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Hardware

LED Book-Light Suggestions? 53

Posted by Cliff from the bleeding-edge-nightlights dept.
Dormous asks: "My wife and I are both night owls and avid readers, and usually one of us goes to bed before the other, hence the need for a small portable light source. We recently had a booklight, and somehow, my wife managed to shatter the light bulb all over the bed. Therefore, I want to find a booklight that uses an LED as the Light Source. Anybody got any ideas where I can find such a thing. I've already tried ThinkGeek."
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LED Book-Light Suggestions? More

LED Book-Light Suggestions?

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  • Umm... [houseofhackers.com]try this... [google.com]
  • Googling for booklight LED [google.co.uk] gives us, at #2:

    A booklight using an LED [yahoo.com]! Who'd have thought it?
    • This looks good, but personaly I find a white page like that very hard on the eyes, it would be nice with a red filter option. As others have stated, this helps night vision.

      Considering the recent breakage, something available now not in over two moths might be nice as well :-)

    • Low light reading over extended periods of time is bad for your eyes.

      Nothing says 'Biatch I can't sleep so I'ma read me a book' like a Halogen Torchiere Floor Lamp with a 300 watt Halogen bulb.

  • Simple homebrew solution (Score:5, Interesting)

    by Gordonjcp ( 186804 ) on Tuesday May 06, 2003 @07:03AM (#5889468) Homepage
    Most of these little clip-on booklights take two HP7 (AA) batteries, giving 3v. Remove the incandescent bulb (or bits of, in your case). Solder a high-brightness white LED in place of the incandescent bulb, and add a series resistor in there somewhere. You'll need to work out a suitable value - some LEDs may not need one at all.

    Another handy mod is to use a fairly bright red LED instead of white. This will make a light that's great for reading maps and star charts at night (for you navigators or astronomers) that won't mess with your dark adaption.
    • red + map = bad. Unless you get a map specificly for it, or use one that just happens to not have any red labels.
    • Mini maglights use a tiny bulb with straight parallel leads stuck in a pair of holes... just about the configuration of a standard LED. Buy a minimaglight, a 2.9something volt LED, and a pair of NiMH AA cells. I suggest the NiMH more for the lower voltage than for rechargeability. That lets you skip trying to fit in a resistor, which I've never managed. LEDs leads tend to be a hair skinnier than the ones on the lamps, so you will probably have to knurl them. I just lightly "bite" them, with vise-grips.
      • I wouldn't use NiMH for this application due to the batteries characteristics. NiMH lose somewhere around 5% of their charge every day just sitting there. High capacity NiCads work just fine and the voltage is lower yet. They are also cheaper. Using them in an application like this you shouldn't have a "memory effect" problem either. NiMH, like Li-ion, are great for high-drain devices.

        But I like your idea. That's the way to go!
      • Most 5mm LED's I've seen are 3.6 to 4.0 volt.
        But anyway, you'll be intrested in this.
        Take off that piece that says do not remove. It just pops off.
        Remove the batteries, the "switch" will fall out.
        Now, bend the + contact straight, and push it out the other side, or wiggle it off (you'll see what I'm talking about).
        Ok, now that piece that said do not remove, is simply held in by 2 posts. Break one off.
        Put the resistor in the post hole, coil one end around the bottom where the + contact used to be, solder/supe
      • Can't argue with 3 years of operation, also can't stop being curious about why this doesn't fry the LED.

        Does running 2.4 volts into an LED with a 2.9V forward drop put it into an operating range where current is in the desirable 20 mA range?

        Thanks,

        Fred
    • You can buy LEDs that screw into a standard bulb fitting.
      This [dansdata.com] webside is crammed with all kinds of useful information regarding LEDs and LED torches. Check it out.
    • ...and add a series resistor in there somewhere...

      Thus blowing away most of the power into heat. A cute current mirror would be better.
      • ...and add a series resistor in there somewhere...

        Thus blowing away most of the power into heat. A cute current mirror would be better.

        What do you mean, "most of the power"? You've calculated the fraction of power sent to the LED vs. the fraction dissipated in the resistor, right? Try supporting that assertion with your calculations.

        While you're at it, tell me where to find a current mirror which is 100% efficient.

