Electrical 04 Flashcards
The permanent magnet in a rotating field AC generator:
a.provides for initial excitation of the voltage regulator via the frequency control unit
b.provides the initial closing of the bus-tie breaker
c.provides the initial excitation of the main generator field
d.controls the final excitation of the generator field
c. provides the initial excitation of the main generator field
In the event of loss of all normal AC supplies, where can AC power be obtained from in flight?
Select 2 answers.
1.From the RAT
2.Directly from the battery
3.From an Inverter
4.From the Catalytic Converter
- From the RAT
- From an Inverter
The frequency of an AC generator is dependent upon;
a.the RPM of the rotor
b.the number of poles on the rotor
c.the RPM of the rotor and number of phase windings in the stator
d.the number of poles on the rotor and the number of phase windings in the stat
c. the RPM of the rotor and number of phase windings in the stator
The purpose of a Constant Speed Drive Unit is to:
a.maintain a constant generator frequency
b.mechanically protect the alternator drive shaft during coupling
c.take part in the voltage regulation
d.take part in the balancing of reactive loads
a. maintain a constant generator frequency
Pulling the fire shutoff handle causes a number of devices to disconnect. In respect of the AC generator it can be said that the:
a.exciter control relay and the generator breaker open.
b.exciter control relay, the generator breaker and the tie breaker open.
c.exciter control relay opens.
d.generator breaker opens.
a. exciter control relay and the generator breaker open.
Aircraft can use;
1.Only 3 phase and only if the frequency and voltage are correct
2.Only 3 Phase Electricity.
3.Single phase or 3 phase electricity, both are available.
4.Only single phase electricity which is derived from one of the 3 phase windings.
- Single phase or 3 phase electricity, both are available.
In order to produce an alternating voltage at 400Hz, the number of poles required in an AC generator running at 6,000rpm is:
Frequency(Hz)= (RPM x Number of Pair Poles (or phases))/60
400Hz = (? x 3) ÷ 60
? = (400 x 60) ÷ 3
? = 8000 RPM
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Why is Voltage control necessary?
a.Voltage control is only necessary if a generator is fitted not an alternator.
b.Without it the voltage of the generator would vary with generator load only.
c.Without it the voltage of the generator would vary with RPM only.
d.Without it the voltage of the generator would vary with RPM and generator load.
d. Without it the voltage of the generator would vary with RPM and generator load.
The essential difference between AC alternators and DC generators (dynamos) is that the;
a.induced windings of the alternators are rotating (rotor), and the dynamos have a rotary inductor coil
b.alternators supply all of the output current through the commutator and brush assemblies
c.induced (output) windings of the alternators are fixed (stator), and dynamos have a fixed inductor (field) coil
d.The alternators generate much less power than DC generators
c. induced (output) windings of the alternators are fixed (stator), and dynamos have a fixed inductor (field) coil
How is voltage controlled in an electrical generation device?
1.A voltage sensitive circuit will control the current through the field.
2.The voltage is monitored and then the rotor speed is changed.
3.Resistance of the output windings will be increased
4.Capacitance is monitored as required.
- A voltage sensitive circuit will control the current through the field.
The voltage regulator of a DC generator is connected in;
a.series with the armature
b.parallel with the shunt/parallel field coils
c.series with the voltage coils
d.series with the shunt/parallel field coils
d. series with the shunt/parallel field coils
In a Frequency Wild AC generation system the;
a.voltage regulator is out of adjustment
b.output frequency is too low
c.output frequency is too high
d.output frequency varies with engine speed
d. output frequency varies with engine speed
The output voltage of an alternator driven by a CSDU depends upon:
Select one:
a.The engine RPM
b.Its line current
c.The generator shaft speed only
d.The continuous adjustment of the field current by the voltage regulator
d. The continuous adjustment of the field current by the voltage regulator
To increase the real load taken by a paralleled AC generator, the
Select one:
a.Generator voltage regulator adjusts the generator rotor torque
b.Generator drive torque and field excitation are increased
c.Generator excitation is increased.
d.Generator drive torque is increased
d. Generator drive torque is increased
A permanent magnet in a rotating field AC generator:
a.controls the final excitation of the generator field
b.provides for initial excitation of the generator field
c.provides the initial closing of the bus-tie breaker
d.provides for initial excitation of the voltage regulator via the frequency control unit
b. provides for initial excitation of the generator field
