. Electrical world. FIG. 3.— riILL LINE OPER.^TING KOO-M. and additional ones known as trunk selectors. The frames are ofheavy angle iron and hardwood. The lower four rows or 100 select-ors, and the upper ones are the trunking selectors. Of course, inthe Grand Rapids exchange, as in any automatic exchange havingmore than 999 telephones and consequently having numbers of fourdigits, two sets of trunking selectors are necessary. There is amplefloor space for at least three more banks of 1,000 selectors, so thatthe exchange has a capacity of 8,000 telephones, and by the removalof some partitions
. Electrical world. FIG. 3.— riILL LINE OPER.^TING KOO-M. and additional ones known as trunk selectors. The frames are ofheavy angle iron and hardwood. The lower four rows or 100 select-ors, and the upper ones are the trunking selectors. Of course, inthe Grand Rapids exchange, as in any automatic exchange havingmore than 999 telephones and consequently having numbers of fourdigits, two sets of trunking selectors are necessary. There is amplefloor space for at least three more banks of 1,000 selectors, so thatthe exchange has a capacity of 8,000 telephones, and by the removalof some partitions even this could be FIG. 4.— TELL-TALE BOARD INTERRUFTERS. Two Other rotao converters are provided for charging the storagebattery plant that operates the selectors. In addition to these, twosets of motors and generators provide the alternating current forthe magneto bells, and a third of similar style but smaller is pro-vided for the night service. An important piece of apparatus in thisdepartment is the interrupter and its reserve duplicate. These are
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
