by winding th
field magnet coils, F, in series with resistance, F1, which will allow only such curren
to pass around the field coils, F, as will give the dynamo a little more than the
required electromotive force at the proper speed of the armature, and also by placing
in series with the field coils. F, and resistance, F-before returning to the armature
on brush, A, coils around the said working magnet, w, which will act upon the
lever, D. in such a manner as that an increase of current will raise the lover which
will swing down as the current falls. The lever, D, is pivoted at one end, as at, a
while the other or swinging end thereof, has a horizontally projecting pin or arm,
on which there is supported one or more contact rings, T, which electrically connect
D
the lever, D, with a series of contact plates, i, which beginning from the bottom
upwards are electrically connected to successively lower points on the resistance, F,
by wires, . The bottom of the resistance, F1, is also electrically connected with the
pivot end, ., of the lever, D, by a conductor, d, so that a current in passing through
resistance, FI, will have a by-path offered, through conductor, d, lever, D, ring, T, to
the contact point,, against which the ring, T, rests, then back through wire, ¿ª³,
belonging to said plate, to the remaining part of the resistance, F. By such means,
more or less of the resistance, F, is short circuited or cut out of the field circuit, as
the lever, D, is raised or lowered by the magnet, w, shifting the position of the ring
or rings, T. When the electro-motive force of the machine is low, the armature falls,
and the rings move down so as to short-circuit more of the resistance, F. This
increases the current around the field coils, and creates a corresponding increase of
current. The reverse occurs in case the electromotive force becomes too great.
:
The magnet, w, acts in itself in such a way as to produce regulation, but is necessarily
prevented from doing its work properly, on account of the friction it has to overcome
and work it has to do. In order to assist such magnet, w, in this work, so as to cause
it to respond properly to any current changes, the said regulating magnet, R, is
applied, and is actuated by the separate cirenit. s, , included between the brushes, A,
and, B, as represented or may be included in series with the field circuit and
magnet, w.
The magnet, R, is made extremely sensitive, so as to respond to slight current
changes, and is provided with a contact lever, k, made in the form of a spring,
connected at, Y, with the field conductor at, Fil, before it reaches the working
magnet, e, after leaving which the conductor, F3, is by a conductor, b, connected to
a contact point, O, which is also connected to a resistance, N, leading to a point, P.
Now if the magnet, R, rises, there will be no contact between, k, and the points, O,
and. P, and the current will continue around magnet, wc, which is made strong enough 4
to raise the lever, D, and rings, T, thereby cutting in the resistance, F', as above
described, until the electromotive force of the machine is lowered to the proper point,
at which time the magnet, R, will move downward, until the end of the lever, k,
touches the point, P. Then part of the current which passes through the magnet, we,
will be shunted from, F, through, Y, k, P, N, O, b, to, F. This will divert part of 4
the current from, w, and weaken it, not enough to let it fall back but enough to cause
it, by the assistance of a friction spring, pressing upon part of the lever, D, to
remain stationary, while the lever, k, contacts on point, P. If, at this point, the
electromotive force of the dynamo should fall below the proper point, the magnet, R,
would descend, until the other end of the lever, k, touches the point, O, thereby 50
cutting the resistance, N, out of the shunt around the working magnet, w; so that all
the current would be shunted from, w, which would cause it to fall, and with it the
rings, T, thereby cutting out the resistance, F', in the field circuit, until the proper
electromotive force in the main line was restored. In such way the magnet, R, would
cause the magnet, we, to rise when lever, k, was up from points, O, and, P to remain 55
stationary, when, k, contacted with, P; and to fall when, k, contacted witli, O, or with
both, O, and, P, with the results above set forth.

page_text: Referring now to Fig. 2, the form of dynamo herein represented is peculiar from
the fact that regulation is produced by means of an auxiliary brush, A¹, placed near
one of the main brushes, and which is electrically connected to such main brush, A,
by a conductor, H, having a certain resistance, F. interposed between the brush, A',
and the point, F1, where the conductor from, A, after it has formed all or part of the field
magnet coils, F, joins with the conductor from, A¹. The purpose of the working
magnet, w, and regulating magnet, R, in this case, is to effect regulation by means of
changes in the resistance between, F₁, and, F, which are effected through the same
instrumentalities as hereinbefore described with reference to Fig. 1, only in this case,
both of the magnets, we, and, R, are energized by the main circuit current, m, which leads
from the point, F, and returns through the lamps, L, to the opposite main
brush, B.
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 what I
claim is,
1. A regulator for a shunt wound dynamo, having the following instrumentalities
in combination; an external resistance in series with the field magnets with a means
of cutting in or out all or part of said resistance, a working magnet to actuate the
mechanism which changes the said resistance, and a regulating magnet which will
cause said working magnet to move or remain stationary, substantially as and for the
purposes herein before described.
2. In a Current Regulator for dynamo electric machines having field magnets in a
derived circuit for producing a current of constant electro motive force, a resistance, F¹,
in series with the field magnet coils, and contact points, i, electrically connected to the
resistance, F, and contact rings, T, suspended upon the arm of a lever, D, adapted
to produce changes in such resistance, as stated in combination with a working
magnet for imparting movement to said lever, D, and a regulating magnet made to
respond to current changes which will cause said working magnet to move or remain
stationary, substantially as and for the purpose herein before described.
3. A regulator for a dynamo of constant current and variable electromotive force
having a main brush, A, and auxiliary brush, A¹, having all or part of the field
coils, F, and a resistance, F, and, F, included in a circuit between said brushes, A,
and A¹, said regulator having the following instrumentalities, a contact mechanism
for taking the current from various points of said resistance, F1, F", a working
magnet for changing the position of contact on the said resistance; and a regulating
magnet which will respond to current changes and cause said working magnet to
move or remain stationary, substantially as and for the purposes hereinbefore
described.
4. A regulating magnet, R, energized by the main or a shunt current of a dynamo,
having a leyer, k, or a means of contacting with two points, O, and, P, electrically
connected by a resistance, N, and connected to the conductor around the working
magnet, w, so that while lever, k, is in contact with, O, the working magnet, w, will
move one way, and while in contact with, P, it will remain stationary, and while not
in contact with either, O, or, P, the said working magnet will move in the opposite
way, substantially as and for the purpose hereinbefore described.
5. In a dynamo regulator, the application and use of contact rings, T, arranged
upon a pin or arm, D₁, in combination with the contact plates, i, substantially as and
for the purposes herein before described.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicant.