Improvements in the Governing of Electric Motors.
Year: 1899

page_text: Date of Application, 7th Mar., 1899
Complete Specification Left, 5th Dec., 1899--Accepted, 17th Feb., 1900
Improvements in the Governing of Electric Motors.
I, JUSTUS ECK, of 5, Priory Road, Chiswick, in the County of Middlesex,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to arrange the winding of one, two or more
motors so that by altering the connections varying speeds and outputs can
be obtained.
In order to effect this, in the case of a single motor, I wind the armature
with two or three sets of windings connected to commutators after the manner
now common to continuous current motors and dynamos.
I also wind the field magnets with one or more sets of winding suitable for
using in series, or in shunt with one or more of the armature windings.
The armature windings are so wound as to generate two or more different
electric pressures when run at the same speed with the same field excitation.
By means of a suitable switch or controller I connect the various armature
windings either independently in circuit or one or more in series so that the
electric pressure generated by them, as they rotate, is added; or so that the
electric pressure of one or more is deducted from that of the other or others.
By this means the resultant electric pressure generated by the entire motor
is varied and in like manner its capability of receiving electricity and con-
verting into power.
I use the field windings as set out above to secure different kinds of regulation
in the motor as well as to secure different or constant excitation.
I, sometimes connect some of the field windings with one or more of the
armature circuits so as to oppose the magnetising effect of other of the field
windings.
In the case of two motors I have the armatures either wound to generate
different electric pressures at the same speed or else to work at different speeds
so as to generate different electric pressures when connected to the same load
and connect them either singly in circuit, or else both in circuit so that their
joint electric pressure is a maximum, or in opposition to one another so that
their joint electric pressure is a minimum.
I am also in this case able to alter the ratio of the electric pressures generated
by the two motors by altering the amount of the field excitation and am thus
able to obtain different maximum and minimum electric pressures.
In the case of three or more motors I also use the armatures either singly
or two or more together to produce a maximum or a minimum or one or more
intermediate joint electric pressures.
I am able to do this by having the armatures, either wound for different

page_text: electric pressures at the same speed or else I arrange them to run at different
speeds and so generate different electric pressures.
I have also in this case greater scope for varying the joint electric pressures
by varying the field excitations as indicated above, in the case of two motors.
Dated this Sixth day of March 1899
I, JUSTUS Eck, of 5, Priory Road, Chiswick, in the County of Middlesex,
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 object of this invention is to arrange the winding of one, two or more
electric motors, so that by altering the connecting up in the electric circuit
of the various elements of the windings, varying speeds and outputs of power
can be obtained.
Figures 1, 2, 3, and 4 illustrate one application of this invention to a single
motor in a diagrammatic form.
In the case illustrated the armature of the electric motor consists of three
elements of winding connected to independent commutators into which the
current is fed by brushes a b, c d, and ef, in the usual manner.
The windings of the three elements of the armature are such as to generate
different electromotive forces if rotated in the same magnetic field.
The field magnet windings are terminated at y h, and j, k, respectively and
are shewn wound for use in series with the armatures.
In Fig. 2 all the elements are shewn connected in series so that the electro-
motive forces generated in three elements of the armature are all in the same
sense as regards the circuit. In Fig. 3, the elements are also connected in
series but in this case the electromotive force generated in the element e, f,
is in the reverse sense to that in a, b, and c d.
In Fig. 4 the elements are still connected in series but the sense of the electro-
motive forces generated in both c, d, and e, f, is in the reverse sense to that
in a, b.
If the relative electromotive forces generated in a b, c d, and e f, are
respectively 4, 2, 1, it is obvious that the effective electromotive forces in the
arrangements in Figs. 2, 3 and 4, generated with a constant current are:-
Fig. 2, Fig. 3, 5-Fig. 4, 1,
und as the power given out by a motor is proportional to the effective electro-
motive force generated by it the power of a motor wound and connected up as
above will vary in proportion to the above numbers.
If however in place of the motor being supplied with a constant current it
is connected to a source of current at a constant pressure then in place of the
output varying as above, either the speed will vary or the output vary in some
other proportion.
It is evident from the above that similar effects would be produced in a motor
wound as above with two four or more elements in the armature of different.
electromotive forces.
Figs. 5, 6 and 7 illustrate in a like manner to the above the case of a motor
with two elements in the armature of different electromotive forces and with

