Ask MetaFilter questions tagged with LED

I'm tired of looking like a zombie in my house!

Zoyashka — Fri, 27 Nov 2009 16:41:51 -0800

Do you have any LED lightbulb recommendations? While researching LED bulbs, it seems there are some pretty nice ones out there and others that are tres terrible!

I would like bulbs that lean towards the traditional soft white, and in a variety of sizes/bases: GU10, PAR 16, PAR 20, and traditional screw in (floor lamps, ceiling fixtures).

Since these darn things are so expensive, I thought it'd be a good idea to pick the collective brain on which brands y'all recommend. Any assistance would be most appreciated!

Thanks!

Electronic Catan

jasondigitized — Fri, 04 Sep 2009 05:37:32 -0800

I want to create a customized Settlers of Catan board. For the purposes of this question, it could also be a custom Monopoly board. I want the pieces ( cities / hotels ) to light up when they are placed on the board. I know I would put LED's in each piece, but besides that, I am not sure if or how I could power up the LED's. I am not an electrical engineer, but magnets, watch batteries or inductive charging sound good to me. Help me make an awesome electronic board game!

Will LED light therapy help reverse all over sun damaged skin?

Anonymous — Mon, 24 Aug 2009 06:35:33 -0800

Old sun-damaged skin all over my body--is it tilting at windmills to consider light therapy? I am older than most of you--I am 58. I used to live in Florida and I tanned a lot during my young adult years. I had always heard that sun damage was "cumlative" but I didn't really see the effects of all that tanning until last year when all my exposed skin turned wrinkly. It is kind of shocking. I feel like I only can look good now if I am covered practically head to toe. My hands are the worst, but the problem is everywhere on all exposed skin. My skin looks about 10-15 years older than I am...and I am serious that it accelerated during last year. I don't have a lot of money, but if there was any value in trying light therapy I would. In attempting to do an online search for correcting sun damage there are mountains of products and "advice" that I can't begin to determine as scam or hype. How can I find out the success rate on something like this?
http://www.light-therapy-led.com/products.htm

Table Hockey in the dark?

DrAlbin — Wed, 05 Aug 2009 23:12:18 -0800

Table Hockey in the dark? I was cleaning out my workshop today and came across two identical devices packed in separate bags, that for the life of me (or Google), I can not figure out what they are. There isn’t a pic link, because it really didn’t get to me until I got to work, and now I have hours to ponder with no answers.

Please me-fites, you’re our only hope.

They were in a crate filled with cables (computer, stereo, TV (Direct TV + Cable)). One end there was a 6-8” piece of black plastic shaped like a hockey stick, But with uniform thickness throughout, near the bent end (think: on the top of the hockey stick blade) there are 2 clear LED’s protruding from the plastic. On the other end (think; hockey stick butt end) there was a wire (approx 4 ft long) terminating with a 3.5mm male stereo jack. (Headphone jack). I hooked it up to my phone, just to see if maybe the lights would light up when sound was played, to no avail.

Anyone have any ideas? Or proof that you are the Google ninja?

I'd like my floor lamps to be more attractive than lightbulbs lying on the floor.

pemberkins — Sun, 05 Jul 2009 21:32:17 -0800

Help me turn a blindingly bright LED tube into a functional and decorative floor lamp! I have two LED tubes (that look vaguely like these, are about three feet long, and have a couple feet of power cord at one end). I would love to turn these into floor lamps. They're pretty blinding on their own, so some sort of lamp shade is in order. So, my questions...

1) What kind of lamp shade should I use for these? I'm happy to buy one (preferably on the cheap) or make one, but it needs to cover the whole tube.

2) What can I use for a base to get the tubes to stand upright on the floor?

Thanks!

Why are LED signs so often seen broken?

LSK — Wed, 01 Jul 2009 20:32:53 -0800

Why are LED signs so often seen broken, at least in part?

E10... G14... 5V... 1W... Bingo!! Help me find this bulb.

