INDUCTANCES AND RESISTANCES 



We proceed by simplifying Figure 4.29. Since inductance oc turns^ the 

 turns ratio of the transformer is {Ljk^Lpy^'^, but we shall not be far wrong if 

 we call this {LjLj)^''^. We have seen that we can represent a mutual inductance 

 by an ideal transformer and a self inductance; doing this in the case of 

 Figure 4.29 we get Figure 4.30. 



.2-, 



Figure 4.30 



Figure 4.31 



Figure 4.32 



We now reflect R^ and Rj^ through the ideal transformer {Figure 4.31), and 

 do a little more tidying to produce Figure 4.32. This is an equivalent circuit 

 for a real transformer with a load. We now consider what happens when G 

 takes specific forms. 



Figure 4.33 



Loaded transformer connected to a constant-voltage type, direct voltage genera- 

 tor — the pulse transformer 



If a real transformer is connected between a load Rj^ and a generator of 

 direct e.m.f. E and internal resistance r {Figure 4.33), then to find out what 



66 



