motors of
this kind have employed, among other
means, self-induction coil one'circuit and
25 dead-resistance the other, have se
cured the same result the special charac
ter the winding the two circuits, and in
still another instance have constructed
the motor that the retarded-current coils were
30 nearly inclosed iron, whereby the self-in
duction such coils was very greatly in
creased. Serial H
o. then con
nect the free ends one set poles means
of laminated-iron bands bridge-pieces of
considerably smaller cross-section than the
45 cores themselves, whereby the cores will all
form parts complete magnetic circuits.
NIKOLA TESLA, NEW YORK, Y.
The invention subject application is
an improvement this last-named plan. 433,701, dated ugust ,
Applicationfiled M
arch26, 1890.
When the coils each set magnets are
connected multiple circuits branches
from source alternating currents, electro-
50 motive forces are set impressed upon
each circuit simultaneously; but the coils on
the magnetically bridged shunted cores
will have, reason the closed magnetic
circuits, high self-induction, which retards
the current, permitting the beginning 55
each impulse but little current pass.
SPECIFICATION forming part Letters Patent No. The pole-pieces are connected
or shunted bridge-pieces These may
be made independently and attached the
pole-pieces, they may parts the forms
or blanks stamped punched out sheet- 95
iron.
ALTERNATING-CURRENT MOTOR.)
To all whom concern:
. ig. 100
Coils surround the pole-pieces and
other coils are wound the pole-piecesC.
33 carrying out the invention construct
a field-magnet having two sets poles in
wardly-projecting cores and placed side by
side, practically form two fields of
force and alternately disposed—that to
40 say, with the poles oneset field opposite
the spaces between the other. ver
tical cross-section the same. known that Nikola Tesla, sub
ject the Emperor Austria-Hungary, from
Smiljan, Lika, border country Austria-
S Hungary, residing New York, the county
and State New York, have invented certain
new and useful Improvements Alternating-
Current Motors, which the following a
specification, reference being had the draw-
io ings accompanying and forming part the
same.nited States Patent Office. (N
om
odel.
and they are disposed alternately—that 85
say, the pole-pieces one set occur line
with the spacesbetween those ofthe other sets.
This invention relates that class alter
nating-current motors which the field-mag
nets are energized coils connected in
15 two circuits derived from the same source
and having different degrees self-induc
tion, whereby the currents one circuit or
branch are retarded more than the other,
with the result producing progressive
20 advance rotation the points maxi
mum magnetic effect the field that main
tains the armature rotation. Their size mass determined by
various conditions, such the strength of
the current employed, the mass size
of the cores which they are appplied, and
other well-understood conditions. 345,389., ASSIGNOR THE TESLA ELECTRIC
COMPANY, SAME PLACE.
A the frame the motor, which prefer
ably built sheets iron punched out 75
to the desired shape and bolted together with
insulation proper character between the
sheets. When complete, the frame makes a
field-magnet with inwardly-projecting pole-
pieces and adapt them the re- 80
quirements this particular case these pole-
pieces are out line with one another, those
marked surrounding one end the arma
ture and the others, the opposite end, .
The construction detail which this
invention illustrated shown the accom
panying drawings. On
the other hand, such opposition being en
countered the other set coils, the cur
rent passes freely through them, magnetizing
the poles which they are wound.
The armature cylindrical form, and
is also laminated the usual way and is
wound longitudinally with coils closed upon 90
themselves. soon, 60
however, the laminated bridges become
saturated and incapable carrying all the
lines force, which the rising electro-motive
force, and consequently increased current,
produce, free poles are developed the ends 65
of the cores, which, acting conjunction with
the others, produce rotation the armature. 70
Figure view side elevation mo
tor embodying the invention.
