AA Flashlight With Strobe and Zoom (DX90634).

Spousal unit's been asking for a front strobe to augment her 360 lumen
regular 3C light, so both can be on at the same time.

Unfortunately, most front bicycle-specific lights have gone to AAA
batteries, presumably to lower the weight and size, but the duration is
very poor. The few AA lights I found had a very flimsy plastic handlebar
mount that looked sure to break, and none were adjustable for
non-straight handlebars. I finally gave up on finding a decent front
bicycle-specific AA LED light and began looking at 2AA flashlights with
strobe mode and spot/flood zoom. There actually aren't a lot of these
available, in fact I only found one on DealExtreme. The other one is
actually the newer MiniMaglite 2AA LED (69 lumens) which doesn't work
well on NiMH batteries.

After about 7 weeks of waiting (ordered just before Chinese New Year),
the Small Sun ZY-A25 arrived at lighting central
http://www.dealextreme.com/p/small-sun-zy-a25-cree-q3-wc-3-mode-180-lumen-white-convex-lens-led-flashlight-1-x-123a-2-x-aa-90634.

Very nice strobe light. Only 180 lumens (claimed), but sufficient for a
strobe or a back-up front light (a quartz-halogen dynamo lamp at 3W (no
tail light) is around 20 lumens). The zoom (spot to flood) works very
well. A tiny amount of rattling of the batteries with Duracells if you
shake the light hard (since battery diameter can vary by 4/100ths of an
inch they need to make the barrel of sufficient diameter to accommodate
this), but a thin shim of paper eliminated rattling completely.

On 05/03/12 07:53, SMS wrote:

(a quartz-halogen dynamo lamp at 3W (no
tail light) is around 20 lumens).

According to http://en.wikipedia.org/wiki/Luminous_efficacy :

2.6 W tungsten glass halogen (5.2 V) produces 19.2 lm/W

ISTM that a quartz-halogen dynamo lamp should produce more like 60 lumens.

What source can you cite that claims only 20 lumens?

--
JS.

On 3/4/2012 3:03 PM, James wrote:
On 05/03/12 07:53, SMS wrote:

(a quartz-halogen dynamo lamp at 3W (no
tail light) is around 20 lumens).

According to http://en.wikipedia.org/wiki/Luminous_efficacy :

2.6 W tungsten glass halogen (5.2 V) produces 19.2 lm/W

ISTM that a quartz-halogen dynamo lamp should produce more like 60 lumens.

What source can you cite that claims only 20 lumens?


My mistake. It's actually 46 lumens for quartz-halogen 3V.

I was looking at a 6V 2.4W "plain" bulb rated at 12 lumens, and
calculating from there to 3W and throwing in some extra for Krypton.

http://www.servicelighting.com/EiKo-41314-24-watt-6-volt-G45-Miniature-Screw-Base-41314-Healthcare-Medical-Scientific-Miniature-Light-Bulb

It's 35 lumens for a 2.4V quartz-halogen.

http://www.reflectalite.com/halogenpage.html

James wrote:
:On 05/03/12 07:53, SMS wrote:

: (a quartz-halogen dynamo lamp at 3W (no
: tail light) is around 20 lumens).

:According to http://en.wikipedia.org/wiki/Luminous_efficacy :

:2.6 W tungsten glass halogen (5.2 V) produces 19.2 lm/W

:ISTM that a quartz-halogen dynamo lamp should produce more like 60 lumens.

:What source can you cite that claims only 20 lumens?

His ass, same as all his other numbers.

--
sig 50

https://www.google.com/search?tbm=is...0l0l0l0l l0l0

On Mar 4, 2:53*pm, SMS wrote:
Spousal unit's been asking for a front strobe to augment her 360 lumen
regular 3C light, so both can be on at the same time.

Unfortunately, most front bicycle-specific lights have gone to AAA
batteries, presumably to lower the weight and size, but the duration is
very poor.

100 hours, on average, is not poor. That's about four months of dark
commuting for me in the winter. 25c per month in batteries.

You should get back to worrying about more interesting things, like
how sloping top tubes violate natures aesthetic or something.