      • After being modded to troll I did a little bit of reserach and found that LEDs are biased to ~3 V. Weird I thought, but then it has to be > than E_g for a visible wavelenght _and_ flood the bands a little bit to get some intensity. So given the V from a pair of AAA batteries there isn't much drop to get a good I going unless you use a small R and anyway LEDS should be I controlled anyway... hmm, guess a cheap'n cheerful solution would be a saturated FET... textbooks say they drop around 0.2 V which gives
    • Funny. I was going to suggest exactly the same thing. I did this about 2 years ago with my incandescent booklight -- $2.00 worth of parts at rat shack gave me a high-intensity red LED and a nice assortment of resistors. 10 minutes with the soldering iron and I had a nice bright red booklite.

      An added advantage of this conversion is that batteries last *MUCH* longer. Using the old incandescent bulb, my booklight went through a set of AA batteries a month. 2 years after switching to the LED, I haven't

  • Low tech solution. (Score:3, Insightful)

    by jotaeleemeese ( 303437 ) on Tuesday May 06, 2003 @07:05AM (#5889474) Homepage Journal
    If one of you is sleeping, the other reads elsewhere.

    At first signs of sleep depravation go to bed.

  • flylight (Score:3, Informative)

    by Hadlock ( 143607 ) on Tuesday May 06, 2003 @07:15AM (#5889495) Homepage Journal
    kensington flylight [vjcentral.com] + 5v wall wart + radioshack toggle switch + 10 min of soldering + epoxying the whole mess to the old booklight's clip

    =

    good early evening project, at the cost of about $20 (you can find flylights @ the apple store and compUSA), and cannibalizing the awnsering machine's wall wart.

  • Demotechs' Nightreader (Score:4, Informative)

    by SisterRay ( 86874 ) <subs=slashdot@rz.xs4all.nl> on Tuesday May 06, 2003 @07:24AM (#5889518) Homepage

    Demotech [demotech.org] ("Design for self-reliance") is currently working on the Nightreader [demotech.org].

    It's a small piece of reflecting foil, put together with two leds sticked in wood and a couple of batteries. The Nightreader is designed to be able to use two or three batteries of various sizes (whatever you have at hand) which have to little power to be used for something else.

  • A Headlamp might work (Score:2, Informative)

    by priceb ( 629287 )
    Petzl sells a small light weight led headlamp called the tikka. This might solve your problem.

  • Astronomers nightlight (Score:3, Informative)

    by laughing_badger ( 628416 ) on Tuesday May 06, 2003 @08:01AM (#5889626) Homepage
    Try the store at Sky and Telescope [skyandtelescope.com]. They sell LED flashlights with red leds. They are really restfull on the eyes when reading in bed and will not keep your partner awake. They are also small enough to prop-up somewhere to illuminate your book.

  • No luck at Think Geek? (Score:3, Informative)

    by skinfitz ( 564041 ) on Tuesday May 06, 2003 @08:08AM (#5889644) Journal
    Now try Google [google.com]

  • Uh... ThinkGeek does have these (Score:4, Informative)

    by highcaffeine ( 83298 ) on Tuesday May 06, 2003 @08:16AM (#5889669)
    Right Here [thinkgeek.com].

    I have two of these, bought through ThinkGeek, and they're great. Both of mine are still on the first set of batteries.

  • LED replacement bulb (Score:4, Informative)

    by Kent_Franken ( 92437 ) on Tuesday May 06, 2003 @08:21AM (#5889690) Homepage Journal
    You can convert any flashlight to LED. These guys [leddynamics.com] have a nifty little LED flashlight replacement bulb in all the normal colors. You can buy one here [ledsupply.com]
  • The ideal booklight does not constrain your position, allowing you to roll from side to side without changing the page illumination. This means it has to be either mounted on the book, or your head. If it is on the book, it inevitably interferes with turning the pages, and it adds weight. So my vote is for a headlamp.

    A headlamp should be not too bright, and provide uniform lighting across the page. This eliminates single LED lights.

    The Black Diamond Ion weighs less than 1 oz, and has an easily adjus

  • The Sam's club in Cary, NC has led lights that will clip to a book. I'm not terribly impressed with mine, ymmv.
  • I recently picked up a petzl tikka [rei.com] led headlamp. It is small, takes 3 triple-a batteries and is damn bright. It uses 3 white LEDs.

    Highly recommended.

    spreer
  • How about sex instead?

  • I have seen LED booklights at Sam's clubs in Houston. Two drawbacks when compared to the usual ones: no jack for external powerpack and they use expensive Lithium Ion batteries.

