| Author |
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Jlnance
| | Posted on Friday, November 30, 2007 - 08:57 am: | 
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No, it's fvwm-1.24r on Red Hat. I have to compile it myself because they stopped shipping it a few years ago. The date on the tarfile is 1999.
I think a regulator would be fun. Can we try it out on your bike? I want to work out the bugs there.  It would be pretty easy to replace the bottom diodes with SCRs and just turn them on when the battery needed a boost. One thing I realized as I was thinking about it all this morning is that the shunt regulator will keep you from frying the electronics on the bike if the battery fails. Thats a nice feature
BTW, I'm surmising from whats been posted that the failure mode we are seeing is that the SCRs get hot and short, and this causes the stator to overheat. It would be good to verify that before we start redesigning things. If it's the stator failing first, we can't fix it by mucking with the regulator. |
Od_cleaver
| | Posted on Friday, November 30, 2007 - 10:00 am: |
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A couple of weeks ago I looked back at the first 12 posters to this thread. 10 stated what parts were replaced. Of the 10, 4 stated that only the stator was replaced.
If this review of mine is accurate, fixing the stator will not solve the problem.
The posters stating that only the stator was replaced were: Xbimmer, Ftd, Aeholton and Dfishman. |
Od_cleaver
| | Posted on Friday, November 30, 2007 - 10:05 am: |
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I made a mistake.
I meant to say the fixing the regulator will not completely solve the problem. |
Al_lighton
| | Posted on Friday, November 30, 2007 - 01:42 pm: |
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Just as an FYI, the 08 bikes have gone back to a single phase stator common (except for lead length) to the sportster models. Says it's a 32 Amp output instead of 38 Amp in the 08 changes brochure, but one of the Buell engineers told me that the usable DC load on the bike was the same. Higher AC voltage? Higher efficiency at the rectification/regulation stage? Not sure, just reporting what I heard. I sure thought is was odd to go to a lower output when the customer feedback I get is folks wanting HIGHER output.
Al |
Jlnance
| | Posted on Friday, November 30, 2007 - 01:59 pm: |
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Al, I suspect the lower output might be because people are having failures with the higher output systems. |
Hughlysses
| | Posted on Friday, November 30, 2007 - 02:05 pm: |
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Regarding the smaller 08 alternator, another possible reason for the downsizing is the engine cooling fan. People are reporting significantly reduced fan operation on the 08's. Buell may have reduced the size of the new alternator based on the average load requirement. Reducing the fan run time (which must be the highest single load on the electrical system) would give you more average power to work with. So, even though the rated alternator output is less, the bike may have more average available "surplus" power.
Make sense? |
Jlnance
| | Posted on Saturday, December 01, 2007 - 09:51 pm: |
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I've been playing.
I left out the gate driver circuit, primarily because I haven't designed it yet. Also need to do something to make sure we don't draw power when the bike is off. The shunt regulator has advantages in both those areas, I'm beginning to see it's appeal
The regulator design is something I came up with in grad school but never could find a reason to use. It happens to fit perfectly here. It's based on the principles of the Delta-Sigma Analog to Digital converter.
In a real delta-sigma A/D converter, the output of a 1 bit A/D converter is subtracted from an input signal to produce an error signal. This error signal is integrated, and on every clock pulse the state of the 1 bit converter is flipped depending on whether the integration is positive or negative. The output of this A/D converter is a pulse train. At any given time, the output is either 1 or 0. If you average the pulses over a period of time, the average value approaches the value of the input.
This regulator works on the same principle. Instead of a clock and a flipflop, we are using the latching behavior of the SCRs as our 1 bit A/D and the AC current from the generator as our "clock." The zener provides a reference voltage on one terminal of the right opamp. The battery voltage is scaled and subtracted from this reference voltage. The difference is our error signal, which we want to drive to zero. We integrate the error voltage. When the integrated voltage is too low, we switch on the SCRs, when it is too high, we turn them off. At any instant we are either sending a large current pulse to the battery or nothing. Over time the average value of these current pulses should be the correct value needed to keep the battery voltage at the desired value.
