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Thread: Easy Bridgelux DIY

  1. #1

    Party Easy Bridgelux DIY

    Wakefield has some pretty nice anodized Heat Sinks they've spec'd specifically for big Bridgelux emitters, although there's certainly nothing preventing you from using them with triple stars or cranked-up XM-L's. The best thing about radial heatsinks is they can work in either up or down orientations without taking a thermal penalty. Throw in a Ledil Brooke reflector, and you have a pretty darn easy DIY LED source with excellent color, output and distribution....and it actually looks pretty good as well. Just tuck the wires inside the fins of the heatsink, and it's pretty 'spiffy' and clean. I use a few of these in my apartment, although this is the older W802. I use a cool-white version as an inspection light, and it's probably the best portable light source I've ever used.

    Unfortunately Bridgelux is moving in a direction of higher voltage / low current which makes things a bit tricky now if you're planning on using more than a couple. Likely easier now just to plan on using a DC/DC driver on each emitter and running a 36 or 48volt DC driver at the front of everything. That way you could add or remove lights as you needed without affecting the others.

    Darn easy solution for DIY though. As a diabolical idea I always though it would be cool to hang something like this in large numbers from a high, dark ceiling using thin, black aircraft wire as both the support and power leads. You'd have a fairly bright, zero maintenance light source that would appear to be floating in the air.




  2. #2
    Flashaholic* FRITZHID's Avatar
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    Default Re: Easy Bridgelux DIY

    nice look and great idea Blasterman! TY for sharing!
    if your not wearing a #12 welding screen than it ain't bright enough! "Hand-Sun H.I.D." 55w & 75w(for sale), Rocky 3w LED, Stanley 109 35w mod'd, Maxa-Beam Gen II, 55w hid/100w incan Vector Twin, 400w MH long arc, 100w MH mid arc. Amondotech n30.

  3. #3

    Default Re: Easy Bridgelux DIY

    I remember when they posted the specs for the Wakefield sinks and didn't have product. I called and pestered them about it, then called wakefield... then Newark pulled the listing Some months later they actually had production and yes, they're as good as he says they are.

  4. #4

    Default Re: Easy Bridgelux DIY

    Very nice. Can I ask what bridgelux you are using?

  5. #5

    Default Re: Easy Bridgelux DIY

    Older W0802 - warm. New ones have a significant efficiency boost. From an engineering perspective I wish the wakefield sink was shorter and wider with fatter fins, but they might be trying to fit a form factor. It's good, but it's not perfect.

    You could easily throw a couple of these on a Mean Well 48D, or equivelant Inventronics power supply and have pretty slick dimming capabilities.

    Working on a artsy lamp using the same sink - stay tuned.

  6. #6
    Flashaholic* bshanahan14rulz's Avatar
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    Default Re: Easy Bridgelux DIY

    I've often wondered what the best way to drive these things is, from a DIY standpoint. I've got tons of switching PSUs from computers that I'd like to take advantage of, but they only spit out a maximum of 12V in stock form. I'm trying to economically retrofit my 500W halogen floorlamp to LED.

  7. #7
    Flashaholic* idleprocess's Avatar
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    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by bshanahan14rulz View Post
    I've often wondered what the best way to drive these things is, from a DIY standpoint. I've got tons of switching PSUs from computers that I'd like to take advantage of, but they only spit out a maximum of 12V in stock form. I'm trying to economically retrofit my 500W halogen floorlamp to LED.
    I remember getting 24V out of an ATX power supply once by using two independent 12V channels ... worked OK on a bench, perhaps not a great plan for pulling any serious amperage with. One can also attempt a similarly risky hack with a pair of power supplies.
    I apologize that this letter is so long; I did not have time to write a short letter

  8. #8

    Default Re: Easy Bridgelux DIY

    Contrary to naysayers, fixed voltage can be used directly with power LEDs provided (A) you have a stable supply with tested voltage (B) you are using emitters that match up their forward voltage in some respect to the supply. One advantage with fixed voltage is that parallel runs are much safer than with current regulated LED supplies.

    One issue with computer PSU's is that the 12volt rail tends to drop as the PSU is loaded although this problem is supposedly greatly negated in newer enthusiast supplies. Assuming you were using Cree XT-E whites, which push ~600mA at 3volts you could run them in a series of four and keep stacking more series as you needed. As long as your supply kept kicking out 12volts everything would be fine. However, if the supply dropped to 11.9 volts you'd be losing up to 1/3 of your current across the XT-E's, and hence 1/3 of your light. I've used variable voltage Mean Well's for fixed voltage builds, and they are rock solid regardless of load. I'd prefer to use a current regulated supply, but sometimes economics doesn't justify it. For instance, the newer Bridgelux have significantly higher forward voltages than the old, and it's pretty easy to combine a 20-30volt LED with a big NES series Mean Well supply, and get obscene lumen levels using a supply that costs less than $50.

