A Method of Producing a Magnetic Flux of Force having a Displace- ment of Phase equal to 90 Degrees or more relatively to the Tension of the Magnetising Current.
Year: 1897

page_text: Date of Application, 12th June, 1897-Accepted, 28th Aug., 1897
A Method of Producing a Magnetic Flux of Force having a Displace-
ment of Phase equal to 90 Degrees or more relatively to the
Tension of the Magnetising Current.
I, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of London,
l'atent Agent, do hereby declare the nature of this invention (which has ..een
communicated to me by Messrs. Hartmann and Braun, of Bockenheim Frankfort-
on-Maine, in the Empire of Germany) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
An alternating current electromagnet made in the usual manner of laminations
or plates of iron and surrounded with magnetising windings will yield in the gap
of an iron armature viz:-" interferricum," a field, which is displaced relatively to
the tension of the magnetising current, to the extent of a considerable angle which
angle however amounts to less than 90 degrees, and even by inserting a throttle-
coil of very high self-induction, a displacement of the field to the extent of
90 degrees cannot be obtained, because the resulting phase receives an average
value lying between that of the two single displacements. If however a device be
provided by which apart from the displacement of phase, already exist-
ing, a further displacement of phase is attained by algebraic addition,
it will then be possible to obtain an angular displacement of 90 degrees
and more.
A means by which this latter object can be achieved in the manner
indicated is afforded by utilizing the so-called "hysteretic phase-displacement,"
by the effect of which the phase of a magnetic flux of force or field is rearwardly
displaced relatively to the phase of the magnetising current. If therefore for the
purpose of magnetising, a current is used, which in itself already possesses a con-
siderable displacement of phase for example between 70 to 80 degrees relatively to
its tension, then by suitably constructing the electromagnet, a hysteretic displace-
ment of phase of the flux of force relatively to the magnetising current, amounting
to 20 degrees or more, can be attained, so that the field of such an electromagnet
is then in all displaced to the extent of 90 degrees or more relatively to the tension
of the exciter-current. For attaining this object the electromagnet is, contrary
to the usual practice, made of comparatively few divisions or sections of iron, or,
preferably one portion of the magnetic circuit, for example the armature of the
electromagnet, is made of solid iron, whilst for the other parts laminations or plates
of iron are employed.
In Figures 1 and 2 of the accompanying drawing are represented two types of
magnets of this kind, in which the portion B provided with windings, is con-
stituted by laminations or plates whilst the armature A has either no sub-divisions
or sections or only one; such magnets, as has been clearly established by experi-
ments, actually furnish at I a field presenting a displacement of phase equal to, or
more than, 90 degrees.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is:
1. A method of producing a magnetic flux of force or field, which, relatively
to the tension of the magnetising current presents a displacement of phase amount-
ing to 90 degrees or more the characteristic feature consisting in the magnetic
circuit being entirely or partly formed of as few sub-divisions or sections of iron as
possible, whereby a considerable hysteretic displacement of phase is produced.
2. The method of producing a magnetic field displaced in its phase to the extent
of 90 degrees or more relatively to the tension of the magnetising current as in
the first claim; the said magnetic field being furnished by an electromagnet which
although consisting itself of a considerable number of sub-divisions or sections of
iron, is provided with an armature which is formed of one piece or but a few pieces
of iron.
Daddah 101. 1
T
1000