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A typical one-line diagram with annotated power flows. Red boxes represent circuit breakers, grey lines represent three-phase bus and interconnecting conductors, the orange circle represents an electric generator, the green spiral is an inductor, and the three overlapping blue circles represent a double-wound transformer with a tertiary winding.
Two-phase power can be derived from a three-phase source using two transformers in a Scott connection: One transformer primary is connected across two phases of the supply. The second transformer is connected to a center-tap of the first transformer, and is wound for 86.6% of the phase-to-phase voltage on the three-phase system.
The two coils at centre are mechanically connected, and are energized in "quadrature" (meaning a phase difference of 90° (π/2 radians) between the flux of the magnets and the flux of the coils). The bottom and upper coils in this particular case have a phase difference of 90°, making this a two phase motor (not to scale).
Induction motors are most commonly run on single-phase or three-phase power, but two-phase motors exist; in theory, induction motors can have any number of phases. Many single-phase motors having two windings can be viewed as two-phase motors, since a capacitor is used to generate a second power phase 90° from the single-phase supply and feeds ...
A further measure of control is provided by using pairs of motors on a vehicle in series-parallel control; for slow operation or heavy loads, two motors can be run in a series of the direct-current supply. Where higher speed is desired, these motors can be operated in parallel, making a higher voltage available at each motor and so allowing ...
An example of this is the function block diagram, one of five programming languages defined in part 3 of the IEC 61131 (see IEC 61131-3) standard that is highly formalized (see formal system), with strict rules for how diagrams are to be built. Directed lines are used to connect input variables to block inputs, and block outputs to output ...
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The two two-phase windings, fixed at right (90°) angles to each other on the stator, produce a sine and cosine feedback current. The relative magnitudes of the two-phase voltages are measured and used to determine the angle of the rotor relative to the stator. Upon one full revolution, the feedback signals repeat their waveforms. This device ...