page_text: the field magnet windings c f and gh, connected as shunts to the armature
circuits.
In this case the effective electromotive force depends also upon the way in
which the armatures are relatively connected up and consequently if the motor
is connected in a constant current circuit the relative speeds and outputs will
be different from what they would be if the motor was supplied with a constant
electric pressure at its terminals, for the reason that the strength of the field
magnets is dependent upon the electric pressure at the terminals of the motor
in the case illustrated.
It is also evident that if, in place of the armature having two elements it
had three or more the range of variation in speed and, output will be much
increased.
Figs. 8, 9, and 10 illustrate the case of a series wound motor with two
elements in the armature of different electromotive forces and three elements
in the field windings namely e f, gh, j k
In Fig. 9 these are shewn all in series with the armature generating electro-
motive force in the same sense. In Fig. 10 the connections of the elements c d,
are reversed and also of the element jk, the effect of reversing ed, is to
reduce the effective electromotive force and the effect of reversing is to
reduce the strength of the magnetic field whilst the same current is flowing
in accordance to the number of turns in jk.
This principle of altering either simultaneously or successively the connections
of the armatures in series and the relative connections of the elements of the
field magnets gives very wide range to the speed and output to be obtained
from the motor.
It is also evident in this case that the number of the elements of the armature
and of the field magnet especially can be increased.
Figs. 11, 12 and 13, illustrate the case of two series wound motors which
may be either of the same size working at different speeds or of different sizes
so that the electromotive forces generated by their armature vary in some
suitable proportion. The armature circuits being marked ab, g- & the
magnet circuits c-d, e-f and j-k, -m respectively.
Fig. 12 shews them connected to generate their electro motive forces in the
same sense and
Fig. 13 shew them connected to generate their electro motive forces in
opposing senses and thus produce results as demonstrated in the cases illustrated
in Figs. 1, 2, 3 and 4. In this case also the number of motors may be increased
and with it increased opportunities of altering the connections and so producing
a number of varying speeds or outputs.
It is desirable that in this case the motors should operate the same Ol'
similar loads.
Figs. 14, 15 and 16 illustrate a similar case to that shewn in Figs. 11, 12
and 13 but in this case the field magnets are divided in sections marked ef,
fy, gh, hj, and p q. qr, rs, st, in the drawings so that more or less numbers
of turns on the magnet winding have current in them according to the position
of the switch arms k, and u and consequently the relative electromotive forces
of the two motors may be altered without altering their relative speeds. In
Fig. 16 the whole of the sections P, Q, 1 r, rs, s t, are shewn inoperative owing
to the position of the switch arm u.
In this case also the number of motors may be increased and the same
conditions as to load apply as in the previous case illustrated by Figs. 11, 12
and 18.
The cases in Figs. 8, 9, 10, 11, 12, 13, 14, 15, and 16 are shewn with series
wound field magnets but similar results may be obtained by winding the magnets
as shunts to the armatures.
In all casts above, where I speak of the electro-motive force of the motor
I refer to what is often called by electricians, the back electromotive force.

page_text: Having now particularly described and ascertained the nature of my said
invention, and what manner the same is to be performed, I declare that what
I claim is--
(1) The connecting up of elements of the armature of an electric motor so
as to produce different effective electromotive forces.
(2) The connecting up of the armatures of two or more electric motors in
series so as to produce different total electromotive forces.
(3) The connecting up of the windings of electric motors, wound substantially
as described, to give different effective windings to their field magnets.
(4) Methods of connecting up one electric motor, wound as described, so that
varying speeds and outputs are obtained if it be supplied with a constant current
substantially as described.
(5) Methods of connecting up one electric motor, wound as described, so that
varying speeds and outputs are obtained if it be supplied with current at a
constant pressure substantially as described.
(6) Methods of connecting up two or more motors as described so that varying
speeds and outputs are obtained if they are supplied with a constant current
substantially as described.
(7) Methods of connecting up two or more motors as described so that varying
speeds and outputs are obtained if they are supplied with current at a constant
pressure substantially as described.