Ideas for amber LEDs for tent lights?

[hank]

I take kids camping for several weeks during the summertime. This year I'd like to make some amber LED wide-area tent lights for evening use. Something like a string of good bright amber "Christmas Light" LEDs would suffice, if I could find them.

Last summer's trip --- for the first time --- they had typical blue-white LED flashlights as tent and evening reading lights, and some of the kids who'd used them didn't sleep well at all, which was quite a surprise. In past years we'd been using astronomy-red lights at night. So I want amber because it's bright enough for reading but doesn't contain the band that delays the start of the sleep cycle.

Simplest: I can get some 12v amber auto clearance lamps, or a handful of the pre-made 12v leds with resistors; we can use 12v rechargeable battery packs, one per tent, because we have a solar panel/dual deep cycle battery setup for recharging smaller batteries routinely

I don't need anything as bright as the Lamina Light Engine for this use, it'd be way too bright for evening tent lighting.

I've got a month or two to play with building something better. If the new Goob-tube (spelling??) comes out by then, running off 123 cells, it might do, but probably will be expensive.

So -- a handful of fairly bright amber LEDs, a rechargeable battery or battery pack, good for a few hours of lighting up a square yard or so of tent area enough to read in.

Ideas welcome.

 

[Lighthouse one]

BestHongkong has 1 watt amber LED's for $3.00 each....you'll have to figure out the mounting yourself. I've overdriven their 1 watt Led's at 700 ma with great results and a good heatsink. So they produce great area light without a reflector. You can use a 1 to 1.5 ohm resistor to cut their ma to around 400 with 3 c-cell batteries. The resistors are hard to locate quickly, so that could be a problem. 2 or 3 in series might work just right without a resistor! Or is that parallel?

 

[Lighthouse one]

Oh, I just remembered that Target has these great inside the tent lights for $3 for 2 lights. They use a single tiny led with a coin cell. Have 170 hour run time and are just perfect for sleeping...not bright enough to read though! Brinkmann Model 809- 3042-1. I use them in my tent.

 

[cratz2]

Someone did a frankenstein green or cyan light a couple years ago that was very area light oriented. I'll see if I can find the thread.

I'd be tempted to put 3 or 6 amber Luxes on a low power board. I'd go three if you just wanted the light to shine in one direction or 6 if you wanted light both forward of and behind the light. Or if you wanted it quite dim, you could probably use 3 amber Luxes, pointing one up, one forward and one reward. No reflectors. If you could get about 100mA to each star, I'd imagine it would be quite a bit of light for a small area and it would keep them cool. I'd try for 350 to 400mA TOTAL to three Luxes.

 

[hank]

The 'Frankenstein' idea sounds right. Coin cell lights aren't bright enough for this use, and I'll use rechargeables (either small 12v sealed lead-acid, which we have for ham radio backup power, or AA NiMH cells in combination).

I can solder ok; finding resistors isn't easy for me, the few times I've tried so far. I'm too new at this. The local electronics store rarely can match an online calculator result (is that "ohms" or "Kilo-ohms"? either way it doesn't exist in the parts bin ....).

I can order from DigiKey or the like, if I know exactly what to get --- I'm not yet good at approximating

 

[cratz2]

Honestly, if I were to build a custom light such as I described above, I'd go with a regulator board if possible. Of course, I wouldn't be looking to build several of them, just one. Or one plus a backup.

Here's the thread I mentioned:

http://www.candlepowerforums.com/vb/showthread.php?t=109594

 

[Sub_Umbra]

I think amber would be a really good color for that application.

 

[2jzpower]

talking about glo-toobs is there any word on the 123A version???

 

[hank]

Oho, this isn't "amber" --- it's red, yellow, and green --- but it'll do, and is specific enough I can build it.
Same result (no blue in the spectrum) that I wanted, and probably better color rendering.
http://www.solorb.com/elect/solarcirc/ledlamp/index.html

 

[hank]

But it sure looks wimpy next to the Frankenlight.

I'll follow your thread there for a while and hope for ideas I can steal and use with yellow/amber or maybe a similar red/green/yellow combination.

