Aircraft Electrical Systems

battery to function " Each spark plug has a separate magneto system " Converts mechanical energy to electrical energy Spark Plugs " Receives 8spark 9 electricity from magneto " Ignites compressed fuel/air mixture inside engine cylinder " Aircraft engines have two spark plugs (two magneto systems) per cylinder " Electricity travels from magneto to magneto spark plug in heavily insulated wires 3 HIGH VOLTAGE Circuit Breaker/Fuses " Protects the electrical system from electrical overload " Overload can cause damage to components in the electrical system " Fuses have an internal metal wire or strip that melts when too much electrical current flows through it " Circuit breakers have a switch that trips if too much electrical current flows through it " The switch can be manually reset instead of replacing it Voltage Regulator " Controls the rate of charge to the battery " Stabilizes the generator or alternator electrical output " Compares the generator/alternator voltage output to the battery voltage Ammeter " Monitors the performance of the electrical system " Shows if the alternator/generator is producing an adequate supply of electrical power " Indicates whether or not the battery receives an electrical charge " Not all airplanes are equipped with an ammeter " Some airplanes have a warning light to alert the pilot of an electrical system problem Master Switch " Turns Electric system on or off " Controls entire electrical system except for Magneto Ignition system, including " interior/exterior lights, " radios, fuel gauges, pumps, " -and 3 engine starter motor " Some airplanes equipped with battery switch and alternator switch (split switch) " Alternator switch (ALT) disconnects alternator from electrical system in case of alternator failure (ALT=OFF) Ground Power Unit (GPU) " Provides aircraft with power from external power supply " Very useful for starting engine in cold weather "Some GPU 9s built into airport jet-ways to reduce wear on a/c systems and to provide immediate power for ground ops Summary Components " Battery " Alternator/Generator " Magneto " Spark Plugs " Fuses/Circuit Breaker " Voltage Regulator Controls/ Tools " Master Switch " Alternator Switch " Ammeter " Ground Power Unit (GPU) References " Wikipedia, (2009), http://en.wikipedia.org/wiki/Electricity , 2-1-2009 " Aeronautical Knowledge Handbook, (2009), http://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.html , 2-1-2009 " Wikipedia, (2009), http://en.wikipedia.org/wiki/Fuse_(electrical) , 2-1-2009 " Aircraft Technical, (2009), http://www.pilotfriend.com/training/flight_training/tech/elec.htm , 2-2-2009 The End

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