PROBLEMS. 397 



CHAPTER IX. THE SYNCHRONOUS CONVERTER. 



94. The plain multicircuit ring-wound armature of a six-pole 

 direct-current dynamo has 360 conductors on its face. These 

 conductors are numbered from I to 360. 



(a) One collecting ring of a rotary converter is connected to 

 conductor No. I. To what other conductors must this ring be 

 connected? Ans. A to 121 and 241. 



(ft) To what conductors must a second ring (B~) be con- 

 nected to give a two-ring converter? Ans. B to 61, 181 and 

 301. 



(c) To what conductors must two additional rings B and C 

 be connected to give a three-ring converter ? Ans. B to 41, 161 

 and 281, C to 81, 201 and 321. 



(d) To what conductors must three additional rings B, C and 

 D be connected to give a four-ringed? Ans. B to 31, 151 and 

 271, C to 61, 181 and 301, D to 91, 211 and 331. 



(e) To what conductors must four additional rings B, C, D 

 and E be connected to give a five-ring converter ? Ans. B to 

 25, 145 and 265, C to 49, 169 and 289, D to 73, 193 and 

 313, E to 97, 217 and 337. 



95. A four-pole, two-circuit, single drum winding has 102 

 conductors numbered consecutively from i to 102. The con- 

 ductors are connected as follows: 1-26-5 1-76-101 . . . 28-53-78 

 and back to I. To what conductors must the three rings A, B 

 and C, of a three -ring converter be connected ? Ans. A to 

 No. i, B to No. 35, and C to No. 69. 



96. Make a diagram of the following winding and show three 

 collecting rings connected to conductors i, 19 and 37. The 

 winding is a four-pole, two-circuit, single drum winding with 54 

 conductors connected up as follows : 1-14-27-40-53 ... 3-16- 

 29-42 and back to i. 



97. A 5o-kilowatt direct-current dynamo is to be used as an 

 #-ring converter. What is its capacity rating when n = 2, when 

 n = 3, when n = 4, and when n = 6? Ans. 42.5, 66, 8 1, and 

 96 kilowatts. 



