. Electric railway journal . switch; the resistance 502 ELECTRIC RAILWAY JOURNAL [Vol. XLV, No. 11 for the No. 2 motor, and through the No. 2 motor andthe limit switch to ground. LS-2 closes for the secondnotch, and the remaining notches to full series are se-cured by cutting out the main starting resistance. In passing from series to parallel, the bridging transi-tion circuit is formed through the switches M-2, J andG. After the / switch is opened, the motors are inparallel with resistance, the resistance is then cut outstep by step and the field connections changed to nor-mal field in the sa
. Electric railway journal . switch; the resistance 502 ELECTRIC RAILWAY JOURNAL [Vol. XLV, No. 11 for the No. 2 motor, and through the No. 2 motor andthe limit switch to ground. LS-2 closes for the secondnotch, and the remaining notches to full series are se-cured by cutting out the main starting resistance. In passing from series to parallel, the bridging transi-tion circuit is formed through the switches M-2, J andG. After the / switch is opened, the motors are inparallel with resistance, the resistance is then cut outstep by step and the field connections changed to nor-mal field in the same manner as was done in the seriesconnection. The line relay, which is placed on a switchboard lo-cated between the two center doors instead of being inthe control box, is energized directly from the 600-voltcircuit. Its contact disk is so connected in the controlcircuit that all unit switches open whenever power fails,permitting the control to advance in regular sequencewhen power is restored, without the master controller. In addition to the usual contacts and fingers for thecontrol circuit, the master controller has interlock con-tacts mounted on the reversing-drum shaft to providefor three auxiliary contacts. Two of these contacts arefor signals and one is for tail-lights. These unusualfeatures will be described in a later article in connectionwith the door signals, marker lights and train linecoupler. The reverse drum acts as a switch to close thebattery circuit to the control. Still another new feature is that both polarities ofthe control circuits are broken at the controller. Thisis accomplished by running an extra train line wirefor the negative side of the magnet coils. As no at-tempt has been made to ground the return circuit ofthe control, local grounds cannot create false circuitsor cause false operation. The line relay cut-out will permit the feeding up ofthe control when power is off the line and the bucking D ^—Q Overload Trip Cover Main Drum Third- rail Shoe
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