. The principles and practice of roentgenological technique . Fig. 50.—Converter unit and control enclosed. ing voltage before being incorporated into themachine. The case or tank is made of heavy sheetsteel, riveted, galvanized, and all jointsflooded with solder. The cover is cast ironand the insulators are standard high-tensionporcelain, bushings, one of which—the nega-tive—contains the transformer, which suppliesthe current to the filament of the Coolidgetube. The control panel contains all the auxiliaryapparatus necessary for operating the con-verter, with the control arranged in the mostc
. The principles and practice of roentgenological technique . Fig. 50.—Converter unit and control enclosed. ing voltage before being incorporated into themachine. The case or tank is made of heavy sheetsteel, riveted, galvanized, and all jointsflooded with solder. The cover is cast ironand the insulators are standard high-tensionporcelain, bushings, one of which—the nega-tive—contains the transformer, which suppliesthe current to the filament of the Coolidgetube. The control panel contains all the auxiliaryapparatus necessary for operating the con-verter, with the control arranged in the mostconvenient manner possible. The switchboard is made of steel and isgrounded, and all operating parts are con-cealed, making it impossible to receive a shockeven when operating the machine in the main switch and motor switch are oper-ated by the same -lever, which prevents excit-. FiG. -Converter and Control Panel withRemoved. Case Tank cover. Porcelain insulators. Coolidge transformer. Rectifier. High-tension transformer. Cover for control cabinet. Control panel. Ballast resistance,i. Coolidge rheostat,j. Auto transformer switch,k. Auto Synchronized motor, Tank,n. Splitter coil. 48 CONVERTER UNIT The voltage, and hence the penetration, iscontrolled by the wheel in the center of theboard. With this, the desired tap on the autotransformer is selected, the variation beingby two kilovolt steps and continuous, i. e.,the voltage may be changed with the tube inoperation without interrupting the currenteven momentarily. This t3pe of control in-sures practically constant penetration, regard-less of the vacuum of the tube, a feature whoseimportance cannot be overestimated. The po-tential once set, only the time of exposureneed be changed to meet varying tube con-ditions. The switch placed where most accessible tothe right hand, opens automaticall
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectradiogr, bookyear1920
