GS Stator

[posplayr]

Electrosport has this little blurb on their website where they mention how dropping out one leg of the stator cause "imbalance" in the system. Might be more BS, not sure, I'm not sure what the real world effect this has either.

The imbalance is in the 3 phase stator output (all three phases are not identical).

A three phase power source applied to a full wave rectifier generates DC with something on the order of 5% or less distortion (residual AC in the output). I don't recall the exact number but it is in this range . When you create imbalance in the phases, then the residual AC increases. On a GS the AC is in the audible range and varies with RPM.

On my GS750 which idled quietly it was actually audible when the leg was switched in and out and would lower the idle slightly. It was obviously as well looking at the AC using a scope. Other than creating more ground bounce (i.e. noise) it is not really an issue as pertains to "imbalance".

You can get an idea about what this means from looking a this chart. It shows the residual AC from ideal rectification. If the three legs are different it just gets more AC at the output. You can use higher number of phases and teh conversion gets better but as you can see more complicated. 3 Phase is popular because of this low distortion with only 3 phases at 120 degrees relative phase difference.

https://en.wikipedia.org/wiki/Rectifier#/media/File:3_phase_rectification_2.svg

https://en.wikipedia.org/wiki/Rectifier

[WolfworksCustoms]

I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...

[posplayr]

I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...

I prefer Electrosport and with a Series R/R they are no problems. The GS1100E stators have been high quality like this one. Heavy epoxy to immobilize the winding. Most people probably do not realize that the are Electromotive forces on the winding which will cause flexure if not supported. A thermal epoxy as you see here is what is used. It is not just for insulation, it is to keep the winding from flexing under the EMF forces. If you see winding that do not appear to have anything but a thin insulation cover, they are going to be less tolerant to usage.


I don't know that all of Electrosport product coating are this heavy but there are superior to most I have seen from any other vendor. If you are still using Shunt R/Rs and burning stators well there is not much anybody can say to help...............

This picture was to document heat damage from a MOSFET Shunt R/R after a 250 mile ride on a brand new ES stator. It was getting hot.

[Nessism]

I'll take a Rick's stator over most others. Less reported issues in my experience. They are more expensive though.

[OldVet66]

I went thru 3 Electrosport stators in one season.....they made good on all, but the swapping really wasnt worth the few bucks you save, IMO....Ive had the TP in 2 different engines now, with no issues....

These Ebay distributors....a buddy of mine haz a KZ1000 (Concourse)....he insists on buying the junk from Ebay, like the Electrosport stuff, spends a week installing, rides for a month, and stuff is shot......I cant understand why some dont "get" that sometimes you need to pay a lil more for quality. Research the manufacturers before you buy. And ya, sometimes ya pay more.....but at least it will LAST....

Theres another guy on Ebay who sells bike electrics....cant remember the name...but thats another loser....oh yeah..."Rick's"...

It's stories like yours or maybe yours that convinced me to follow posplayer and convert to a Series R/R. Electrosport sells Shunt R/R's and that or any other Shunt R/R and electrical system condition is the culprit, not the stator in the majority of cases. In this you do not know what you are talking about. Electrosport actually makes good stators along with Ricks and many of our members have had real good luck with Ebay stators. I have only heard of a couple of cases on an 1150 I believe where an Electrosport stator failed that had been fitted with a Series R/R and that was a fit problem with the stator where some wires were out of place and got pinched in installation. You are complaining about the result of having used Shunt R/R's not crappy stators. It's not your fault because that is the majority of R/R's on the market and you wouldn't have known, but now you are in a place that knows better and you can correct that problem and incorrect statements with the information posplayr has brought to everyone's attention. I'm talking about bikes with three phase AC generators like the GS so anything with another system I can not answer for and is not within my experience. Posplayer's picture below of a failing Electrosport stator is exactly the results of using shunt R/R's no matter what the quality of the unit and not the stator at all.

[Nessism]

It's stories like yours or maybe yours that convinced me to follow posplayer and convert to a Series R/R. Electrosport sells Shunt R/R's and that or any other Shunt R/R and electrical system condition is the culprit, not the stator in the majority of cases. In this you do not know what you are talking about. Electrosport actually makes good stators along with Ricks and many of our members have had real good luck with Ebay stators. I have only heard of a couple of cases on an 1150 I believe where an Electrosport stator failed that had been fitted with a Series R/R and that was a fit problem with the stator where some wires were out of place and got pinched in installation. You are complaining about the result of having used Shunt R/R's not crappy stators. It's not your fault because that is the majority of R/R's on the market and you wouldn't have known, but now you are in a place that knows better and you can correct that problem and incorrect statements with the information posplayr has brought to everyone's attention. I'm talking about bikes with three phase AC generators like the GS so anything with another system I can not answer for and is not within my experience. Posplayer's picture below of a failing Electrosport stator is exactly the results of using shunt R/R's no matter what the quality of the unit and not the stator at all.

