315:
347:
238:
38:
188:
50:
246:
804:
572:
556:
may use magnetos because they are lighter in weight than an ignition system relying on a battery. Small internal combustion engines used for lawn mowers, chain saws, portable pumps and similar applications use magnetos for economy and weight reduction. Magnetos are not used in highway motor vehicles
329:
De MĂ©ritens is best remembered today for his production of magneto generators specifically for lighthouses. These were favoured for their simplicity and reliability, in particular their avoidance of commutators. In the sea air of a lighthouse, the commutator that had been used previously with dynamo
283:
The rotors first used were wound as sixteen axial bobbins, one per pole. Compared to the bipolar dynamo, this did have the advantage of more poles giving a smoother output per rotation, which was an advantage when driving arc lamps. Magnetos thus established a small niche for themselves as lighting
372:
Kennedy himself developed a simpler version of this, intended for lighting use on ships, where a dynamo and magneto were assembled on the same shaft. Kennedy's innovation here was to avoid the need for brushgear at all. The current generated in the magneto is transmitted by wires attached to the
417:
available from their permanent magnets. The fixed excitation of a magneto made it difficult to control its terminal voltage or reactive power production when operating on a synchronized grid. This restricted their use for high-power applications. Power generation magnetos were limited to narrow
600:
makes the simple magneto alternator a more practical proposition as a power generator, as these permit a greatly increased field strength. As the magnets are compact and of light weight, they generally form the rotor, so the output windings can be placed on the stator, avoiding the need for
547:
Magnetos adapted to produce impulses of high voltage for spark plugs are used in the ignition systems of spark-ignition piston engines. Magnetos are used in piston aircraft engines for their reliability and simplicity, often in pairs. Motor sport vehicles such as
302:(1834–1898) developed magnetos further for this purpose. His innovation was to replace the rotor coils previously wound on individual bobbins, with a 'ring wound' armature. These windings were placed on a segmented iron core, similar to a
467:
bearing to bring the turbine into the wind. The brake disk, with its attached rare-earth magnets, rotates to form the armature. A plywood disk carrying multiple axial coils is placed alongside this, with an iron armature ring behind it.
583:
for local battery station service in magneto exchanges were equipped with a hand-cranked magneto generator to produce an alternating voltage to alert the central office operator, or to ring the bells of other telephones on the same
224:
The surviving machine has an applied field from four horseshoe magnets with axial fields. The rotor has ten axial bobbins. Electroplating requires DC and so the usual AC magneto is unworkable. Woolrich's machine, unusually, has a
364:, an electrical engineer from Manchester, England, developed a combination of magneto and electro-magnet generator, where the magneto was used only to supply the field to the larger alternator. These are illustrated in
396:
of the generator feeds some of its output current back into the field coils, which in turn increases output. Because of this, the field 'builds up' regeneratively, though this may take 20–30 seconds to do so fully.
400:
Use of magnetos here is now obsolete, though separate exciters are still used for high power generating sets, as they permit easier control of output power. These are particularly common with the transmissions of
333:
The de MĂ©ritens magneto generator illustrated shows the 'ring wound' armature. As there is now only a single rotor disk, each horseshoe magnet comprises a stack of individual magnets, but acts through a pair of
529:, a French doctor, developed and manufactured a magneto with a variable outer voltage and frequency, through varying revolutions by hand or varying the inductance of the two coils, for clinical experiments in
280:, along the axle. This had the advantage that each rotor disk could at least share the flux of two expensive magnets. The machine illustrated here uses eight disks and nine rows of magnets: 72 magnets in all.
373:
rotating shaft to the dynamo's rotating field coil. The output of the dynamo is then taken from the stator coils. This is 'inside-out' compared to the conventional dynamo, but avoids the need for brushgear.
330:
generators was a continual source of trouble. The lighthouse keepers of the time, usually semi-retired sailors, were not mechanically or electrically skilled enough to maintain these more complex machines.
621:. These must operate at high speeds, directly coupled to a turbine. Both types share the advantage of the output coils being part of the stator, thus avoiding the need for brushgear.
557:
that have a cranking battery, which may need more ignition timing control than a magneto system can provide, though sophisticated solid state controllers are becoming more common.
292:
140:
or battery failure. For redundancy, virtually all piston engine aircraft are fitted with two magneto systems, each supplying power to one of two spark plugs in each cylinder.
