SH 775 R/R test

[tom203]

Here are some test results comparing my old shunt SH-232 R/R to the series SH-775.

Disclaimer- I have no idea how accurate my ac current clamp meter is at frequencies above 60 Hz; I know it's accurate on 3 phase 60 Hz stuff. I suspect it might be pretty good at 120 Hz (1200 rpm), but at 400 Hz, who knows.
On the good old SH-232;
at 1200 rpm, stator line current = 6.5 amp ; R/R output 12.8 volts DC
at 4000 rpm, stator line current = 11 amp; R/R output 14.2 volts DC

On the SH-775
at 1200 rpm, stator line current = 6.7 amp; R/R output 13.0 volts DC
at 4000 rpm, stator line current = 6.8 amp; R/R output 14.2 volts DC

With the SH-775, turning off headlight, resulted in an immediate drop of stator line current to 3.5 amp at 1200 rpm.

The tests were done with a bike that had ran for good half hour first, so everything should be toasty warm. The stator used was stock suzuki- likely 30 years old.
Apparently, the SH-775 is limiting the current flow from stator to what the bike needs at the moment- and no more.

[eil]

Science!

Thanks for getting these numbers. Did switching off the headlamp at any point during the SH-232 test do anything? (I know your tests were intended to show the difference between the two R/Rs, but I like to get those kind of data points as a sanity check.)

[eil]

And since I might need a new R/R in the near future, where does one buy a SH-775? Didn't see any on eBay (just jewelry and motherboards) and Google wasn't a help either.

[Killer2600]

Science!

Thanks for getting these numbers. Did switching off the headlamp at any point during the SH-232 test do anything? (I know your tests were intended to show the difference between the two R/Rs, but I like to get those kind of data points as a sanity check.)

On a shunt type regulator switching off loads does nothing to the current coming from the stator. If you still have the bike wired as from the factory with a stator leg going to the left handlebar and then back down to the regulator turning off the headlight would drop that legs current to zero. But alas we aren't even testing the 3 legs independently.

[posplayr]

On a shunt type regulator switching off loads does nothing to the current coming from the stator. If you still have the bike wired as from the factory with a stator leg going to the left handlebar and then back down to the regulator turning off the headlight would drop that legs current to zero. But alas we aren't even testing the 3 legs independently.

Actually if Tom has his stator hooked right to the r/r with the factory switch removed and with the stator leg current he is doing he should see the following:
Shunt r/r when the load is reduced the excess power is shorted into the stator and stator current rises dramatically.
For series r/r when the load is reduced the stator current is also reduced in proportion to the load reduction.

I agree having the additional data point would be nice, it sounds like the measurement is certainly accurate enough to conclude the sh-775 is really a series type r/r and has improved low rpm output voltage.

Another question Tom are you measuring RMS per phase? I have to check but I think total current will be sqrt(3) times the rms leg current.
One additional set of tests are total dc current on the red r/r wire. You can compare to my results.

[btbarb]

sourcing

And since I might need a new R/R in the near future, where does one buy a SH-775? Didn't see any on eBay (just jewelry and motherboards) and Google wasn't a help either.

A specific post: Polaris part number 4012941

A whole thread: SH775 Sourcing

[posplayr]

I checked the data I previously measured. I'm pretty sure that the Current plotted is the line current time sqrt(3) . The SERIES current did seem to track the DC current measurements I made with the same device on the R/R (+) line.

At the minimum of 6.5 amps for the 1200 RPM SHUNT R/R that corresponds to 11.25 amps which is pretty close to what I usually quote as the idling current generated where the battery is not being charged (corresponding to 12.8 volts at the battery or the same as resting voltage).

At the high end 4000 RPM for the SHUNT we have
I_total=sqrt(3)*11 amps = 19 amps which is less than my graph at about 26 amps. 19/26= 73%

For the series at 4000 RPM you are measuring 6.8 amps where measured right about 15 amps so
I_total=sqrt(3)*6.8 amp = 11.77 amps compared to 15 amps
11.77/15= 78%

so it would appear that your meter is probably only 75% sensitive at 400 Hz (4K RPM) RPM and almost spot on at 120 Hz(1200 RPM).

[posplayr]

In the next chart in the pdf file, I have the plots of a Compufire (but un-regulating) R/R showing at 1K RPM a an RMS current flow in a single leg of 6.87 amps which matches your numbers pretty well. At 1500 RPM mine showed 9.2 amps so the current is coming up smartly.

My bike had an Electrosport stator installed so the fact it is a little higher at a lower RPM is not a surprise. That has always been the claim from Electrosport even through by the time your get to 4K RPM and the rotor magnetics saturate the difference in stator currents (compared to a stock or other replacement) is negligible.

This little boost of current at low RPM is why I still suggest the Electrosport stator when used in combination with a SERIES R/R. If you use the Electrosport stator with say a FET R/R (and especially a bit CC bike) you will burn it up.

