. Elements of radio telephony . mployed, above this value, double-commutatormachines are preferable. The standard 2000-volt generator I A^ voltoge SStSSSSL m&r JlSlSiStSiSL to/oacf msmM sui ^ Fig. 16.—Rectifier connections in which but one-half of the alternating .current wave is utilized. built by one manufacturer has two 1000-volt windingsbrought out to separate commutators on each end of theshaft. The two windings are connected in series to produce ■2000 volts. The field excitation on this machine is prefer-ably arranged to be furnished from a separate low-voltagesupply, thus keeping the fi
. Elements of radio telephony . mployed, above this value, double-commutatormachines are preferable. The standard 2000-volt generator I A^ voltoge SStSSSSL m&r JlSlSiStSiSL to/oacf msmM sui ^ Fig. 16.—Rectifier connections in which but one-half of the alternating .current wave is utilized. built by one manufacturer has two 1000-volt windingsbrought out to separate commutators on each end of theshaft. The two windings are connected in series to produce ■2000 volts. The field excitation on this machine is prefer-ably arranged to be furnished from a separate low-voltagesupply, thus keeping the field circuit entirely insulated fromthe high-voltage windings. 36 ELEMENTS OF RADIO TELEPHONY Rectifier ^Rectifier systems are applicable fromabout 500 volts upwards. Although they may be usedbelow 500 volts, the difficulties involved in smoothing outthe wave usually make the generator preferable. High-powered tubes require high-voltage and low-currentsupply, hence rectifiers utilizing pure electron emission are. m com wsmmsimmm fy/g/} vo/tagedirect- curnenf: /oiY {/offageaffemcting Fig. 17.—Rectifier utilizing both halves of the alternating current wave. better suited than those of the mercury arc type. As com-mercially manufactured they much resemble the powertubes which they are designed to supply except that the gridbeing unnecessary is of course omitted. Fig. 16 shows theconnections employed where one tube is uged and only one-half of the wave rectified. Double-wave rectification em-ploying two tubes and utilizing both halves of the wave ismuch to be preferred in the case of radio telephone trans- VACUUM TUBE OSCILLATORS 37 mitters. The currents in the various portions of the circuitindicated in Fig. 17 are illustrated in Fig. 18. The con-denser Ci acts as an electrical storage reservoir for theenergy which passes into it in impulses as dehvered from therectifier. The irregularities are further eliminated bythe series inductance coils, Li and L2, which are co
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectradio, bookyear1922
