PHASE METERS 



545 



FIG. 329. Diagram for Siemens and Halske arrangement of phasing lamps. 



fm 



*W *. 



The e.m.f. acting on lamp No. 1 will be: 



E oa + E a 'o' = O 



The e.m.f. acting on lamp No. 2 will be: 



The e.m.f. acting on lamp No. 3 will be: 



FIG. 330. Vector diagrams, Siemens and Halske phasing lamps. 

 35 