[Killer2600]

Actually if Tom has his stator hooked right to the r/r with the factory switch removed and with the stator leg current he is doing he should see the following:
Shunt r/r when the load is reduced the excess power is shorted into the stator and stator current rises dramatically.
For series r/r when the load is reduced the stator current is also reduced in proportion to the load reduction.

I agree having the additional data point would be nice, it sounds like the measurement is certainly accurate enough to conclude the sh-775 is really a series type r/r and has improved low rpm output voltage.

Another question Tom are you measuring RMS per phase? I have to check but I think total current will be sqrt(3) times the rms leg current.
One additional set of tests are total dc current on the red r/r wire. You can compare to my results.

All that to illustrate the figures given in the first post? Is your profession that of a teacher by chance?

[posplayr]

All that to illustrate the figures given in the first post? Is your profession that of a teacher by chance?

No I just speed more effort verifying I'm correct or to see if there is something wrong. I don't like to go off 1/2 cocked making statements.

Something you are probably not aware of is that the SH-775 is the first mass produced Series R/R that is not coming from the aftermarket. There has not been any measurement to date posted here or anywhere else that I am aware. I have been asked to do measurement on the device but chose not to go through all the hassle of removing my soldered Compufire, installing a SH-775 and then restoring mine back to it's prior condition.

Tom admittedly was using the wrong meter for the measurement , and the result was to leave some uncertainty in the results. My contribution was to confirm that his data matched my previous data when you would expect his meter to be close, and I confirmed that his numbers made sense even if inaccurate when the RPM rose and you would not expect it to be accurate.

My conclusion in all this is the SH-775 is a quality Series R/R implementation and is the "new" preferred solution to R/R choices and that it should take the top honors as being the vastly superior price performance choice for an 3 Phase PM charging system (The Compufire is high quality just 2X the price).

Further, I was confirming my prior recommendations for a Electrosport stator with real data comparing a stock stator to a Electrosport.

So I'm sure you should be able to understand that in order to make such bold statements, that I would want to be absolutely sure in drawing these conclusion because there will be alot of people buying the SH-775 and we would not want to have lead them astray.

Does that make sense ?; As a seasoned engineer, that is how I have to conduct my self!

[tom203]

posplayr said...
"Actually if Tom has his stator hooked right to the r/r with the factory switch removed and with the stator leg current he is doing he should see the following:
Shunt r/r when the load is reduced the excess power is shorted into the stator and stator current rises dramatically."

Yeah, I wasn't interested in observing/proving this with the shunt SH-232, but I was curious to see how the SH-775 dealt with a sudden drop off in load. So far, I'm impressed and Shindengens have proven very reliable , but I have a backup shunt R/R installed in case there is a problem!

[posplayr]

posplayr said...
"Actually if Tom has his stator hooked right to the r/r with the factory switch removed and with the stator leg current he is doing he should see the following:
Shunt r/r when the load is reduced the excess power is shorted into the stator and stator current rises dramatically."

Yeah, I wasn't interested in observing/proving this with the shunt SH-232, but I was curious to see how the SH-775 dealt with a sudden drop off in load. So far, I'm impressed and Shindengens have proven very reliable , but I have a backup shunt R/R installed in case there is a problem!

If you did check that it would be quite convincing despite using your 60Hz current clamp

[tom203]

If you did check that it would be quite convincing despite using your 60Hz current clamp

I'll run the SH-775 for a while and get ambitious later! Unfortunately, my typical ride is 3 hours maximum and the Maine climate ain't hot enough to really test if there is a potential heat problem. It's rated 35 amps with decent airflow- far above what my stator can deliver.

[posplayr]

I'll run the SH-775 for a while and get ambitious later! Unfortunately, my typical ride is 3 hours maximum and the Maine climate ain't hot enough to really test if there is a potential heat problem. It's rated 35 amps with decent airflow- far above what my stator can deliver.

You have confirmed B.) below, just looking for confirmation of A.). No need to preheat before serving up results

A.)Shunt r/r when the load is reduced the excess power is shorted into the stator and stator current rises dramatically.
B.)For series r/r when the load is reduced the stator current is also reduced in proportion to the load reduction.

[Killer2600]

My conclusion in all this is the SH-775 is a quality Series R/R implementation and is the "new" preferred solution to R/R choices and that it should take the top honors as being the vastly superior price performance choice for an 3 Phase PM charging system (The Compufire is high quality just 2X the price).

Further, I was confirming my prior recommendations for a Electrosport stator with real data comparing a stock stator to a Electrosport.

So I'm sure you should be able to understand that in order to make such bold statements, that I would want to be absolutely sure in drawing these conclusion because there will be alot of people buying the SH-775 and we would not want to have lead them astray.

Ah, so your in sales

If you did check that it would be quite convincing despite using your 60Hz current clamp

I'd like to know what clamp tom is using and it's accuracy tolerances. You know just to verify whether his stator could possbly test different than yours or his clamp/meter indeed lacks in accuracy in the amount you indicate.

Just cuse, I like to be through and analytical when there's time to waste