Electrosport's stators make more power than a stock Suzuki stator, and as such there is more power shunted back into itself. I suspect that leads to increased failure of these units. Yes, a series R/R solves that problem but I think their basic approach to maximize output is not the best for general users.

Basscliff was using RM Stator a while back and he suffered a number of failures in a short time. Can't remember what he did to solve that issue just remember he had lots of troubles with the cheap Chinese stators.

[OldVet66]

You would be correct but paired with the series R/R the extra output is not a problem as you pointed out. It just compounds the problem paired with the shunt R/R's. My parts bike had something like 4,600 miles on it when I bought it and had burned stator connectors already. It was a story about three Electrasport stator failures in a row (and it was determined that it was the new Electrasport shunt R/R's that caused them) that caused me to adopt the Series regulator. That the industry is not responding and hanging on to the old technology because it is cheap is beyond me. I'm guessing stator replacement has become a profitable industry in itself.

[posplayr]

Electrosport's stators make more power than a stock Suzuki stator, and as such there is more power shunted back into itself. I suspect that leads to increased failure of these units. Yes, a series R/R solves that problem but I think their basic approach to maximize output is not the best for general users.

Basscliff was using RM Stator a while back and he suffered a number of failures in a short time. Can't remember what he did to solve that issue just remember he had lots of troubles with the cheap Chinese stators.

I'll try and put some detail to your point that invalidates your conclusion. Yes the Electrosport claims to increase power but as I have described this is only in an low RPM range where a different stator wind would produce lower voltage. Basically at idle the Electrosport will give a higher voltage. Once you get to 2500 RPM that benefit is largely gone as you are starting to saturate the magnetics and approach maximum current capability of the rotor. At 3500 RPM and above there is going to be no difference in power produced.

As far as how to get the highest idle voltage and the best stator longevity I recommend the Compufire R/R with the Electrosport stator.

The Compufire uses MOSFETs whereas the SH-775 uses SCRs so all else being equal you will see a higher output voltage at idle (say 1000 RPM).

With the Electrosport stator wind it will produce a higher output voltage at this same RPM. I have never done a stator swap out to confirm their claims , but assuming it is valid it would be highest at low idle. 20% power increase would correspond to approximately 10% (sqrt(1+.2)-1)=9.5%) voltage increase or if we were idling at 1000 RPM and were at 12.8V with a more traditional stator, the electrosport would produce 12.8*1.095=14.0V. This is probably the maximum extent of what the electrosport benefit because as soon as it gets to 14.25-14.5V it will be regulated. And yes this mid range RPM is where more power will be generated.

So while the statement that the Electrosport produces more power is true, it is only in a low voltage situation from 1000-2000 RPM where it will be noticeable and beyond that there is no difference.

beyond this, you can also be confident that the Electrosport rotors were designed by someone that understand electromotive forces on the stator winding. See the heavy epoxy. That will ensure years of longevity and protection against vibration and EMF.

On A GS at least, it is far worse to use a MOSFET SHUNT regulator like the FH008, FH0012, FH0020.!! That is because these MOSFETS are very efficient shorts and they will run cooler than your average SHUNT R/R that traditionally uses SCRs. What You say my MOSFET R/R running cooler is bad? Yes because any heat the SHUNT R/R does not dissipate is being dissipated in the stator making it run hotter.

Yes I will admit the worst combination is a Electrosport (higher low RPM output)with SHUNTING MOSFET R/R, but the MOSFET R/R is the worst part delivering between 10-20 more watts back to the stator than a old style SCR SHUNT R/R.

See my picture above about where the power is dissipated to understand this. If the total power is not dissipated in the load or the R/R then it is dissipated in the stator. So when running down the road with your engine at 4-5K RPM and the charging system is at maximum due to rotor limitations, loads are the same, if the R/R is running cooler then the stator is hotter.

[OldVet66]

Jim, you continue to baffle me at times but I sure am glad you are here to guide us through.

[Gorminrider]

Of course anybody looking to just solve the problems and move on would simply just install a SERIES R/R and all these revelations, and workarounds would become mute.

but when "anybody" is on the road (too far from Amazon's drone service) with a non-regulating charging system,"anybody" might find unplugging a stator leg worth a try.

From looking at the image and the reticle centered on the stator (as well as the high resolution of the image) I think it is safe to say that the Messpunkt, is an average in the near region of the center retical. This does not imply that the engine oil will be 34.7 degrees cooler using the Compufire, but that the stator is running substantially hotter with the shunt R/R.

We will disagree as to what is "safe to say". "The colours are an important part of the presentation . Also, just in passing, per the "reticule centered on the stator" the centre of the stator is hollow . The coils would seem more pertinent.

[posplayr]

Stator_Power_Rolloff.jpg

Jim, you continue to baffle me at times but I sure am glad you are here to guide us through.

