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Experimental Electrical Engineering and Manual for Electrical Testing for Engineers and for Students in Engineering Laboratories Volume 1

Name: Experimental Electrical Engineering and Manual for Electrical Testing for Engineers and for Students in Engineering Laboratories Volume 1
Author: Vladimir Karapetoff
ISBN: 9781235923166

by Vladimir Karapetoff

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Synopsis

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 Excerpt: ...only two or three lamps in series, replacing the rest of the lamps by some ballast resistance. The operation of the lamps is much steadier under such conditions. 210. Means for Maintaining Constant Current.--It is explained in § 207 that when arc lamps are operated in series, current must be maintained constant from the power house. The first series arc lamps on the market were built for direct current, and special constant-current generators were used to operate them. Of these the ThomsonHouston, the Brush and the Wood arc-light machines have been the most popular. With the advent of the alternating-current arc lamp these machines have been gradually abandoned; regulation of alternating-current circuits being accomplished far more simply by constant-current transformers (Fig. 188). Dr. Steinmetz, in connection with his magnetite lamp (§ 204), proposed to use mercury vapor rectifiers in connection with direct-current arc-lamp circuits. The magnetite lamp is essentially a direct-current lamp; a rectifier is placed between the lamps and the secondary of the constant-current transformer. In this way, the lamps are fed with hightension pulsating unidirectional currents, while the generation, transmission and regulation are accomplished with all the simplicity inherent to alternating currents. This system apparently has good chances for success, although the mercury rectifier has not yet had a sufficient practical test as to its reliability. 211. Thomson=Houston Arc Light Machine.--Although this type of constant-current machine has been much used in direct-current arc lighting, the machine is no longer manufactured. Many of them are still, however, in regular operation. These machines have been built for voltages up to several thousand volts, and for o...