We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
MANAGERS AND PROJECTIONISTS 601
RELATIVE POSITION OF THE TWO COILS.— While Fig. 197 shows the theoretical construction of the transformer, in actual practice the two coils are either wound one over the other, or they are placed side by side. In any event they are as close together as they can possibly be gotten, in order that the secondary coil be located in the strongest part of the magnetic field set up by the action of the primary coil and the core.
Broadly, this describes the general plan of construction and action of the transformer. Those who wish to delve more deeply into the matter of transformer construction and action may do so by consulting Hawkins' Electrical Guide No. 6, pages 1377 to 1456, wherein will be found a very complete, well illustrated description of the construction, the theoretical and the practical action of the transformer.
LOW VOLTAGE TRANSFORMERS.— For use on projec tion circuits, where the supply is alternating and it is for any reason not deemed expedient to rectify the current by means of a motor generator or mercury arc rectifier, there are a number of devices which are in fact nothing more or less than low voltage transformers. These transformers are made especially for use on projection circuits. They pass under various trade names. The three best known and most largely used are the "Economizer," which was the invention of J. H. Hallberg; the "Inductor," which is the product of the Nicholas Power Company, and the A. C. to A. C. "Compensarc," which is made by the Fort Wayne branch of the General Electric Company. They are all of the type known as "constant current transformers."
These devices take A. C. directly from the supply lines and deliver A. C. secondary current at arc voltage. They are all so constructed that the amperage of the secondary may be altered, usually in three steps, merely by the manipulation of a suitable switch connected to taps from the primary winding, (see Fig. 200), modified by the fact that in the older types of one of them, the economizer, the change in secondary amperage is accomplished by means of changing the primary connections, either directly or by means of changing the position of a plug fuse, instead of by means of a switch. They are, of course, all of them step down transformers. The maximum capacity of these transformers is 60 amperes, but most if not all manufacturers make a special high capacity instrument.
We would suggest to manufacturers of this type of trans