Arrangement of coils-Size and number of turns of wire-Holding the armature-Winding coils-Mark- Separating the fields-Tension of wire-Winding in the FIFTY-WATT DYNAMO CHAPTER I FIFTY-WATT DYNAMO This little machine, when properly constructed, is exceedingly efficient and will be found very useful to the experimenter. When finished and connected up in "shunt" it is equally applicable as a motor or a generator and can be used in either capacity without any change in wiring or connections. The output when driven as a generator, at a speed of three to four thousand revolutions per minute, is ten to thirteen volts and about five amperes. This gives sufficient current to light six miniature 6 c.p. lamps. When used as a motor and connected with five cells of storage battery it will develop one-twelfth horse-power. This is sufficient to drive a small lathe or a sewing machine on any and all ordinary work. The field and armature are built up of punchings of electric steel which, being much more permeable to the magnetic current than cast iron, require a smaller bulk. The weight of the entire machine when completed will be about five and one-quarter pounds. This is a machine the punchings, castings and material for which can be purchased in the rough. Many amateurs are ambitious to construct a machine of this description but are afraid to attempt it for the reason that, at the first glance, the work appears so difficult and seems to require an extensive equipment of o d d d Q FIG. 2.-End View of Machine Before Winding. machines and tools for its successful accomplishment. The machine can, however, be constructed by anyone having an ordinary foot-power lathe which will swing six inches over the lathe bed. Of course, the better the |
