5W... uh, 3W LED Headlights at less than $40 each

julesa

julesa

10 kW
Joined
Jun 23, 2008
Messages
950
So I'm putting together a couple headlights, one for my bike and one for my wife's.

I found two of these 5W LED MR-16s on eBay, $27.00 shipped for both. I got the cool white 12-degree spot. They should have great throw, and hopefully there's enough spill to make a couple nice headlights.
14712.jpg

http://cgi.ebay.com/ws/eBayISAPI.dl...c=closed_view_item&usedrule1=CrossSell_LogicX

The LED auction has this note : "10~17VDC power supplies are strongly recommended" I got a pair of these DC-DC converters for $22.50 shipped, also on eBay. They're 15V but can be adjusted down to 12V if needed.
405019.jpg

http://cgi.ebay.com/DC-DC-Converter...emQQptZLH_DefaultDomain_0?hash=item3351f99d30

I found a pair of MR-16 enclosures for $25 at my local auto parts store. Same ones available here at JC Whitney:
g13730gsw1.gif

http://www.jcwhitney.com/OPTRONICS-...TS/GP_2003730_N_111+10201+600027856_10101.jcw

Everything's in the mail right now, I'll report back on how well the LEDs work once I've got everything put together. I noticed all the MR16s at my local hardware store had flood reflectors - I think the narrowest beam was 45 degrees. So I also ordered a 12v 20W 15-degree spot halogen from eBay to compare with the LED. The shipping was more than twice what the bulb cost, but I wanted an apples-to-oranges comparison rather than apples-to-hamsters.

I guess it's not super efficient to convert to 15V and then convert again in the MR-16's driver circuit to whatever the LED likes, but at least this way if something doesn't work right I can just use 20W halogens, and maybe overvolt them a bit if they're not bright enough, or even upgrade the DC-DC converters to handle 55W halogens. Or buy three more pairs of enclosures, wire them in series, and have four lights on each bike. :twisted:
 
Should have known the price on those LED bulbs was too good to be true. They only draw about 3.8 watts. Still brighter than a 20w halogen at 12v but not much brighter.
 
12 degree is actually a pretty wide spread for a single LED, even a 5 watt one. You want throw, you need to go with something less than half of that ...you want real throw, get a 2 degree Carclo LED optic.
 
A laser would have even more throw. :) Personally, I think 12-15 degrees is about right for me. Being able to clearly see a pothole 100 feet off is just as important as seeing the one right in front of me.

I might try to find some real 5W LEDs with a 12-15 degree beam in an MR16 package and put two of them on each bike. But I'm probably going to have to pay $25-$30 each, just for the bulbs... :evil: Or maybe I'll just start over and do a DIY LED driver. grrr. :evil:
 
Looks like you will have it a bit less work with a light that already fits. I used the same chrome fixture and Tyco converter on my build. http://endless-sphere.com/forums/viewtopic.php?f=3&t=7716&start=15 Scroll down for the post. Think I wound up using a 6deg lens, as there was too much spill and not enough center light with the 12deg lens I tried. With 5W instead of the 3w as I used you may be fine. There are several programmable dc-dc converters that will give your new light all the functions of the regular bike lights including several dimming and flashing modes although thats another $20-$30. I will be waiting to see the outcome of your build.
 
Nice! Thanks for the link!
Hm. Maybe RLD was right, I guess I'll try the 6 degree lens if I can find one, though I can't imagine going down to 2 degrees. :) Thanks for the tips, guys.

Where did you buy your LEDs and lens from? Looks like Mouser has pretty good prices on the LEDs...

I'll probably build something like this instead of buying a fancy driver circuit:
http://www.instructables.com/id/Power-LED_s---simplest-light-with-constant-current/

:shock: 10W LEDs, $30... mmmmm maybe too much but... :twisted: :twisted: :twisted:
http://www.mouser.com/Search/Refine.aspx?Keyword=897-LZ420CW10

OTOH might be too much heat for the little wally world light fixture... :(
 
OK, I'm going to buy a couple SSC P7 10W LEDs (900 lumen :twisted: ). I'll have to figure out a way to get good thermal conductivity to the metal case, and probably under-drive them some, but at least I won't have to worry about them being bright enough.

EDIT: just occurred to me that I'm going to be wasting a lot of energy with one 10W at ~4V since my dc-dc won't put out much less than 12v... so I'd be better off with three 3W LEDs.
 
julesa said:
Nice! Thanks for the link!
Hm. Maybe RLD was right, I guess I'll try the 6 degree lens if I can find one, though I can't imagine going down to 2 degrees. :) Thanks for the tips, guys.

Where did you buy your LEDs and lens from? Looks like Mouser has pretty good prices on the LEDs...

I'll probably build something like this instead of buying a fancy driver circuit:
http://www.instructables.com/id/Power-LED_s---simplest-light-with-constant-current/

:shock: 10W LEDs, $30... mmmmm maybe too much but... :twisted: :twisted: :twisted:
http://www.mouser.com/Search/Refine.aspx?Keyword=897-LZ420CW10

OTOH might be too much heat for the little wally world light fixture... :(
Click to expand...


