Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise .. (1916)
Swingle, Calvin F. (Calvin Franklin), b. 1846 · Chicago, F.J. Drake & company · leaf 1077
dynamo 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. 435a 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 bar…