    Bridgelux has some 12.5 volts emitters in their LS line, but you'd need a PSU that sustains 12.3volts or so to be worth the trouble. Otherwise, just look at Mean Well's LPC series because they are a lot of bang for the buck and current regulated.
    Last edited by blasterman; 05-29-2012 at 11:13 PM.

  9. #9

    Default Re: Easy Bridgelux DIY

    Thanks Blaster.
    What specs does that LED use?
    Im thinkin those sinks arent big enough for a HO bridgelux RS.
    I like the hanging light idea.

  10. #10
    Flashaholic* bshanahan14rulz's Avatar
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    Default Re: Easy Bridgelux DIY

    I'm actually thinking about running some arrays offa just plain jane fully rectified 120V mains with a cap to numb the flickering. I think the value of the cap may determine the final DC output, and its a give an take between getting the most voltage with messy voltage, or getting cleaner but lower voltage.

    Depending on how my self-teaching PSU design theory class goes (Read: google for info on designing PSUs), I may just go with a ready-made solution, because being able to dim the light would be extremely useful, rather than having to choose between off and 10000lm.

  11. #11
    Flashaholic* Steve K's Avatar
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    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by bshanahan14rulz View Post
    I'm actually thinking about running some arrays offa just plain jane fully rectified 120V mains with a cap to numb the flickering. I think the value of the cap may determine the final DC output, and its a give an take between getting the most voltage with messy voltage, or getting cleaner but lower voltage.
    Kinda fun to do, in some ways. The effective resistance of the LEDs works with the filter capacitance to form a RC filter, effectively. The resistance is low enough to require a pretty large capacitance. At the voltages being used, this can add up to a large, pricey capacitor (or multiple capacitors).
    I did something similar, at a low power level, for a backlight for a piece of stained glass. I set up a simple current regulator in each string of LEDs, and it worked out okay.
    http://www.flickr.com/photos/kurtsj0...7626354608597/
    The complexity was significant, but the circuit was simple. The biggest concern, honestly, are the potential failure modes. I did my best to make sure it would fail safely, but who knows what strange event I didn't anticipate?? There's something to be said for buying a nice commercially made, UL listed power supply.


    Quote Originally Posted by bshanahan14rulz View Post
    Depending on how my self-teaching PSU design theory class goes (Read: google for info on designing PSUs), I may just go with a ready-made solution, because being able to dim the light would be extremely useful, rather than having to choose between off and 10000lm.

    I still have the urge to build a proper switching power supply for a good LED light too. The complication is that an isolated power supply is safer due to the transformer blocking any direct contact with mains power in the event of the eventual failure. The transformers are usually custom devices, and not something you just buy from Digi-key. Transformer design is an interesting art, but takes time and skill to do. For lights that I can design to be very well insulated (electrically), an non-isolated buck converter is still appealing.

    Steve K.

  12. #12

    Default Re: Easy Bridgelux DIY

    The big Bridgelux emitters have '120volt / rectified circuit' written all over them. Still, with big DC supplies being so cheap I still prefer to use those, if not for the reduced 'deathfactor' alone

    For example, let's take a Mean Well SE-200-27, which you can find online for less than $40. That's a 200 watt PSU with an adjustment range from 26-32 volts. Combine it with a Bridgelux
    BXRA-56C1600-B-00 which drives at 30volts at 500mA and costs $17 for ~1700 lumens (stock). You could easily over-drive the emitter a bit and match or exceed 2000lumens. You could easily drive 10 of those bad boys with the SE-200, and still be over 100 lumens per watt. You could build the equivelant of two 4x54watt fluorescent fixtures with the LED rig and a total of ten emitters. DIY rocks, man.

  13. #13

    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by blasterman View Post
    The big Bridgelux emitters have '120volt / rectified circuit' written all over them. Still, with big DC supplies being so cheap I still prefer to use those, if not for the reduced 'deathfactor' alone

    For example, let's take a Mean Well SE-200-27, which you can find online for less than $40. That's a 200 watt PSU with an adjustment range from 26-32 volts. Combine it with a Bridgelux
    BXRA-56C1600-B-00 which drives at 30volts at 500mA and costs $17 for ~1700 lumens (stock). You could easily over-drive the emitter a bit and match or exceed 2000lumens. You could easily drive 10 of those bad boys with the SE-200, and still be over 100 lumens per watt. You could build the equivelant of two 4x54watt fluorescent fixtures with the LED rig and a total of ten emitters. DIY rocks, man.
    Tied together with a boost circuit so that each one is isolated separately, or are you talking about resisters in parallel ?

