. Practical wireless telegraphy; a complete text book for students of radio communication . rator drops butit may be increased correspondingly by the reduction of resistance. Low values of voltagemay be secured at the terminals of the alternator by an external fixed resistance 24 con-nected in series with the generator rheostat. This is shunted by the switch indicated in thedrawing. The overload relay employed in conjunction with the automatic starter has the magnetwinding 20, which may be called the tripping magnet, and the second magnet winding 22,which may be called the holding magnet. Wind
. Practical wireless telegraphy; a complete text book for students of radio communication . rator drops butit may be increased correspondingly by the reduction of resistance. Low values of voltagemay be secured at the terminals of the alternator by an external fixed resistance 24 con-nected in series with the generator rheostat. This is shunted by the switch indicated in thedrawing. The overload relay employed in conjunction with the automatic starter has the magnetwinding 20, which may be called the tripping magnet, and the second magnet winding 22,which may be called the holding magnet. Winding 20 is in series with the D. C. armature onthe negative side of the line. If more than a predetermined number of amperes flow throughthis winding, the lever 14 is drawn up, breaking the circuit of the solenoid winding 11through the contacts 13 and 14. Immediately afterward the circuit through winding 22 isclosed through contacts 14 and 21. This causes the lever 14 to be held in that position untileither the main D. C. line switch or the starting switch 17 is opened. SERIES FIELDRHtOi. 110 VOLT Fig. 76—Hand Starter Connected to Motor Generator with Differential Motor Winding. One terminal of the solenoid winding 11 is connected to the positive pole of the D. C. lineat point 12. The circuit continues through the fixed resistance 9, shunted by the switch 10,through the contacts 13 and 14 of the overload relay, through contacts IS and 16 of theantenna switch, to a terminal of the winding 20, which is of negative polarity. Hence it isreadily observed that the solenoid winding is connected in shunt to the D. C. line wheneither contacts 15 or 16 or the starting switch 17 is closed. The switch 10 in shunt to the resistance 9 is automatically opened by the plunger A ofthe automatic starter when it is in the full vertical or running position. The resistance coils of the motor starter, connected in series with the D. C. line to thearmature, are progressively cut out of the circui
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
