The Montgomery advertiser., 1901-09-12
1Ae ADvERT RTISER'Sss
 M HOME STUDY CIRCLE

separated the sheet iron from the sides of tbe containing trough; cast iron con- tracts were Inserted at proper intervals.
 steS SS ases ana ar s@aaf osn Ssfn der the control of the motorman. A inaghetic blowout at the first contact ef- iiss itSsseiy surpresssd the the th arc when shut cut out portion of the field winding. called the loop" thus. in the extreme position, the field magnet would be weak ture4. When moving at slow speeds near ly all the resistance would be In circuit. and the rheostat would often be red hot. but .uninjured, With this method also From the very first the railway engi- neere realized the economy Of starting es with th the two og in ssTie Ss for ducep to one-half; then for securing the highest speeds the motors could be cha1ged so as to be in mnltipls.,k For years the attempts to attain this result were sincere. expensive and discouraging. The controlling switches were so arranged as td break the circuit during the change jumps the wire ana one sees the flash a yard long follow the rupture. he can get an idea of the fireworks inside the switch fiash and burning were fatal to the scheme. 4 controller was finally devel- oped by the General Electric Company which avoided some Of the cases of the
 
 unavoidable arcs. The main circuit was at no time broken, bt@ the ingenious de- vice was used of ncmentarily cutting out one motor altogether during the transi- ton from series to parallel the other mo magSeti .'biow-ositS dissipated the or ''Fs FEE form fSparAf Of controller Is so generally usedl that its outside appearance Is familiar to everyone The central space Is occupied by the main cylinder Of wood elevVn sets of contract fingers attached to various wires stand cn the left; the cylin- drical reversing switch Is in the upper right hand space; just below 1t Is the ob- long coil that energizes the magnetic blowout, one pole Is the entire back of controller -bdx, the other pole is hinged away to expose the interior: on this re- movable pole are mounted partitions of lneulhting material. which enter spaces between the contact fingers and help sup presa the arcs; at the bottom are two in case of accident. Current from the trolley passed around the blowout coil and then arrives at the uppermost set of contact e fingers; as the cylinder & IS turned, ned cannpt he fully detailed In this short article. There are ten combinations. which can be traced by aid of the fol-
 l-aioters in series with whole of re-
 2~Siotors in series with one-half of
 
 S-Iioters in series with none of resis- tance.
 l-liotors in series. none of resistance, fieldl weakened.
 | 5-$ame as g. 6--one motor only in circuit with one- half of resistance.
 7-6ne motor in circuit with none of reeiStance.
 g. Motors in multiple with one-half of resistance. a... Motors in multiple, with none of re- slsta3lce.
 10 4Motors in multiple. with none of re- sistahce and field weakened.
 BM going from to the current is reduked to a lesser value, but the car meaAwhile has gotten under way, hence the feduced current Is often able to pro- ducel an accelerated speed. Seven Is ofteH made the same as 6; 5. 6 and ! the index plate but employed to tide over the critical change from series to paral- Tel. As far as 6. the two motors being in sefies each gets but 250 volts; at 6 and a slight jerk Is felt as the full 800 volts Is impressed on one motor; second jerk Is felt at as the second motor suddenly adds, It's torque; at 10 final jerk Is felt as bg weakening of the fields large srushI of current ensues and highest speed begi2s. Three, 1, 2 and 10 are economical running points. but 10 should be used for leveIs tracks only. Some road superin- tendents to prevent hill climbing at such rateA cut out this combination.
 Once under full headway. the current consumption is independent of the start ing devices; the more frequent the stops and more delayed the traffic, the greater parallel controllers, Experience has shown that in ordinary city use. the sub stitution of controllers for rheostats has enabled the operation of B per cent more cars without any increase in the current genefating plant.zt
 (Copyright 190o.)