. An elementary manual of radiotelegraphy and radiotelephony for students and operators . orthe armature thicker than No. 26, Brown and Sharp gauge. Thissize is equivalent to No. 28^ British The armature wiresmust be wound with great care, otherwise they are apt to fly offin consequence of the great peripheral speed. It is practicable torun such an armature at a speed of 3000 revolutions per minute,equivalent to a peripheral speed of 375 feet per second. In another type of machine constructed by Tesla, magneticleakage was avoided by making adjacent poles on the same sideof the armature
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . orthe armature thicker than No. 26, Brown and Sharp gauge. Thissize is equivalent to No. 28^ British The armature wiresmust be wound with great care, otherwise they are apt to fly offin consequence of the great peripheral speed. It is practicable torun such an armature at a speed of 3000 revolutions per minute,equivalent to a peripheral speed of 375 feet per second. In another type of machine constructed by Tesla, magneticleakage was avoided by making adjacent poles on the same sideof the armature of the same polarity. In this y^ ^ ^ U second form the armatureconsisted of a copper platein the form of a disc witha large hole in it (see and 4). The plate wascut through by radial slitsalternately at the insideand outside edge, so as todivide the plate up into azigzag strip. This platewas clamped on a centralboss fixed on a shaft (seeFig. 4) and caused to re-volve between the twoparts of a field magnethaving a large number ofinwardly projecting poles,same polarity and facing. Fig. 3. all those on one side being of thean equal number of like poles onthe opposite side, of tlie opposite polarity. In this manner, thedisc was perforated by the magnetic flux passing across from oneset of poles to another, and the passage of the strips into whichthe disc is cut up, into and out of these streams of magnetic flux 84 RADIOTELEGRAPHY gives rise to the electromotive force in the armature. The arma-ture winding therefore consisted of a single disc-shaped conductorequivalent to a zigzag winding, and this was driven at a highspeed so that the radial elements of the armature cut acrossstreams of magnetic flux. A very strong excitation could there-fore be employed without producing any wasteful leakage chief defect of this design of armature is that unless the slitsin tlie disc are very close together, so that the width of the radialbar or slice is not more than -^ inch, ther
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
