Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise on the care and management of steam engines, boilers and electric machinery (1922)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 1077
amo is very weak, the resistance of the ^^short cir-cuit^ formed by the dynamo brush is also very weak andtherefore the current may be quite strong. This current isthe main cause of sparking in dynamos. The number ofbars constituting a commutator depends upon the windingof the armature, and the… … Fig. 435 A SINGLE COIL ARMATURE OF MANY TURNS there are many reasons against making the number of barson a commutator very great. Increasing the number ofbars in a commutator increases the cost of manufacture,and in smaller dynamos, if the number of bars be increasedbeyond a certain extent, each…
