Stator Papers clarification sought

[Anonymous]

I've been reading over the stator papers, and like the carb clean-up links, I find it all very helpful. However, I could use some additional explanations.

First:

There is some language in one paragraph that confuses me. Paragraph #11 (approximately; starts, "As Ritzo Muntinga . . .") states, "by design, the regulator/rectifier unit does not regulate the third phase!" Yet the last line of this paragraph reads as follows: "So we end up with a battery filled to the brim, and the regulator/rectifier unit trying to give the battery everything it has from the third phase."

I'm a little confued as to how the R/R is giving the battery anything from the 3rd phase if the R/R is not regulating the 3rd phase. Is the unregulated 3rd phase being sent directly to the battery? Is that what is meant by "everything . . . from the third phase?"

Second:

How is 3rd phase sunk "right away" via "a wily wiring scheme"? I take it from the diagram of the "typical charging system" that most (typical) 3rd phases are NOT sunk off right away by some wiring scheme. If so, what would our wily wired GSs' typical charging systems look like? I know that on the schematic for my 850L there is a phase that does not follow the other two phases directly to the R/R. I assume this is the 3rd phase. But if I recall correctly (I'm at work), that 3rd phase wanders off to a connection and then doubles back to the R/R.

Third (and finally, I think):

If my lights were off most of the time, as on bikes for the Japanese market, would this be a non-issue? What if a Japanese rider rides at night?is he/she frying the coils then? And then, am I to understand that since I (in the U.S.) always have my lights on, and since the 3rd phase is sunk "off . . . right away," are my coils always taking the heat, so to speak, of that 3rd phase? In other words, is a catastrophic stator coil meltdown eventually inevitable?

I guess that ought to cover it all for now. Thanks for any feedback/input.

[daveo]

the 3rd phase initially bypasses the RR and feeds the headlights as you saw in the schematics, this is fine as long as the lights are always on, after it feeds the lights any leftover V. is regulated via the return leg you noted, and on to the battery. This does not happen if the lights are not on and the voltage can't return, the 3rd phase can run unregulated and overheat, as it's not feeding anything. You can easily just regulate the 3rd phase by omitting the headlight switch loop, feeding the 3rd phase to the sw. return lead on RR., and feed the headlight from a fused source and/or relay to eliminate this

[focus frenzy]

first, the electrical system used on our bikes regulates output by shunting excess power to ground. (odd but it gets the job done)

prior to 1980 they had a headlight switch that alowed you to turn off the headlight, when the headlight was turned off the switch also disconected 1 leg of the stator as the excess power could over heat the regulator as it tried to cope with the extra 55-60 watts that normaly goes to the headlight.

the output of the third leg has to be regulated as the stator puts out over 60 volts AC (@5krpm) I have found plenty flaws with the stator pages, notice that there is no fault chart for the regulator section? they think it can never fail. (mine has)

besides the one leg can not provide all the power needed by the ignition and lights, two legs can't provide enough power to charge with the lights on.
some of the 80 and later model GS bikes still hade to loop for the third phase but it just went up and through a loop right back down to the regulator.

[humhead]

the output of the third leg has to be regulated as the stator puts out over 60 volts AC (@5krpm)

Remember that the output of the stator has to be rectified (changed from 60v AC to ~14v DC), but not necessarily regulated (Kept within a specified DC voltage range) The stock R/R Rectifies all 3 legs of the stator, but only regulates 2 of the 3 legs.

I have found plenty flaws with the stator pages, notice that there is no fault chart for the regulator section? they think it can never fail. (mine has)

The tests described in part C of the stator papers check both functions of the regulator/rectifier. It would have been clearer if the regulator tests were under a seperate heading.

[focus frenzy]

the output of the third leg has to be regulated as the stator puts out over 60 volts AC (@5krpm)

Remember that the output of the stator has to be rectified (changed from 60v AC to ~14v DC), but not necessarily regulated (Kept within a specified DC voltage range) The stock R/R Rectifies all 3 legs of the stator, but only regulates 2 of the 3 legs.