 

[nerdgineer]

...but doesn't contain the band that delays the start of the sleep cycle....

Huh? What band is that? Is there a reference for this?

 

[agangofatoms]

My tent light is a modified Princeton Tec Impact XL. I took the cone off the Princeton Tec Sport Flare and screwed it on the Impact XL. For a two to four man tent it's a perfect (1 watt) LED tent light. It's even ideal for winter camping since lithium batteries can be used in it.

I'm actually surprised PT hasn't started to sell the Imapct XL with the cone for use as a tent light. I think such modified Impact XL is the perfect tent light.

 

[VidPro]

i would want to string 4-5 per plus a resister for a 12V system, as opposed to resistering each.
or just run a parellel set off of 2x 1.2v ni-mhy type batteries , with a tiny resister to each parellel item.

there is a amber that is just right/cheap for your application, cause they are dumping them at 10C each unit.
http://www.quickar.com/prodview.php?session=DZHv5fs8&id=76

that guy also sells a PCB board (not as cheap), that is perfect for slapping together 30 of these "superflux" or 5mm leds on a 1foot board. it saved me a lot of time.

we tested this cheap led PAIRED with bluewhite leds to get to a incadescent looking light. they ambers are NOT as bright as a white led, cause of course they have no PHOSPHORS, so its not as efficient , but they had a nice color, as far as single spectrum colors go.

 

[Phaserburn]

Coleman makes/made? a CCFL 4AA light that had an amber cover. Lots of amber flood lumens (or white if you move the cover) and good runtime.

http://www.coleman.com/coleman/images/products/5397A720_500.jpg

 

[hank]

> the band that delays the start of the sleep cycle....
Start here, this blogger did a very clear collection of links:
http://psychcentral.com/blog/archives/2007/03/12/light-and-dark/

I added everything I'd come up with into her coments area recently.

 

[jtr1962]

Funny because I have zero problems falling asleep with blue lights or white lights containing a lot of blue. The blue LED power light on my PC points towards my bed, is quite bright, and is about 7 feet away. I think the problem in many cases isn't the color of the light but the fact that there is light at all. Some people just can't fall asleep unless the room is completely dark. Others can tolerate a small amount of light in the tens of lumens. Still others like myself have no problems at all falling asleep in a room fully lit with daylight. In fact, since I'm noctural by nature I personally sleep better in a well lit room.

I don't know if amber LEDs is a real answer here. They're less efficient than whites and color rendering is poor. And like those awful sodium vapor streetlights anything lit by them aesthetically looks horrid, sort of like a bad LSD trip. Something like the WH bin Cree XR-E might be a much better answer than using amber LEDs. The Cree XR-E has a more even spectrum (less pronounced blue spike and smaller yellow-green valley) than other white LEDs to start with. The warmer WH bin means that the blue hump is yet smaller relative to the yellow hump. What all this means is that the color rendering is excellent, the color accuracy is quite good (way better than under amber LEDs or incandescent), and there still isn't an excessive amount of blue in the spectrum.

And while we're talking about the negative effects of blue lighting on some people, let's not forget that lighting which is too yellow can have equally detrimental effects on some. I would probably get a major headache within ten minutes under your amber tent lights. Even under incandescent I get bad headaches within an hour because my brain just can't autocolorbalance light at that low of a color temperature. It just feels as if there's a haze over my corneas. I imagine I'm far from the only one affected by yellow light in this manner.

 

[MattK]

Just a thought:

This: http://www.batteryjunction.com/ufoledcaliwi.html or this: http://www.batteryjunction.com/ufoledcali.html

Plus
one of thse #360? : http://search.store.yahoo.com/cgi-b...//store.yahoo.com/cinemasupplies/&query=amber - you can also find this stuff locally, I see you're in Berkeley so try this http://maps.google.com/maps?hl=en&s...rkeley,ca &ie=UTF-8&oe=UTF-8&um=1&sa=N&tab=wl

 

[abvidledUK]

Amber / red filter over lens ?

Rosco.

