use series regulator rather than shunt regulator?

[Lonthemon]

I Know the honda reg/rec fix is effective and cheap; however, I want to install a series type regulator rather than a shunt regulator (to reduce the stator current). I believe a reduced stator current will increase the stators life, by allowing it to run cooler. Is using a series type regulator a good idea? why or why not?
I think it will allow my stator to last forever.

 

[ArttuH]

Well, generally speaking a series type regulator is a good idea. It would decrease average load on the stator which should result longer live for the stator.

But it's not so easy to make working series regulator for our bikes. Normal linear regulator isn't a good idea since the heat dissipation will be rather high, like 100W or even more. It would require very large heat sink. A shunt regulator dumps most of the extra power to the stator coils. That's why the regulator doesn't need large heat sink and why the stator have so hard life.

A switch mode regulator is another option. They have good efficiency so they doesn't produce much heat. But designing a switch mode regulator for a bike is quite demanding task. Mostly because input voltage have very large variation, from 15 V to over 100 V, depending on load and rpm.

I have designed some kind series regulator for my bike. It's kind of switch mode regulator but not normal style I have tested a prototype for several years and it seems to work pretty nice. Keeps the voltage where it should be and doesn't run too hot even it doesn't have any heat sink (except its aluminium box). I should finish the design and build "production version" but have been too busy and lazy for that.

 

[Steve]

The easiest way to reduce the stator current and, therefore, regulate the output, is to control the strength of the magnetic field.

That "wheel" has already been invented. It is called an "alternator". \\/

Yes, it's more efficient, produces less heat and has the potential for far more output, but it also takes a bit more room. Space constraints were critical in the design of our biikes, and so was simplicity. The smaller stator-and-rectifier/regulator design won out.


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[SPARKSS]

Well, generally speaking a series type regulator is a good idea. It would decrease average load on the stator which should result longer live for the stator.

But it's not so easy to make working series regulator for our bikes. Normal linear regulator isn't a good idea since the heat dissipation will be rather high, like 100W or even more. It would require very large heat sink. A shunt regulator dumps most of the extra power to the stator coils. That's why the regulator doesn't need large heat sink and why the stator have so hard life.

A switch mode regulator is another option. They have good efficiency so they doesn't produce much heat. But designing a switch mode regulator for a bike is quite demanding task. Mostly because input voltage have very large variation, from 15 V to over 100 V, depending on load and rpm.

I have designed some kind series regulator for my bike. It's kind of switch mode regulator but not normal style I have tested a prototype for several years and it seems to work pretty nice. Keeps the voltage where it should be and doesn't run too hot even it doesn't have any heat sink (except its aluminium box). I should finish the design and build "production version" but have been too busy and lazy for that.

Howdy Art. I've been toying with some thoughts on this idea as well. Suzuki actually had a bit of an idea with the 3 phase pair unswitched until the headlight was turned on. Shedding power dissipation OF the stator is the key which, as wound in many usual forms, uses too light a wire with too high a voltage output in my opinion.....the shunt an attempt to square-the-output low in order to develop a required average output power. I've rewound a few times (WYE) and have tried a parallel wound #19 winding at first and progressively have increased wire size to 18 and lesser turns (down to 21 or so per pole now in an attempt to keep input voltage closer to target). I suspect that a linear arrangement with heavier wire (16 or 14) and fewer turns would improve longetivity a great amount and might be a key to using a linear regulator. The OEM type windings would just translate the power dissipation into high voltage low current for both the stator and linear regulator which is what you know from your mentioning of 100W. Other than that, a switching arrangement shedding load from the alternator winding seems like the plan and averaging downwards (I suspect this may be what you've done). Any thoughts?

 

[SPARKSS]

The easiest way to reduce the stator current and, therefore, regulate the output, is to control the strength of the magnetic field.

That "wheel" has already been invented. It is called an "alternator". \\/

Yes, it's more efficient, produces less heat and has the potential for far more output, but it also takes a bit more room. Space constraints were critical in the design of our biikes, and so was simplicity. The smaller stator-and-rectifier/regulator design won out.


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If it produces AC it's an alternator. What you've described is a controlled field alternator. A nice design in this regards (except it's typically bulky) is the brushless controlled field where the rotating claw would be the only thing on the crank. (See Delco 30si for typical construction idea).

 

[Lonthemon]

Thanks for your input, I love the GSRESOURCES. I sure wish these bikes had automotive style alternators. Anyway, I'm thinking of using the following between the rectifier (rectifier only) and the battery: http://www.fourwinds-ii.com/v2/?c=flexcharge&i=006
It is advertised as quite efficient (meaning small heat loss?)
It is capable of charging batteries from many sources: outboard motors, permanent magnet wind generators. I don' think our 3-phase alternators are very much different.

 

[Steve]

If it produces AC it's an alternator.