I have found plenty flaws with the stator pages, notice that there is no fault chart for the regulator section? they think it can never fail. (mine has)

The tests described in part C of the stator papers check both functions of the regulator/rectifier. It would have been clearer if the regulator tests were under a seperate heading.

the rectifier only rectifies the AC to DC, how does it cut the voltage down to 14 volts?

[humhead]

the rectifier only rectifies the AC to DC, how does it cut the voltage down to 14 volts?

I'm not sure how it's done. An educated guess would be that the diodes in the rectifier are chosen for their ability to produce a 14v dc output from a 60v ac input. I found this on the web:http://www.kpsec.freeuk.com/componen....htm#rectifier

Terry

[duaneage]

The regulator section uses a device called a zener diode. A zener diode is connected in reverse and allows voltage to flow after it has reached a certain point. The Zener diode then becomes a control device for teh regulator. The zener "tells" the output transistors of the regulator to switch on when the voltage goes below a certain point, say 12.9 volts (it depends on the circuit designers preference) and as soon as it rises to a point that is OK the transistors switch off.

In reality this should govern the output but the sensing for the actual load is more complicated than that. Current flow is sometimes sensed so that if too much is flowing the regulator will back off and then try again, keeps things calm and cool.

some circuits use a separate sensing wire that give + or - feedback to the regulator to see how it si doing. the Honda regulators use this method. this is more reliable and uses a circuit called a comparator to adjust quickly the voltage output.

A properly designed regulator will give the stator and rectifier diodes a high impedance ( or resistance) that reduces current flow and heat when charging is not needed ( like on the highway). Suzuki OEM regulators seem to send the output from the diodes straight to ground where it generates heat and allows current flow.

This is a simplistic explaination of how these RRs actually work, I hope you all get the general idea.

[focus frenzy]

AH! that clears things up!
I am aware of the odd dumping to ground method of regulating output, sounds strange but its simple and works and is reasonably reliable.
the Honda method of using a remote sensing wire is a better way of regulating output as it looks at what the battery/system is actually getting and adjusting for that.
with the Suzuki method of adjusting output you could have a bad connection in the wiring causing a voltage drop to the battery and the regulator wouldn't "see" it and adjust for it.

some newer class 8 trucks have switched to a remote sens wire so the alternator can adjust for the voltage at the battery instead of just regulating output. it allows them to charge the batteries faster.

you can have 14.5 volts at the alternator but once it gets all the way back to the batteries it is only 13.5 volts.
with the remote sensing wire it will turn up the output to 15.5 volts to compensate for the one volt drop in the wiring.

[humhead]

Thanks duaneage! Your explanation is a lot easier to understand than the one in the factory service manual.

Terry

[Anonymous]

You can easily just regulate the 3rd phase by omitting the headlight switch loop, feeding the 3rd phase to the sw. return lead on RR., and feed the headlight from a fused source and/or relay to eliminate this

Since I'm at work again, I assume the "3rd phase to the sw. return lead on the RR" is the wire returning from the headlight loop.

This looks like a good idea. I'll take a look at the bike and schematic and make a go at it. No offense to Electrex-USA, but this appears to be a less expensive modification. At least it is something for the short term. And if coil failure does happen, there's always a new one and RR that can be bought.

Also, this is proving to be a good "opportunity" to become familiar with the electronics and wiring of my 850. Two years back I resurrected my Yamaha XS650, and anyone who knows those bikes, knows their wiring, etc. In fact, I found that the official schematics (from multiple sources) were wrong on some key areas of the charging system. But hey, the previous owner couldn't figure this out, and I got the bike for free.

Thanks.

[duaneage]

Near the fusebox you should find the wires that come FROM the stator third lead and go TO the light switch. All you must do is unplug the connection going to the switch and reconnect it to the lead that goes to the RR.

This takes the switch out of the loop, I did this and when I am at a redlight for a while I turn off my headlight and it keeps the voltage way up in the 13.9 range even at idle. Before, this would remove a leg of the stator and I saw little improvement,

These bikes will actually run down the battery if idled long enough, if the battery is weak to begin with.

[focus frenzy]

when the electrex regulator was working I had a positive charge rate at idle the suzuki one just manages to keep up at idle.
the electrex regulator worked beutifully, it just didn't last long.