. Journal of electricity, power, and gas . Fig. 1. Speed Controller. :S hp. 115 Volts. This device consists of a starting rheostat, the arm ofwhich is provided with a projection carrying a sliding con-tact which moves over the contact buttons connected to thefield resistance. An auxiliary arm on the right-hand side ofthe rheostat front serves to maintain a short circuit on thefield resistance during the period of starting the motor, andon the starting resistance, when the arm is turned back tovary *ife running speed of the motor by regulating the Fig. 2. CR 144lSpeed Controlling
. Journal of electricity, power, and gas . Fig. 1. Speed Controller. :S hp. 115 Volts. This device consists of a starting rheostat, the arm ofwhich is provided with a projection carrying a sliding con-tact which moves over the contact buttons connected to thefield resistance. An auxiliary arm on the right-hand side ofthe rheostat front serves to maintain a short circuit on thefield resistance during the period of starting the motor, andon the starting resistance, when the arm is turned back tovary *ife running speed of the motor by regulating the Fig. 2. CR 144lSpeed Controlling Panel, When starting the motor, the starting arm can not beleft in any position on the contact buttons, due to the actionof a spring, but must be turned to the right until it engagesthe auxiliary arm forcing the latter to be retained by theno voltage release coil. The auxiliary arm then withholdsthe spring actuating the starting arm and thereby makesit possible to leave the arm in any position on the field con-tacts, which will give the desired speed control of the the operator releases the rheostat arm at any positionwhile it is being moved to the right during the startingperiod, it will immediately return to the off position. Uponfailure of voltage the retaining coil is demagnetized, releas-ing the auxiliary arm, which in turn releases the spring which carries the starting arm to the off position, thus open-ing the motor circuit. The rheostat is so designed that it requires a little extrapressure to move the arm beyond the maximum speed poin
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Keywords: ., bookcentury1800, bookdecade1890, bookidjo, booksubjectelectricity
