Part 2
Now lets get to the technical discussion and see if you can defend yourself:
You have directly or indirectly made statements that voltage fold back is (i.e. a decreasing voltage level at 5000 RPM ,13.0V, from say 2500 RPM ,13.5V), are a normal part of OEM R/R behavior). I put it in red because that is your style, but I would not stoop to your behavior and use the large RED fonts.
I am stating it in this way as I have literally and purposefully said the said the opposite. A normal OEM GS R/R should not fold back like this and I provided several factors which would cause the intrinsic design of the R/R to not fold back.
And yet I showed that there are intrinsic aspects of the design of the R/R which do act to cause foldback.
This thread started with Chucky wondering about the fact that he had decreasing Voltage with increasing RPM.
I stated that In some cases this DOES occur ... even In a reasonably well functioning charging system.
I probably did not sufficiently qualify my case. Let me provisionally restate it this way:
Normally the charging system will hold the voltage fairly constant as RPMs change.
However in SOME installations the charging system will show a peak around 1500-2000 RPM and then slowly decrease after that.
If the charging voltage is somewhere within in the range of (say) 15-13.5 volts over the entire range from 2000 to redline, then I would consider this acceptable.
Perhaps not optimal, but not unacceptably abnormal.
If the charging voltage drops below 13.5 volts anywhere within this range than this is unacceptable and must be corrected.
Even if the charging voltage remains above 13.5 volts the entire way, you should clean all connectors, grounds and fuses.
I base this not on some (groundless in your particular case here) pie in the sky theoretical argument, but on having read other people say that their system actually does that.
Read post 7 in this thread for an example.
Its not a great example, but I did not solicit for Steve to say what he did.
In my time here I have seen at least 5 other similar posts by others.
Some even more specific about the seeing the effect in an apparently well running bike.
I'd like to find them, but finding semi-random posts from anytime in the last 3 or so years ...
I have seen the effect on my bike, although it is not a particularly relevant example.
Chucky's system is still very slightly folded.
You were right on the SCR. I either forgot what an SCR was or never knew. I assumed it was acting like a simple FET with zener control. As it turns out this is a very much more crude form of control than I had anticipated. The "crowbar" control is more likely see in an application to do overvoltage shunt protection and not a feed back control of a DC supplu voltage. This is a detail that is really irrelevant as anybody following this post will soon figure out.
And this is where you are wrong once again Posplayer.
Once again you screw up a detail. And once again this is a detail that actually is hugely relevant. This little detail changes the charge voltage from monotonically increasing to having a peak and then decreasing with RPM.
previously I wrote:
When an SCR fires, it totally shorts that leg of the stator out. (the other bridge diode prevents it from shorting the battery too)
It will provide absolutely no charging current or voltage. NONE. ZIP. ZERO. Not until the SCR turns off again.
It does not clip the top. the voltage at that point falls to the battery's resting/discharging voltage, and remains there till the next stator leg starts to charge.
And here is the important part. When the RPMs are such that the stator voltage is just below the trigger point, the charging voltage is as high as it will get.
When the RPMs rise a bit more, the SCRs just barely trigger, and it will allow most of the cycle through to charge the battery before it triggers. So the charging voltage is still fairly high, but starting to drop.
As the RPMs get higher, the Stator voltage rises more quickly, so the regulator triggers the SCRs earlier in each stator's positive half cycle.
So although the stator would charge even higher if it could, less of each cycle is allowed to go through. So the average charging voltage actually drops as the RPMs go higher.
As the RPMs go higher and higher, less and less of the stators current is allowed to go through, and the battery is charged less and less.
If you still have trouble picturing what is happening, think of it like PWM (pulse width modulation) where the duty cycle drops as the RPMS increase.
And that
ABSOLUTELY POSITIVELY does happen, and it
ABSOLUTELY POSITIVELY does cause the Charge voltage to drop as the RPMS increase.
And that is what this whole discussion is about.
And that is why I told you you had to understand the SCRs and the way they work. In detail.
Details, Details, Details.
Now the above sounds like you should have strongly decreasing charge voltage as the RPMs go up.
But don't forget that only 1 or 2 (depending on model) of the stators legs are regulated.
The other 1 or 2 are actually monotonically increasing.
So when everything is just right, the two effects balance each other out, and the charging voltage is stable with changes in RPM.
But sometimes something doesn't match up perfectly and there is a slight decrease in voltage with increasing RPM.
Even after you've troubleshot everything, and cleaned everything possible.
It just does it.
Its not normal, but its apparently not damagingly abnormal.
And the people are always puzzled by it, because it seems intuitively
wrong.
cause darn it, the voltage SHOULD go up when you go faster, how can it not.
And thats what I believe is going on in those cases.
And thats the point I was trying to make to Chucky.
Some of your other comments are not worth discussing because you appear to have a very possessive affliction for your own Regulator design and since you basically patterned it after the OEM topology you apparently feel since there is "guilt by association" you have to defend the Suzuki design as if some one was assailing your own personnel design.
This isn't really the thread to discuss it, but I'll make a few quick comments.
First of all, talk about rude ...
Second: Defend the topology ??? AFAIK ALL the Permanent Magnet alternator chargers from ALL the OEMs use basically the same topology. From the 70s to today.
Even your vaunted Hondas.
The GS series design has some problems, but the topology apparently works when properly immplemented.
Yet you know better than the manufacturer of just about every motorcyle ever made. Talk about arrogance.
The only real difference is in the triggers, and I don't approve of Suzuki's trigger.
This makes perfect sense since you could not see clear to avoid some of the same obvious error conditions and faults that the OEM regulator has, you need to defend that design in order to defend your own design.
Nice vauge generalities there posplayer, do you have some specific error conditions and faults in mind.
The only really obvious one I can think of for Suzuki is that it is sensitive to overvoltage: Don't jumpstart from a running car.
Mine is protected from that: You could jumpstart from a running semitractor with a 24 volt system and it would survive.
The starter, igniter and every light on the bike would be destroyed, but the rectifier/regulator would survive.