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 at right-angles create an electromotive force (ELF) ELF – VOLTS – occurr when electrons move in the wire • Vice Versa: Electricity produces magnetism Vice Versa: Electricity produces magnetism

Aircraft Electrical System Power Sources

Battery • 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 • 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 • 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 • 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

Airplane Electrical Systems Ammeter • Monitors electrical system performance Two types • To/from battery • Alternator load

Aircraft Electrical System Controls Voltage Regulator • 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 • 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 – 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 • Two plugs fire simultaneously in Each Cylinder from Each Spark Source • Efficiency – More even spark – More even, steady burning – More complete burning – Spark improves burning in all areas of cylinder – Plug fouling – A problem

Airplane Electrical Systems Battery • Stores Electricity • Powers Engine • Short-term Power

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 • Magneto Powered Engine essential for Glass Panel can run without Battery Cockpits power • Glass Panels Can’t

Glass Cockpit Power - Critical • 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 • 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. • Timing of magnetos is • The distributor in the magneto determined in the development phase. It is picks up the high voltage important to prevent pre- current from the coil and ignition and/or detonation. delivers it through the coil to the spark plugs. • 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? • Most small aircraft are equipped with a 28-volt direct current OR (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.

Electrical System, (in a nutshell) • 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. • Inside the cockpit, you will find an ammeter • Some instruments require electricity to function

Know Your Systems • 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? • ER Procedures 101 • Retractable Gear = extended? • Flaps retracted or extended? • Transponder/Comms avail? • Aviate • Best Landing Site • 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 • Alternator • Battery • Ammeter • Master Switch • Circuit Breakers & Fuses • Magnetos

Airplane Electrical Systems Battery • Stores Electricity • Powers Engine • Short-term Power

Magnetos • Supplies current to plugs • Changes mechanical energy to electrical • Each A/C has 2 magnetos • Provides redundancy • Improves combustion • Magneto is engine-driven

Summary • Electrical Systems • Alternator • Battery • Ammeter • Master Switch • Circuit Breakers & Fuses • Magnetos

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 : • 115 Volt Alternating Current (AC) @ 400 Hz • 28 Volt Direct Current (DC) Most aircraft engines provide power to generate AC generator (alternator) power.

El Elect ectrical rical Sys Syste tems ms • 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 – 28 VDC • Each of the engines on an aircraft drives an AC generator (alternator).

Electrical Power System Components • AC Generator or Alternator • Constant Speed Drive: in this case would be the belt driven by the engine. • Today's modern small aircraft contain all of this inside the alternator: – Integrated Drive Generator – Transformer Rectifier Unit – Generator Control Unit