Identifier: cyclopediaofappl04amer (find matches)
Title: Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc.
Year: 1916 (1910s)
Authors: American Technical Society
Subjects: Electric engineering
Publisher: Chicago : American Technical Society
Contributing Library: Northeastern University, Snell Library
Digitizing Sponsor: Northeastern University, Snell Library

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irst, how the sec-ondaries are to be connected in parallel to supply current to one andthe same receiving circuit; and second, how the secondaries are to beconnected in series to supply current to a recei\ung circuit. Thistest is made as follows: Connect a terminal, say a, Fig. 290, of the secondary of one transformer to one terminal c of the secondary of the other transformer. Then connect two110-volt lamps in series (or a voltmeter) to the other two terminals b and d.If the lamps do not light (or if the voltmeter gives no deflection), then first, 329 316 ALTERNATING-CURRENT MACHINERY the terminals a and c are the proper ones to connect together to one servicemain; and the terminals h and d are to be connected together to the other servicemain; and second, the terminals a and c are not the proper ones to be connectedtogether, but h and c are properly connected together in order to connectthe two coils in series, the other two terminals a and d being connected to theservice mains. 330
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ALTERNATING-CURRENTMACHINERY PART V CONVERSION OF ALTERNATING INTODIRECT CURRENT III spite of the increasing use of alternating currents, there isalways a demand for devices of various kinds for converting thepower received from an alternating-current circuit into power inthe form of direct current. Thus, many electro-chemical processes,electrolytic refining of silver and copper, the charging of storagebatteries, and direct-current motors all require direct current. Elec-tric power, as is well known, can be transmitted long distances mosteconomically by the three-phase alternating-current system employ-ing high voltages. The demand for direct-current power ariseswhen the power is to be utilized at the receiving end of the line. The conversion from alternating current to direct current isaccomplished in practice in the following ways: (a) by the rectifying-commutator; (b) by the aluminum valve rectifier; (c) by the mercury-vapor rectifier; (d) by the rotary (or synchronous) converter;

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