How long are you intending on riding the thing at a time? You may find a dynamo isn't even necessary, as you can get LiPo packs quite cheaply that'll handle a 3A load for hours, and only weigh a couple of grams.
Senior Member
How long are you intending on riding the thing at a time? You may find a dynamo isn't even necessary, as you can get LiPo packs quite cheaply that'll handle a 3A load for hours, and only weigh a couple of grams.
Senior Member
You can buy drivers on ebay specifically for the T6. They have entire bike mounted T6 available for < $40. Here is an example: http://www.ebay.com/itm/1200-Lumens-...item257591132c
3 modes on the LED, driver is powered by 2X 18650s, and comes with a charger and mounting accessories. These things are nice because of the large reflector they are normally mounted in, and they are as bright as anyone's headlights. You can easily fluoresce street signs from 3 blocks away with it.
Not saying you should buy the cheap light in the link, but all the parts you would need to build a very nice one are readily available.
Senior Member
Hi,
As "Things" said, LiPo packs or 18650 batteries are a better choice. Why? simply because the friction generated by the dynamo will make you waste more energy than add only 200 grams of battery.
A deflector is absolutely necessary, as you need to focus the beam on the road. I have developed with a friend a system for a "night mountain bike competition in the woods", 4x18650 (4x 2500mAh) batteries, and 2 lights on the bike :
-One with a large angle deflector (40°) to light what is near the bike and
-The seconde light with small angle deflector (10°) for long-range beam.
One other important detail, LED needs to be cooled with a good heatsink. I have a flash light whith a XM-L T6 @3A, after 8-10 minuts, the whole flashlight becomes hot, really hot. So if you plan to run the LED for a long time (>10minuts), heatsink needs to be installed
For the driver, if you have a P3 in a drawer, you can try with that, but with heat losses depending of the voltage...
The other greeeaat solution; HID 35W light with a temp of 4300K, and a 11.1V 3S lipo battery with 5 Ah capacity. 1,5-2H of running time and bright as hell!!
Senior Member
found a good solution here
http://www.ebay.co.uk/itm/2511527376...84.m1423.l2649
Eat Sleep Lase Repeat
Senior Member
alright, resident LED weirdo here, and I have to chime in and correct some misconceptions =)
there is no way that LED will make 250 lumens at 3W. that's an outdated (well, compared to Cree's other offerings) emitter that will at 3W (~3.6Vf and 0.85A) put out 160 lumens.Originally Posted by absolom7691
with flashlights, the lower cost chinese sellers will lie about ratings more than those cheap pointers on ebay.
the ssc p7 is quite the dated emitter, however, this is a pretty decent bin so the output isn't bad. you're going to be losing ~30% in output comparing it to the most modern emitters, which isn't too much.
ultrafire isn't the brand of the emitter, it's the generic brand of many chinese companies that throw together flashlights. sometimes there are quality products sometimes there aren't.
ssc is the brand, "seoul semiconductor"
I haven't had a single one of those emitter turn out well. usually the phosphor is applied quite poorly and the output has strange colors. ratings.. well, I doubt that they are to par with their ratings but I have not bothered to measure one in an integrating sphere.
now we're getting somewhere. however, "t6" should not be part of the name of the emitter. it's a Cree XM-L. that's allTake a look at the "XM-L T6" led,
this is one of the most efficient LEDs on the market
http://www.ebay.com/itm/Top-Cree-Sin...item35bf8e080e. T6 is just the efficiency rating.
cree datasheets say it's more around 3.33V. at 3A that's almost a watt!
no! T6 is *not* an LED. it's a Cree XM-L which, in this case, isn't possible to get to 1200 lumens. yay chinese ratings!
sure, drivers are available, but all you need is a constant current driver.
that is all
Senior Member
I have the same torch just not Ultrafire brand.
It is bright - its the one that a non direct reflection from a picture frame left me with a 5 min after image of the sensor!
However, I will say one thing about all of these higher colour temps, HID included. That is sodium street lights seem to cancel them out.
I 1st noticed this with HID in my car. Around town, the light on the actual road surface seemed less than normal halogens, not that that mattered as it was brightly lit anyway. However, on dim sub surban streets it was much better and on country lanes, they were definitely much brighter than halogen. The lights themselves look bright to look at directly ie to oncoming vehicles, but the light on the road seems to get cancelled out by the street lamps.
I've also noticed the same with my torch. On a lit road it seems not very bright at all. On a unlit path or in back garden away from the sodium lamps, its many many order of brightness better than a conventional torch bulb.
Senior Member
lucky on a lit road you can see what's in front of you then and you don't need a bright light :-)
i need one for pitch black county roads
Eat Sleep Lase Repeat
Senior Member
Yeah exactly.
That's the conclusion I came to and I found HID lights great for dark roads.
I've also found the torch great for dark paths etc, it really is very very bright. I don't think you'll go far wrong with one of those on your bike.
Senior Member
beats last time where i gaffer taped a torch to my handle bar
Eat Sleep Lase Repeat
Junior Member
One of good headlamp is this one http://www.armytek.com/products/flas...ard-xm-l2.html
Posting Permissions
Reply With Quote