Re: Busch & Mueller "Big Bang"---the ultimate bike light?

02-06-2007, 01:56 PM

On Feb 5, 5:56 pm, "Chalo" <[Only registered and activated users can see links. ]> wrote:
> > But then, IMHO I think the DiNotte lights, while nice, seem to have a
> > pretty high mark-up.
>
> Funny to me that the Li-ion lights command such a premium, when the
> cell voltage of Li-ion and the forward voltage of high-flux white LEDs
> are a nearly perfect match. I've made my own LED lights using 3 x
> NiMH cells in the same way-- no drive electronics, no driver losses,
> no additional packaging or extraneous points of failure. (And no low
> beam, of course.)

Chalo, what LED did you use?

- Frank Krygowski

02-06-2007, 02:36 PM

Frank wrote:
>
> Chalo wrote:
> >
> > I've made my own LED lights using 3 x
> > NiMH cells in the same way-- no drive electronics, no driver losses,
> > no additional packaging or extraneous points of failure. (And no low
> > beam, of course.)
>
> Chalo, what LED did you use?

I used Luxeon I emitters and Fraen collimating optics. I coupled them
well to efficient heatsinks and drove them at currents upwards of
500mA. This was when the Luxeon III was new and pricey, so I took the
cheap option. Next time, I'll use Luxeon K2 mounted on Star PCBs.
Those are more power efficient, brighter, cheaper, and easier to mount
than the ones I used for my lights.

See my reply to Will for more information.

Chalo

02-06-2007, 02:56 PM

Chalo wrote:
> Frank wrote:
>> Chalo wrote:
>>> I've made my own LED lights using 3 x
>>> NiMH cells in the same way-- no drive electronics, no driver losses,
>>> no additional packaging or extraneous points of failure. (And no low
>>> beam, of course.)
>> Chalo, what LED did you use?
>
> I used Luxeon I emitters and Fraen collimating optics. I coupled them
> well to efficient heatsinks and drove them at currents upwards of
> 500mA. This was when the Luxeon III was new and pricey, so I took the
> cheap option. Next time, I'll use Luxeon K2 mounted on Star PCBs.
> Those are more power efficient, brighter, cheaper, and easier to mount
> than the ones I used for my lights.
>
> See my reply to Will for more information.
>
> Chalo
>
Did you design the electronics and lay out a PCB?
You sound like a budding engineer.
I have been considering designing a super efficient switching power
supply to maintain constant output from either Alkalines at 1.5 volts or
NiMh at 1.2 volts each. Lithium is too expensive and NiCads are pretty
much history.
Bill Baka

02-07-2007, 12:15 AM

Bill Baka wrote:
>
> Did you design the electronics and lay out a PCB?

Nope. For controlled-current drive electronics, it's easier and
cheaper-- and much more compact-- to use something like this:
[Only registered and activated users can see links. ] (for 3V source)

Or this:
[Only registered and activated users can see links. ] (for 12V source)

> You sound like a budding engineer.

I'm a machinist and prototypist by trade. I just left a private space
program that I helped to start up in 2001.

> Lithium is too expensive

I've bought several 2400mAH lithium cell phone batteries for $5 to $6
including shipping. As long as they keep letting cell phones go out
of production, there will be a steady source of cheap lithiums and
chargers in useful sizes for LED bike lights.

Chalo

02-07-2007, 02:45 PM

Chalo wrote:
> Bill Baka wrote:
>> Did you design the electronics and lay out a PCB?
>
> Nope. For controlled-current drive electronics, it's easier and
> cheaper-- and much more compact-- to use something like this:
> [Only registered and activated users can see links. ] (for 3V source)
>
> Or this:
> [Only registered and activated users can see links. ] (for 12V source)

Cool site. I might not have even known about it but it looks like
somebody took the work out of my do it yourself project. Now I have one
more bookmark.
>
>> You sound like a budding engineer.
>
> I'm a machinist and prototypist by trade. I just left a private space
> program that I helped to start up in 2001.

Many "good" machinists are good at other stuff too. A good friend of
mine is a maintenance mechanic and is into electronics on the side.
>
>> Lithium is too expensive
>
> I've bought several 2400mAH lithium cell phone batteries for $5 to $6
> including shipping. As long as they keep letting cell phones go out
> of production, there will be a steady source of cheap lithiums and
> chargers in useful sizes for LED bike lights.

That may be due to the cell phone phenomena, but can work out for a
small bicycle, too. My Cateye may get Lithiumed.
Thanks, Chalo, that is good input.
Bill Baka
>
> Chalo
>