SquidLips — Sat, 13 Jun 2009 10:17:34 -0800

Please help me find replacement light bulbs for my gadget. Some time ago I purchased two USB Lava Lamps from ThinkGeek. The lights have since burnt out and I cannot seem to find replacements.

The base lists the replacement bulbs: E10 G14 5V 1W. E10 is the base, 5V 1W are obvious, but I'm not sure what G14 is - not really relevant to the question but would be interesting to know. I've tried Radio Shack and local hardware stores with no luck. Googling gives me nothing but overseas sites that simply want you to mail them for more information, and a couple that offer online ordering but with a minimum of 1000 pieces... a little overkill for my needs.

Does anyone know where I could get a small supply of these online (from a domestic supplier), or for bonus points, someplace local to the Minneapolis area that carries them in-store?

Super Bonus Points if a source also supplies LED versions. I'm pretty sure they wouldn't work as well because the little sparklies are moved around by the heating quality of the light bulb, but I'd be interested in trying it nonetheless just to see the result.

Why did Glasgow need it?

Joe Beese — Sun, 07 Jun 2009 14:52:05 -0800

ScotFilter. Or LedZepFilter. Why did Glasgow need it? The first disc of the Led Zeppelin DVD is a record of their January 9, 1970 performance at the Royal Albert Hall. [A must-hear, btw.]

During the oldies-medley section of "How Many More Times", Plant - while encouraging a clap-a-long - says to the audience in a knowing tone: "You're going to do it [sex, it seems] in Birmingham and Cardiff. You're going to do it in Glasgow... and Glasgow needs it."

Why did Glasgow need it - whatever "it" was? Were Glaswegian coal workers suffering in a strike at the time? Did the city have a reputation for being tight-assed?

never meaning no harm

Antidisestablishmentarianist — Fri, 05 Jun 2009 09:34:43 -0800

What is the best auto racing simulation? I currently have no gaming equipment. After reading this comment, I decided to hone my driving skills with a simulator. Thing is, I have no equipment other than a mac laptop. In a way this is a bonus because I am not tied into any particular solution.

What I want: the most realistic competitive driving experience I can get. I don't care if I need a PC, a PSx, a Wii or ?? The only real reason I would really buy a gaming system, or a PC, would be for this. A great selection of real tracks would also be excellent, I plan to drive competitively on some midwestern circuits, and the preparation would be very helpful. Autocross and rally or rallycross tracks would be nice.

I plan to buy a specialized seat, a force feedback wheel, and a big TV.

So, what is the best driving simulator not taking tracks into account, and what is the best one if you want a wide array of real tracks? Availability of an online gaming experience would be an appreciated extra.

thanks in advance for what I know will be good advice.

Put a "star" on our "tree"!

siclik — Wed, 20 May 2009 11:24:12 -0800

Your suggestions for lighting the top of a 50 ft. sculpture being displayed at our state fair? I work for a manufacturing company that is manufacturing and donating a 50 foot tall metal sculpture, to be displayed at our state fair later this summer. I can't give away too much as we've agreed not to disclose any sensitive information yet, but picture a tall steel structure: 50 ft. tall, base has a 40 ft. diameter. The sculpture consists of three separate structures, coming together to form one larger structure (i know it's vague, but the "3" is important).

At first, we thought of putting different colored LEDs (right, white, blue) on the top of each of the smaller structures so they would come together at the top and form a "flame" of sorts.

Then I thought about doing something like this but thought it would look pretty silly in the day light and I'm not sure how well it would hold up to heavy winds 50 ft. up.

Now, we're considering mounting different colored laser lights (perhaps moving) at the top so people all around the fairgrounds can spot the sculpture.

Your thoughts? We're in Oregon and would really appreciate any input that you can provide. Specific suppliers in our area would be great, if possible.

BLACK DOG

crazylegs — Mon, 13 Apr 2009 16:55:45 -0800

Who did the big band version of Black Dog and where can I find it? Once, years ago, I heard a Big Band version of Led Zeppelin's song 'Black Dog'. I've been trying to find it on You Tube with no luck. Who did this version?

