Fig. 8.
Edison Dynamo.
Current continuous in the circuit. A wire which is + when above the spindle, will be - when below it, and as the spindle revolves the current changes in the various wires from - to + as they reach the top, so that it will always therefore be + in the upper brush and - in the lower one, and will accordingly be continuous through the circuit. It will be seen in the illustrations of various continuous-current dynamos, that though their shape and arrangement differ, the mode of collecting the current is much about the same as I have described above. [Figs. 8] and [9] show some of the continuous-current dynamos at present in use.
Fig. 9.
Brush Dynamo.
Alternating-current dynamos. I will now explain the nature of an alternating-current dynamo.