Welding; theory, practice, apparatus and tests, electric, thermit and hot-flame processes . om of the barrel asthe other pole. The sidesof the barrel were the high peakloads caused by a largeThomson machine, The Elec-trical Times^ has this to say:Central station engineers have hitherto been somewhatchary in connecting electric welders of large size to their mainson account of the fluctuating nature of the load, although thereare numerous instances of small welders being so used. A veryinteresting installation has recently been completed in Londonby the Electric Welding Comp
Welding; theory, practice, apparatus and tests, electric, thermit and hot-flame processes . om of the barrel asthe other pole. The sidesof the barrel were the high peakloads caused by a largeThomson machine, The Elec-trical Times^ has this to say:Central station engineers have hitherto been somewhatchary in connecting electric welders of large size to their mainson account of the fluctuating nature of the load, although thereare numerous instances of small welders being so used. A veryinteresting installation has recently been completed in Londonby the Electric Welding Company, Limited, in which a welderof 90 capacity is worked off a single-phase power supplyat 400 volts. In order to prevent undue fluctuations of voltageon the mains, a special substitutional resistance is installed, builtin three sections, each controlled by a switch, so that one or moresections can be put in circuit according to the size of the workbeing welded. A large liquid resistance is also employed toprevent an undue rush of current, when the primary circuit September 5, Fig. 17.—Thomson type reactive coil, forcontrolling current in welding machine. THE THOMSON PROCESS 49 of the welding transformer is closed, the plates being raised andlowered by a small motor through suitable gearing. The con-trolling switch of the welder is so arranged that when put in theon position it starts the plate-lowering gear, thus graduallycutting out the starting resistance, and vice versa. This plantis in continuous operation, and no inconvenience to other powerusers in the neighborhood has been reported. Another welderof smaller size has also been connected to this circuit. In thiscase a special economy coil is used as a regulating device. To facilitate the working of electric welding machines onpolyphase circuits, Professor Elihu Thomson has recently pat-ented a method of winding the trans-formers to prevent unbalancing thephases. This will doubtless lead toconsiderable develop
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1910
