Yes there are brushes in alternators.
They provide the connection to the rotating armature which controls the
strength of the magnetic field generated by that winding and so the
power generated by the stationary alternator windings.
The brushes are small compared to dynamo brushes as they handle
only light current.
The stationary windings generate the power in a multi phase 'frequency
wild' form which is then rectified by the diodes. The fact that alternators
are
multi phase with many diodes is also the reason that a diode failure can
sometimes be hard to detect.
John Dowson
At 08:57 AM 6/10/99 -0500, rtriplett@bjservices.com wrote:
>
>
>Date: Wed, 9 Jun 1999 10:52:36 -0700 (PDT)
>From: Malcolm Walker <>
>Subject: Re: TR6: report - Lucas:1 me:0
>
>
>On Wed, 9 Jun 1999, Rob Christopher wrote:
>
>> repair/replacing. To review the symptoms, the light goes out when the
>> car is above 1500rpm (and the headlights become brighter) but comes back
>> on when it drops to idle. I don't want to have to keep the engine at
>> 2000rpm while I work on it to keep the battery charged. If I can't find
>> a replacement easily, what do I need to buy/replace/refurbish/repair to
>> "rebuild" and alt?
>
>Start with brushes, they're the things that wear out (and symptoms of worn
>brushes are was you describe). You might want to think about replacing
>the bearings too, if possible.
>
>Other things that go (with different systems) are the diodes, and the
>regulator. This might be a regulator problem, but as the brushes are a
>wear point, I'd start with them.
>
>Are there brushes in an altenator? I'm not trying to be a smart a** here, I
>really don't know, but thought since it's an AC generator they were brushless.
>I've only worked on generators which DO for sure have brushes, but always just
>exchange altenators. The symptoms described above make it sound like a bad
>diode, causing just half-wave rectification, therefore less current available.
>Regards,
>Richard
>
>Regards,
>Richard
>
>
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