Advantages and Disadvantages of Ad and Dc Essay

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HSC PHYSICS > MOTORS AND GENERATORS| AC & DC

Gather secondary information to discuss the advantages and disadvantages of AC and DC generators and relate these to their use.

AC generators

Advantages
 The slip rings of an AC generator have a continuous surface that allows the brushes to remain in contact with the ring’s surface. Thus the brushes in an AC generator do not wear out as fast as in a DC generator as they do not create an electric short circuit every half-turn.  Therefore they required less maintenance and is more reliable that DC generators.  AC’s voltage can be changed by transformers. It is more readily transformed to different voltages than DC.  Because of this property, AC can travel longer distances on
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By 1882, his company was installing DC generators and electric lighting systems. Edison’s company had created many electrical appliances that run on DC such as light bulbs and other home appliances. He had a vested interest in DC as he owned hundreds of DC power stations and all his company's electrical inventions ran on DC.

DC

DC

a a

& American engineer George Westinghouse bought the USA patent rights for the AC transformer. Tesla’s invention of the induction motor in 1888 largely popularised the commercialisation of AC. o AC induction motors is run by continuously moving a strong magnet back and forth near copper/aluminium that induces eddy currents in the copper/aluminium plate, which will cause it to follow the movement of the magnet – generating rotational kinetic energy. o Because AC induction motors do not require a commutator (as kinetic energy is created by induction), it has the advantage of higher efficiency and lower maintenance as no contact of material is needed. o 90% of motors are AC induction motors – used in fans, hair dryers, fridges, washing machines and vacuum cleaners

AC

AC


Problems with DC
 Power could only be transmitted short distances from the generator because of  split ring commutator wore out quickly, higher maintenance reduces efficiency and increased costs  there was no efficient method of changing the DC voltage so electricity produced at the
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