ALTERNATOR

摘要

1513270 Alternators MOTOROLA AUTOMOBILE SA 22 Dec 1975 [9 Jan 1975] 52396/75 Heading H2A An alternator has a rotor, a field winding 22, a stator with a first output winding 17 and a second output winding 18, means 20, 21 for rectifying the outputs of windings 17 and 18, and means for adding the outputs of windings 17 and 18, the output current of winding 17 (curve 13, Fig. 1, not shown) being greater than that of winding 18 (curve 12, Fig. 1) at rotor speeds below a predetermined speed and less than that of winding 18 at rotor speeds above said predetermined speed. The invention is applicable to automobile alternators of multiple monophase and multiphase type. In a three phase embodiment, Fig. 2, each phase of the low-output first winding 17 is wound on only half the elementary magnetic circuits-(EMC's, each equal to one pole pitch) of the stator with for example, 26 turns of 0À92 mm diameter wire in an EMC, and each phase of the highoutput second winding 18 is wound on the other EMC's with, for example, 13 turns of 1À3 mm diameter wire in an EMC. In each phase, winding 17 is in sets of stator slots alternating with slot sets receiving winding 18, Fig. 3 (not shown). The output voltage at terminals +, - is maintained constant by a regulator 23 which also supplies the field winding 22. In a second three-phase alternator, Figs. 4 and 5 (not shown), the low-output winding (25) again occupies only half of EMC's, has more turns per EMC, and is of thinner wire than the high-output winding (26), but the high-output winding (26) occupies all EMC's whereby in phase three sections of winding (26) overlie three sections of winding (25) and the output is affected by mutual inductance. In a similar embodiment Figs. 6 and 7 (not shown), each phase of the low-output winding (28) is connected at one end to the centre of the corresponding phase of the high-output winding (27) and at the other end to the corresponding, section of the rectifier 21. One or both of the output windings may be star-connected instead of delta-connected.