Tesla on the d.c. motor
In a paper presented before the American Institute of Electrical Engineers
in 1888, Tesla criticized the illogical construction of the d.c. motor.
``In our dynamo machines, it is well known, we generate alternate currents
which we direct by means of a commutator, a complicated device and,
it may be justly said, the source of most of the troubles
experienced in the operation of the machines. Now, the currents, so
directed cannot be utilized in the motor, but must - again
by means of a similar unreliable device - be reconverted into their
original state of alternate currents. The function of the commutator
is entirely external, and in no way does it affect the internal workings
of the machines. In reality, therefore, all machines are alternate
current machines, the currents appearing as continuous only in
the external circuit during the transfer from generator to motor.
In view simply of this fact, alternate currents would commend
themselves as a more direct application of electrical energy,
and the employment of continuous currents would only be justified
if we had dynamos which would primarily generate, and motors
which would be directly actuated by, such currents.''
Adopted from T.C. Martin, "The Inventions, Researches and
Writings of Nikola Tesla," New Work: Electrical Engineer, 1894, pp. 9-11
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