VOLTAGE RATIO IN SYNCHRONOUS CONVERTERS 231 



designate the angle of belt span by <}>. The belt reduction factor 

 is then 



, / \ 



*m=-sin -sin-, ...... (10) 



which is plotted in Fig. 31 for different values of the belt span ($) 

 and for several harmonics. The reversal of the various harmonics 

 with the change in belt span is here shown clearly. 



TAP VOLTAGE 

 For this purpose Eq. (i) may be written: 



e' = a\[q\ sin (w/+0i)+93 sin (3 0^+63) 



+<?5 sin (5to/+05)+. . . qm sin (ww/+0m)+etc.] . (n) 

 where 



_ 



qm= v gam 2 -\-qi>m 2 and 0m=tan -1 -^-. 



am 



The wth harmonic in the tap E.M.F. is then 



sn 



The amplitude of the fundamental is 



2N 

 



x 



where km may be taken as equal to sin , the limiting value of 

 Eq. (5), as Nsp approaches infinity. Then 



-Naiqism;=qiEi sin 7, .... (12) 

 ic p p 



