KR. BIRKELAND. 



M.N. Kl. 



consequence of this, regard has been paid, not only to the primar\- coil 

 of the current-breaker, but also to that of the inductorium. 



Rapidly moving interruptor such as the one here described, does 

 not require any contact at all for breaking oil' the primary current. 



The principal contact, /", in the centre of the ebonite plate, E, may 

 thus be dispensed with, so that the primär)- curcuit is always continuous 

 and closed. 



Aerial lino 



r"iK. •). 



This can be done when the induction-currentbreaker is constructed 

 in such a manner that the primary current can be reduced by induction 

 to o, when the secondary circuit is suddenly broken at the numerous 

 contacts, h. 



In very rapidly-working interruptors of 'the last-named kind, both 

 direct currents and alternating currents can be employed. In the latter 

 case, the period of the moving up and down of the ebonite plate with 

 the contacts must be twice that of the alternating current, the secondary 

 current must be closed when the electromotive force is o, and the 

 breaking ofif ought to be performed when the intensities of the currents 

 arc maximal. 



Instead of employing, as here, a [separate current-breaker, C, and 

 inductorium, I, they can be combined in one apparatus, by replacing the 

 secondary coil of the inductorium by a tertiary coil outside the two 

 previous ones on the transformer-shaped inducting system. 



