Aircraft Electrical Systems
What is Electricity? 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 at right-angles create an electromotive force (ELF) ELF – VOLTS – occurr when electrons move in the wire •
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Vice Versa: Electricity produces magnetism
Vice Versa: Electricity produces magnetism
What is Electricity? 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 at right-angles create an electromotive force (ELF) ELF – VOLTS – occurr when electrons move in the wire •
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Vice Versa: Electricity produces magnetism
Vice Versa: Electricity produces magnetism
Aircraft Electrical System Power Power Sources
Battery •
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Provides Electrical Power when Alternator or Generator is not available Several types of Batteries –
Most Common – Lead-Acid Battery •
Lead and Acid produce electrical charge
Electrical battery •
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Small, light, not a lot of power Simple and effective built to last Recharges during flight from Alternator or Generator
Aircraft Electrical System Power Sources Alternator Converts Alternating Current (AC) to Direct Current (DC) For electrical system uses DC is easier to use, Lower volts, Safer • • •
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Also, provides Current to Battery to maintain battery power at max levels •
Aircraft Electrical System Power Sources Generator Produces Direct Current (DC) For electrical system uses DC is easier to use, Lower volts, Safer •
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Like Alternator- provides Current to Battery to maintain battery power at max levels when Battery •
is “off –line”
Aircraft Electrical System Controls
Aircraft Electrical System Controls Master Switch Controls ALL aircraft electrical power from Source to Use Points Left Side Switch controls Alternator Power Source •
Right Side Switch controls Battery Power Source •
Aircraft Electrical System Controls Circuit Breaker & Fuses Protect individual electrical User Systems from Electrical Overload (too much power) •
Breakers and Fuses do Same Job Difference: Replace a Fuse Reset a Circuit breakers Technology Improvement Fuses- Older Technology Circuit Breakers – Newer Technology
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Airplane Electrical Systems Ammeter Monitors electrical system performance Two types To/from battery Alternator load •
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Aircraft Electrical System Controls Voltage Regulator •
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Volt is a measure of Electrical Power Voltage regulator automatically maintains constant voltage level
Master Switch
Master Solenoid
Starter Solenoid Electrical Switch •
starter solenoid relays a large electrical current from origination source (Battery or Auxiliary Power Unit – APU) to rotate Starter Motor
Starter Switch
Starter •
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Electric Motor connected by special gearing to Engine Crankshaft Rotates at very high speeds to rotate Engine Crankshaft Engine Crankshaft rotation Aircraft Engine Magnetos
Magneto •
Magneto is a Field Generator –
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Rotating Magnet surrounded by loops of conducting wires
Rotating magnets generate electrical current flow through wires Aircraft engines have TWO Magnetos for Redundancy –
Safety feature – two spark sources are better than one
Magneto Systems
AND, TWO Spark Plugs •
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Two plugs fire simultaneously in Each Cylinder from Each Spark Source Efficiency –
More even spark
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More even, steady burning
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More complete burning
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Spark improves burning in all areas of cylinder Plug fouling – A problem
Airplane Electrical Systems Battery
Stores Electricity Powers Engine Short-term Power
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Magneto and Electrical System By Cory and Amanda
Electrical System- 727 Simplified
Magneto and electrical system Jonathan Hord
Magnetoes are self-sufficient Air, fuel and spark starts engine
Glass Cockpits •
Electrical power is essential for Glass Panel Cockpits
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Magneto Powered Engine can run without Battery power Glass Panels Can’t
Glass Glass Cockp Cockpit it Pow Power er - Critic Critical al •
Backup Battery – 30 Minutes??
Aircraft Electrical Systems
The End – Fly Safe!
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 block. The distance the piston travels in a cylinder is called the stroke. In 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.
ELECTRICAL & MAGNETO Brian Bates, Baron Gould, & Richard Lynch SYSTEMS FOR SMALL AIRCRAFT
The Magnetos •
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A magneto operates on the principle of electromagnetic induction, is self-contained and engine driven A magneto provides the electrical power for the ignition system to keep the engine running once the engine has been started. A magneto is a combination of a low voltage alternating current generator and a high voltage coil and distributor.
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The distributor in the magneto picks up the high voltage current from the coil and delivers it through the coil to the spark plugs. •
Timing of magnetos is determined in the development phase. It is important to prevent preignition and/or detonation. Small, general aviation aircraft 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)
Alternator or Generator? •
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Most small aircraft are equipped with a 28-volt direct current (DC) electrical system, because an alternator produces more output for less weight compared to a generator and can produce a specific amount of power at a much lower rotational speed. An alternator drives the electrical devices and stores energy in the battery. The battery provides the power to crank the starter.
