Aircraft Electrical Systems What is Electricity? Electromagnetic - - PowerPoint PPT Presentation
Aircraft Electrical Systems What is Electricity? Electromagnetic Induction was Electromagnetic Induction - movement of electrons through wires (or conductors) to create electric current. Magnets passed across a closed-loop of wire
Electromagnetic Induction was
Induction - movement of electrons through wires (or conductors) to create electric current.
across a closed-loop
create an electromotive force (ELF) ELF – VOLTS – occurr when electrons move in the wire
produces magnetism
What is Electricity?
Vice Versa: Electricity produces magnetism
Alternator or Generator is not available
– Most Common – Lead-Acid Battery
power
built to last
from Alternator or Generator
Converts
to maintain battery power at max levels
Produces Direct Current (DC)
to Battery to maintain battery power at max levels when Battery is “off –line”
Controls ALL aircraft electrical power from Source to Use Points
Alternator Power Source
Battery Power Source
Systems from Electrical Overload (too much power)
Technology
Power
automatically maintains constant voltage level
Electrical Switch
electrical current from
Auxiliary Power Unit – APU) to rotate Starter Motor
connected by special gearing to Engine Crankshaft
speeds to rotate Engine Crankshaft
rotation Aircraft Engine Magnetos
– Rotating Magnet surrounded by loops of conducting wires
electrical current flow through wires
Magnetos for Redundancy
– Safety feature – two spark sources are better than one
simultaneously in Each Cylinder from Each Spark Source
– More even spark – More even, steady burning – More complete burning – Spark improves burning in all areas of cylinder – Plug fouling – A problem
essential for Glass Panel Cockpits
can run without Battery power
Minutes??
Basic Electrical/Magneto Aircraft System
A cylinder is a central working part of an engine. The space in which a piston travels. Multiple cylinders are arranged side by side by the engine
the cylinder is where combustion occurs.
A busbar in electrical power in distributing refers to thick strips of copper and aluminum and conducts electricity within a switchboard, distributing board, or other electrical apparatus.
Brian Bates, Baron Gould, & Richard Lynch
principle of electromagnetic induction, is self-contained and engine driven
electrical power for the ignition system to keep the engine running once the engine has been started.
a low voltage alternating current generator and a high voltage coil and distributor.
picks up the high voltage current from the coil and delivers it through the coil to the spark plugs.
The Magnetos
determined in the development phase. It is important to prevent pre- ignition and/or detonation.
are usually equipped with two magnetos for efficiency, smoother operation of the engine, and redundancy, to prevent the loss of the system if one magneto were to fail (L & R)
with a 28-volt direct current (DC) electrical system, because an alternator produces more
to a generator and can produce a specific amount of power at a much lower rotational speed.
electrical devices and stores energy in the battery.
to crank the starter.
Alternator or Generator? OR
connects the electrical buses and the devices to the battery through a switch, the master switch.
to crank the starter which will start the engine. Now, since the engine is running, the engine will supply power to the alternator and recharge the battery.
to create spark, ignite fuel and crank the engine.
Electrical System, (in a nutshell)
an ammeter
electricity to function
manual (POH) and aircraft flight manual (AFM) to learn how to identify and possibly handle any electrical problem in flight.
you should know whether or not an emergency landing is necessary.
Know Your Systems
Glenn Research Center, http://www.grc.nasa.gov/WWW/K-12/airplane/icengine.html, 1-11-2008 Glenn Research Center, http://www.grc.nasa.gov/WWW/K-12/airplane/elecsys.html, 1-11-2008 Pilot Friend, http://pilotfriend.com/training/flight_training/tech/elec.htm, 1-11-2008 http://selair.selkirk.bc.ca/systems1/Engines/Aircraft%20Magneto%20systems.html, 1-11-2008
Mark Kinder Nathan Williamson Richard Douglas AVIA 112
energy to electrical
aircraft electrical systems generate, regulate and distribute electrical power throughout the aircraft. Many aircraft flight instrument systems use electricity
many different voltages both AC and DC
Most aircraft engines provide power to generate AC generator (alternator) power.
generate, regulate and distribute electrical power throughout the aircraft.
different voltages both AC and DC
– 115 VAC @ 400 Hz – 28 VDC
drives an AC generator (alternator).
– Integrated Drive Generator – Transformer Rectifier Unit – Generator Control Unit
the functions of a dynamo, contact breaker points, "condenser", and ignition coil.
a coil, and also operates a contact breaker, interrupting the current and causing the voltage to be increased sufficiently to jump a small gap. The spark plugs are connected directly from the magneto output.
with associated voltage regulators, current limiters, or other protective devices.
provide power to the starter motor.
provide ignition,
– generator or alternator takes on the tasks
circuit breakers or fuses.
Magneto-equipped aircraft engines are typically dual-plugged, that is, each cylinder has two spark plugs, with each plug having its own separate magneto; This arrangement provides:
– redundancy in the event of a failure of one of the magnetos. – more complete and efficient burn of the fuel mixture, and – if placed far apart in the combustion chamber, decreases burn time, allowing higher engine speeds.
For this reason, double plugging is also used in high performance automobiles and motorcycles.
Magneto Internals Magneto Components
996 835 MAGNETO GENERATOR P12W150
1
996 821 1 MAGNETO FLYWHEEL P12W150 1 From serial# 4084219 & above 996 820 MAGNETO FLYWHEEL 1 Up to serial# 4084218
2
996 849 COIL KIT P12W150 1 2-5 996-840 STATOR PLATE ASSY.
Converts
to maintain battery power at max levels