CHAPTER V 

 ROTARY CONVERTERS 



1. Assume that the graph representing the flux density in the 

 air-gap of a rotary converter is rectangular and is constant over 

 the entire pole pitch. Also assume that the armature winding 

 is uniformly distributed. Calculate the ratio of the single- 

 phase alternating-current voltage to the direct-current voltage. 

 Assume that the coil pitch and phase spread are each unity. 



2. In problem 1 calculate the ratio of the four-phase alternat- 

 ing-current voltage to the direct-current voltage. Assume that 

 the coil pitch is one and that the phase spread is one-half. 



3. In problem 1 calculate the ratio of the three-phase alternat- 

 ing-current voltage to the direct-current voltage. Assume that 

 the coil pitch is one and that the phase spread is two-thirds. 



4. In problem 1 calculate the ratio of the six-phase alternat ing- 

 current voltage to the direct-current voltage. Assume that the 

 coil pitch is one and that the phase spread is one-third. 



5. In problem 1 calculate the ratio of the twelve-phase alternat- 

 ing-current voltage to the direct-current voltage. Assume that 

 the coil pitch is one and that the phase spread is one-sixth. 



6. Assume that the air-gap flux density in a rotary converter 

 is constant under the poles and is zero between them. The 

 ratio of pole arc to pole pitch is two-thirds. Also a>-ume that 

 the armature winding is uniformly distributed. Calculate the 

 ratio of the >ingle-phase alternating-current voltage to t In- 

 direct-current voltage. Assume that the roil pitch and the phase 

 spread are each unity. 



7. In problem 6 calculate the ratio of the four-phase alternat- 

 ing-current voltage to the direct-current voltage. Assume that 

 the coil pitch is one and that the phase spread is one-half. 



8. In problem r calculate the ratio of the three-phase alternat- 

 ing-current voltage to the direct-current \ .\--ume that 

 the <-oil pitch is one and that the phase spread is two-third-. 



9. In problem r. calculate the ratio of the six-] rnating- 



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