Jota Regulator replacement

Harry Lime said:
Christ! I'm fairly good at electronics, but I've just read (some of) that Aprilia thread over lunch.

I'm just going next door to kill myself  ;)
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Phew! I'm not the only one!

The psychology of some of those guys fascinates me! Especially the first one who basically preened his feathers, puffed his chest out and said 'pick holes in my wonderful theory you bastards'. Then he got upset when they did!
I believe the basic facts would have filled the back of a fag packet, rather than all that ego puffed Obfuscation.
 
Shall I distill what I've learnt
1. Original Nippondenso not really up to it and had to be wired through the light switch
2. Shindengen SH530- widely used throughout later Jap bikes, good cheap replacement and allows the lighting switch wiring to be dispensed with.
3.Later Shindengen FH010/012/020, marginally better again, will run slightly cooler, but probably not worth the extra bucks.
..............alright, I'll collect my coat.
 
No, No, No, you can't bale out this early, still got another 3 pages at least to go, haven't even touched on religion, beer, Aussie rules. ;)
 
Ppuxley said:
1. Original Nippondenso not really up to it and had to be wired through the light switch
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The original ND is just another 3-phase shunt regulator. It doesn't have to be wired through the light switch. If you don't want it wired that way, just wire the switched phase direct from alternator to RR the same as the other two phases. That way it's no different to the SH530.

You mention that the original ND is not up to the job. I'm just wondering where that comes from. Does their track record indicate that they're unreliable, or have a history of cooking themselves?

The reason I ask is that I've just fitted one to my RGS Mongrel (bypassing the headlight switch). I actually have a SH530 that I could have used. I chose to fit the ND purely on dimensional considerations. It's a bit smaller and fitted the space a little better. Can I expect it to self-destruct?

As for the RR thread on the Aprilia forum, I found it quite interesting. There's a lot of good info there (thanks for posting the link Drikko). The original poster who wrote the long diatribe appears to know what he's talking about, although he did make one minor slip-up when he mentioned "PMA field coil" (PMAs don't have field coils). I think his motive was genuinely to help people understand the issue rather than feather preening. It was a couple of follow-up posters that tried to up-stage him, but he handled it politely enough.

When trying to explain something to an audience who will have various levels of understanding, it's a fine balance between providing a coherent explanation and sounding like a tosser. Some will get it and appreciate it, some will be utterly confused, some will see it as showing off, others might nit-pick (that would be me  :D) and a few will feel patronised, take offence and try to discredit the original poster. You can't please everybody. Expressing another opinion, or correcting errors is fine, but it's not very helpful if it descends into a pissing contest.
 
Played with the idea of running all three wires from the alternator directly to the RR as opposed to having one running through the headlight switch. Found that just the two wires provided adequate charge to the battery so decided to leave things as designed. The company must have had good reason to do it that way, perhaps to reduce the load on the RR. Just a thought.
 
Cam, I am currently working in the Training Department at work, the most critical part of the job is to impart the most relevent information with the fewest words and somehow keep the assembled masses engaged and even entertained (no 'Death by Powerpoint').
So I know where you are coming from, but it is a lot more difficult than it looks.
For what it is worth 'imho' the Aprilia link is a prime example of how NOT to do it.

Terry, I'm with you.
I'm just glad whatever setup I have 'works' at the moment.
 
I agree Simon. On occasions I've had to give technical presentations. It's not an easy thing to do.

The bloke on the Aprilia forum had some good info there but readers had to filter it out of the accompanying dross. I probably wouldn't have done any better myself. I'm often guilty of over-explaining things.
 
Before I retired, I was a technical author, writing maintenance manuals for the destroyers being built in Adelaide, had to keep things simple for the 'skimmers'.
Most of the time was spent syphoning all the crap out of the OEM documentation.
 
The original ND is just another 3-phase shunt regulator. It doesn't have to be wired through the light switch. If you don't want it wired that way, just wire the switched phase direct from alternator to RR the same as the other two phases. That way it's no different to the SH530.
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I assume - but have never had the interest to check - that the OE unit can't handle the full output (less ignition draw) of the ND alternator.
 