Sorry for the late reply I got some of the stuff here at Cutter.

http://www.cutter.com.au/categories.php

and more at

http://www.dealextreme.com

You can get the stars, they sell them bare, and solder on the LED yourself if you want.

more stuff for you. http://www.bikeled.org/
 
Is there any reason why a cheap $5 LED flashlight working off batteries wouldn't do?
 
$5 flashlight is going to be using some pretty low powered LEDs, it might be bright enough to see your feet in the woods at midnight on some cold dark stormy night, but seeing black cat 200 yards ahead of you at 30mph on that same night, it ain't going to cut it.

These Cree based LED lights replace 25 watt Automotive halogen driving lights bulb for bulb, and when clustered, replace HID lighting, while using just 3 watts per LED.
 
OK, if you are after that much light output.... how is the economics vs. HID?
 
Find out what LEDs these lights are using... and try them....

http://www.aircraftspruce.com/menus/el/landinglights_aeroled.html
 
I ended up buying six Cree XR-E R2s, and some three-lens collimators to make two light fixtures. After thinking about how I'm going to heatsink these guys I decided to learn something about lost-foam aluminum casting and just design my own fixtures. Total cost for both lights, and backyard casting tools, welding gloves, etc. should be a little over $100 by the time I'm done, not counting the wasted money trying to get a decent amount of light out of those cheap MR16 fixtures. I'll post pix when I'm done.

The LEDs are $6.32 each from here:
https://www.dealextreme.com/details.dx/sku.15943

I think with HID I'd be lucky to get two bike lights for $250, and I wouldn't have nearly as much fun. :twisted:
 
Cree 7090s are what I used on my first build also. Three is just enough with the 6 degree throw lens but two lights with three leds should be much better. Old CPU heatsinks work very well and they come in so many sizes and shapes. I think DX sells some for that purpose also. Looking forward to seeing your finished project.

lightpartswwires.jpg
 
Got my LEDs and lenses in the mail yesterday!

I'm building two bikes right now, one light for each. The Cree XR-E R2 WG LEDs should be able to take three watts each, so with three LEDs per light, 3W at somewhere around 85 lumen/watt, each light should produce a little less than 800 lumen. I decided to design my own fixtures 'cause I think they're going to get hot at 9W total. Even if I could bond a heatsink to the fixtures I bought earlier (the same ones you have), I don't know how thermally conductive the fixtures themselves are. So I'm designing my own and casting them in aluminum.
 
Mine get a bit more than luke warm but never hot. Have all the elctronics in the bag on the back of the bike open to air. Had to machine a couple of parts to get things just right in hte fixture. I be waiting for pics of the build and final product.
 
I suppose yall know about these:
http://www.ebikes.ca/lights/
What Justiin used to cross Canada.
 
Thanks Paul. I looked at those, but I don't think they'll be bright enough for my taste.
 
Here's what you need! :D
http://en.wikipedia.org/wiki/Carbide_lamp
:twisted: :mrgreen:
 
Got a Sylvania LED MR16 at the home-improvement store. 6 degree spread. Damn bright for 12W. [edit: 12V] White, not blue. >30 meter throw.
$16
mr16-1.jpg
Case runs about 110 degrees fahrenheit.

corporate propaganda (pdf):
http://www.sylvania.com/content/display.scfx?id=003692049
 
TylerDurden said:
Got a Sylvania LED MR16 at the home-improvement store. 6 degree spread. Damn bright for 12W. White, not blue. >30 meter throw.
$16
Click to expand...

:shock: :shock: :shock: 12W is a lot of LED at $16!

waitaminnit, the spec sheet says 2.8 w and < 30 lm... so I think those are probably about on par with the LED MR16s I bought earlier in this thread. Three cree LEDs in a custom fixture should be many times brighter.

Takes more time and money though, I still haven't been successful at casting anything in aluminum. My bubble gum, duct tape, and baling wire backyard foundry so far has only just barely cracked 1250 degrees F, it needs to get just a little hotter. Stupid duct tape keeps melting. :wink: j/k
 
While the lumen rating is low, the light is *very* focused. It is much better/brighter than the Sylvania 120V 3-led PAR20 unit with edison base I tried last week. I was lighting up the tops of trees with the new 12V bulb.

I would use it as a bike headlight. Two would be excellent.

I get them at a place called Menard's, a midwurst home-improvement center. They also carry Feit brand led products that are much weaker.
 
Cool, it would go well with the cheap MR16 fixtures linked earlier in this thread, anyway.
 
Oh.. my bad, I just realized I made the typo 12W in the earlier post. Should be 12V. sorry. :oops:

I have been testing one with a wall-adapter that puts out 15V dc, it seems to tolerate it ok. Don't know for how long, though.
 
You must log in or register to reply here.
Back
Top