Any advice, particularly construction/fabrication related, for this lighting oriented site-specific installation?

carnival of animals — Wed, 18 Mar 2009 07:26:51 -0800

A couple of friends and I are organising a site-specific installation for the Smart Light Festival (flash w/ sound) to be held in Sydney from May 26 to June 14 this year. While I would appreciate any advice on bringing an installation like this to fruition, I was hoping specifically to get feedback on our plans to pre-fabricate the components (basically if they seem feasible, and if there are cheaper more efficient ways of going about it, how to use less energy, and especially how we could reuse or recycle the materials). I apologise for the very open-ended question, but as this is still in the concept phase I felt it wasn't appropriate for MeFi Projects. Here are some early renders and some background information on the festival, including the brief (PDF) we went by.

The festival will roughly coincide with the government's plans to phase out incandescent lightbulbs, and is designed to emphasize the importance of energy efficient lighting and the issue of light pollution. Our expression of interest was recently accepted and we are still in the planning phase, but hope to have sponsors on board and shop drawings complete for fabrication by the end of this month. The three of us are graduated architecture students.

What it is
A miniaturized abstraction of the Sydney CBD in the form of about 40 to 50 lanterns, ranging from about half a metre to 2 metres tall, with LED spotlights illuminating them from within. The lanterns correspond to city blocks; the colour of the lanterns to the level of energy consumed by each block, and the light pollution emitted.

Aim
We want the installation to be a thing of beauty, and an attraction. But once the visitor approaches, we want to invoke a certain sense of unease; to get them to question the source of the Sydney's night time beauty, and what it's costing the Earth. We hope to do this mainly through sound -- by creating a kind of ambient track using samples of buildings 'humming' (air conditioners, background noise of plumbing, etc.), which intensifies as the visitor approaches.

Site
If things go to plan, the installation will be in the forecourt of Customs House (google map). This is a very public space along Sydney Harbour, with a lot of through traffic. Our installation is one of many along the festival's 'light walk'.

There's also a lot of night lighting, but we will ask that as much as possible be turned off while the installation is on (about 5 to 11pm?). If possible we want to power the lights using car batteries which have been discarded with some juice left in them. (A lighting consultant we talked to suggested this.) We'll have mains power for speakers.

Lanterns
We want to pre-fabricate the lantern frames out of galvanized or painted mild steel, roughly in the shape of a box kite frame. We are in contact with a steel fabricator about this, but are wondering if there is a more environmentally friendly option, as we aren't sure what to do with the steel afterwards. (Our university might take it for their metal workshop, but not 40-50 lanterns worth!) The problem is that the lanterns need to be weatherproof, vandalproof, and relatively idiotproof (public liability) for the 3 weeks the festival. Same thing with the fabric 'sock' that will go over the frame. We're wondering if heavy-duty calico will do the trick?

Lights
A lighting consultant we talked to about this suggested that LED spotlights (shaped like a halogen uplight, but with a dozen or more LEDs as the light source) would be our best, most energy efficient option. The largest red lantern in the renders will hold a locked box containing the car batteries/other power source, LED controllers, and a laptop/ipod shuffle for the sound. We are not crystal clear on where the power outlets are, but were told they will be at the north end of the forecourt. As we may have to fence the installation (not our choice), running wire between lanterns shouldn't be a problem.

We're not of one mind about this, but we were also thinking about dangling/suspending individual LEDs closer to the surface of the lanterns, which briefly fade on and off at irregular, fairly infrequent intervals to simulate the turning on and off of lights, and to give the installation some movement visually. This might be over-complicating the already substantial challenge of wiring up all this lighting though.

(I was wondering if there might be a way to do this using something like LED throwies, but that's a lot of batteries to dispose of, and how to turn them on/off?)