I know what I'm talking about may sound mysterious, but just ask yourself what is the conversion efficiency of the GS Charging system?

Basically there is a certain amount of power available from the engine for a given RPM. If the conversion efficiency of the charging system remained constant or in other words linear, then you can expect both the current and voltage to rise in proportion to RPM (this is a consequence of what is known as Lentz's law)

https://en.wikipedia.org/wiki/Lenz%27s_law

Lenz's law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux and to exert a mechanical force opposing the motion.

Basically force on a wire and the current through it is a reversible process (conservation of energy)which is why a motor is a motor when you drive it with current or a generator if you drive it mechanically. But I digress .

What this means is that in an ideal world the electrical power out (P=I^2R=V^2/R) of the GS Charging system should increase to the square of RPM. And in fact in the low RPM range 500-1500 RPM it does. But around 1500-2000 RPM this squared law rise (double the input quadruples the output) is not realized! The output of the stator starts to roll off. Why? It is magnetic saturation ; Real materials like iron, steel and magnets have pronounced saturation effects.

You can visualize this as the materials having a lot of randomly aligned electrons when not in a magnetic field, but as the magnetic field becomes more pronounced the electrons align themselves with the magnetic field. But they can only align themselves and the more in alignment they are the less additional magnetic flux you get.

I'm no motor designer, but anybody who has studied the performance of basic DC motors will know these things are true. This is a very real effect and is well known , documented and obvious when you start taking measurements. So you can not take a stator that is in a charging system producing 150 watts and rewind it to produce 300 watts. It is impossible because it is the rotor and its magnets as well as the iron flux paths around the stator that dictate how much flux can be supported no matter if you run the engine up to 10K RPM or 15K RPM the charging system saturated and conversion efficiency drops correspondingly.

So Lentz's Law applies to ideal materials or materials that are not saturated. Most motors and charging systems run well into saturation because it is cheaper to run something to the max and get the design power levels than to design something that does not saturate but is capable of generating 10 times what you are using it for.

https://en.wikipedia.org/wiki/Saturation_(magnetic)

This is the main explanation of why the much heralded 20% power increase of the Electrosport stator can only be at low RPM as I described above and calculated as nominally a 1V increase at slow idle.

The fast rise in current and even faster rise in power that suddenly flatlines is due to "magnetic saturation effects"

[posplayr]

We will disagree as to what is "safe to say". "The colours are an important part of the presentation . Also, just in passing, per the "reticule centered on the stator" the centre of the stator is hollow . The coils would seem more pertinent.

You see what you want to see in the information.

If you understood the physical process of IR sensing you would realize that you can not see the hole anymore than you can see the coil. IR does not make the aluminum cover invisible or transparent for that matter. It can only read the surface temperature of the cover.

If you consider for the briefest moment the principles of heat flow especially in a material as thermally conductive as aluminum you would realize that the even relatively small temperature gradients across the cover are due to very large temperature differentials behind the cover (the IR can't see behind the cover). To overstate the obvious, that is because heat flows so well in aluminum that it takes a whole lot of heat flow to generate a temperature differential.
Anybody familiar with welding aluminum can readily attest to this.


The point is that you are only looking at a small part of the real thermal differences behind the cover. The SHUNT controlled stator has to be much much hotter to support such high thermal gradients across the aluminum cover.


If a 34.7 degF differences on the surface of the cover is not enough to convince you that the SHUNT stator is going to be remarkably hotter than SERIES controlled then I have no words for you that I wish to post.

[Brendan W]

Would it be correct to say that the rate of change of flux in the stator poles is what induces the emf in the windings. If you could somehow support all the windings in the rotor without a core the emf would be much less and that the stator poles saturate at some point making increases of speed and or number of windings irrelevant.

[DimitriT]

Without a controlled experiment on a bench setup running at set speeds with a fixed load and a thermometer measuring precisely, we only have a guess as to what's going on.

[Nessism]

Where I work we use a fair number of motors and differences in how the stator is wound and wire size have an effect on current consumption and performance in general. I don't know at what rpm the magnetic field is saturated on a GS charging system using various stators but I do know my bike sees a fair bit of time in the lower rpm regions, and if stators are burning up because of too much power being shunted back in themselves then what's the point in maximizing current output at a lower rpm when the system doesn't need it?

Everyone is free to do what they want but I don't see the point in high output stators unless you are driving electrical loads beyond the bike as stock. Every GS I've ever bought or owned had a stock stator and the charging system functioned okay after fixing R/R grounds in the system. Clearly though, a lot of stock stators burn out so there is value in fixing the wiring system and installing a series
R/R. My unofficial survey of stator failures has the chinese made aftermarket units (Electrosport and RM Stator) failing at a higher rate than stock or Rick's. That's why I spent the extra money on a Rick's recently. They make no claim about being high output and the quality seems good.