GB190309601A - Improvements in Dynamos. - Google Patents

Abstract

9601. Latour, M. June 29, A.D. 1902, [date applied for under Patents Act, A.D. 1901]. Field magnets, special means for separately exciting.-Relates to a method of exciting continuous-current dynamos by means of alternating currents and to the application of dynamos excited in this manner as the exciters of alternating-current dynamos. The alternating currents are supplied to the field coils of the dynamo through brushes which correspond in number to the phases of the current and are revolved in such a manner as to produce a stationary field instead of the rotating field which would be produced if they were stationary. The brushes may rub on two or more collector bars as may be required, and the inductor collector may be of opposite polarity to that of the exciting-coil. The collector may be detached from the inductor system. When the use of revolving brushes with a stationary inductor is undesirable, the inductor sections are connected to rings which are connected to revolving collector bars. In applying a dynamo excited as described above as the exciter of an alternator so as to obtain a compound alternator exciter, a compound transformer in the circuit of the alternator is arranged to supply the alternating current used to excite the continuous-current dynamo which excites the alternator. The transformer may be replaced by two exciting or field coils on the dynamo ; these coils have separate collectors, and are connected respectively in series with the alternator and to its terminals. A double inductor system for the dynamos, comprising two stators arranged in parallel and one carrying continuous currents if desired, may otherwise be employed. The inductor may have the coils wound on the circumference of the core as usual, and may also have projecting pole-pieces. One exciting-dynamo may be used with several alternators.