Sponsorship
I shouldn't go into detail, but we are hoping to get donations in the form of materials from the manufacturers of any products we use, and may offer some space on the information panel on the largest red lantern, plus other exposure (such as on our website, any printed material) to other potential sponsors. Is there anything else we might do to attract sponsors, and give them value for the money they contribute? (We want to avoid 'branding' the lanterns as much as possible.)

Thanks!

How to build a replacement bulb for my projector.

Chamunks — Mon, 09 Mar 2009 11:52:33 -0800

I'm looking to buy a projector off a classifieds site but the only issue is it requires a new bulb upon purchase. Besides the obvious problems that could come of this like having no way to proove that it works. I was wondering how difficult it would be to replace the lamp with some High powered LED's. Things I have come up with that could pose issues:

Will the led's have a similar disbursal pattern as the bulb, since this is probably true how much could it effect it.

I'm considering some Cree XR-E Q5's from deal extreme (since they're cheap). I dont want to have to modify things on a massive scale i just want to come up with a different kind of bulb On the cheap.

Since these leds are only about 220 or so lumens AFAIK I will probably have to build a small array and use small mirrors to focus the light?

The site that i buy from, unless theres a better suggestion, will be here. They say that one of these leds produce 1000mA: 214 ~ 228lm (Lumens).

I need to make a total lumen "quota" of 1200 lumen (approx 6 leds), while still dissipating heat properly and not having to rebuild the whole projector...

NOTE: The projector that im looking at is a used well kept Hitachi pjtx-200

Any advice suggestions will be greatly appreciated.

Help me get started with basic electrical engineering!

gchucky — Sun, 01 Mar 2009 07:48:54 -0800

Help me get started with basic electrical engineering! For at least a year now, I've wanted to build a computer-controllable LED lattice of sorts. There are a handful of people out on the Internet that have done it, and there are relatively cheap parts available. The problem is that I haven't done any sort of electrical engineering before, so I really don't have any idea how resistors and transistors work, how to read electrical diagrams, how to mount and connect parts on a board, or things like that. No idea how the processors mount to the boards and what pins connect with what, and so on.

I'm a programmer by trade, and I think that I can pick this stuff up relatively quickly. So basically, I'm looking for a way to get started. Can anyone recommend some books, some websites, maybe a bunch of YouTube videos or something? Anything would be helpful, I think.

Can a grow light save my plants?

washburn — Mon, 16 Feb 2009 17:43:33 -0800

I'd like to hang a small screw-in type grow light (not a giant florescent tube) above my plants to help them out. Possible? I'm tired of watching my plants die! A few months ago, I moved into an apartment with north-facing windows, and my plants have been slowly languishing ever since (my plants are standard pothos and other hardy purchases from big chain-stores that have managed to survive). It occurred to me today that it might be an interesting idea to hang a light-bulb sized grow light (i.e. not a long florescent tube), perhaps with an aluminum hood, a few feet above my plants to supplement the indirect light from the window. Then I could set a timer to supply some extra light for a few hours of the day.

But this is sort of tricky, it turns out. I'm not sure about a number of things:

1) Are small screw-in (compact florescent or other) grow lights very good? They seem hard to find--chain stores usually carry only the big florescent ones that aren't too viable for the average living room. What about LED grow lights, or etc.? (This thread seems to indicate that plain-old normal florescent lighting (even from a compact bulb?) can be helpful to plants--is that true?)

2) If there are small grow lights that really work, what is the best source for these in terms of price (and quality)?

3) I'd like to hang a light maybe between 3 or 4 feet above the plants. Is that too high for it to provide significant benefit?

Hopefully I can get some advice about using a small grow light to help with growing normal foliage-type plants, rather than for the intense cultivation of tomatoes or, umm, other things.

Blingtastrophe!

mykescipark — Tue, 30 Dec 2008 23:04:39 -0800

Where in Los Angeles (or within an hour's driving distance) can I get a whooooooooooole bunch of LR41 batteries on last-minute notice? After a week and a half of already impressive screw-ups, my lovely online LED battery retailer has now sent me the wrong order for the third time. Today is, obviously, New Year's Eve. My costume requires approximately 300 LR41 batteries (or equivalent 1.5v miniature watch batteries such as AG3, 392, V3GA, RW87, G3, & SR41) - right now. Where can I go in L.A. to acquire such things in mass quantities?