On 3/4/2012 12:53 PM, SMS wrote:

Very nice strobe light. Only 180 lumens (claimed), but sufficient for a
strobe or a back-up front light (a quartz-halogen dynamo lamp at 3W (no
tail light) is around 20 lumens). The zoom (spot to flood) works very
well. A tiny amount of rattling of the batteries with Duracells if you
shake the light hard (since battery diameter can vary by 4/100ths of an
inch they need to make the barrel of sufficient diameter to accommodate
this), but a thin shim of paper eliminated rattling completely.

Attached it this morning prior to the wife's morning commute. The strobe
is powerful enough that the strobe from the 3C isn't needed in the
daytime anymore, but at night both a strobe and a solid light are needed
at night for seeing and "being seen."

I used an all steel mount (conduit hangers) which is very secure and
allows adjustment in all axises. It uses a thumb screw to tighten/loosen
the clamp around the flashlight barrel, so it's not quite as quick as a
slide, strap, or lever, to remove it at work.
http://i43.tinypic.com/jphd1e.gif

On 3/5/2012 8:02 AM, landotter wrote:
On Mar 4, 2:53 pm, wrote:
Spousal unit's been asking for a front strobe to augment her 360 lumen
regular 3C light, so both can be on at the same time.

Unfortunately, most front bicycle-specific lights have gone to AAA
batteries, presumably to lower the weight and size, but the duration is
very poor.

100 hours, on average, is not poor.

If it's 100 hours on AAA batteries it's either a very low power light or
it's using a high quantity of AAA batteries. You choose. Don't know
where you got "on average" from, or which light you're talking about.

Look at a light like the Planet Bike Blaze 2W ($55) which is roughly
equivalent in lumens to the Small Sun ZY-A25 (146 claimed versus 180
claimed). It's rated at High/low/flashing run times of 5/12/18 hours
http://ecom1.planetbike.com/3045.html. That's with 2AA batteries. I
was going to just buy that light until I saw the mount on it. Since
it'll be used only on strobe, 18 hours would be sufficient.

Then look at an 80 lumen Cree® XR-E light that's powered by three AAA
batteries, i.e.
http://www.coleman.com/coleman/colemancom/detail.asp?product_id=4347-717
rated at 5 hours high/20 hours low (they don't rate flashing). At 160
lumens it would be half the battery life, 2.5 high/10 hours low.

After trying several 3xAAA powered lights with sufficient power, the 5
hour rating on that Coleman is just about right. Batteries needed to be
replaced every week or so for a commute where the headlight is on full
power at night, and on strobe in the morning.

There are some very low power AAA front (white) flashers on the market
(which can also be operated in non-strobe mode) which are not even
sufficient for a "being seen" light. These _will_ run for hundreds of
hours on a set of batteries.

You need to learn to look at the big picture, not just take one factor
out of context. If you're getting 100 hours out of a 2AAA or 3AAA
headlight at 60-80 lumens I'm sure everyone would love to know about
that light (or those batteries).

On 3/5/2012 8:38 AM, sms88 wrote:

You need to learn to look at the big picture, not just take one factor
out of context. If you're getting 100 hours out of a 2AAA or 3AAA
headlight at 60-80 lumens I'm sure everyone would love to know about
that light (or those batteries).

BTW, it may be instructive to compare battery capacities:

An AA Duracell battery is rated at 1.5V/2850mAH/4.275WH
An AAA Duracell battery is rated at 1.5V/1150mAH/1.725WH

Given that many LED front lights that run on AAA batteries use three
cells versus two cells for AA, the WH ratings would be 5.175WH for 3xAAA
and 8.55WH for 2xAA, so the two AA Duracell batteries provide about 65%
more power than three AAA Duracell batteries.

There is little or no cost difference between AA and AAA batteries even
though an AA battery has about 2.5x the capacity.

When it comes to NIMH cells, the AA batteries have an slightly greater
advantage. Not much effort has been put into maximizing the capacity of
AAA cells, i.e. an Eneloop AAA is 800mAH versus 2000mAH for AA.

An AA Eneloop battery is rated at 1.2V/2000mAH/2.40WH
An AAA Eneloop battery is rated at 1.2V/800mAH/0.96WH

Two AA Eneloop batteries have about 67% more capacity than three AAA
Eneloop batteries, while costing 33% less.