  • Lightwedge (Score:3, Informative)

    by linuxwrangler ( 582055 ) on Tuesday May 06, 2003 @10:11AM (#5890617)
    Since you want us to use Google for you, how about the top sponsored link: http://www.lightwedge.com/

    It's a flat LED illuminated sheet you lay on the page you are reading so the light doesn't shine on your partner.

    • Re:Lightwedge (Score:3, Interesting)

      by Anonymous Commando ( 6326 )
      You mean the LightWedge [thinkgeek.com] that he couldn't find on ThinkGeek?

      I don't normally bitch about Ask Slashdot... but for crying out loud, either this guy didn't actually look at Think Geek, or he must have missed the "Gadgets" [thinkgeek.com] section, where the LightWedge is a "Geek Pick".

  • Tektite [tek-tite.com] makes a whole line of LED flashlights and such. You might find something there.
  • I've used camping headlamps for reading in bed and other nocturnal residential navigation (raiding the fridge, letting the dog out, checking out noises...oh, no don't go there,) Anyway, I think they work better than book lights.

    REI has a cool one Petzl Zipka LED Headlamp [rei.com] that isn't big and bulky. It also has a lens kit [rei.com] that would address some night vision issues (red filter, etc.)

    I really like how small it is and I am tempted to get one myself to replace the ancient (circa 1990) clunker I have.
  • #1 result [ems.com] on Froogle [google.com]. (not to mention results #2, 3, and all the text ads).

    Once again [medicalmedia.com].
  • I'd Suggest the SPRACHT SP1022 Wherever Light UB.
    http://www.spracht.com/wherever-gear/whereve r -ligh ts.htm
    The Spracht light uses a flexible gooseneck led lamp like the unit described, but it terminates in a coaxial power connector. The connector connects to three adaptors:
    -A USB adaptor for laptops
    -A Cigarette Lighter adaptor for the car
    -A 3 AA battery pack with belt clip (Handy for repair work)
    If you need to run the unit with mains power it should be readily achived by rigging a gender bender
  • and somehow, my wife managed to shatter the light bulb all over the bed

    It may just be me, but I would probably take that as a hint... Maybe spend less time reading and more time with her? Just a thought.

  • Lightwedge (Score:3, Interesting)

    by jensend ( 71114 ) on Tuesday May 06, 2003 @12:06PM (#5891806)
    I can't get to sleep at night without reading, and this used to really bother my roommate (who has a hard time getting to sleep if it's not dark). I got a LightWedge [lightwedge.com] for Christmas, and it's helped a lot. It really doesn't noticeably illumine anything except the page. However, there are some caveats:

    1. You need to keep the batteries fresh and the surface really clean, or you'll hurt your eyes trying to read with too little light.
    2. It's inconvenient for books with a page surface larger than it or for books with extremely thin pages (I can't use it for my Bible because the very light pages stick to the wedge by static and end up creasing badly when I try to turn the page).
  • My wife and I have these. Lightweight, waterproof, three triple A batteries, dimmable with three power settings, and two blink settings. We got them from Campmore.com for around $30. Excellent buy.
  • I think I'd get one of these, they look well thought out:

    http://www.lumatec.com/UltraLife.htm [lumatec.com]
  • I need a booklight too, but I mostly read paperbacks and have had no luck finding a good one that is designed for the size/shape of a softcover book. I'm considering hot-gluing a keyring-size flashlight to my nose. Any better suggestions?
  • A quick Google for LED "reading light" revealed the following:

    LumaTech [ccrane.com] makes a nice one. 100 hours on 4 AAA's...YMMV. $19.95 from here [windandweather.com].

    LightWedge [wbthub.com] makes another, $34.95, available through Amazon. Customer reviews available. 100 hours/charge as well.

    There are more....Google before posting...seriously. Do your own dirty work.

    ><>
  • I know how to use google. I have googled so many iterations on "LED Book Light" that my LEDBOIGHT keys on my keyboard have broken. I asked this question because I thought some of you slashdotters might have some insight on the problem.

    To those that did have some insight, thank you.
  • You can light an LED from the mains if you wire another diode "back-to-front" in parallel and a 0.1uF capacitor in series. Ideally put a metal film resistor of a few hundred ohms in series unless the cap is X-rated. (This is to limit the current flow into the capacitor at switch-on; the voltage is above half max for about 2/3 of the time and a discharged capacitor is pretty much a short circuit. The fuse in the plug won't know the difference anyway.) As soon as the voltage gets above 2V the LED strikes,

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