354:
Both dynamos and alternators required a source of power to drive their field coils. This could not be supplied by their own generator's output, without some process of '
42:
314:
691:
Magnetos for
Automobilists, how Made and how Used: A Handbook of Practical Instruction in the Manufacture and Adaptation of the Magneto to the Needs of the Motorist
392:
removed the need for a magneto exciter. A small residual field in the iron armature of the field coils acted as a weak permanent magnet, and thus a magneto. The
155:, for the same purposes or to the same extent as either dynamos or alternators. Only in a few specialised cases have they been used for power generation.
346:
489:
One popular and common use of magnetos of today is for powering lights and USB powered devices on bicycles. Most commonly, a small magneto, termed a
843:
365:
718:
237:
418:
fields, such as powering arc lamps or lighthouses, where their particular features of output stability or simple reliability were most valued.
136:, in which keeping the ignition independent of the rest of the electrical system ensures that the engine continues running in the event of
825:
493:, rubs against the tire of the bicycle and generates power as the wheel turns. More expensive and less common but more efficient is the
957:
Schiemenz, I.; Stiebler, M. (2001). "Control of a permanent magnet synchronous generator used in a variable speed wind energy system".
816:
613:, an early rare-earth type, let permanent magnet alternators be used in applications that require an extremely robust generator. In
998:
Lee, R.G.; Garland-Collins, T.K.; D.E. Johnson; E. Archer; C. Sparkes; G.M. Moss; A.W.Mowat (1988). "Electrical Power
Supplies".
306:, so as to form a single continuous hoop. This gave a more even output current, which was still more advantageous for arc lamps.
472:
20:
210:
726:
497:
that rotates neodymium magnets around a copper coil in a claw pole cage inside the hub of a wheel. Commonly referred to as
429:, particularly self-build designs, are widely adopting magneto alternators for generation. The generators use rotating
1011:
974:
706:
Electricity in the service of man: a popular and practical treatise on the applications of electricity in modern life
291:(1794–1853) became particularly known for this type of arc lighting generator and founded the British-French company
261:
Most early dynamos were bipolar and so their output varied cyclically as the armature rotated past the two poles.
1053:
447:
to produce direct current (DC). This current either directly pumps water, is stored in batteries, or drives a
175:
machine, which used an electromagnet to produce the magnetic field, was developed later. The machine built by
635:
471:
In large sizes, from the 100 kW to MW range, the machines developed for modern wind turbines are termed
202:
195:
151:, for which their simplicity was an advantage. They have never been widely applied for the purposes of bulk
264:
To achieve an adequate output power, magneto generators used many more poles; usually sixteen, from eight
866:
610:
437:
402:
113:
730:
205:. In 1842 John Stephen Woolrich was granted UK patent 9431 for the use of an electrical generator in
618:
37:
1033:
250:
171:
in 1831. The first machines to produce electric current from magnetism used permanent magnets; the
31:
218:
137:
27:
895:
521:
The magneto also had a medical application for treatment of mental illness in the beginnings of
655:
585:
361:
350:
Wilde machine, where a small magneto (top) powers the field coils of a larger alternator below.
152:
124:
for ignition is now limited mainly to engines without a low-voltage electrical system, such as
784:
318:
299:
276:
by using more magnets. As this was still an inadequate power, extra rotor disks were stacked
187:
448:
413:
Magnetos have advantages of simplicity and reliability, but are limited in size owing to the
254:
226:
191:
82:
809:
One or more of the preceding sentences incorporates text from a publication now in the
49:
526:
179:
in 1832 used a rotating permanent magnet to induce alternating voltage in two fixed coils.
66:
838:
836:
8:
889:
502:
74:
959:
IEMDC 2001. IEEE International
Electric Machines and Drives Conference (Cat. No.01EX485)
689:
1021:
980:
833:
426:
389:
385:
1007:
984:
970:
597:
566:
433:
272:
available was limited by the magnet metallurgy, the only option was to increase the
209:, rather than batteries. A machine was built in 1844 and licensed to the use of the
93:, although it is usually considered distinct from most other alternators, which use
962:
764:
630:
542:
460:
452:
444:
430:
277:
265:
121:
927:
910:
854:
850:. Vol. III (1903 (five volumes) ed.). London: Caxton. pp. 205–206.
575:
Swedish telephone (ca. 1896) with the hand crank of the magneto on the right side
522:
393:
377:
176:
168:
133:
109:
614:
506:
484:
273:
206:
201:
The first electrical machine used for an industrial process was a magneto, the
164:
86:
966:
245:
1047:
885:
820:
810:
490:
414:
355:
288:
269:
944:"The triplets - 10 foot diameter brake disk wind turbines | Otherpower"
1003:
381:
105:
303:
943:
658:
for a discussion of their development from bipolar to multipolar fields.
