Testing of Electro-Magnetic Machinery and Other Apparatus

452 Pages·1905·11.46 MB·English

by  Bernard Victor Swenson

TESTING OF
ELECTRO-MAGNETIC MACHINERY
AND OTHER APPARATUS

TESTING OF
ELECTRO-MAGNETIC MACHINERY
AND OTHER APPARATUS
BERNARD VICTOR SWENSON, E.E., M.E,
It
OF THE UNIVE.RSITY OF WISCONSIN
BUDD FRANKENFIELD, E.E.
OFTHE NERNST LAMPCOMPANY
VOLUME
I.
DIRECT CURRENTS
THE MACMILLAN COMPANY
LONDON: MACMILLAN & Co., LTD.
1909
4
COPYRIGHT, 1904
BY THE MACMILLAN COMPANY
Setup,electrotypedandprintedJanuary,1904
ReprintedAugust,1905; October,1907;
March,1909
PRESSor
THENEWERAPRINTINGCOMPANY.
LANCASTER.PA.
A
-4
PREFACE.
This book was written because the authors have felt the need
of a treatise of this nature, and because others have expressed
a similar feeling.
The treatise will be in two volumes and is intended for use
as a college text-book and also as a work of reference for engi-
neers. The procedure followed is that which has been used
for some years in the dynamo laboratories at the University
of Wisconsin, but the treatment is of a character which makes
it suitable for general use in other institutions. The field cov-
ered by the present volume is that of direct-current electro-
magnetic machinery and apparatus, and is almost exclusively
confined to dynamo-electric machinery. It is assumed that
due instruction in precise electrical measurements has been
previously received in a course which is adapted to suit the
requirements of the electrical engineer. The text refers in nu-
merous places to various books and publications so as to make
it serviceable in connection with any first-class college course in
direct-current dynamo machinery. This also adds to the value
of the treatise as a reference book. The second volume (which
is in course of preparation) will deal with alternating current
machinery and apparatus.
The treatment of each experiment is self-contained. Stress is
laid on this feature, as it is believed to be of marked value in a
work of reference; and, in a text-book, it allows the instructor
great latitude in arranging a course to suit the individual needs of
his students. The order of experiments adopted is a convenient
one to follow in the college laboratory, but it may be judiciously
changed as dictated by convenience, without injuring the proper
sequence of the work.
VI PREFACE,
A
dynamo laboratory course should be designed to fix the
theories learned in the class room or lecture room, at the same
time giving as much of the commercial side of testing as is
possible without sacrifice to the teaching of fundamental prin-
ciples; and it should also be designed to develop self-reliance,
resourcefulness and ingenuity in the student. Success in the
latter function depends largely upon the personality of the in-
structor. He must hold himself in reserve rather than give a
student a fact that can reasonably be obtained by working for
it; he must encourage every spark of originality that can be
found and he must instill into his students his own enthusiasm
;
and love for science. At the same time the spectacular worker
must be curbed by an inflexible insistence that all regular labora-
tory work be performed in a thorough manner. The authors be-
lieve that the method of this book is truly in harmony with the
above proposals.
Many young men enter the laboratory with no previous ex-
perience in the practical operation of dynamo machinery and
-apparatus. They may be able to transform equations, prove
theorems, and talk intelligently about characteristic curves, but
are often entirely at sea in applying their knowledge to a con-
crete case in the laboratory. For this reason, the major portion
of the treatment of each experiment is devoted: (i) To
a review of the theory; (2) to the particular experimental
method involved; and (3) to practical applications of the
particular subject. The experimental observations required
"
for the test are enumerated under the heading Data." This
has been found of great assistance in making the laboratory
work thorough. Questions which bear directly upon the sub-
ject are asked at the end of many of the experiments. These
are introduced with the object of stimulating independent thought
and observation, and they therefore bear upon important though
less evident relations of the phenomena involved. The authors
believe that real value arises from formal questions only where