dx.com cree bike light max voltage ?

Ypedal

Ypedal

100 TW
Joined
Dec 27, 2006
Messages
12,534
Location
Moncton NB, Canada
Got a few of these :
http://dx.com/p/lzz-t6-cree-xm-l-t6-600lm-3-mode-white-bicycle-bike-light-headlamp-black-golden-4-x-18650-197245

received them just a moment ago.

page says 5.4~8.4 V

But it also says modes high/med/low and it's actually high/low/strobe . so the page is not exactly accurate..... :|

View attachment 2

dx-light2.JPG

dx-light3.JPG

Does anyone recognize the driver, and can anyone tell me what the max V In might be ? .. without going thru the add one cell at a time until it fails method. :oops:

edit : I just tested it on 2 cell , 8.2v and it works , very bright.. good throw.. will test it tonight outside and compare to my collection of flashlights and Lumenators.
 
I guess the answer is it depends what battery or DC converter you plan to run it off.
I have a 4x XML light that came with a similar 2S2P 18650 battery to yours, so I know it can take atleast 8.4v or a 2S lipo pack
During my tests I accidently powercycled my CC-CV power supply resetting it to its default 12v setting. It didnt blow straight away and lasted a minute before I cut the power. Presumably it would have gone pop during that time if it was going to, so I think it's probably OK. This would be ideal for me as I run my other lighting off a 12v 100w DC-DC converter so it'd be conventient to have

So the question is, can you afford the trial and error if you up the voltage and it goes pop ? :p
These things have gotten insanely cheap of late so I'm happy to push the boundaries a bit and if it does blow then I'll post about it here and chalk it up as a R&D data point :)
 
absolutely... I got 3 of them.. so 1 is a guineapig if nobody else knows.. I would hope it has a hvc to save itself but at this price.... who knows unless someone tries it. .. .I was hoping someone had already done the trial by fire... no biggie.. i'm off to the bike shop to pick up a new cruiser .. then the tests begin. :p
 
I run one of these http://www.ebay.com.au/itm/3x-CREE-XM-L-T6-LED-3800Lm-Bike-Bicycle-Light-Lamp-HeadLamp-HeadLight-SET-/150769605573?pt=AU_Cycling_New_&hash=item231a919bc5&_uhb=1
on a 3S lipo. Still running sweetly after several months.
I tried the 12volt lipo after the discussion on this thread, http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=43794
Hope this helps.
Cheers,
Matt.
 
How does it compare to the lumenator?

Ypedal said:
Got a few of these :
http://dx.com/p/lzz-t6-cree-xm-l-t6-600lm-3-mode-white-bicycle-bike-light-headlamp-black-golden-4-x-18650-197245

received them just a moment ago.

page says 5.4~8.4 V

But it also says modes high/med/low and it's actually high/low/strobe . so the page is not exactly accurate..... :|

View attachment 2

View attachment 1



Does anyone recognize the driver, and can anyone tell me what the max V In might be ? .. without going thru the add one cell at a time until it fails method. :oops:

edit : I just tested it on 2 cell , 8.2v and it works , very bright.. good throw.. will test it tonight outside and compare to my collection of flashlights and Lumenators.
Click to expand...
 
Too bad there aren't any reviews on the item. Usually on DealExtreme.com, I read the reviews and someone there has identified the innards.

But, I would go past 2S on these things with the 8.4V setting.

This driver will take 17V http://dx.com/p/5-mode-p7-led-driver-circuit-board-for-flashlight-dc-0-8-4-2v-106805
 
I run my Magicshine (same led I think) off of 12 v and it has lasted so far about 1.5 years.
otherDoc
I mostly run it as a daytime flasher.
 
How does it compare to the lumenator?
Click to expand...

I still have to do a camera comparison but i took a P7 flashlight, the Lumenator Gen.2 and the DX light outside last night and the Lumenator gives a smooth flood of light while the DX light is more of a spot/throw beam.. I also picked up a Lumen Meter not long ago so we can compare that as well. 8)

Looks like the emitter took a hit..
dx-light4.JPG
 
Not quite related, but there is a good discussion about using cheap DC-DC ebay converters with cheap Cree lights.
It works pretty well:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=46833

Mark.
 
Ypedal said:
the back side.. nothing looks charred.
Click to expand...

Looks like that driver that I linked to that will accept 17V DC input. But maybe your board is still OK and it is just the emitter that burnt up with all that juice. Have another one to test at a "safer" voltage? :D
 
Ypedal said:
well.. i can confirm one thing.... they do NOT have over-voltage protection :x .. and 10S( 36v ) will kill them !
Click to expand...
Damn man, of course they won't take 36v when they're designed to run on 8v :lol:
As others have said 12v is probably doable safely but 36 is just asking for trouble. DC-DC converters are cheaply and readily available if you're not running high voltage (ie over 60v)
I did note when testing my unit on 12v that it caused the emitters to glow very faintly, even when turned off. I gradually turned the voltage up from 9-12.5 and it caused them to come on softly. So it might be the case that higher voltage over ~11v is causing the driver to "leak" power straight through to the emitter. If this theory is correct then I imagine running it on around 15v would probably make it run fairly brightly and probably the max you could safely push. Though losing the functionality to turn it off and change modes is not worth the hassle IMO.

