. Electric railway journal . two windings, thatthrough the manganin coil beingconstant, while that through thetemperature coil varies inverselywith the resistance, which in turn isdetermined by the temperature. Theaccompanying electric circuit dia-gram shows the scheme in outline,and a photograph of the indicatorswitchboard is also diagram shows, in addition to the indicator andconnection plugs, the following essential accessories: Arheostat of variable resistance to permit compensationfor variation in the test-circuit voltage which maynormally be 125 or 250; a test switch
. Electric railway journal . two windings, thatthrough the manganin coil beingconstant, while that through thetemperature coil varies inverselywith the resistance, which in turn isdetermined by the temperature. Theaccompanying electric circuit dia-gram shows the scheme in outline,and a photograph of the indicatorswitchboard is also diagram shows, in addition to the indicator andconnection plugs, the following essential accessories: Arheostat of variable resistance to permit compensationfor variation in the test-circuit voltage which maynormally be 125 or 250; a test switch and resistor toshow whether the instrument is working or not; filmcutouts at the machine to protect the operator bygrounding the line in case the voltage rises above 400;a transfer plug and receptacles for use in shifting theindicator to one temperature coil or another. The temperature coils are made of copper wire woundin a thin form and pressed flat so as to be non-induc-tive. In the machine winding they are connected by a. TEMPERATURE INDICATOR SWITCH-BOARD - ^hvwwv o- Variable 5Resistancec Fuses[ Test Sw. Armored Cut-out =at Machine J~=- inMachine [tut J= Transfer •I— Transfer=1 Receptacles CIRCUIT DIAGRAM, SHOWING CONNECTIONS OF TEMPERATUREINDICATOR AND ACCESSORIES three-conductor armored cable to a combination terminaland cutout box mounted on the machine. This box car-ries the terminals for attaching the leads from thecoils and for the extension leads to the instrument. The Denver Tramway has replaced its five-light, 600-volt clusters in the downtown district by 110-volt, 100-watt and 200-watt nitrogen filled lamps. The economyeffected by these lamps warranted the installation of amotor-generator set so individurl lamps cculd be used. ELECTRIC RAILWAY JOURNAL 69
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkmcgrawhillp
