The Great KB Regulator & Rectifier project.

[Warr]

.....is a generic DC/DC converter, much like the ones linked below that are a weeeeee bit cheaper:

http://www.jaycar.co.nz/productView....Max=&SUBCATID=

Allun great input to a problem way too many of us have encounted with todays bikes. If the manufactures had spent a few more $'s on proper alternators with slip rings and a controllable stator magnet we wouldnt be having this conversation! Sadly slip rings dont work so well in an oil-filled enviroment

But .. to my point... is the heart of the Jaycar box likely to be a LM317 or similar?

[notme]

Allun great input to a problem way too many of us have encounted with todays bikes. If the manufactures had spent a few more $'s on proper alternators with slip rings and a controllable stator magnet we wouldnt be having this conversation! Sadly slip rings dont work so well in an oil-filled enviroment

But .. to my point... is the heart of the Jaycar box likely to be a LM317 or similar?

The jaycar box is a rebranded Kemo unit, from the specs it has to be a simple switchmode unit.

There are heaps of similar things out there, the Jackoff unit was just the first google found for me that matched the specs i searched for :-)

If it was me, I'd probably go for something a bit higher in quality because automotive environments are harsh on electronics, but there's no need to go up to the extremes of that european unit that was mentioned....or to fit a reg at all if the application doesn't demand it!


You're right - if bikes had car style charging systems they would be a buttload more reliable, but in the interests of cost, weight, complexity you just don't see it very often.

[xwhatsit]

Woot! I'd like to see this microcontroller version -- at least I can understand software

Now with the Great KB Shunt Regulator v1.0 (GKBSR 1.0), forgive me, I'm not too bright -- upstream of this we build the little wee rectifier you described in the other thread. I've got three wires coming from my alternator, three phase. These are... combined? Just join the wires together or summat? And then the two `Off-page connectors' listed there, this being rectified sort-of-DC by now, the top one is the positive rectifier output and the bottom one is the negative rectifier output but we connect it straight to earth?

Sorry. I'm sure my questions reflect a profound lack of knowledge in these things

[CookMySock]

HTH your understanding

Yeah I mainly wanted to refer to the open-circuit voltage possibly being impractical, but after further reading I think I am wrong here. Even if it was 500V, many common SCRs will handle that. I still think his comment about hitting the limits of stator insulation are possibly an issue. Stators are designed to have their outputs clamped by the regulator, not run (almost) free at (near) their terminal voltage - the difference is several orders of magnitude. We shall see.

For the microcontroller operated version, further reading material here ;
http://services.eng.uts.edu.au/~venk...l/pe05_nc6.htm
edit:better link


The SCRs might be a bit noisy though, and the uC will have to follow the three stator outputs. Overkill ?

cheers,
Steve

[notme]

Overkill would be:

- Full wave synchronous rectifier bridge
- Complete microprocessor control, monitoring alternator, battery, and internals (temp, faults etc)
- Preemptive fault notification - e.g. an error code that tells you your battery is going to fail soon, not just that it has (which is still a step up from the systems we currently have!)
- Efficiency improvement and size reduction

As for the stator insulation issue - the manufacturer will design the alternator for worst case isolation i.e. the RR fails open and the bike is at full revs. It's part of compliance testing of any consumer product to think of and test for scenarios like that. It even gets to the point of stupidity at times - that's how anal the testing agencies are.

Many years ago my father was importing a line of electric lawnmowers into the country, and the testing agencies here had a complaint re the safety of the units. The complaint was that a person could potentially get a shock if the lawnmower's electric motor developed a short circuit that led to the shaft becoming live, because the blades are metal and bolted to the shaft.

Now if someone touches the blades, they will get a shock. Since the only real scenario where this could happen also involved the motor not stalling and blowing the fuse (hence removing the shock hazard), dad deduced that the mower had a built in safety feature that would stop people getting a shock - thier fingers would be cut off by the spinning blades!
Needless to say, the testers didn't go for it, and the mowers were allowed in to the country only if they had a plastic joiner between blade and motor shaft. So the mowers gained a reputation for throwing blades off when they hit the tiniest obstacle in the grass, and never sold well, and were not re imported after the initial shipment.

