Anyone converted a stock alternator (1100 or 1300) to High Capacity ?
- Thread starter aSTerix
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Never heard of anybody needing more power then a stock ST13. I think most are happy with the ST11 after the 40amp upgrade.
W0QNX
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Honda already makes a model like that called a Civic.
They have one available-- its called a gold wing
..yeah but it doesn't lane split very well
Not the new one though, its more like recaro seat on wheels rather than a posturepediaThey have one available-- its called a gold wing
If you really need more power, find a way to mount an automotive alternator somewhere.
I don't need more power, just more current at 12v so the Star to Delta is an easy fix. My query was regarding what RPM it got up to charging voltage. I can mitigate this by shifting the starter circuit to a separate lithium or capacitor (which I was planning anyway) and moving to LED (which I was also planning on doing)
Shawn K
Professional Cat Confuser
You just defined power.
Saying that you need "more current at 12v" is just another way of saying that you need more power.
I have to respectfully diagree. I am talking about 12v versus the normal 14.5 v ish
To save me trying to justify it,here is a link http://www.reuk.co.uk/wordpress/education/star-delta-wiring-for-alternators/
Basically alternators can be wound as Star or Delta (usually Star)
The basic difference between star and delta is that star generates a high voltage at a low current, and delta generates a low voltage at a high current. The total (no load) power generated is the same.
The air con unit works most efficiently at 10-12v not 14.5v but needs lots of Amps . If it ran efficiently at 14.5v then I could leave the alternator as Star
This is also a common mod (ie change to delta) on cars that have massively powerful sound systems, same deal they just need 12v but lots of current
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I'm no expert on the subject but I think where you're assuming something that's not correct is your voltage would drop by 1.732x so you'd be outputting about 8.4v instead of 14.5v.
Current goes up by 1.732, voltage down by same ratio. TANSTAAFL
Current goes up by 1.732, voltage down by same ratio. TANSTAAFL
There must be a way to calculate what you will get if you change your alternator from Star to Delta, but I would think you would need more measurements than you could easily make - unless you had some pretty sophisticated instrumentation. In addition to the voltage measurements at a given rpm, I think you would need # of turns of each coil, and magnetic field strength, maybe even coil wire size and resistance.
I'd think that the alternator would have to be designed for either way you wire it. If you pump more current through the coils (even at lower voltages), you will generate more heat leading to potential insulation failure and a burned out alternator. Fifty amps is a whale of a load.
I'd think that the alternator would have to be designed for either way you wire it. If you pump more current through the coils (even at lower voltages), you will generate more heat leading to potential insulation failure and a burned out alternator. Fifty amps is a whale of a load.
here is a system that works on 14.5v 
https://newatlas.com/entrosys-motorcycle-airconditioner-review/30585/
https://newatlas.com/entrosys-motorcycle-airconditioner-review/30585/
John OoSTerhuis
Life Is Good!
IIRC, some riders in the last Iron Butt ran personal air conditioner systems. I can see where that would be a nice farkle in Dubai.
You beat me to it. That's the wye-to-delta voltage ratio, the same reason you get 208v line-to-line on a 208Y/120v 3ph system.
To supply the desired voltage, a wye alternator would have to be rewound so each winding puts out the desired voltage in delta.
As for TANSTAAFL, there was a small audio company by that name here, where they designed and built constant-current amps.
They didn't last very long. The company, not the amps.
CC/CV amplifiers, a blast from the past, still use some at home. The basement and garage are fed by 70v systems. Not the best for bass accuracy, but easy to manage and wire distance is negligible. Sometimes the loss of quality is a trade-off for the use. Compromise is the name off the game. I don't go to the garage for high-quality tunes.
Power is power. If the A/C unit you want to use is so critical of voltage then they need to redesign it.
I imagine they already did.
12v is a nominal measurement. Everybody talks about something running at 12v and they are talking about running it in a vehicle and they already know that the voltage in a vehicle fluctuates. Nobody talks about transforming 14.4v on a standard alternator to 12v because then your battery would die from not being sufficiently charged. Battery 'nominal' voltage at rest is 12.6. If you want only 12v you need a new battery too.
This topic got me to wondering about alternator AC and DC voltages. I could probably google it, but does anybody know why the alternator puts out something like 70v AC on each phase just to generate a full wave rectified 14.5v DC?? I suspect it probably has something to do with 70v being supplied at no load, but drops a lot after a decent load is applied, dunno.
My apologies for not being clear. I have installed fixed-voltage audio distribution systems with multi-tap transformers for wattage selection, but that's not what I meant.
The amps I'm talking about were designed and built for use as high-fidelity audio amps, not for audio distribution.