I like this, as opposed to the standard phase controlled rectifier setup, because we do not need to have any timing circuitry that attemps to fire the SCRs at a specific phase angle. Attempting to do that would be problematic with a variable frequency generator like we have here. The gate drive circuitry should also be simpler here. We can don't need to drive each gate individually, we can drive them all in parallel and just let the forward biased SCR select itself.
(Message edited by jlnance on December 01, 2007) |
Reepicheep
| | Posted on Sunday, December 02, 2007 - 05:31 pm: |
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I'll have to chew on that a while when I am not so tire... it looks cool.
I had the same experience you did... I heard the Buell regulator was a shunt and thought 'it was designed by a mad man'. Then I started thinking about how to design replacements, and the designer suddenly looked quite rational |
Jlnance
| | Posted on Sunday, December 02, 2007 - 07:18 pm: |
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I think either my batter or regulator is on the way out  |
Florida_lime
| | Posted on Sunday, December 02, 2007 - 07:41 pm: |
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On the way out ......
to the Ducati dealer......  |
Jmhinkle
| | Posted on Monday, December 03, 2007 - 03:45 am: |
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"to the Ducati dealer...... "
That right there is funny! |
Xbimmer
| | Posted on Saturday, December 08, 2007 - 07:09 am: |
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Important issue, bump. |
Maximum
| | Posted on Monday, December 10, 2007 - 12:09 pm: |
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OK...you can officially add me to the list.
After blowing several headlight bulbs last week, the dealer replaced my voltage regulator and battery. Within a couple days the bike was hesitating on start up again.
Yesterday, after a two hour ride, I checked my battery with a multi-meter and it indicated 10.8 volts. I started the bike and at idle it now showed 9.4 volts. At 5000 rpms it showed 11.0 volts. I had to jump the Uly this morning, but was able to ride it back to the dealer.
Their Buell tech is off today, but fortunately they do have a new stator in stock and will be replacing it for me tomorrow.
I start my trip from Alabama back home to Colorado on Friday...so I'm glad the problem surfaced here rather than in the middle of my trip! |
Ft_bstrd
| | Posted on Monday, December 10, 2007 - 12:19 pm: |
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Steve, let me know if your're coming through. I'd love to dine with ya! |
Jlnance
| | Posted on Monday, December 10, 2007 - 09:28 pm: |
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After blowing several headlight bulbs last week
That indicates a regulator that isn't regulating. Has anyone else noticed this when theirs failed? |
Jmhinkle
| | Posted on Tuesday, December 11, 2007 - 12:15 am: |
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My problem wasn't blowing lights, it was that they would surge high and low while riding. My speedo stopped working along with the odo, but everything else like the clock and tach worked. I thought the VR was bad, but they replaced both items. I think one going bad fries they other. It also took out the battery because I got it back too weak to start the bike. I left it on the tender for a few days and it was enough to get it to start for the dealer on trade in. |
Bugnut
| | Posted on Wednesday, March 05, 2008 - 08:30 am: |
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Mines headed to the dealer again. 21k and it took a crap last night. Looked back at my reply on this thread on the second VR @ 15k, first @ 5k. So 5 to 10k per regulator. Humm, I smell an issue....
Mike |
Maximum
| | Posted on Wednesday, March 05, 2008 - 10:19 am: |
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My last regulator they replaced, actually turned out to be the 77 connector. After the bike left me stranded twice within 90 miles (two days after coming out of the shop), I had to tell them to double check the connector, and sure enough, that is what it was.
(Message edited by maximum on March 05, 2008) |
Portero72
| | Posted on Monday, June 02, 2008 - 01:14 pm: |
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Add my name to this list-bad VR plus stator. Happened 40 miles after I got it out of Tucson HD for a blown right fork seal. Problem is, I live in TX and was on a road trip(covered elsewhere in BB+D). Gonna call the service writer and have the tech check the 77 connector before I FLY back to pick it up. Booooo, crappy electrical components. HOORAAY, Red Stripe! |
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