Better Generator Designs.

[68C]

While thinking about our permanent magnet alternaters and the various ways they are controlled, either dumping the output as heat or opening the output lines, I remembered other motorcycle designs.

 

The one I liked was fitted to the Yamaha XS750, XS850, XS1100 bikes.

They had a fixed inner excitation coil and a fixed outer conventional stator coil. There was a metal claw arrangement that spun between them. The inner coil current could be adjusted by the voltage regulator to create a magnetic flux, the rotating claw created a changing magnetic flux which induced current in the outer coil. This assembly was narrow and fitted on the end of the crankshaft as with the V11, the voltage regulator monitored the output and adjusted the inner coil current to suit. This seemed a lovely solution for a motorcycle, it could be sealed,as the rotating claw stirred up the air aiding cooling. It did not need to 'dump' energy so less load needed to drive it. No extra bearings and no brushes to wear out. I understand the development of rare earth magnets and cheaper electronics led manufacturers to abandon this system - the old story of a cheaper inferior solution.

 

Even better is the "Switched Reluctance Generator". Mechanically even simpler than our rotating magnet alternators, there is only a metal rotor and fixed stator windings and clever electronics. They can be built fairly narrow to suit a crankshaft mounting and these devices can even be used as both generator and motor, even solves the loose magnet problem in our starters!

 

Google Scientific Research Publishing https://file.scirp.org› pdf › EPE2012060... for a better explanation than I can give.

 

So who will be the first to measure up a Yamaha XS1100 alternator?

[swooshdave]

It depends on if you think the added complexity is worth the benefits.

 

I think using a MOSFET regulator makes sense, clear benefits for the same price as a the SCR ones.

[68C]

Just a bit of fun, cannot see me really doing it.

[Tomchri]

Nothing wrong with a little fun,, I bring the fuel to this fire .

Cheers tom.

[al_roethlisberger]

What about something like this:

 

https://gtmotocycles.com/collections/electronics/products/eme-h-o-charging-system-upgrade

[68C]

Now that looks like the grown up solution. Hope they don't just dump the excess power as heat.

[bbolesaz]

The Enduralast system works just like the normal Guzzi system.  So yea, dumping heat.  Airhead Beemers use a car like alternator, where there is a coil within a coil. The inner coil only energizes when voltage drops. So no excess heat.  Just some super fussy and unreliable brushes plus rotors which have a tendency to open.  Modern beemers tend use off the shelf Bosch alternators.

[al_roethlisberger]

The Enduralast system works just like the normal Guzzi system.  So yea, dumping heat.  

 

 

Understood, but until we have something drastically different like the original post, I was just wondering if anyone had looked into the EME rotor and regulator, their quality, reliability and what type (e.g. MOSFET) of regulator it is.

[bbolesaz]

It looks like the Enduralast for Guzzi uses a larger stator and rotor. I would assume the regulator is MOSFET.

[68C]

Are we sure the early and late bikes have the same size alternator fitting? I ask as I looked at several sites offering higher output alternators, most only listed up to the late 90's.