190 



THE ROYAL SOCIETY OF CANADA 



Oscillograms and Curves, of the performance of Iron Clad Trans- 

 formers with various kinds of Transient and Permanent Phenomena, 

 are shown, and are compared with values calculated on the assumption 

 of simple circuit constants. No correction is made for the Inductance 

 of the Oscillograph leads, the Inertia and the Elasticity of the moving 

 system and the Voltages generated by the motion of the suspension 

 in the magnetic field. The errors so introduced are generally small 

 at low frequency. The principal one being an oscillation at start if 

 the vibrator is even slightly underdamped. The source of this is 

 easily recognized from the frequency of the disturbance and the mean 

 curve through the oscillation is approximately correct. 



71te Current Transformer. 



M 



(?rd7r2f^ 



Fig. 1 



Let 



t = Time 



R = Resistance 



L = Self Inductance 



M = Mutual Inductance 



N = Number of Turns 



i = Current 



K = Arbitrary Constant 



The suffix 1 indicates the primary and the ^ the secondary. 

 Equating E.M.F.'s in the Secondary circuit 



(1) Lo di2 + Rji^ = - M Nj di^ 



or 



dt 



dia + R2_ i^ = - 

 dt L2 

 The general solution of which is 



R, 



N, dt 



M N, 



dt 



(2) 



K € 



L, 



and 



(3) The iparticular solution is 



- M N, cH_i 



l7n7 dt 



1, = 



D + R,2 



L3 

 Where D = d 



dt" 



(il) 