Point is, you can be sure that mr Honda or mr Suzuki was made to go through the same hoops and all possible scenarios, no matter how stupidly inconceivable, will have been thought out - so i doubt that the insulation on a stator is going to pose a problem.

[davereid]

Now with the Great KB Shunt Regulator v1.0 (GKBSR 1.0), forgive me, I'm not too bright -- upstream of this we build the little wee rectifier you described in the other thread. I've got three wires coming from my alternator, three phase. These are... combined? Just join the wires together or summat? And then the two `Off-page connectors' listed there, this being rectified sort-of-DC by now, the top one is the positive rectifier output and the bottom one is the negative rectifier output but we connect it straight to earth?

Yeppers...

If you built the rectifier in the other thread, and wired your alternator into it, then you could connect its output, into the GKBSR 1.0.

This would give you a working RR, for under $40, that would work on virtually any bike.

In electronics the "rule of 99" applies. That is, the first 1% of the design gives you 99% of the desired outcome.

GKBSR 1.0 needs to be built to test it. But its a 10mm bolt for a 6mm load. Its almost certain to be reliable and tough, as long as it is given a decent heatsink to get rid of the heat.

I'll tart up the schematic to show the rectifier, and outline the problems for constructors if I have some free time next week.

Then we will start on a micro based one.

[davereid]

...Stators are designed to have their outputs clamped by the regulator, not run (almost) free at (near) their terminal voltage - the difference is several orders of magnitude. We shall see...cheers,
Steve

Hi Steve,

You have made a good point.

Manufacturers have lots to consider when making a stator.

You could use really strong magnets, but a few turns of very thick wire.

A "short fat" stator.

It will have a flat output curve, delivering lots of amps, with output voltage really dependant on rpm as it has a low internal resistance. This would be great for direct lighting coils, as at idle you would get enough to get lights going, and at 5000 rpm, you would have everything well lit up. This kind of stator would be hard to regulate with a shunt regulator. It would just keep on moving electrons and melt !

Or you could make a "tall thin" stator. Lots of turns of a finer wire.
Higer terminal voltages allow battery charging at lower rpm. Higher internal resistances mean its easy to regulate with a shunt regulator. And high rpm is not a problem. But, most of the time you are wasting energy, as you have to regulate this beast as terminal voltage varys wildly with load as well as with rpm.

These can produce quite high terminal voltages at high rpm- no load. And often, its only the enamel paint that is your insulator !

[Warr]

A whole week and no word from the experts

A smart charge controller

All sounds good talking about it but is it possible.
At the moment any extra power is dissipated back into the stator coils by means of the SCR's firing and shorting out that phase.

The series regulator option is unworkable due to the power dissipation of the regulator.

The switched mode version sounds exciting .. where does the Pulse Width Modulated setup fit in ??

[davereid]

A whole week and no word from the experts

All sounds good talking about it but is it possible.
At the moment any extra power is dissipated back into the stator coils by means of the SCR's firing and shorting out that phase.

The series regulator option is unworkable due to the power dissipation of the regulator.

The switched mode version sounds exciting .. where does the Pulse Width Modulated setup fit in ??

I sort of felt there was no interest in this project as the thread was very quiet.

And maybe the shunt regulator meets everyones needs, as it quite capable of handling most bikes, indeed its all we ever used for the first 100 years of motorcyclng !

But if there is a real interest, I'll design a PWM system. My preference is using analog electronics, so anyone who wants to build the system need merely purchase the components, and no software needs to be obtained, and no micros programmed.

As I stated right at the beginning, it needs others to come on-board to build them and test them.

[pete376403]

Hey I'm keen - I've got a mid 80s Suzuki with a charging circuit that makes Lucas stuff look good.
I can't design electronics at all but I can follow circuits and build stuff.

Looking forward to a design I can make and try

[Warr]

Will put my hand up also to prototype designs with merit !!

[birdhandler]

count me in as well

[Ixion]

I'll build and test.

[Squiggles]

Ill give it a go as well

[Warr]

Here is a commercial switched mode system
http://www.hotbikeweb.com/tech/0608_...tem/index.html