V Fill in the gaps with correct prepositions.
1 Aircraft ac generators range __ size ___ thetachometer instrument generator __ to the 90,000volt-ampere generators. 2 Generators are categorized as either brush-type or brushless. 3 Regardless __weight, shape, or rating, practically all ___these generators have the following common characteristics. 4 The ac generator field (rotor) is a rotating magnetic field ___ fixed polarity. 5 Regulating the rpm __the rotating magnetic field controls the voltage frequency. 6 Controlling the strength __ the magnetic field regulates the voltage. 7 A three-phase generator isactually three separate power sources enclosed __one housing. 8 Each output winding produces 120 voltsas measured __ n to a, b, or c (phase voltage). 9 The line voltage found __a three-phase,WYE-connected system is the vector sum __ the voltagesgenerated __ two separate phase windings. 10 Because a 120-degree phase difference exists ___ thevoltages, they reach their peak amplitudes __- differenttimes. 11 __ the four-wire, grounded-neutral, WYE-connectedsystem, the neutral wire attaches __ the frame __theaircraft (ground). 12 The three-phase wires run __ buses,which supply power __ various loads. 13 A bus is a primarypower distribution point that is connected__ the mainpower source. 14 The connections ___ loads requiring 120volts are between one __the buses and the aircraft frame. 15 The load connections requiring 208 volts are___ two __the buses (phases).
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