:-) White LED bulk-buy #2 progress update and a few ideas... [Long]greenspun.com : LUSENET : TimeBomb 2000 (Y2000) Preparation Forum : One Thread |
Greetings TB2K!
OddOne here again (as if the post style and subject weren't a giveaway) with more information on white LEDs in general and the second white-LED bulk buy in particular...
I'm posting this as a new thread as I'm going to let loose a bunch of information, distilled into categories. This post will thus be a touch long.
Quick jump to...
...The latest on White LED Bulk-Buy #2;
...Ideas for white LED products I (and you? let me know!) would love to see on the market;
...White-LED products I've found in my brief searches;
...A synopsis on the pros and cons of white LEDs as light sources;
...The required link to my white LED info website. Gotta have that. ;-)
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The latest on White LED Bulk-Buy #2
So you want to get a few white LEDs to tinker with, huh? My second shot at coordinating a bulk-buy directly from the manufacturer is underway. As of now (midnight US Central time, Wednesday, 04 August, 1999) I have a total of 435 LEDs listed, not including my part, which will depend upon how many I need to order for my own white-LED products. If that total, ncluding my part, tops 1,000, we'll each be able to purchase them at the $1.60-per-LED rate. If enough people get on the bandwagon to top 5,000 the price per LED drops to $1.20.
Nichia can drop-ship orders for up to 2,000 from their US offices, but anything larger gets shipped from Japan and that takes a couple weeks. (Also, Y2K and present global conditions being what they are, it might be hard to get these in the coming months, so gettign them now might be prudent.)
If you would like to get some of these or have questions about the bulk-buy, please let me know who you are and how many you want, and do so before August 15th. Check this post for the basics on how it works.
If you're interested in information regarding the terms of this bulk-buy, which mirrors the first one, or info on the first bulk-buy and how it went, try these posts (listed in reverse order, newest to oldest):
= W h i t e L E D B u l k - B u y # 2 =
The end of the first white-LED bulk-buy...
White LEDs, bulk-purchases, and a webpage of drivers...
White LEDS and buying in bulk. Pooling orders together...
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Ideas for white LED products I'd love to see come to market
So far what I have in my little brain is that I'd love to see ready-made flashlights sporting them that could be found at Small-Mart or other retailers instead of strictly mail-order. Barring that, a retrofit kit would be nice. I've hand-refitted a Mini MagLite (the 2-'AA' variety) to sport six LEDs and use four 6-volt batteries to fuel it, but it'd be a WHOLE lot easier to go buy something and convert the flashlight. If I didn't have years of electronics expertise to help out I'd be clueless about doing a conversion myself, and I suspect that the populace that lacks the requisite skills might like a simple conversion kit.
Think I should create and offer a kit? If so, for what lights in particular? Better still, what white-LED products would actually be useful to you? Post here or E-mail me.
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White LED Products I've found in my brief searches
This is FAR from complete, so if you find something let me know via post or E-mail and I'll check into it.
BTW... These links, like all the others I post, will appear in new broswer windows.
- Jade Mountain, Inc.
- Their LED lighting products - They have a LOT of LED-based products. I've built better in some cases and am humbled in others, but there's a lot here.
- Alternative Energy Engineering
- Their lighting products - They offer a handful of white-LED products, including a novel outdoor unit that looks like a lamp on a gooseneck.
- HDS Systems
- Their Action Light - This is the best LED flashlight design I've seen yet, but at $299 it'll truly cost you.
- OddOne's White LED Products
- PWM Driver and LED Arrays - I like these. But hey, what can I say, I'm biased. ;-)
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A synopsis on the pros and cons of white LEDs as light sources
This is a modified version of a post I made on TB2K and refined for possible inclusion on a future WRP if Cory wants to add it...
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With Y2K coming at the expected one-second-closer-every-second rate, those that are prepared to do so mentally are preparing for problems in a more physical sense. Some folks are going or will soon go off-grid, severing ties to the power grid in favor of electrical independence. As a result, white LEDs have become objects of interest from both the Y2K prep crowd and the off-grid folks for extremely low-power lighting. This article will discuss the pros and cons of white LEDs in lighting applications.
My information is derived form real-world use of my own white LEDs. I also have a website up that is devoted to white LEDs, their uses, and information. References to this website might appear in the article, so I'll give you the URL now:
OddOne's White LED Information: http://www.geocities.com/SiliconValley/Bay/4397/
First, the positives...
- White-LED flashlights have much longer usable life on a set of batteries than an equivalent incandescent bulb does. A LOT longer. Take good care of the LED-based flashlight and it'll serve you for a very long time, especially in the case of the aluminum-bodied ones that have such a durable casing. Just don't drown the light (read: Drop it in water) or trash it, and take care to check the batteries for leakage, etc.
- Dramatically increased toughness and impact resistance. (Ever had a flashlight bulb go south just from the light being dropped? I have. Trashing a bulb could be a very bad thing in a post-SHTF world, especially if that was your last bulb.) If each LED is properly mounted with a spacer to help take the shock, white LEDs can survive very severe drops. Spacers cost eight cents in single quantities from Mouser Electronics, and a 1/4" 4-40 (non-threaded) nylon spacer works very nicely as well and can be procured from small hardware stores for a dime or less each.