Blinking LED novelties, retail, in Manhattan?

ellanea — Fri, 19 Dec 2008 06:09:44 -0800

Moderate to large quantities of blinking LED novelties, retail, in Manhattan? Mostly looking for things in the line of toys, balls, frisbees, or musical instruments, but apparel, jewelery, or barware would be OK in a pinch. Open Sunday a plus. Anyone been dazzled and/or annoyed walking into some ungoogleable hole-in-the-wall recently?

How is this color-changing LED array being driven?

jjjjjjjijjjjjjj — Tue, 18 Nov 2008 12:18:24 -0800

Electronics/LED Folks: I bought a few cheap, poorly-assembled LED color-changing orb-things and I'm pretty sure they're the coolest objects I have ever owned. I cracked 'em open, and damned if I know what is going on in there, but it looks simple/cheap as all hell. Help me figure it out, I'll post a build-log/parts list somewhere, and in short-order we can all be ass-deep in home-made, disarmingly sublime mood-lighting. So it's about the size of a tennis-ball, made of hard, milky plastic, and it cycles in a smooth, slow gradient between Red, Green, and Blue. (8-Second Video: Globe On, Globe Off). That's it. It doesn't look like much, and it's no danger of "blowing anyone away" or anything, but lemme tell you... it has absolutely transfixed the dozen or so people that've been to my house in the week I've owned it. I'm talkin' young, gadget-savvy folks who absolutely should know better. But we all love the stupid little thing.

Cracked it open, and inside are three 1.5V watch batteries, 3 LEDs (one each: red, green, blue), a resistor, a switch, a board, and a tiny mysterious shiny black spot.

I'd like to know what method they're using to cycle thru these colors.

This schematic represents my closest attempt at understanding the build. I'm sure you'll agree that there is at least one key element missing. It is my (unfounded, but) strong suspicion that this missing element is a very simple one (though I am very interested in answers, simple or otherwise).

MORE PICTURES:
* LED board, top
* LED board, bottom
* Switch/Battery assembly

There's a huge chance that I've unknowingly left out something of dire importance. I will try to clarify/photograph anything that is needed. I have the disassembled globe on my workbench as we speak... multimeter at the ready.

Another related question: Would there be any way to run a common anode high-power RGB LED star off of a configuration similar to what is being used in the globe above? I'm interested, very generally, in novel methods that can be used to drive RGB (or separate "R, G, and B") LEDs. I'm slowly getting the hang of PWM and microcontroller/Arduino-based methods, and I like what I've learned... but I've not come across much that deals with any other methods. Thanks to all.

How do I make a light-based alarm?

ocherdraco — Tue, 11 Nov 2008 15:00:57 -0800

I want to make an unobtrusive, light-based alarm to help me remember to take my pills. What do I need to do? I have a pill that I have to take once in the morning and once in the evening (but not at a particular time). I'd like to create a little alarm that can live on top of my dresser and light up twice a day to remind me to take it. Maybe with LEDs. It does not need to show the time (and in fact, I'd rather it didn't).

My searches online to figure out how to make one keep leading me to those expensive "gradual daylight" alarms, but that's not what I need. I'd like this to be as simple, and as small, as possible.

I am good at putting things together, but have no special skills with electronics.

Four Years of Dedicated Service

Monstrous Moonshine — Tue, 04 Nov 2008 15:29:27 -0800

Powerbook G4 (hardware?) woes, followed by death of battery LEDs. Firstly, excuse my style of description.

Yeah, I gave my laptop a tap to the side, which was followed by the Beach Ball. The charge was low (according to the battery LEDs), so I let the thing cool down and, after a little charging, I started the computer. Backlight came on, but the screen remained black. The fan quickly turned on; it was obvious to me the thing was working very hard at some futile task.