100:
Hand-cranked magneto generators were used to provide ringing current in
769:
752:
553:
549:
494:
456:
335:
322:
214:
148:
117:
94:
90:
872:
860:
842:
708:, Cassell & Company, limited, 1886 p. 227, preview on Google books
41:
Demonstration hand-cranked magneto made circa 1925, on display at the
580:
530:
221:, the manufacture of buttons, buckles and similar small metal items.
125:
101:
217:. Such electroplating expanded to become an important aspect of the
455:. A typical design is an axial-flux generator recycled from a car
144:
129:
143:
Magnetos were used for specialized isolated power systems such as
571:
464:
19:
This article is about small generators. For larger designs, see
510:
440:
172:
78:
70:
609:
By the late 1980s, developments in magnetic materials such as
991:
997:
104:
systems. Magnetos were also adapted to produce pulses of
241:
de MĂ©ritens' 'ring wound' armature and single pole piece
929:
A Wind
Turbine Recipe Book: Axial Flux Windmill Plans
789:
Biographical
Dictionary of the History of Technology
687:
43:
Musée d'histoire des sciences de la Ville de Genève
956:
873:Kennedy, Electrical Installations, Vol. III, 1903
861:Kennedy, Electrical Installations, Vol. III, 1903
1045:
777:
704:Alfred Urbanitzky (Ritter von), Richard Wormell
501:, both devices are in fact magnetos, producing
57:magneto generator for arc lamps, of around 1870
163:Production of electric current from a moving
829:(11th ed.). Cambridge University Press.
768:
570:
345:
341:
313:
249:The generator from Souter Lighthouse at
244:
236:
186:
48:
36:
925:
908:
814:
591:
473:permanent magnet synchronous generators
1046:
516:
21:Permanent magnet synchronous generator
884:
26:For the Marvel Comics character, see
750:
536:
753:"The early history of gold plating"
744:
408:
13:
604:
14:
1065:
815:Hawkins, Charles Caesar (1911). "
182:
89:. It is categorized as a form of
802:
617:, such generators can replace a
421:
287:The Belgian electrical engineer
950:
936:
919:
902:
878:
719:"Woolrich Electrical Generator"
667:Actually a higher AC frequency.
451:that can supply the commercial
232:
97:rather than permanent magnets.
81:, a magneto does not contain a
795:
711:
698:
681:
661:
648:
309:
73:to produce periodic pulses of
1:
688:Selimo Romeo Bottone (1907).
674:
229:to rectify its output to DC.
203:Woolrich Electrical Generator
196:Woolrich Electrical Generator
16:Electricity-producing machine
785:"Meritens, Baron Auguste de"
560:
7:
912:How to Build a Wind Turbine
624:
478:
403:diesel-electric locomotives
268:arranged in a ring. As the
114:internal combustion engines
10:
1070:
751:Hunt, L. B. (March 1973).
636:Faraday's law of induction
596:The development of modern
564:
540:
482:
158:
25:
18:
967:10.1109/IEMDC.2001.939422
619:flux switching alternator
112:of some gasoline-powered
848:Electrical Installations
641:
370:Electrical Installations
251:Science Museum in London
116:to provide power to the
32:Magneto (disambiguation)
894:. McGraw-Hill. p.
826:Encyclopædia Britannica
219:Birmingham toy industry
28:Magneto (Marvel Comics)
926:Piggott, Hugh (2009).
909:Piggott, Hugh (2005).
694:. C. Lockwood and son.
576:
351:
326:
258:
242:
198:
153:electricity generation
58:
46:
30:. For other uses, see
1054:Electrical generators
574:
376:The invention of the
349:
342:Self-exciting dynamos
317:
295:to manufacture them.
293:Société de l'Alliance
255:Frederick Hale Holmes
248:
240:
190:
55:Société de l'Alliance
52:
40:
891:Electrical Machinery
592:Future possibilities
527:Duchenne de Boulogne
298:The French engineer
167:was demonstrated by
67:electrical generator
517:Medical application
509:produced by a true
503:alternating current
459:and hub bearing. A
427:Small wind turbines
378:self-exciting field
319:Auguste de MĂ©ritens
300:Auguste de MĂ©ritens
75:alternating current
770:10.1007/BF03215178
723:Birmingham Stories
598:rare-earth magnets
577:
505:as opposed to the
434:rare-earth magnets
352:
327:
259:
243:
199:
59:
47:
567:Telephone magneto
537:Ignition magnetos
266:horseshoe magnets
122:ignition magnetos
71:permanent magnets
1061:
1038:
1037:
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748:
742:
741:
739:
738:
729:. Archived from
715:
709:
702:
696:
695:
685:
668:
665:
659:
654:See the related
652:
631:Electromagnetism
543:Ignition magneto
461:MacPherson strut
453:electricity grid
445:bridge rectifier
409:Power generation
134:aircraft engines
110:ignition systems
1069:
1068:
1064:
1063:
1062:
1060:
1059:
1058:
1044:
1043:
1042:
1041:
1029:
1028:
1019:
1018:
1014:
1002:. Vol. 1.