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Electrical System, (in a nutshell)
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The second electrical system connects the electrical buses and the devices to the battery through a switch, the master switch. The battery provides the power 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. The magnetos continually work to create spark, ignite fuel and crank the engine. •
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Inside the cockpit, you will find an ammeter Some instruments require electricity to function
Know Your Systems
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Read the pilot’s operating manual (POH) and aircraft flight manual (AFM) to learn how to identify and possibly handle any electrical problem in flight.
In the event of a power failure, you should know whether or not an emergency landing is necessary. Evaluate Conditions VFR or IFR = Nav equipment? Retractable Gear = extended? Flaps retracted or extended? Transponder/Comms avail?
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ER Procedures 101
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Aviate
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Best Landing Site
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Communicate
References 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
Electrical & Magneto Systems
Mark Kinder Nathan Williamson Richard Douglas AVIA 112
Outline Electrical Systems
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Alternator Battery Ammeter Master Switch Circuit Breakers & Fuses
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Magnetos
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Airplane Electrical Systems Battery
Stores Electricity Powers Engine Short-term Power
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Magnetos •
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Supplies current to plugs Changes mechanical energy to electrical
Each A/C has 2 magnetos Provides redundancy Improves combustion
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Magneto is engine-driven
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Summary Electrical Systems
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Alternator Battery Ammeter Master Switch Circuit Breakers & Fuses
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Magnetos
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Electrical System
Magneto Systems
Typical Ignition System
aircraft electrical systems generate, regulate and distribute electrical power throughout the aircraft. Many aircraft flight instrument systems use electricity Aircraft electrical components operate on many different voltages both AC and DC Most aircraft systems use : •
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115 Volt Alternating Current (AC) @ 400 Hz 28 Volt Direct Current (DC)
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Most aircraft engines provide power to generate AC generator (alternator) power.
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The function of the aircraft electrical system is to generate, regulate and distribute electrical power throughout the aircraft. It is essential for the flight instrument systems. Aircraft electrical components operate on many different voltages both AC and DC However, most of the systems use: –
115 VAC @ 400 Hz
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28 VDC
Each of the engines on an aircraft drives an AC generator (alternator).
Electrical Power System Components •
AC Generator or Alternator
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Constant Speed Drive: in this case would be the belt driven by the engine.
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Today's modern small aircraft contain all of this inside the alternator: –
Integrated Drive Generator
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Transformer Rectifier Unit
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Generator Control Unit
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How they WoRk! •
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The ignition magneto combines the functions of a dynamo, contact breaker points, "condenser", and ignition coil.
The engine spins a magnet inside 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.
All pilots are…
Aircraft Electrical and Magneto Systems Corey Hjalseth Ali Spirggs Fernando Rodriguez
Aircraft Magneto Systems •
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A magneto is a combination of low and high voltage current generator and distributor. The magnetos ignition coil transforms low voltage to high voltage. The distributor picks up the high voltage from the coils and delivers it to the spark plugs for ignition.
Magneto Diagram
Aircraft Electrical Systems •
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The purpose of an aircraft electrical system is to generate, regulate, and distribute electrical power through the entire aircraft. It consists of a battery, an alternator, and regulators for these devices. The alternator charges the battery just like in a car.
Electrical System Run Through •
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The master switch turns on the battery. The battery turns on all of your aircraft lights. The Alternator is activated along with the radio and instrument lighting. The alternator continues to work and recharge the battery and thus light the aircraft.
Aircraft Electrical System Diagram
General Aviation Aircraft Electrical and Magneto Systems
By: Silvia Fresnedo, Mark Tison and Karen Fisher
Electrical System •
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The airplanes electrical system consists of a battery and a generator or alternator with associated voltage regulators, current limiters, or other protective devices. The primary function of the battery is to provide power to the starter motor. After the engine starts, the magnetos provide ignition, –
generator or alternator takes on the tasks of powering: Radios Instruments lights Electrical landing gear Flaps Recharging the battery •
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Individual circuits are protected by circuit breakers or fuses.
Electrical System
Magneto System 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: –
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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 System
Magneto Components Magneto Internals
Questions?
Electrical and Magneto Systems
Mark, Godfrey, Shane
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2
996 835
MAGNETO GENERATOR P12W150
996 821
1 MAGNETO FLYWHEEL P12W150 1 From serial# 4084219 & above
996 820
MAGNETO FLYWHEEL 1 Up to serial# 4084218
996 849
COIL KIT P12W150 1 2-5 996-840 STATOR PLATE ASSY.
How the Electrical system works