 

[VidPro]

there is not a lot of red, comming out of a white led to begin with :-(
better to filter a light that has a spectrum, like a incadescent. you will squeese out some yellow, mabey a bit of amber, but a red filter will put the level of the bluish "white" leds to the level of about 4 red leds a single luxeon red driven with 2 ni-mhys would be brighter

look 1/2 the way down this page, at the cool colorised spectrum charts.
http://candlepowerforums.com/vb/showthread.php?t=110795&highlight=spectrum

deal extreeme has them cool tent lights for 5$ they are huge , and bright and have 3 different modes or ammounts of leds light at a time.

 

[2xTrinity]

Funny because I have zero problems falling asleep with blue lights or white lights containing a lot of blue. The blue LED power light on my PC points towards my bed, is quite bright, and is about 7 feet away. I think the problem in many cases isn't the color of the light but the fact that there is light at all. Some people just can't fall asleep unless the room is completely dark. Others can tolerate a small amount of light in the tens of lumens. Still others like myself have no problems at all falling asleep in a room fully lit with daylight. In fact, since I'm noctural by nature I personally sleep better in a well lit room.

I don't know if amber LEDs is a real answer here. They're less efficient than whites and color rendering is poor. And like those awful sodium vapor streetlights anything lit by them aesthetically looks horrid, sort of like a bad LSD trip.

I actually find I can get to sleep sooner working with cool white light. It's more a question of intensity than color temperature. The reason is that I find that my eyes can resolve text/details a lot better with cool white than with warm white light, so I find I don't need nearly as much light to actually see what I'm doing. For example I can see a lot better (both seeeing where I'm going, and especially reading or resolving detail) in parking lots that are dimly lit with cool-white metal halide lamps, than with parking lots that are very brightly lit with high pressure sodium (or worse, low pressure sodium) -- which is essentially the effect amber LEDs will give you.

Something like the WH bin Cree XR-E might be a much better answer than using amber LEDs. The Cree XR-E has a more even spectrum (less pronounced blue spike and smaller yellow-green valley) than other white LEDs to start with. The warmer WH bin means that the blue hump is yet smaller relative to the yellow hump. What all this means is that the color rendering is excellent, the color accuracy is quite good (way better than under amber LEDs or incandescent), and there still isn't an excessive amount of blue in the spectrum.

I'd second the suggestion for the XR-E WH bin. Recently when reading in bed I've actually switched from using an incan bulb, to using a "floody" WH-Bin Cree led that is dimmed way down. I can read much more comfortably than with the incan, and find it doesn't "wake me up" as much.

One good-tint white LED will be more effective for the kids to read with than several high-powered amber lights, and power consumption will be much lower as the LEDs are inherently much more efficient, and you'd be able to get by with less light.

And while we're talking about the negative effects of blue lighting on some people, let's not forget that lighting which is too yellow can have equally detrimental effects on some. I would probably get a major headache within ten minutes under your amber tent lights. Even under incandescent I get bad headaches within an hour because my brain just can't autocolorbalance light at that low of a color temperature. It just feels as if there's a haze over my corneas. I imagine I'm far from the only one affected by yellow light in this manner.

While I can tolerate 2700k incan no problem, I find I am most comfortable under light with a color temp in the 3500k - 5000k range, meaning those "Reveal" filtered incan, good quality fluorescent (high CRI, no flicker), or WH bin Cree LEDs (only LEDs I have that fall in that range)

I see that one person suggested a mix of Green and Red -- that would be a huge improvement over amber as there would be at least some ability to differentiate color. Also, judging by trying to navigate in the dark with monochromatic coin-cell lights, I find that the green is the most effective color -- as that's where the eyes are naturally most focused.


Also, as for the issue of sleep cycles being reset due to blue light. From what I've read about that, that cycle is most sensitive to deep blue or violet light -- the effect peaks at around 420nm. The blue component of LEDs is closer to 470nm, with almost no deeper blue/violet. Incans and especially fluorescents though do output those shorter wavelengths. Though I certainly haven't done a study, I think it's plausible then that the sleep-inhibiting effect would be less noticeable with an LED than with a "warmer" appearing light source -- especailly if less total light is used.