 http://en.wikipedia.org/wiki/Polyphase_system  http://en.wikipedia.org/wiki/Induction_motor#Principle_of_operation |
What distinguished Tesla
from the rest of the world at the time was his passion to
harness the power of alternating current. Direct current
was very inefficient because it could not achieve the high
voltages needed to carry electricity over long distances.
This resulted in the need for numerous power stations at
very short intervals. Alternating current on the other hand changes direction 50 to 60 times every second, hence the name 'alternating current.' This meant that higher voltages could be achieved along with efficiency. Power = Current * Voltage
No one before Tesla had been able to produce a motor able
to run on AC directly. Most systems at the time had to
convert AC into DC for the available motor technology. His
invention was a motor that could run off a rotating
magnetic field. How this works is the stator of the motor
is supplied with an AC current. The stator creates an
magnetic field and the rotor rotates in sync with
alternating current oscillations. The illustration at
right shows the rotor rotating with the different
oscillations. Below is a diagram of a basic induction
motor.More voltage means more power |
 http://www.automatedbuildings.com/news/jul01/art/abbd/abbd.htm |
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