BAS Alternator- Part 2

The Plot Thickens…

I worked on the alternator again this morning, I decided it was time to remove the pulley and get the case open, one way or another. I beat on the pulley with a hammer some more, put some penetrating oil on it, pried at it, and just as I was about to fire up the angle grinder to destructively remove it I decided I’d give it a few more concerted whacks with the hammer, just since I was going to destroy it anyways… and pop! the tapered bushing flew out and the pulley was free.

First impression: This is not like any other alternator I’ve seen before…

Let’s see what’s going on here.

Stator looks pretty normal, looks like it’s wound with the same wire in the same method as a regular alternator.

The rotor, on the other hand… first off it’s got eight pole pairs, as opposed to the usual six. Secondly… what’s that in between the claw teeth?

Little ferrite bar magnets, in fact!!

Now, a couple comparison photos, comparing a standard GM parts bin ’90s Delco Remy alternator (I believe it was used on a northstar cadillac) to the BAS alternator. Stators:


Notable, aside from the different number of pole pairs and the magnets are the lesser gaps between the claw teeth, and the smaller angle of taper- the BAS alternator teeth are closer to rectangular than the the standard teeth are. I don’t know what this all means, but I would hazard a guess that these changes will improve the efficiency of the machine.

Coooool! Now I need to come up with a commutation sensor and controller, and some way to get a sprocket on the shaft. I’m glad I did not have to destroy the original pulley. Given the knowledge that it’s running 8 pole pairs the Austria Microsystems AS5134 won’t work (6 pairs max), maybe the CUI AMT303 is still an option.

Posted on September 5, 2011 at 10:31 am by Henry · Permalink
In: Electric Vehicles

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