OCR Text |
Show This x;-.d Smallest Motor? A correspc; ::,nt of the 3!ectrical World writes t'.vit he has just completed complet-ed a motor T.hich weighs only 5.5 grains and 5s, he believes, the smallest in the world. Its commutator, which measures .045 inch in diameter, ia made up cf four gold segments insulated insu-lated from each other with mica. The shaft on which the commutator is mounted Is .003 inch in diameter. Fiber Fi-ber insulation is used between the commutator and the shaft. The tiny armature, .00 inch in diameter, has four pole pieces and is wound with No. 40 silk covered copper wire. The weight of the revolving part is 1.25 grains. Between the armature and the yoik two field c.oils are provided. The silver brushes measure .012 inch in diameter and are held against the commutator by springs .004 inch- in diameter. In over all dimensions the motor measures 19-G4 inch long and 11-64 inch high. All visible parts are finished in Roman gold. Wlien connected con-nected to a small flashlight battery, the motor runs at a very high speeds |