Electrical System

Most aircraft are equipped with either
 14 or 28 volt direct current electrical systems.  Volts are essentially potential energy.  ie: Regardless of which items you turn on or off, the system will always consist of 28 volts.

Components
Alternator/Generator
Battery
Master/Battery Switch
Alternator/Generator Switch
Bus Bar, Fuses or Circuit Breakers
Voltage Regulator
Ammeter/Loadmeter
Associated electrical Wiring

An amp is a unit of current.  So for example a landing light uses 15 amps to generate enough power to illuminate.

Knowing that battery is 24 volts or 12 volts is akin to knowing whether something needs AA or AAA batteries.

Bus Bars simplify wiring for voltage to be distributed.

Fuses/Circuit Breakers protect the circuits from electrical overload.  The reason that amp numbers are listed on the circuit breakers is to determine how long we can operate the system using battery power only.  In practice, it will be less than whatever we would calculate (based on how long it took to discover the failure followed by time required to troubleshoot).

Ammeter monitors performance of electrical system - shows if alternator or generator is producing an adequate supply of power to the battery and other components.

Loadmeters indicate a more direct indication of powered being supplied from the alternator to the electrical components.


Alternator Control Unit is composed of Voltage Regulator and OverVoltage Relay.  Voltage Regulator controls rate of charge to battery by stabilizing electrical output from alternator/generator.  Think of it as communication.  Flaps need 15 amps.  Voltage regulator sends 15 amps to the flaps.    Voltage output will be higher than battery voltage to keep battery charged.  Whatever isn't needed is grounded.  If too much output is generated from alternator, overvoltage relay kicks in and trips alternator.  Resetting alternator should correct the problem.

Hydraulic Systems
There are numerous applications of hydraulic power depending on complexity of the aircraft.  It can operate wheel brakes, landing gear, and some constant speed propellers.  On larger aircraft, it can be used to power flight control surfaces, wing flaps, and other systems.

Basic hydraulic system consists of reservoir, pump, filter, and selector valve to control flow, and actuators.

Servos can be single-acting or double-acting.  Mineral-based hydraulic fluid is most widely used type.

Landing Gear
Many GA aircraft have fixed landing gear, but more complex aircraft often use a hydraulically-powered system with actuators to send pressure up or down.  Downlocks keep wheels locked in place while pressure (between 1000-1500 PSI) keeps wheels up.

Anti-Ice/Deice Systems
Anti-ice is used to protect against formation of ice.  Deice exists to remove any ice that already is present.  Most light aircraft only have carburetor heat and pitot heat to combat icing.

Airfoil Anti-Ice/Deice
Inflatable deicing boots consist of a rubber sheet bonded to leading edge of airfoil.  When ice builds up on leading edge, an engine-driven pneumatic pump inflates the rubber boots.  This inflation cracks the ice and hopefully forces it to fall off.

Thermal anti-ice systems direct hot air from compressor section of engine to leading edge surfaces.

Weeping Wings use holes in leading edge by pumping antifreeze solution through holes.

Windscreen anti-ice uses a flow of alcohol over the windscreen

Additionally windscreen heaters may be turned on electrically.  This may cause some magnetic compass deviation if used.

Propeller Anti-Ice also use alcohol or heating elements.