. The Street railway journal . -tifier equipment designed forrailway work, shows that thehigh potential alternatingcurrent is fed in parallel totwo step-down transformerswhose secondaries are con-nected to the slip rings oftwo distinct rectifiers, the de-livery circuits of which arejoined in series The seriesconnection of the deliverysides of the rectifiers is de-sirable on account of the factthat each machine operatesbetter at a lower than at ahigher e. m. f., and the e. necessary for traction isgreater than the value thatcan conveniently be obtainedfrom one rectifier. It will beseen fro
. The Street railway journal . -tifier equipment designed forrailway work, shows that thehigh potential alternatingcurrent is fed in parallel totwo step-down transformerswhose secondaries are con-nected to the slip rings oftwo distinct rectifiers, the de-livery circuits of which arejoined in series The seriesconnection of the deliverysides of the rectifiers is de-sirable on account of the factthat each machine operatesbetter at a lower than at ahigher e. m. f., and the e. necessary for traction isgreater than the value thatcan conveniently be obtainedfrom one rectifier. It will beseen from Fig. 3 that eachrectifier is provided with twocommutators and two dis-tinct sets of auto-transformerwindings. This constructionhas been adopted for me-chanical symmetry, and inorder that the core materialmay be economically two auto-transformerwindings can be arranged forseries connection, althoughthe arrangement is somewhatsimpler when they are con-nected in parallel, as shownin Fig. 3. A plan view of two regu-. FIG. 4.—PLAN OF RECTIFIER January 12, 1907.] STREET RAILWAY JOURNAL. 69 The rectifiers shown in Fig. 4 have a combined direct-current capacity of 400 kw at 235 volts, the alternatinge. m. f. impressed upon each rectifier being 155 volts, theefiSciency at full load being 91 per rcent. By shifting thebrushes the e. m. f. can be varied from 20 to 280 volts witha constant supply pressure of 165 volts. It is stated thatthe commutation is excellent at 1500 amps., and that loads I I
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
