Starring torque

Operation A 3 phase motor self starts due to a rotating magnetic field in the windings If a single phase was applied to one winding, it would simply pulse and produce no torque If we could simply ‘push’ the rotor, it would begin to spin for the same reasons in a 3 phase motor

11p viet82vp 16-08-2012 45 9   Download

AC motors convert AC electrical energy to Mechanical energy. AC motors: the armature of rotor is a magnet (different to DC motors). the stator is formed by electromagnets (like in DC motors). Effects of AC Supply on Magnetic Poles Consider the rotor to be a permanent magnet. Current flowing through conductors energize the magnets and develop N and S poles. The strength of electromagnets depends on current. First half cycle current flows in one direction. Second half cycle it flows in opposite direction...

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One way to solve the single phase problem is to build a 2-phase motor, deriving 2-phase power from single phase. This requires a motor with two windings spaced apart 90o electrical, fed with two phases of current displaced 90o in time. This is called a permanent-split capacitor motor in Figure

22p viet82vp 16-08-2012 48 4   Download

Permanent-split capacitor motor One way to solve the single phase problem is to build a 2-phase motor, deriving 2phase power from single phase. This requires a motor with two windings spaced apart 90o electrical, fed with two

22p viet82vp 16-08-2012 40 4   Download

Single Phase Motors • Similar to a 3 phase induction motor with squirrel cage rotor and main stator windgs. Main wndgs Centrifugal switch Rotor Laminated stator slots Wndgs Start wndgs .Run (main) and Start (Aux) Windings • The stator has two

3p viet82vp 16-08-2012 37 4   Download