Resistance, and Self- Capacity of Magneto Windings. 51 



(b) Armature out of Housing. 



The various coefficients obtained with the armature out of 

 the housing are plotted in %s. 10, 11, 14. From the curves 

 it is evident that the results agree closely with those fore- 

 shadowed in the remarks at the beginning of the paper* There 



Fig. 12. — Carve showing variation in secondary self-inductance as 

 obtained by calculation, using the curve of fig. 16. 



20 



18 



12 



10 





5xicr 



15 



Frequency 



20 25 



per second. 



30 



SBxlO^ 



Out of housing, secondary inductance 

 from 1200 ~ to 3000 ~ . 



97 henries 



□ = Experimental points. 



q = Points obtained by calculation from fig. 16. 



Armature with brass end-plates ; in housing. 

 Rotor position = after full advance break. 



is little variation in the inductance of either primary or 

 secondary with frequency. The variation of the former is 

 greater than the latter, since it is wound nearer to the iron 

 core and leakage effects are smaller. The effective resistance 

 is reduced very considerably and it increases at a more rapid 

 rate than the frequency. This is due to the absence of large 



E 2 



