Engines - Electrical System

Electrical System Purpose:

powers basic flight instrumentation and sophisticated weapon delivery systems

Two forms of electricity:

AC and DC

Military Aircraft utilize which kinds of electricy:

Primarily AC (lighter, simpler, reliable) but still utilize DC in some instances

Generators

transformers mechanical energy into electrical energy. AC generator may be referred to as alternators.

Constant Speed Drive

a hydromechanical linkage between the engine and the generator. It will convert fluctuating RPMs from the engine into constant RPMs to ensure steady voltage output.

Inverter (electro-mechanical)

transforms DC into AC, used if the AC generator fails

Transformer Rectifier (electric)

transforms AC into DC, highly reliable and rugged

Battery

provides DC power typically used for emergencies, two way flow with the essential bus

Buses

Distribution Networks

Essential Bus

Safety of Flight

Primary Bus

Mission

Secondary Bus

Convenience

Starter Bus

used to start the aircraft's engine

Switches

Manual means to control power. Located in the cockpit to energize or de-energize a system.

Circuit Breakers

manual or automatic means to interrupt power

Fuses

automatic circuit protection from an overload or excess current

Warning Light

signal system malfunctions to the aircrew.

Master Caution Panel

provides pilot with a centralized warning center

Auxilliary Power Unit (APU)

provides the aircraft independence from external power, connected to the accessory gear box with a drive shaft. can also be utilized in emergencies

Ground Support Equipment

externally supplied power for aircraft operations on the ground

What bus charges the battery?

DC Essential Bus