Dellortoman said:
The original ND is just another 3-phase shunt regulator. It doesn't have to be wired through the light switch. If you don't want it wired that way, just wire the switched phase direct from alternator to RR the same as the other two phases. That way it's no different to the SH530.
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Cam
That was something I was trying to understand where this got discussed in another thread about the the switch shorting out.
What I couldn't understand was.... Why would Laverda go to the trouble (and expense) of running the third phase through the light switch if it was perfectly alright not to? I don't think that got answered or if it did I missed it.
Before I understood that the SH530 could do the job with all 3 phases directly connected, I proposed using a relay to switch in the third phase with the lights, at least you wouldn't be running the generator load through the switch.
Anyway that obviously became unnecessary when Red et al just said use the SH530.
 
G'day Pat

There are two ways to deal with excess output from the alternator.
1. Shunt it to earth via the RR (the normal situation)
2. Cut it off at the source (disconnect one or more alternator phases)

The switching of one phase partially does option #2. I suspect the only reason Laverda chose to switch the third phase with the lights is that it avoids the RR having to dump the excess charging current, thereby avoiding a bit of heat dissipation through the RR.

Perhaps the guys at the Laverda factory thought the ND RR's heat dissipation capacity was a bit marginal, and any unnecessary heat should be avoided. That's why I asked the question - are they prone to meltdowns?

My RGS Mongrel has bugger-all electrical loads other than ignition (all lights are LED and I don't expect to be using the horn for extended periods). So I guess we'll see how the RR copes with the full 3 phase alternator output going to a LiPo battery in the long term. Although I don't expect to be doing too many road miles on it. If it dies I'll just replace it with the SH530.

Perhaps I should connect the RR via extended leads and tuck it in my jacket on cold days  :D

Cam

 
At the risk of opening a can of worms..........I thought Lipos needed special balanced chargers to stop them bursting into flames, certainly the ones I use for motive power on RC Aircraft need that. I couldn't just hook them up to a normal regulated 12v supply.
Or is there a gizmo that regulates 12v automotive charging voltage specifically designed for charging Lipos?
 
The LiPo I bought was supplied specifically as a motorcycle battery. It didn't come with any special charging instructions. It's all a bit of an experiment for me.
Looks like I have two potential sources of spontneous combustion - the RR and the battery  :o
Perhaps I'd better carry a fire extinguisher.
 
SSB PowerSport Lithium Batteries are also one of the only Lithium Ion Batteries that can be charged using normal 12V car battery chargers / alternators.

Not sure if they are the only ones that will accept charge from a normal 12v alternator. Probably plenty of other brands do as well, just need to check their specs.
 
Dellortoman said:
Looks like I have two potential sources of spontneous combustion - the RR and the battery  :o
Perhaps I'd better carry a fire extinguisher.
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Full Automatic Fire Supression System required, I think.
You're the man for the job aren't you, Cam?

Dellortoman said:
Never mind that I spent about 10 years designing fire suppression systems for such companies.

Cam
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I've been reading up in different ignations and one of my long term questions has been how many AMP's do the coils draw? Haven't wired the bike with amp meter but from what I have read the closest answer has been 3A / coil

Anyone have anything better ?

Jugs_S
 
It's not a simple answer. Measuring it with an ammeter may be useful, but it depends how you do the test (statically or dynamically) which depends what you want to do with the measurement when you have it. Anyway, you don't need to measure it. You can work it out.

During the coil's dwell cycle (the period it's energised for) current will start at zero and ramp up to maximum at coil saturation when it fires. At which point the current drops to zero again, where it stays until the next cycle starts. You can estimate the maximum current by dividing voltage by coil resistance. So for a 3 Ohm coil in a 12 V system, its current will max out at about 4 Amps. 

Yes, I know that V=IR is only applies to DC circuits, and it's not that simple in reality because of coil inductance, blah, blah. But to give a full answer would take half a textbook. The above is a good enough approximation for primary wire sizing or battery selection.

If you're trying to figure out the load on the bike's electrical system (to size a battery for a total loss system for example), work on about 25% of V/R average current per coil.





 
Almost correct my friend but V=IR applies to AC circuits as well, just that R varies depending on the timing/phase blah de blah.......but at any one point in time capacitors and inductors are a resistor and V=IR applies, just that at the next point in time R is different.......

But yer totally right, measuring variable voltage circuits such as AC or switched circuits to coils is fraught with errors ie is RMS, peak, or just wrong...... you'll only get a vague idea with even expensive multimeters. An oscilloscope is the only answer :)



 
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