Aircraft Electrical Systems Part 2 Flashcards
If there is an area which contains a large number of positive ions and another area which contains a large number of electrons a -
continuous flow of electrons is set up, which is know as an electromotive force(EMF)
Consider a battery with a negative pole terminal and a positive terminal. Which one possess excess electrons?
The negative pole
Opposition to the flow of electrons is called?
and generates?
Resistance
Heat
The rotating loop in an AC generator is called?
The armature
The AC generator can be modified to produce a DC current, turning it into a DC generator, before leaving the generator by?
using a DC commutator
considering a DC armature, viewing from the front with the North pole on the right. The side of the armature passing downwards of the north pole will always -
be connected to the negative bush
considering a DC armature, viewing from the front with the North pole on the right. The side of the armature passing upward of the south pole will always -
be connected to the positive bush
Which pole of a magnet is positively charged?
The south pole
considering a DC generator:
Control of the voltage output is usually accomplished by varying the strength of the magnet using some of the generated current, which is coiled to the magnet, this is called?
Self-excited
what does this definition explain:
This term refers to the stage, or position, of an alternating current expressed in degrees from 0 to 360 during a cycle.
Phase
Stator is relevant to which generator?
AC alternator
A single-phase AC alternator rotor consist of?
two poles of opposite polarity
The type of generator/alternator that is not self excited?
The AC alternator
Considering the alternator:
As the rotor turns it induces a current in the coils which is converted into DC, without the use of a commutator, by a -
rectifier
Three phase alternator output industry standard is?
400 Hz
The three phase frequency can be controlled with following formula:
Frequency = number of poles x number of rotor revolutions / 60
If there is no control over the RPM of an alternator, the frequency of its output will vary with engine RPM. Such an alternator is referred to as a -
frequency wild alternator
To maintain the constant frequency required for AC systems a method of ensuring that the generator is driven at a constant speed is required. The solution to this is the -
Constant Speed Drive
The CSD is located between -
the engine and the generator
Transformers are used to?
convert AC supply at one voltage and frequency to AC at a different voltage, whilst keeping the frequency the same.
Transformers are only used in -
AC systems
