Chp 17 Electrical Systems Flashcards
What are the two types of current electricity
Alternating current
Direct current
Electricity produced by Magnetism is?
Alternating current
What determines the current flow as a result of magnetism induction?
Strength of the magnetic field
The number of conductors passing through the field
Speed with which field is crossed
A generator in which slip rings and brushes carry the current from the armature produces?
Alternating current
When a conductor is moving parallel to lines of magnetic flux, the current in the conductor is?
At its minimum
The electricity produce from the armature coils of the DC generator is
Alternating current
A generator in which a communator and brushes carry the current from the armature produces?
Direct current
The current that flows in a DC generator field coil is taken from the?
Generator armature
The magnetism for producing in the initial excitation current in a DC generator is?
Residual magnetism in the generator frame
The voltage produced by a generator when no field current is flowing is?
Residual voltage
Residual voltage in a DC generator is approximately how many volts or less?
2 V
Residual voltage is lost when a generator is disassembled it is restored by what?
Field flashing
When flashing the field of a DC generator current is directed through the field coils in the blank direction as normal flow?
Same direction
In a shunt connected DC generator the field coils are in what with the Armature?
Parallel
In a compound wound DC generator the voltage regulator Is in the blank field?
Shunt field
The core of the armature used in a DC generator is made up of what?
Laminated soft iron
The position of the armature in a DC generator in which there is no potential difference between the ends of the adjacent coils is called the blank and blank
Neutral position or neutral plate
The neutral plane of an uncompensated DC generator shifts as the blank current changes
Armature
The brushes of a DC generator are located in the neutral plane to minimize what?
Brush arcing
What is magnetic flux
Lines used to represent a magnetic field
What is magnetic field
The invisible but measurable force surrounding a permanent magnet or current carrying conductor
What is a slip ring 
A smooth continuous ring of brass or copper mounted on the rotor shaft of an electrical generator or alternator. Brushes riding on the smooth surface of the slippering carry current into and out of the rotor coil
What is a rectifier
A device that allows electrons to flow in one direction while preventing their flow in the opposite direction
What is a commutator
A mechanical rectifier mounted on the armature shaft of the DC generator. Carbon brushes riding on the commutator carry current into and out of the armature
What is Pulsating DC
Direct current who voltage periodically changes, but who’s electrons flow in the same direction all of the time
Note
A DC generator produces alternating current, but is rectified by the commutator and brushes before leaving the generator
What is a permanent magnet
A piece of hardened steel that has been exposed to a strong magnetizing force which has aligned the spin axis of the electrons surrounding its atoms
What is an electromagnet
A magnet produced by an electrical current flowing through a coil of wire
What is residual magnetism
The magnetism that remains in the field frame of a generator when no current is flowing through the field coils
What is residual voltage
The voltage produced in a generator armature when the armature is rotated in the residual magnetism
What is flashing the field
A maintenance procedure that restored residual magnetism to a DC generator field frame
What is a short circuit
A low resistant connection between two points in electric circuit
What are the three types of field generators
Sorties
Shunt
Compound
What is a slow blow fuse
A special type of circuit protection device that allows a momentary flow of excess current, but opens the circuit if the excess flow is sustained
What is a current limiter
Pass a momentary excess of current, but if the circuit uses more than the generators rated current for an extended period of time, a fuse will sever and protect the component
Reverse current cut out and switch
Protects the generator from acting as a motor is the battery voltage is higher than the generators voltage
Carbon pile voltage regulator
A voltage regulator for a high output dc generator that uses a stack of pure carbon disk for the variable resistance element
What are the three primary advantages of dc alternators of ax
More sets of field poles produce current at a lower speed.
High current produced in stationary component is rectified by semi conductors diodes
An alternator charging system is lighter weight than a generator charging system
What is the rotor of a dc alternator composed of
Coils and poles
What is distributed pole stator winding
Alternator stator windings wound in a sieries of slots in the stator frame
What’s the two parts of a dc alternator
Rotor and stator
What’s transformed ac power to dc power
Transformer rectifier
What is a constant speed drive
Component mounted between an ac generator and an aircraft engine that holds the generator speed and frequency constant as the engine varies through its normal operating state
Inverter make up
28 volt 115 volt 3 phase and 400 hertz