That's interesting that atleast part of the circuit is still working to give you the green LED after you putting 36v into it. The quickest test is to put your multimeter across the output of the driver and see if there anything there. In hindsight I guess lifting a leg off the LED and measuring the output from the driver would have been a safer bet. Though I would have assumed the driver would blow first, not the LED. But then I still wouldn't have put 36v into it :p
 
lmao.. it was not intentional ..

My dad dropped in and i was showing him the new bits, in a pre-coffee state i plugged the light into a 10S pack sitting on the bench instead of the 2S pack used the night before .. and without even pushing the ON button i got a quick and very short flash from the light and that was that.

and .. i just killed a 2nd one.. :lol: .. woops... i wanted to test the voltage at the emitter and managed to short out the aluminum heat sink with the probes.. again.. got one second worth of light and then zap... this was with the driver plugged to 2S but the light was off..

so i have one left.. best to test the lumen output and take those pictures before i fry it also lol..
 
Ypedal said:
lmao.. it was not intentional ..

My dad dropped in and i was showing him the new bits, in a pre-coffee state i plugged the light into a 10S pack sitting on the bench instead of the 2S pack used the night before .. and without even pushing the ON button i got a quick and very short flash from the light and that was that.

and .. i just killed a 2nd one.. :lol: .. woops... i wanted to test the voltage at the emitter and managed to short out the aluminum heat sink with the probes.. again.. got one second worth of light and then zap... this was with the driver plugged to 2S but the light was off..

so i have one left.. best to test the lumen output and take those pictures before i fry it also lol..
Click to expand...


hilarious
 
Well, the important spec on the LED (Cree XM-L T6) is that it will take 3A maximum http://www.cree.com/~/media/Files/C...d Modules/XLamp/Data and Binning/XLampXML.pdf.

There are a few really cheap ( < $5 ) adjustable voltage output DC-DC converters on DX.com which say they will supply 3A maximum, but I don't know if that means that there is a current limiter on them or just that at about 3A, they begin to poop out. I'd suggest getting one of those, connect an ammeter in series with the LED, and start dialing the voltage up until you get to 3A or thereabouts. Then, if it holds up, you can just wire it into your light circuit.

Cameron
 
Mine managed to take 14S Lipoly for a split second when the crappy LM2572HV dc:dc converter failed, blew out the control section so it just stayed on high (and this finally died) - those cheap 10W LED driver units will work on a pretty wide voltage range and run the 10W cree emitters just fine.
 
I have a very similar, if not identical light. You probably already know, but what I do is use an AC to USB adapter. I run that at my pack voltage input, and then output USB to the light. The 5V usb output is perfect for the light, and the $3 USB AC adapter is holding up well so far.
 
As we all love modifying cheap Chinese stuff here, I think this would be a good place to share this:

As these are close enough to a Magicshine 808 the diffusers should fit, various vendors sell a diffuser (search for macishine wide angle) which makes the hot spot around three times the width.

The other problem is light spill - These puppies are so bright that even the excess light around the hot spot can be very distracting for people coming the other way. Have a look at the beam shot for the Lumenator above and imagine coming the other way...

I had a bit of a play with one of mine and I think I've got that problem licked.

I'll start with a reference shot with the wide angle diffuser fitted (the light is about 500mm from the wall)

The spill light just about reaches the power board.

Add a simple cowl over the top (made from a spray can lid)

Definitely better, down to the centre punches.

What happens if I add a little electrical tape over the lens?

That's more like it.

So I head outside and hold the light sideways:

There is very little other light out there, 99% of what you see is from the magicshine, nice clean cutoff a little above the hot spot.

The finished product.


Cheap, simple and effective.
 
I have a solution for making lights suitable for oncoming traffic that I have yet to implement, but I know works since I have tested it with tape and a light.

Using a Cree light with a 'projector' lens (convex) rather than the usual reflector is similar to an HID headlight in the manner the light is projected to the road. With that in mind, we can mimic the behavior of a Bi-xenon headlamp to create a sharp cutoff at the horizon, only projecting lights below this line. This eliminates the glare towards drivers and puts a nice beam on the road.

To do this, we just need to tape off the bottom portion of the projector on the inside (the flat side internal to the light). This will only allow light to flow through the top side. And since a projector provides a flipped image, only the road is illuminated. Here is a diagram showing the theory:

hid_projector.jpg
 
On the basis that there are bucketfulls of conventional type lights against a handful of the type with these lens on dx.com, and prices are similar for both types I would assume popular choice goes to the regular type lens. If those other sort where any better they would sell, so they'd be more than a sideshow of sales items.
 
You must log in or register to reply here.

Similar threads

M
Request for advice on first build
Replies
6
Views
2,236
wturber
wturber
M
Got my new bike light... pretty disappointed...
2 3
Replies
61
Views
7,815
friendly1uk
friendly1uk
will_newton
  • Sticky
Keywin E-bike Lab Parameter Designer Software Manual-ver 1.2
2 3 4
Replies
99
Views
131,426
icbcChina
I
will_newton
Keywin E-bike Lab Parameter Designer Software Manual ver 1.2
Replies
4
Views
46,583
will_newton
will_newton
Back
Top