The computer only correctly started once. After, like, taking out the battery, three PMUs, blah blah... The thing stopped working again mid-trash-emptying. Earlier, I noticed the LEDs only work when the computer's plugged in. Now the LEDs are always dead. :| What?

I'm itching to crack the thing open and look for something loose. If you have some advice for key signs of easy fix/dead mother board/etc... lemme know.

CFL or LED?

drstein — Sun, 26 Oct 2008 11:25:55 -0800

Should we buy CFL or LED bulbs? We're in the process of replacing all of the bulbs in the house with more energy efficient lights and the concept of newer LED units has piqued our interest.

I have 5 can lights (using PAR bulbs) in the kitchen. One is on a separate switch, so I put a CFL in it but we've been less than thrilled with it so far. It's a Phillips bulb and literally takes 2 minutes to reach full brightness, which is annoying. The LED bulbs are bright instantly.

Have any of you folks purchased LED bulbs? Happy with the light output? Noticed any energy savings? There are many to choose from but since they're a bit more expensive, we want to make a decent choice. (The ones we've seen aren't as expensive as the one on ledwaves. Our local Wal-Mart actually has an entire aisle of CFL bulbs and LED bulbs.)

WSXGA+ LED, where art thou?

knave — Fri, 24 Oct 2008 19:16:08 -0800

LongshotFilter: Does anyone know if any 15.4" WSXGA+ panels with LED backlights are coming to market soon? As far as I can tell, no one is selling a 15.4" laptop with a WSXGA+ (1650x1080) LED-backlit screen (I'd love to be proven wrong!). I know it's unlikely, but does anyone out there have any idea if there's one in development or coming to market any time soon?

My current alternatives are basically 1440x900 LED or 1650x1080 CCFL, and I just can't make up my mind between the two.

I want to use my iPhone 3G's headphone jack to power an LED.

buzzbash — Sun, 19 Oct 2008 19:22:41 -0800

How can I use the iPhone 3G's headphone jack to power an LED? I've cut the speakers off from an old set of headphones, and now I want to wire the headphone jack and attached wires to a small, white LED bulb. I'm hoping to use the LED for illumination when I take macro close-up photos with the iPhone's built-in camera. I've already rigged up a macro lens to the camera, I just need the LED attached to the end of the headphone wires to illuminate the shots.

BTW, provided I get the headphone jack to power the LED, will volume control affect the LED's output in anyway?

Thanks!

Why can't I make this work? LED angst inside

puckish — Mon, 11 Aug 2008 23:54:52 -0800

Using a AA battery, two pieces of speaker wire and an LED, I am trying to make a simple circuit. I am meeting with complete failure. Help! I read books for a living. I do not program computers, wire electronics, play with oscilloscopes, or regularly work on projects that require modulating a radio frequency. That said, I'm bored for the summer and looking for new projects. Choice A is a neat LED nightlight, and so I find myself (once again) trying to teach myself simple electronics, and (once again) meeting with middling levels of success.

Basically, I'm trying to wire an LED to a battery. I am following this instructable. I am using a 1.5V AA battery and a 1.7V LED, using a lower-level power supply on the assumption that I don't yet have to learn how to wire a resister. I realize that there are TWO steps to this process - making the connections, and putting the LED in one of two orientations. And yet...my LED fails to light.

I realize that this is possibly the most basic question I can be asking here, but does anyone have thoughts on what I might be doing wrong? Pictures here

Scrolling LED message sign

msacheson — Tue, 22 Jul 2008 14:13:33 -0800

Where to buy electronic scrolling LED message sign ... in person? I can find what I *think* I want to buy online, but this is something I really want to see in person before ordering, so I know what I'm getting. I don't want to be like a bride on her wedding night who opens the big package and says, "Is that what I ordered?" you get the idea.

More info: I want a scrolling message sign to use in my 6th-grade math classroom. Put students' names on there for good achievements, birthdays, whatever. You know, for the kids.