- The light tends to be more uniform in color balance, although this seems a bit odd at first since it looks to the eye to be bluish-white. Fewer dark spots as well. The light tends to taper off smoothly off-axis. Shadows are generally crisp and well-defined. Generally superior in terms of usability than incandescents. The light is visible for a LONG way off (three to five miles in my tests, in clear conditions at night) and reflective surfaces are visible for two miles or more with no source other than the LEDs. Street signs glow as if self-lit and car reflectors shine like they were lit up from within from a long way off.
- White-LED lights also use a lot less current than incandescent bulbs for the same luminous output at spot's center, stretching those batteries a lot farther. Use Lithium batteries with their ten-year shelf-life, or NiMh (NOT NiCd!!!!) rechargeables with a solar charger and your light could last longer than your possession of it. (Take that as a hint to safeguard it if TSHTF. Others may see it and want it. I planned to build a few small six-LED units for barter items.)
- With some creativity, you can build really small but really effective flashlights. One of my LED projects, a six-LED flashlight, is about 3" long and an inch in diameter. For my next white-LED trick I planned to build a three-LED light using a single 12-volt 23A or equiv. battery that would be an inch square and half an inch thick. A postage-stamp light. (Photos of the converted flashlight are posted on the White LED Information website, mentioned above.)
- The best advantage is that they are really easy to work with if you have a rudimentary understanding of electronics. Just keep the voltage below their maximum rated limit and they'll last for a LONG time. (Nichia's model # NSPW500BS white LED has a 100,000-hour rated lifetime, which is about 11 YEARS of continuous operation.)
Now, the negatives...
- White-LED lights need higher voltages than incandescent, although they stretch the power usage much farther. (My six-LED flashlight, which was converted to LED from incandescent, runs on two A544/PX28A/equiv. 6-volt alkaline batteries for about twenty hours total. The two batteries combined are almost the size of a single 'AA' battery. They are widely available at Radio Shack, Wal-Mart, K-Mart, etc.)
- White-LED lights need a certain number of LEDs to be effective. I'd not use less than three LEDs for reading at close ranges, and six LEDs can produce enough light to use for moving around with comfortable levels of visibility. Single LEDs on lithium watch batteries (such as those little keychain jobs like Photon lights) are good for very basic applications but that's about it. So, if you get a white LED flashlight, I'd strongly recommend getting one with six LEDs if you can find one. (Again, my six-LED flashlight, which was converted to LED from incandescent, is bright enough to read text by from several feet away.)
- White LEDs are visible for a long way off, which could be a problem if you are being pursued or need to approach a potential target or meal with stealth. They just seem to "jump out" to the eye, more so than typical incandescent flashlights. Their output has that cool fluorescent "feel" to the eye.
- For brighter light, you'll need to drive them with a high-efficiency driver to get the most out of your batteries. See my LED driver page for schematics for a basic timer-chip-driver that can push hundreds of LEDs at once with minimal drain. You'll need a decent level of hobbyist-type expertise with electronics to build one, but it'll be well worth it. My second LED driver prototype drives 36 white LEDs off eight 'AA' batteries. (The driver and LED arrays will soon be available for purchase; visit the White LED Information website for more details and pricing.) I've had the same batteries running it for a few months now. It consumes less than two watts of power at 12 volts at full brightness and you can see it for MILES...
- The LEDs themselves are static-sensitive. Small static charges can toast them. Proper handling precautions for anti-static semiconductors are required to prevent damage. They are also VERY intolerant to overvoltage conditions, so take steps to protect them against exceeding their maximum voltage rating.
- The biggest downside is cost: They are REALLY expensive. Nichia wants $ 1.60 EACH IN THOUSAND QUANTITIES for theirs! And that's direct from the manufacturer. If you'd like to buy plain LEDs to play with, wait for the next LED bulk-buy and get in on it; it'll save you a LOT of $ over buying them in small quantities from distributors. [ NOTE: Bulk-buy #2 is going on now, so get in on it a.s.a.p.! Start by E-mailing me with how many you want. Time's a' wastin', so hurry! ]
Hope all that info helps out everyone that wanted to know! If you would like more detailed info, want to buy or build a driver, or want to know a few sources for the lights, E-mail me. I have PLENTY of info.
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The required link to my white LED info website. Gotta have that.
Here's the URL: http://www.geocities.com/SiliconValley/Bay/4397/
I'm always looking for new info to post there, so if you have or find any, or have this killer LED project you made and want to share info on, or whatever relates, please drop me a note about it.
Well, this concludes this bout of long-windedness... If you have anything (constructive please, there's been too much hostility on the forum lately) to add that might be useful to the rest of us, please tack on your notes below. If you've got questions or concerns or info of interest that warrants a more direct discussion, drop me a note.
The ever crazed OddOne...
-- OddOne (mocklamer_1999@yahoo.com), August 04, 1999