TRANSFORMER DIAGRAMS AND REGULATION 



87 



no load; (3) to keep primary terminal e.m.f. unchanged. Scale 

 all vectors and determine a regulation for each case. (20 min.) 



22. Draw a typical diagram for a constant-potential to constant- 

 current transformer, (a) with a large number of lamps on the 

 circuit and (b) with one or two lamps. (10 min.) 



23. Draw complete diagrams for a transformer without iron 

 core, (a) with the coils wound together, turn for turn, and (b) for 

 the coils slightly separated. Explain the effects of these condi- 

 tions upon the form of the diagram. (15 min.) 