Yeah, I know that, but if you happen to slip in a discussion and mention that we have 'alternators' on our bikes, somebody will chime in rather quickly and say "it's not an alternator, it's a STATOR".

Sad fact, but unfortunately, I have seen it happen.

I was just trying to keep it simple. 8-[

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[ArttuH]

Howdy Art. I've been toying with some thoughts on this idea as well. Suzuki actually had a bit of an idea with the 3 phase pair unswitched until the headlight was turned on. Shedding power dissipation OF the stator is the key which, as wound in many usual forms, uses too light a wire with too high a voltage output in my opinion.....the shunt an attempt to square-the-output low in order to develop a required average output power. I've rewound a few times (WYE) and have tried a parallel wound #19 winding at first and progressively have increased wire size to 18 and lesser turns (down to 21 or so per pole now in an attempt to keep input voltage closer to target). I suspect that a linear arrangement with heavier wire (16 or 14) and fewer turns would improve longetivity a great amount and might be a key to using a linear regulator. The OEM type windings would just translate the power dissipation into high voltage low current for both the stator and linear regulator which is what you know from your mentioning of 100W. Other than that, a switching arrangement shedding load from the alternator winding seems like the plan and averaging downwards (I suspect this may be what you've done). Any thoughts?

I think that re-winding the stator with heavier wire and fewer turns have some advantages. It changes output voltage closer to the target, just like you said. It also increases current output. On the other hand you will need more rpm to get full charging voltage out which may be a problem sometimes, for example in slow city traffic. Increased current capability may be too much for the original regulator too.

With re-winded stator a linear regulator might be a viable solution. But it would be balancing between low rpm output and heat production at higher rpm.

My regulator design is basically a controlled rectifier bridge. It passes pulses from the stator to the battery if battery voltage is below the target and blocks the pulses if the voltage is too high.

 

[SPARKSS]

I think that re-winding the stator with heavier wire and fewer turns have some advantages. It changes output voltage closer to the target, just like you said. It also increases current output. On the other hand you will need more rpm to get full charging voltage out which may be a problem sometimes, for example in slow city traffic. Increased current capability may be too much for the original regulator too.

With re-winded stator a linear regulator might be a viable solution. But it would be balancing between low rpm output and heat production at higher rpm.

My regulator design is basically a controlled rectifier bridge. It passes pulses from the stator to the battery if battery voltage is below the target and blocks the pulses if the voltage is too high.

I sure agree on the balancing act. With the rewind what I've had in mind was a net-zero effect on the battery at about 2000 rpm. I have rarely been caught in extended slow traffic and I guess even that has never happened at night (though once it happened in heavy rain.....and there I was kicking it along for an hour - I'd have worried about the engine more except for the rain !).

The controlled rectifier bridge is an idea I've been working on also. Basically was thinking of 3 SCR's in the line outputs......with 3 conventional diodes in the grounded side. Thinking of switching on average DC such that low voltage = early trigger.....high voltage late trigger. Then I got thinking fancy about providing error LED's based on high current w/low voltage and conversly high voltage with low current (reg failure or open battery/charging etc......protection for conventional or SS ignition or other SS modules)
If I find time might model this with Electronics Workbench.

 

[nabrams]

On Suzuki bikes I've seen there is a permanent magnet which rotates relative to the stator - the "rotor". The magnet's strength is not varied.
Many other bikes have a different approach: They use a coil-induced magnetic field rotor. The strength of the magnetic field is varied based on need - this reduces stress on the stator. The problem with this design is that these coil rotors fail quite often (happened to me twice on Honda bikes). The centrifugal force on the windings combined with heat eventually (typically after 10,000 - 20,000 miles of riding) causes the the coating on the windings to be worn away, shorting out the coil - resulting in zero or little magnetic field and a bike that won't charge. A quality field coil rotor is hard to come by.

 

[rustybronco]

Excuse my ignorance, it's been a long time since I was heavy into electronics,
but how about winding the three phases of the alternator with a heavier gauge wire for more current, then switching in one phase at a low rpm then out again at a higher rpm, then building it into your series regulator. less voltage to regulate, heat to dissipate, more current at low rpms, say @ 13.6-13.8v levels?

 

[ArttuH]

The controlled rectifier bridge is an idea I've been working on also. Basically was thinking of 3 SCR's in the line outputs......with 3 conventional diodes in the grounded side. Thinking of switching on average DC such that low voltage = early trigger.....high voltage late trigger. Then I got thinking fancy about providing error LED's based on high current w/low voltage and conversly high voltage with low current (reg failure or open battery/charging etc......protection for conventional or SS ignition or other SS modules)
If I find time might model this with Electronics Workbench.

If I remember correctly I have the SCRs in the ground side. This way they are easier to trigger. I have also a simple warning light control which warns about too low or too high voltage but I'm not sure if it's worth of added complexity. The most difficult thing in design is handling fault conditions, like short circuit or no load. Without load voltage from the stator can go up to 200 V and the regulator must withstand it.