Handy man's workshop and laboratory . turn attracting an iron armaturewith hammer, striking the gong. Because the batteries wouldrun down rapidly, it was deemed of advantage to make use of 28o HANDY MAN S WORKSHOP AND LABORATORY the lighting current already on the premises, in connection withthe transformer referred to. As the primary windings were con-nected across the no-volt mains at all times, and the secondaryonly closed at intervals, it was important that as little currentas possible pass through the primary windings and register onthe meter, when the secondary was open. A sufficient num
Handy man's workshop and laboratory . turn attracting an iron armaturewith hammer, striking the gong. Because the batteries wouldrun down rapidly, it was deemed of advantage to make use of 28o HANDY MAN S WORKSHOP AND LABORATORY the lighting current already on the premises, in connection withthe transformer referred to. As the primary windings were con-nected across the no-volt mains at all times, and the secondaryonly closed at intervals, it was important that as little currentas possible pass through the primary windings and register onthe meter, when the secondary was open. A sufficient numberof pieces of soft stovepipe iron were cut each 6y2 inches long and1% inches wide, to make two piles, each i1/^ inches high; and anumber of pieces 5 inches long and 1% inches wide were alsocut to make two piles, each i1/^ inches high. These were wellcoated with shellac varnish, and then arranged as shown at Cin Fig. 225, forming two right angles, the shorter pieces beingplaced between the longer pieces at one end in each case. The. Fig. 225—Construction of the small transformer corner of the pile in each case was then squeezed down in a vise,and the iron well wrapped with adhesive insulating tape, puttingon several layers, but not covering the outer ends for a space of1% inches. After releasing the vise, that portion at the anglewas also covered with tape. The secondary coils were then puton, consisting of 100 feet of No. 16 double cotton magnet wire,on each of the angle pieces, or 200 feet altogether, and well coatedwith shellac, the windings being in such direction that when thetwo angle pieces were brought into contact at the exposed ends,they formed a continuous magnetic circuit. The windings wereall in one direction. These secondary windings were then cov-ered with two layers of cotton cloth, well coated with shellacvarnish, and the primary windings were put on over the second-ary, consisting of 650 feet of No. 28 double-covered cotton mag- HANDY MANS WORKSHOP AND LABO
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Keywords: ., book, bookcentury1900, bookdecade1910, booksubjectworkshoprecipes
