Nikola Tesla Books
THE CONSTRUCTION OF LARGE APPARATUS 191 time it is believed that no difficulty will be experienced. The core is built up of sheets of silicon steel .017 inch thickness and cut to the sizes shown in Fig. 5. Reference to this drawing will disclose the fact that 448 pieces of each of the two sizes will be required. It is suggested that this steel be purchased from some transformer manufacturer already cut to size, as it is practically impossible to buy silicon steel in such a small quantity in the open market. Assuming that the steel has been obtained, the legs A and E of the core may be assembled by placing the pieces alternately first to the right and then to the left, showing a 3-inch overlap as indicated in Fig. 6. Each pile will have assumed a thickness of approximately 4 inches at this time and the pack should be tightly compressed in a vise and bound with friction tape. The pieces forming the leg B may then be inserted one at a time to form the connecting yoke. This is rather a tedious process, but it offers the only practicable method of making a joint that is both mechanically strong and good from a magnetic standpoint. Fig. 6. Short leg of core on which winding is placed
