[email protected] (Myra VanInwegen) wrote in message
news:<
[email protected]>...
>
[email protected] (Graham) wrote
> > If you had front and rear LED's powered by dynamo which were roughly as powerfull as
> > conventional dynamo lights. Surely this would need a much smaller and much lower drag dynamo
> > than the type needed to power conventional incandescent bulbs.
>
> As has been pointed out several times, white LEDs do not supply more light per watt than
> halogen bulbs.
>
> > Also the lights could run off re-chargable batteries, and when the batteries were low, the
> > dynamo could be used during daylight to re-charge batteries of the LED's and so eliminate the
> > problem of lights going out when stopped. And as LED's last almost infinitely it would eliminate
> > the risk of bulbs blowing and give almost infinite lighting.
>
> The rest of your post suggests that you're not very up on modern dynamo technology. First of all,
> I use a dynamo that never slips in the wet and has drag so low that I can't even feel it. It's a
> fairly inexpensive (35 Great Britian Pounds when ordered from Germany) Shimano hub dynamo.
> Building it into a wheel didn't cost anything as I build my own wheels... So the goal of having
> lower drag for the same brightness of lighting is already met.
>
> Second, if you get decent dynamo lamps, they don't go out when you stop. Busch & Mueller make
> front halogen lights with a white LED backup (powered by a capacitor that charges as you ride and
> keeps the LED going for about 5 mins) and the back light is already a red LED (with a capacitor to
> prove backup for 5 mins) to take advantage of the fact that LEDs produce red light far more
> efficiently than bulbs.
>
> Third, dynamo bulbs last a very long time. Red LEDs of course never burn out, and my front bulb
> has been going -- don't remember how long, at least a year, with quite a bit of use. So already a
> dynamo setup gives almost infinite lighting.
>
> Doesn't seem like there's much improvement to be made, at least not in the areas you were thinking
> of improving. There is improvement to be made in making dynamo systems brighter. I eagerly await a
> good 6W dynamo setup, which will double the lighting power you get with a 3W setup. There are
> standards being established for 6W setups, it's just a matter of time before people start to make
> really good systems that go with them.
>
> -Myra
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Ok point taken so what you're saying is (and excuse my ignorance about electronics) that red LED's
are more efficient than incandescent bulbs but white ones are not, because the light has to be
filltered to make it white. So if thats the case would it not be possible to make a dynamo which had
a LED rear light and a incandescent front light. Therfore you could put more power through the front
light. or has this already been done?.
By the way I do use a dynamo (cheap bottle type) and the bulbs especially the rear ones only seem to
last a few months, I have tried fitting a voltage regulator but it dosent seem to make much
difference.
Graham
