Excerpt from Transformer Practice: Manufacture, Assembling, Connections, Operation and TestingThe development of the alternating-current transformer dates back about 25 years. At that time very little was known re garding design for operation at high voltages, and the engineer of the present day can scarcely realize the difficulties encountered in the construction of the early transformers.The high-voltage transformer made long-distance trans mission work possible, and the increased distances of transmission stimulated the design of large transformers. In the early days of transformer development as many as 15 to 20 transformer secondary windings have been connected in series to facilitate the operation of a long-distance transmission system, the maxi mum rating of each transformer being not greater than 10 kw. However, a method of constructing large transformers has long been devised by which an enormous amount of power may be transformed in a single unit. Such designs embody principles of insulation for high voltages and various methods for maintain ing a low operating temperature. Ten years ago a 500-kilowatt unit was considered to be a large size of transformer. The history of ten years' development has shown a most interesting process of evolution: it has marked more than a tenfold increase in size up to the present day.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.