Page:Popular Science Monthly Volume 89.djvu/801

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�Q AmatGur ■ Electrician

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��An Improvised Coil Winder for Electrical Apparatus

COIL winding is a very difficult operation for the amateur, espe- cially where it is desired to have the outside surface smooth and neat. To do it correctly the spool upon which the wire is wound must be re- volved at a medium speed while the wire is fed on with a guide or by hand.

The work of winding some coils 10 in. long was quickly accomplished by the aid of a machine made as shown in the illustration. Two trestles were used to which a baseboard or ways of the devised lathe were attached. The tail-stock consisted of a wood block fastened to the ways with a bolt having a thumb-nut on the underside. The block was bored centrally near its upper end and a bolt placed in it with a waste nut screwed to one sur- face for the feed. A hand -wheel found in the scrap served to turn the bolt. The end of the Ijolt was filed down to a point for the dead center.

The lathe- head Winding an eighteen-inch

consistcdofabreast improvised lathe

drill attached with clamp-bolts to a piece of the proper height fastened to the opposite end of the ways. A spur center was used in the drill-chuck for turning the spool. Spools of varying lengths can be placed between these centers and turned by means of the crank on the drill.

In winding the coil the ordinary wood rest can be used as a guide for feeding the wire. — Willard George Cook.

��De-Sulphating Storage- Battery Plates

NE of the chief causes of loss of efficiency in lead accumulator cells is sulphation. White sulphate of lead usually forms on the active material and at a point where it is least wanted — at the junction of the metal supports and the pero-xide. The formation of this sulphate is due either to the impurities in the oxide employed, foreign sub- stances in the lead or lead alloy, or chemical impurities in the sulphuric acid or water.

One way to remove the sulphate is to charge at a somewhat higher rate than normal and to continue charging some little time after the cells are gassing freely. This meth- od either reduces the sulphate to the peroxide or causes it to fall away from the plate. A quicker and more satis- factory way, how- ever, is to add about I oz. of sodium car- bonate (Na2 CO3) to each cell. This not only reduces the tendency of the ele- ments to sulphate, but rapidly removes the salt that is al- made of a breast drill ready formed. If

the amount mentioned docs not result in removing the sulphate, another ounce can be added to each cell; but no more than this should be put in. Unless the cell is in a very bad condition i oz. will usually do the work. After putting in the sodium carbonate, the cell or cells, should be charged at a rate of from 13 to 15 amperes for 8 hours.

The de-sulphating solution should be

���coil on an

��mixed with a varying amount of water, de-


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