Electrical Systems Flashcards
Electrical equipment
Starter motor
Electric fuel pump
Stall warning indicator
Fuel gauge
Ammeter
Pitot heaters
Annunciation panel
Nav lights
Strobe lights
Anti collision lights
Landing lights
Instrument lighting
Cabin dome light
Dc suppliers
Battery (engine not running)
Alternator or generator (engine running)
Battery
Provides initial electrical power to turn over and start engine
Supplement alternator
Emergency electrics
12v or 24v
Commonly found along engine firewall
Battery parts
Electrodes( dissimilar metals) in electrolyte solution
Electrons mass on negative electrode causing electrodes to flow from negative to positive current
Chemical reaction
Primary cannot be recharged
Secondary can be recharged
Lead acid wet cell
Nicad ( nickel cadmium) wet or dry
Nickel metal hydride
Lithium polymer (lipo)
Emergency battery strip
In front of instructor
Only the necessary functions 90 mins…(30v)
Standby AI
Floodlight with emergency switch on
Alternator
Main electricity (recharges battery)
Produces ac rectifier changes to dc
Located on engine (mechanically driven by engine)
Uses some of current to keep its own coil energised
Alternator vs generator
Generator
Heavier and larger
Less power per rpm
Permanent magnets
rotating conductor(armature) energy source moving (arcing and energy loss)
Self exciting (retains residual flux doesn’t require battery to start)
Uses split rings to convert ac to dc (split rings lose current in transfer)
Sometimes split rings with rectifier
Some of current used to keep field coil energised
Alternator
Stationary conductor (stator) energy source is stable
Rotating bar/electro magnet (rotor)
Semi permanent magnets
Use rectifier for ac to dc
Diode
One way valve allows flow one direction
3 arranged diodes act as rectifier (switch and add ac currents to create dc current)
Voltage regulator
Required due to varying rpm
Adjust voltage output
1 number of coils
2 rotation speed
3 field strength
Senses output and adjusts field winding current (then adjusts magnetic field)
Current limiter
Prevents rated voltage from being exceeded by adjusting field
Reverse current and prevention
When battery output exceeds generator/alternator Battery could discharge through armature or field
Generator uses relay (voltage operated switch makes generator main source when it exceeds battery output)
Alternator uses field relay to prevent battery discharge
Bus bar
Conductor and distribution centre of electric system
All electricity goes through bus bar
Ammeter
Measures current flow
Left zero
Measures alternator current output
0=
1engine off battery on
2engine running alternator switch off
Centre zero
Measures current flow with regard to battery
Battery charging (positive reading) or discharging (negative reading)
Master switch
Controls electrics except ignition
Two halves
1 battery
2 alternator
Protection devices
Protect from overload (fire)
Circuit breakers (pop) can be reset once
Fuses (blow) no reset
Overload switch (switch off) can be reset
