AF Generators and Alternators

Integrated drive generators employ a type of high output AC generator that utilizes

A brushless system to produce current

Aircraft which operate only AC generators (alternators) as a primary source of electrical power normally provide current suitable for battery charging through the use of

A stepdown transformer band a rectifier

When necessary during operation, CSD disconnect is usually accomplished by

A switch in the cockpit

A CSD unit drives a generator through the use of

A variable hydraulic pump and hydraulic motor

The purpose of a rectifier in an electrical system is to change

Alternating current and direct current

How are generators rated

Amperes at rated voltage

An aircraft electrical circuit control relay is

An electrically operated switch

A battery-generator system provides direct current. On installations requiring alternating current from the battery-generator system, it is necessary to have

An inverter

How is a shunt wound DC generator connected?

Both fields are shunted across the armature

The inductor type inverter output voltage is controlled by the

DC stator field current

What is a method used for restoring generator field residual magnetism

Flash the fields.

What is required when operating two aircraft AC generators in parallel

Frequency and voltage must both be equal.

The voltage in an AC transformer secondary that contains twice as many loops as the primary will be

Greater and the amperage less than in the primary

One advantage of using AC electrical power in aircraft is

Greater ease in stepping the voltage up or down

Which motor would be most likely to have an armature brake?

Landing light retraction motor.

What is the cause of generator brush arcing

Low spring tension.

CSD driven generators are usually cooled by

Oil spray

A CSD unit that is disconnected in flight, due to a malfunction such as overtemperature, may be reconnected

Only on the ground by maintenance personnel

What is the ratio of turns between the primary cool winding and the secondary coul winding of a transformer designed to triple it's input voltage

Primary will have one third as many turns as it's secondary

What is the frequency of an alternator dependent upon

RPM

In an AC circuit with no phase lead or lag, which is true?

Real power equals apparent power.

Certain transport aircraft use AC electrical power for all normal operation and battery furnished DC electrical power for standby emergency use. In aircraft of this type that operate no DC generators, the batteries are kept charged by

Rectifiers which use the aircraft's AC generators as a source of power

If the integrated drive generator (IDG) scavenge oil filter is contaminated with metal, you should

Remove and replace the IDG

The strength of the core of an electromagnet depends upon the material from which it is constructed and which of the following

The number of turns of wire in the coil and the applied voltage

How can it be determined if a transformer winding has some of its turns shorted together

The transformer will get hot in normal operation was

How many cycles of AC voltage are produced in a six pole alternator of the revolving field type for each revolution of the rotor?

Three

Why are the iron cores of most induction coils laminated

To reduce the effects of eddy currents.

What is the maximum amount of time a circuit can be in operation and still be an intermittent duty circuit

Two minutes

How does the magnetic brake used to stop rotation of an electric motor armature operate

a friction brake is applied by a spring and released by a magnet

One purpose of a growler test is to determine the presence of

a shorted armature

During ground operation, aircraft generator cooling is usually accomplished by

an integral fan

If any one generator in a 24-volt dc system shows low voltage, the most likely cause is

an out of adjustment voltage regulator

The major advantages of AC over DC is the fact that it's current and voltage can easily be increased or decreased

by the means of a transformer

The commutator of a generator

changes alternating current produced in the armature into direct current as it is taken from the armature.

The most common method of regulating the voltage output of a compound DC generator is to vary the

current flowing through the shunt field coils

If a generator is equipped with a vibrator-type voltage regulator, the actual time the voltage regulator points remain open

depends on the load carried by the generator

To what depth is a mica insulation between the commutator bars of a DC generator undercut

equal to the width of the mica

The pole pieces or shoes used in a DC generator are a part of the

field assembly

Residual voltage is a result of magnetism in the

field shoes

The starting current of a series wound DC motor is passing through both the field and armature windings produces a

high starting torque

What is the principal advantage it series wound DC motor

high starting torque

When dc generators are operated in parallel to supply power for a single load, their controls include an equalizer circuit to assure that all generators share the load equally. The equalizer circuit operates by

increasing the output of the low generator and decreasing the output of the high generator until they are equal

Which is the most accurate type of frequency measuring instrument

integrated circuit chip having a clock circuit

The method most often used in overcoming the effect of armature reaction is through the use of

interpoles

A series-wound DC electric motor will normally require

more current at low RPM than at high RPM

Some electric motors have two sets of field windings wound in opposite directions so that the

motor can be operated in either direction

The overvoltage control automatically protects the generator system when excessive voltage is present by

opening the shunt field circuit

If the reverse current cutout relay contact points fail to open after the generator output has dropped below battery potential, current will flow through the generator armature

opposite the normal direction and through the shunt field in the normal direction

To test generator or motor armature windings for opens,

place armature in a growler and connect a 110V test light on adjacent segments; light should light.

An armature in a battery charging system is for the purpose of indicating the

rate of current used to change the battery

The poles of a generator are laminated to

reduce eddy current losses

Which of the following is not one of the purposes of interpoles in a generator

reduce field strength

If the positive field lead between a generator and a generator control panel breaks and is shorted while the engine is running, a voltmeter connected to generator output would indicate

residual voltage

A voltage regulator controls generator voltage by changing the

resistance of the generator field circuit

Which type of DC generator is not used as an airplane generator

series wound

When using an ohmmeter to check the continuity of a generator field coil, the coil should

show very low resistance if it is a series field coil

During inspection of an anticollision light installation for condition and proper operation, it should be determined that

the anticollision light can be operated independently of the position lights

In a generator what eliminates any possible sparking to the brush guides caused by the movement of the brushes within the holder

the brush pigtail

In troubleshooting an electrical circuit, if an ohm meter is properly connected across a circuit component and some value of resistance is read,

the component has continuity and is not open

Static inverters are electronic devices that change DC to AC with the

use of an oscillator

A voltage regulator controls generator output by

varying current flow to generator field coil.

The voltage output of an alternator may be regulated by controlling the

voltage output bot the DC exciter

Which of the following are the major parts of a DC motor? 1. armature assembly 2. field assembly 3. brush assembly 4. commutator 5. pole piece 6. rheostat 7. end frame

1, 2, 3, 7

In installations where the ammeter us in the generator or alternator lead, the ammeter can be redlined at what percent of the generator or alternator rating

100%

How can the direction of rotation of a DC electric motor be changed

Reverse the electrical connections to either the field or armature windings.

Where is the generator rating and performance data located

Stamped on the generator data plate