Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Grimeton Radio Station, Varberg' has mentioned 'Poles' in the following places:
Occurrence Sentence Text Source
The principle used is that of a generator (also called alternator) with an exact large number of poles driven to an exact speed matching the number of pole changes with the desired output frequency (f = poles/2 * revolutions).
Like turning the dynamo of a bike: a dynamo has for instance four poles and by turning this at 100 revolutions (turns) per second the output will be 200 Hertz.
If the number of poles in the dynamo is increased to 80 the same driving speed will produce a 4xc2xa0kHz signal.
Increasing both the number of poles and the turning speed makes higher frequencies possible.
Between points a and b there will be a signal of 15 (because of 30 poles) times the number of revolutions.
The turning rod with electrical windings creating a coil will undergo a sequence of north and south magnetic poles.