. The practical telephone handbook and guide to the telephonic exchange . and the cell be-comes exhausted when thesolution of sal-ammoniac isused up. Most of the other formsof dry cell are similar tothis, differing only in detailsof the various pastes internal resistance ofthese cells is much lowerthan that of the wet formof Leclanche, being whennew only about *1 of anohm; the cells will, there-fore, give a powerful currentthrough a small externalresistance. The isabout 1*4 volts per cell atfirst but rapidly falls when in action. Dry cells should bekept in a cool place, or they
. The practical telephone handbook and guide to the telephonic exchange . and the cell be-comes exhausted when thesolution of sal-ammoniac isused up. Most of the other formsof dry cell are similar tothis, differing only in detailsof the various pastes internal resistance ofthese cells is much lowerthan that of the wet formof Leclanche, being whennew only about *1 of anohm; the cells will, there-fore, give a powerful currentthrough a small externalresistance. The isabout 1*4 volts per cell atfirst but rapidly falls when in action. Dry cells should bekept in a cool place, or they will become actually dry, andwill fail to give current. The Delafon Cell.—This is a successful cell made in both awet and dry form. The special feature appears to be anagglomerate mixture which instead of being mixed with somebinding ingredient and then solidified by heat and pressureis merely subjected to great pressure to effect of this are bound to the carbon plate by wrappings ofcord and canvas. In the dry cell the immobility of the liquid. Fig. 20 BA TTERIES 37 electrolyte is obtained by a special preparation having feculaas a basis. Mr W. E. Cooper, in bis work on Primary Batteries, givesthe results of a comparison of tests of a number of differentforms of Leclanche cells, including dry forms, and thefollowing particulars of the behaviour of different forms of cellswhen worked continuously through an external resistance of10 ohms has been mostly based on his table with the additionof particulars in regard to the Delafon dry and wet cells. Dry Cell Relative Useful LifeEfficiency in days. 21-5 8-1 Weightlb. 6 Capacity days per . 3-41 Hellesen . . 21 10 3 1 3-26 Obach . 20 7-7 2 4 3-42 Six-Block Leclanche 10 15-4 9 8 1-52 Porous Pot „ 6 7 7 8 •93 Agglomerate Block „ 4 4-2 6 12 •58 Delafon, Dry . 44 20 2 14 6-96 „ Wet . 18 22 7 14 2-83 The Daniell Cell.—In the matter of constancy, the Daniellcell is superior to all others when
Size: 1110px × 2252px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
