alt.energy.renewable

Tater tater1337@ posted to :

> On Aug 30, 11:37 pm, clare at wrote:
>> On Thu, 30 Aug 2007 16:42:51 -0700, Tater
>> wrote:
>> >On Aug 30, 10:32 am, gearhead wrote:
>> >> > Cars used to have permanenet magnet generators
>>
>> >> Which cars? Are you sure?>From what I know of antique vehicles
>> >> with dc generators -- series-
>>
>> >> wound, with segmented commutators -- they did not use magnets.
>> >> I speak from my experience with antique Harleys and GM trucks.
>> >> The only vehicles I know use magnets are motorcycles, and they
>> >> use
>>
>> >your experience needs to be corrected. yes they had commutators,
>> >because the magnets were in the case, not the armature.
>>
>> >had some nice suckers in there, most autoshops pulled em out to
>> >use for welding magnets
>>
>> In north america virtually NO automotive DC generators had
>> permanent magnets Up untill only a few years ago, not even
>> automotive STARTERS
>
> odd, I could have sworn that we would store screwdrivers and
> wrenches on the generators while working on cars. must have been
> magic pixie dust that let them stick
>
> also remember trying to pull them apart to clean commutators. the
> shafts seemed to have an unexplicable attraction to the blocks of
> metal on the motor casings, you know, where the feild coils would be
> in an alternator.
>
> you are talking about the north america on earth, right? fords,
> chevys, and such from the 60s and 70s? generators that were about 3
> times as long as delco alternators and maybe 2/3s the diameter?

See also MoosFET's post. Typically the old commutator DC generators
had a softly magnetizable core. It would hold about 10% of normal
field. This was useful when push starting older automobiles with
drained batteries.