THE LEAKAGE FACTOR. 



Allowing again the induction in the air-gap to be the same for dif- 

 ferent frequencies, which is a more or less challengeable proposition, 

 it follows from formula (5) that the total number of active con- 

 ductors around the circumference of the field must also be the same, 

 for the pole-pitch is inversely proportional to the frequency, hence 

 the product of the frequency into the number of lines of induction per 

 pole remains the same if the induction in the air-gap is the same. 



57. The magnetizing current, however, being proportional to the quo- 

 tient of the induction (B divided by the number of active conductors 

 per pole, is thus inversely proportional to the frequency. The leak- 



FIG. 21. 



age factor is, according to formula (12), directly proportional to the 

 pole-pitch, or inversely proportional to the frequency because the 

 pole-pitch is, in the case under consideration, inversely proportional 

 to the frequency hence it follows that, as the magnetizing current 

 has been shown to be proportional to the frequency, the diameter of 

 the semi-circle remains constant for all frequencies. 



58. Fig. 21 shows the clock diagram for the same motor, but for dif- 

 ferent frequencies. The maximum energy that the motor is capable of 

 taking in, and, therefore, also the maximum output, is the same for 100 

 ~, 50 ~, or 25 ~. But the maximum power factor is consider- 



39 