996:
992:
977:
961:. p. 872.
955:
951:
942:
941:
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924:
920:
907:
903:
883:
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871:
867:
859:
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844:Kennedy, Rankin
841:
834:
803:
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783:
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778:
749:
745:
736:
734:
717:
716:
712:
703:
699:
686:
682:
677:
672:
671:
666:
662:
653:
649:
644:
627:
615:guided missiles
611:samarium–cobalt
607:
605:Guided missiles
594:
569:
563:
545:
539:
523:electromedicine
519:
487:
481:
424:
411:
344:
312:
235:
211:Elkington Works
185:
177:Hippolyte Pixii
161:
35:
24:
17:
12:
11:
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1067:
1057:
1056:
1040:
1039:
1012:
1006:. p. 58.
1000:Guided Weapons
990:
975:
949:
935:
918:
901:
886:Croft, Terrell
877:
865:
853:
832:
821:Chisholm, Hugh
794:
776:
743:
710:
697:
679:
678:
676:
673:
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623:
606:
603:
593:
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565:Main article:
562:
559:
541:Main article:
538:
535:
518:
515:
507:direct current
485:Bicycle dynamo
483:Main article:
480:
477:
449:mains inverter
423:
420:
410:
407:
366:Rankin Kennedy
343:
340:
311:
308:
234:
231:
207:electroplating
184:
183:Electroplating
181:
165:magnetic field
160:
157:
120:. Use of such
87:direct current
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4:
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2:
1066:
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939:
931:
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914:
913:
905:
897:
893:
892:
887:
881:
875:, p. 208
874:
869:
863:, p. 207
862:
857:
849:
845:
839:
837:
828:
827:
822:
818:
812:
811:public domain
798:
790:
786:
780:
771:
766:
762:
758:
757:Gold Bulletin
754:
747:
733:on 2015-04-02
732:
728:
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714:
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701:
693:
692:
684:
680:
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657:
656:bipolar motor
651:
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629:
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602:
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555:
551:
544:
534:
532:
528:
524:
514:
512:
508:
504:
500:
496:
492:
491:bottle dynamo
486:
476:
474:
469:
466:
463:provides the
462:
458:
454:
450:
446:
442:
439:
435:
432:
428:
422:Wind turbines
419:
416:
415:magnetic flux
406:
404:
398:
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391:
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363:
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356:bootstrapping
348:
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289:Floris Nollet
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763:(1): 16–27.
760:
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700:
690:
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586:(party) line
578:
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399:
394:shunt wiring
375:
369:
360:
353:
332:
328:
297:
286:
284:generators.
282:
263:
260:
233:Arc lighting
223:
200:
162:
142:
106:high voltage
99:
62:
60:
54:
1030:|work=
601:brushgear.
554:snowmobiles
550:motorcycles
525:. In 1850,
438:three-phase
362:Henry Wilde
336:pole pieces
310:Lighthouses
304:Gramme ring
253:, built by
149:lighthouses
147:systems or
118:spark plugs
95:field coils
85:to produce
77:. Unlike a
737:2017-09-12
675:References
581:telephones
495:hub dynamo
457:brake disk
390:Wheatstone
323:lighthouse
227:commutator
215:Birmingham
192:Commutator
138:alternator
126:lawnmowers
91:alternator
83:commutator
69:that uses
1032:ignored (
1022:cite book
1004:Brassey's
985:110847930
727:Thinktank
561:Telephone
531:neurology
431:neodymium
325:generator
132:, and to
130:chainsaws
102:telephone
1048:Category
888:(1917).
846:(1903).
625:See also
479:Bicycles
368:'s work
145:arc lamp
823:(ed.).
813::
579:Manual
499:dynamos
465:azimuth
436:with a
386:Siemens
278:axially
194:of the
169:Faraday
159:History
108:in the
63:magneto
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817:Dynamo
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443:and a
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382:Varley
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274:field
1034:help
1008:ISBN
971:ISBN
552:and
270:flux
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
