| 摘要 |
1,083,964. Automatic voltage control. HARNISCHFEGER CORPORATION. Feb. 26, 1965 [March 13, 1964], No.8272/65. Heading G3R. [Also in Division H2] In a power transmission system, e.g. for a mobile crane, wherein an I.C. engine-driven alternator supplies a number of synchronous or induction motors whose speed is to be related to that of the engine, the alternator is excited so as to produce a constant voltage to frequency ratio. Excitation is provided by the rectified voltage of a separate, engine-driven, three-phase exciter 33 which is retroactively controlled by variation of resistance 50 in its field circuit 21 by a series of finger contacts operated by a coil 20 connected across the exciter through an adjusting rheostat 11. To compensate for armature reaction in the main alternator the voltage applied to the operating coil 20 may be bucked by a voltage corresponding to load current which is impressed across a Zener diode 13. A protective relay 14, 15 disconnects the exciter field 21 if its voltage becomes excessive. |
