The secondary winding consists of one hundred turns of No. 10 B. & S. gauge double-cotton-covered wire. Fifty turns are wound on each leg, over the primary, several layers of paper being placed between the two.
Fig. 184.—Leg with Heads in Position for Winding.
A "tap" is brought out at every ten turns. The taps are made by soldering a narrow strip of sheet-copper to the wire at proper intervals. Care must be taken to insulate each joint and tap with a small strip of insulating tape so that there is no danger of a short circuit being formed between adjacent turns.
After the winding is completed the transformer is ready for assembling. The yoke pieces of the core should be slipped into position and the whole carefully lined up. The transformer itself is now ready for mounting.
Fig. 185.—How to make a Tap in the Primary by soldering a Copper Strip to the Wire.
The base-board measures 11 x 7 3/4 x 7/8 inches. It is shown in Figure 192.
The transformer rests upon two wooden strips, A and B, 4 1/4 inches long, 1 1/4 inches wide, and 3/4 of an inch high. The strips are nailed to the base so that they will come under the ends of the core outside of the fiber heads.
The transformer is held to the base by two tie-rods passing through a strip, C, 6 inches long, one-half of an inch thick and three-quarters of an inch wide. The strip rests on the ends of the core. The tie-rods are fastened on the under side of the base by means of a nut and washer on the ends. When the nuts are screwed up tightly, the cross-piece will pull the transformer firmly down to the base.