  14. #14

    Default Re: Easy Bridgelux DIY

    No Resistors - at all. The Mean Well has adjustable voltage, so trim it to where you want.

  15. #15

    Default Re: Easy Bridgelux DIY

    Can someone supply a link to the Wakefield under discussion at Newark or some place like that?

  16. #16

    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by fnj View Post
    Can someone supply a link to the Wakefield under discussion at Newark or some place like that?
    Rather than link, and run afoul- search for bridgelux. At the bottom of the screen after you pick a chip there will be a list of accessories or supported products, including the Wakefield heat sinks.

    You can also look under new products- mine was front page.

    Lastly, here is a PN for one: 23T0729

  17. #17

    Default Re: Easy Bridgelux DIY

    The Wakefields also list which specific Bridgelux emitter they are designed to handle so you don't have to do the math.

  18. #18

    Default Re: Easy Bridgelux DIY

    Those Wakefield heatsinks look pretty nice, but the price is way over my budget!

  19. #19

    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by Horsefeathers View Post
    Those Wakefield heatsinks look pretty nice, but the price is way over my budget!
    Seriously? They're about 5 to 20$, depending on size.

    How little were you looking to go?

  20. #20

    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by purduephotog View Post
    Seriously? They're about 5 to 20$, depending on size.

    How little were you looking to go?
    The price for the Bridgelux 4500lm emmiter heatsink is $36.51 at Newark. I don't recall the price for the Bridgelux BXRA-56C1600-B-00 heatsink that blasterman referred to but I think it is around $20.00. Maybe you're right, but the $36.50 caught me a bit by suprise.

  21. #21

    Default Re: Easy Bridgelux DIY

    For bigger arrays I use a large CPU heatsink and fan, or brick type heat sink from Heat Sink USA and drop a low RPM 80-120mm fan on it. The Wakefields are pricey, but I've contacted local aluminum mills and the price wouldn't be much better for shorts runs. Biggest hassle is 'lapping' the ends with extruded aluminum given I know I could design a more efficient cross section than the Wakefields.

  22. #22

    Default Re: Easy Bridgelux DIY

    Quote Originally Posted by blasterman View Post
    For bigger arrays I use a large CPU heatsink and fan, or brick type heat sink from Heat Sink USA and drop a low RPM 80-120mm fan on it. The Wakefields are pricey, but I've contacted local aluminum mills and the price wouldn't be much better for shorts runs. Biggest hassle is 'lapping' the ends with extruded aluminum given I know I could design a more efficient cross section than the Wakefields.
    Ahhh. I see the problem- that unit 19754-M-AB is listed for just under 19$ for me due to some contract pricing.
    Please accept my apologies, I didn't realize there was that much of a difference.

  23. #23

    Default Re: Easy Bridgelux DIY

    Is there a Wakefield heatsink for the Bridgelux ES series emitters? I am having trouble finding the model number for them.

    I was looking through Wakefield website and the heatsinks for 15 watt Bridgelux LED's is around $10.00--which is not that bad. If they have one for the ES series that would be great.

    One question I do have, is about running long (10-15 feet) wires from the power supply to the LED's. Is that going to be a problem? Or does the higher voltage DC handle the distance okay?

    purduephotog said: "Ahhh. I see the problem- that unit 19754-M-AB is listed for just under 19$ for me due to some contract pricing. Please accept my apologies, I didn't realize there was that much of a difference."

    No worries. At the < 2000 lumen led heatsinks I think the prices are reasonable at less than $11.00.

    Horsefeathers

  24. #24

    Default Re: Easy Bridgelux DIY

    Long wire runs require appropriate wire gauge to minimize voltage drop. If you are running a constant current driver, then the driver will adjust for the voltage drop accordingly. If you are running a constant voltage power supply, then selecting the right wire will be more important. If you have excessive voltage drop in the wires, you can adjust the current limiting resistor value (which you really should run, even if it's not necessary by the voltage drop of the emitter) to compensate.

  25. #25

    Default Re: Easy Bridgelux DIY

    One question I do have, is about running long (10-15 feet) wires from the power supply to the LED's. Is that going to be a problem? Or does the higher voltage DC handle the distance okay?
    18 AWG speaker wire, which I use for most of my longer runs, has a resistance of like .5 ohm per 100 feet. That alone is negligible Any runs shorter than that aren't even worth calculating.

    Even with current regulation some energy is lost due to heating of the wire, but Evil is correct.

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