3 to 9W VPG … variable power generator

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ConRAD
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Re: 3 to 9W VPG … variable power generator

Postby ConRAD » 2 Mar 2018, 7:02am

SA_SA_SA wrote:... CJ made some suggestions to them to make it better (ie simpler to fit and lighter) and so a nice modern alternative to the FER spoke dynamo but it seems they have so far ignored them .... :(

... at least FER/AUFA could be disengaged when not in use !!

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Brucey
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Re: 3 to 9W VPG … variable power generator

Postby Brucey » 2 Mar 2018, 7:06am

ConRAD wrote:
Brucey wrote:...all manifest high drag into an open circuit load ...

... something must be wrong :shock:


I think it to do with eddy current losses, in laminations that are not made in very expensive material, but I'm not certain about that.

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SA_SA_SA
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Re: 3 to 9W VPG … variable power generator

Postby SA_SA_SA » 2 Mar 2018, 10:40pm

ConRAD wrote:... at least FER/AUFA could be disengaged when not in use !!

It needed to be, especially with the drag whemn turned by 16in wheel sokes!!
The eco sun is apparently very easy to spin off load, so similar to expensive hub dynamos in lack of worry about drag.
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ConRAD
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Re: 3 to 9W VPG … variable power generator

Postby ConRAD » 3 Mar 2018, 7:16am

SA_SA_SA wrote:... the eco sun is apparently very easy to spin off load ...

.. and would you be really ready to rely on it for a long time considering that, thanks to its gears ratio, it will likely to spin at about 20,000 rpm (twentythousand rpm!!) at 20 km/h ??

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SA_SA_SA
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Re: 3 to 9W VPG … variable power generator

Postby SA_SA_SA » 4 Mar 2018, 2:39pm

ConRAD wrote:.. and would you be really ready to rely on it for a long time considering that, thanks to its gears ratio, it will likely to spin at about 20,000 rpm (twentythousand rpm!!) at 20 km/h ??....

I am not a mechanical engineer: ask CJ.... Would you prefer a belt or two?
The two rubber belts in the FER2002 suited some peoples use . It seems fairer to consider the eco-sun as an alternative to the missed FER2002 than a hub dynamo...
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Brucey
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Re: 3 to 9W VPG … variable power generator

Postby Brucey » 4 Mar 2018, 3:10pm

In regular all-weather use, I would say the chances of something like that lasting very long would be vanishingly small.

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SA_SA_SA
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Re: 3 to 9W VPG … variable power generator

Postby SA_SA_SA » 4 Mar 2018, 7:31pm

Then perhaps CJ suggested a more robust alternative to the cogs.... :)
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ConRAD
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Re: 3 to 9W VPG … variable power generator

Postby ConRAD » 7 Mar 2018, 5:00pm

…. hard to believe it, but this is the new Neco Rove claimed to deliver 15W at 12 km/h from an 18poles/20magnets three-phase hub dynamo :? :? :?

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mercalia
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Re: 3 to 9W VPG … variable power generator

Postby mercalia » 7 Mar 2018, 5:06pm

if only I had supeman's legs :(

Brucey
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Re: 3 to 9W VPG … variable power generator

Postby Brucey » 7 Mar 2018, 5:39pm

looks as if it weighs a ton and 15W output is probably at the expense of 20-30W input, which would be similar to towing a well-loaded trailer.

Personally I'd rather find a way of not needing 15W of electricity on the bike....

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SA_SA_SA
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Re: 3 to 9W VPG … variable power generator

Postby SA_SA_SA » 8 Mar 2018, 8:13pm

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ConRAD
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Re: 3 to 9W VPG … variable power generator

Postby ConRAD » 16 Mar 2018, 7:50am

… so at the end it appears that somebody is finally moving on newer “3-phase” bicycle generators.
Just prototypes of course, though very interesting and well promising (IMO).

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Brucey
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Re: 3 to 9W VPG … variable power generator

Postby Brucey » 16 Mar 2018, 10:33am

the velogical design looks quite neat. I think that to be able to bung a cheap 'O' ring tyre on as needed is a good feature (you could carry spares at all times, e.g. beneath the headset top cap, and fit one in seconds if needed), and a large wheel running on the rim offers the possibility of low drag and quiet running (hurrah!). That the whole top cap shrouds the workings presumably means the chances of water getting into the bearings is reduced somewhat. I don't much like the bracket it mounts on though, it looks lousy.

Despite my basic disdain for such devices (which is as much due to failures of execution rather than conception), provided it was quiet with low drag, I would entertain such a device if it made about 2W or so, single phase, even if it was a bit flickery at low speeds. This would, with an efficient LED lightset, be enough to see and be seen by, (enough for occasional use anyway) and would promise an all-up weight (including lights) of less than 200g.

I would still use a hub dynamo on a bike that sees more regular night-time use, but I would not object to having such a device fitted onto pretty much any other road-going bike, outside of true racing machines. Basically anything with mudguards would probably get a lightset like that, if it did what I would hope for.

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ConRAD
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Re: 3 to 9W VPG … variable power generator

Postby ConRAD » 17 Mar 2018, 8:54pm

Worth to point out that:

1. It appears that, besides some other restrictions, Velogical (single or 3-phase doesn't matter) requires rims with perpendicular flanks

2. Above 3-phase approach requires, as a compulsory and integral part of the 3-phase overall solution, an AC to DC converter for the simple reason that it isn’t imaginable to have a 3-wires grid going around the bicycle … unless you’re well prepared to have a totally unbalanced and asymmetrical 3-phase distribution !!

3. About flickering: flickering is actually something related to single phase dynamos only since all the 3-phase versions mentioned above generate, as “final product”, a DC current considered that they MUST pass through some AC/DC whatsoever conversion prior of any possible utilization.
Generally speaking however, generated frequency is strictly related to spinning rate and number of poles, single phase or 3-phase making no difference at all. Now, considering that a common hub dynamo is 26/28 poles and generates something like 32-34 Hz at 20 km/h, and considering that Velogical is something like 12 poles/27mm driving wheel (i.e. 25 times smaller than a 28” wheel !!) it will likely to make something around 350-400 Hz at 20 km/h … so flickering at this point will be the last of the problems !
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nigelnightmare
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Re: 3 to 9W VPG … variable power generator

Postby nigelnightmare » 18 Jun 2018, 11:03pm

Consumerprice 3-Phase Generator (without charger)

Direct Marketing in the EU: € 200,00 / including sales taxes, plus shipping/PP; out of the EU: € 168,07 plus local taxes, shipping/PP

How much? :shock:

+ a cut off speed of 60kph! So you're belting down a steep hill at night and suddenly your lights go out..... :twisted: :roll:
I'm regularly topping that on my recumbent, downhill obviously. :mrgreen:

Edit.
Have just read that it's the charge circuits that cut off not the lighting.