This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ...and Molor Company's Arc Welding Set. Another differentially wound generator, specially intended for electric are welding work, is made by the Lancashire Dynamo and Motor Company, Limited, of Trafford Park, Manchester. It is shown coupled direct on the same bed-plate to its motor in Fig. 38, while a diagram of the windings of the two machines is given in Fig. 39. As will be observed, the arrangement of the winding is different in several particulars from the windings of the machines which have been described above. There is a shunt winding A which is connected across the armature of the generator, and has a regulator in circuit with it, and a series winding which is in the arc welding circuit, and there is a third separately excited winding B which, however, is arranged in series with the field winding of the motor across the supply mains. In describing the arrangement the makers write as follows: qThe arc may be struck across the armature of the generator without any resistance in circuit, and the plant is capable of running for short periods with the armature of the generator short circuited.q The windings A and B tend to assist one another, while the winding C opposes both, and hence tends to lower the generator voltage. No series resistance is used in the welding circuit. At the moment of touching the work with the electrode there is a tendency for an excessive current to flow in the generator circuit. This current, of course, flows through the series winding, and is limited to the value which) will demagnetise the generator field by an amount sufficient to prevent any larger current from flowing. Similarly, when an arc is struck, the resistance of the circuit is increased, and the current tends to fall. This tendency is...This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition.
|Title||:||Electric Welding and Welding Appliances|
|Publisher||:||Rarebooksclub.com - 2013-09|