As the coils are energized, the magnetic field they produce between them induces an electric current in the rotor. Other parts of motor: Ages 9—12. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space.
To control the speed of an AC motor make it go faster or slower , you have to increase or decrease the frequency of the AC supply using what's called a variable-frequency drive.
The speed of the rotor will depend on the AC power, and the speed can be controlled by changing the input supply power. The number of separate electric currents energizing the coils independently, out of step, is known as the phase of the motor, so the design shown above is a two-phase motor with two currents energizing four coils that operate out of step in two pairs.
Who Invented the Electric Motor?
This rotating magnetic field has a speed which is known as the synchronous speed. These coils are designed to produce a rotating magnetic field, which turns the rotor the moving part of the motor in the space between them. The difference in speed is called slip and increases with load. January 31, 2013.
In these motor, the rotor is squirrel cage type. New York: Inside the stator, there's a solid metal axle, a loop of wire, a coil, a squirrel cage made of metal bars and interconnections like the rotating cages people sometimes get to amuse pet mice , or some other freely rotating metal part that can conduct electricity. But here in the induction motor, we only need to give supply to the stator winding for operation.
The original AC induction motor patent. Toggle navigation Quantum Controls. The rotor conductors and end rings form a complete closed circuit.
In this type of motor, the rotor is cylindrical core which is laminated to avoid power losses. Facts on File, 2004. With his partner George Westinghouse, Tesla championed AC, while Edison was determined to run the world on DC and dreamed up all kinds of publicity stunts to prove that AC was too dangerous for widespread use inventing an electric chair, to prove that AC could be lethal, and even electrocuting Topsy the elephant with AC to show how deadly and cruel it was.
US Patent 4,311,932: