Jim Thompson wrote:

On Wed, 18 Jan 2012 20:48:13 -0500, Jamie
t wrote:


Jim Thompson wrote:


On Wed, 18 Jan 2012 18:46:14 -0500, Jamie
et wrote:

[snip]


And let us not forget that these non-pm alternators have not used
brushes for the field for years now. Nothing but bearings and the
unexpected mishap to take place now.


[snip]

Huh? How does that work?

...Jim Thompson

They have not been using brushes in alternators in cars for a long time
now. They may still use them in very large units however.

Since you never believe me on anything, maybe you can believe others.

He

http://www.pearen.ca/dunlite/BrushlessAlternators.pdf

Jamie



OK. I've not seen that in a passenger car. My Q45 has slip-rings.

...Jim Thompson

Talking about slip rings. We still operate many large AC motors (Eddy
current clutches) via slip rings.. They actually work much better for
constant tension control over today's preferred vector systems.

But, they are getting old like the rest of us and soon to see their
demise.

Jamie