Lecture 2 - DC Machines Flashcards
1
Q
At what point should brush contact change from one commutator segment to the next?
A
The point at which the voltage is zero across the two segments
2
Q
What is armature reaction?
A
Distortion of the main field due to the effects of armature current
3
Q
What is the purpose of commutating poles?
A
To counter act armature reaction
4
Q
What component causes a generator to produce a DC voltage rather than ac voltage at its output terminals?
A
A commutator
5
Q
In a DC generator when does the maximum instantaneous voltage occur?
A
When the coil is passing through the horizontal plane
6
Q
The commutator acts as a what?
A
mechanical reversing switch
7
Q
An AC generator uses a …. and a DC generator uses a ….
A
AC generator uses slip rings
DC generator uses a commutator
