Suggest an LED for 12V night-light system

[Darell]

OK, I need your help. I have a small 12VDC solar/battery system that powers various items around my house. What I'd like to do is use that 12V source to burn some green (or blue) LEDs as nightlights in a few rooms (I'll just poke them through the ceiling, and let them burn 24/7 since I have tons of excess Amp/hrs.

What I'm looking for is a green or blue LED with a wide angle that produces about as much light as one of those plug-in lime-lights. Any idea about how much light that is? Thoughts on an LED that would fit the bill? Obviously I'll step the voltage down with resistors, but I don't know what sort of brightness of LED I should look for. I don't want it too bright (I suppose I could get relatively bright ones and under-drive them until I'm happy with the output) but I'd rather start off with a reasonable brightness.

Any and all input is appreciated. And if you have some LEDs sitting around collecting dust that you think would work, I'd be happy to buy or trade something for them.

 

[snakebite]

i use 3 white nichias in series with 100-330 ohm resistor.
you can use a pot too.
the blue and green leds with a 3.x volt rating all work fine.

 

[Darell]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by snakebite:
i use 3 white nichias in series with 100-330 ohm resistor.
you can use a pot too.
the blue and green leds with a 3.x volt rating all work fine.

<HR></BLOCKQUOTE>

Hi Snake - I'd seen that you were doing this same sort of thing. Three white Nichias sounds way too bright for what I'm looking for. Remember I want something only as bright as a LimeLight - about 1/2 or 1/3 as bright as an infinity (not six times as bright!) I want just enough light to keep from bumping into things and stepping on the dog.

 

[Brock]

Hey darell, depending on voltage and the LED's I have 4 in series that lightup on my solar system. Usually my batteries sit about 13.6v. They are dim, but I use them more as an indicator then a light. They pull about 4mA at that voltage.

 

[Darell]

Hi Brock -

Yeah, I'm thinking that would certainly be my most efficient route: LEDs in series instead of each with dropping resistors. I'll just have to decide how many to put on each loop.

Any clue how bright I should shoot for to be just like a limelight? I suppose I can just buy some mid-brightness ones, and keep adding them in series until I like the output. Are the ones you're using rated at 20mA - but you're severly under-driving them? I have no idea how low you can drop the current and still have them light.

 

[Brock]

Yes, I figured that running 4 in series would use the least amount of power overall. The problem is if I run the battery bank to about 12.4v the LED's drop out since it isn't enough power to light them. Yes, the 4 are white Nichias, rated at 20mA. They are more focused then a limelight, but very close in brightness when shined up at the ceiling.

The Pal idea is one way, or an Eternal light with only one LED burning on the lowest setting?

 

[Darell]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Brock:

The Pal idea is one way, or an Eternal light with only one LED burning on the lowest setting?<HR></BLOCKQUOTE>

Yeah, well... now we're starting to talk about some serious money. And what I really want to do is use my free solar power that's just being wasted right now.... I just need to order up some LEDs and start playing with them. Thanks for you help.

 

[Coherence]

Consider alien skin. It really is remarkable, and you don't need to route any wires around...

 

[snakebite]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by darell:
Hi Snake - I'd seen that you were doing this same sort of thing. Three white Nichias sounds way too bright for what I'm looking for. Remember I want something only as bright as a LimeLight - about 1/2 or 1/3 as bright as an infinity (not six times as bright!) I want just enough light to keep from bumping into things and stepping on the dog.<HR></BLOCKQUOTE>
i use a 10k pot as a dimmer.
works fine on the nichias but i recently got some oddballs that go a sickly color if you dim them.maybe isp korea? the blues and greens will be ok.

 

[Darell]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Coherence:
Consider alien skin. It really is remarkable, and you don't need to route any wires around...<HR></BLOCKQUOTE>

Hey - Thanks for pointing me there. I'd never heard of the stuff, and missed the original post. My biggest problem is that I want to subtly illuminate sevearl rooms that typically remain pretty dark all day. I don't want to have to run around and charge everything up each day. BUT, I really should order some, and see how well it does for my need. Sounds like great stuff for halloween costumes too!

 

[Mike]

You might want to consider the rectangular wide angle white LEDs that Paul who used to do the whiteleds.net site was selling. I think he still has some available. His e-mail is [email protected]

They make a nice area light. You could string 3 or 4 in series and put however many you want in each room. This is a nice cheap solution ($1.75 each). These are just as bright as the standard 20 degree Nichia LEDs that everybody uses, except that the light is spread over a very wide angle. The light is very white.

 

[Darell]

Thanks Mike -

Sounds like a GREAT plan. I'm looking for exactly what you're talking about - a very wide beam. And the price is right. I'll zip him an email right now.

Thanks again,

 

[Blades]

Whacky question...Would it be possible to run some LED's off a phone jack?? Isn't there some voltage there?? Probably not enough, but just pondering. Usually when the power goes out I still have a landline phone that will work.

Blades

 

[MY]

What would be the simplist way to get the 43 v. phone line down to what a couple of LEDs would need?

 

[Badbeams3]

How about running 3 in series with a variable pot...this way you can adjust them up or down. Maybe use white and drill the holes in the ceiling at angles, so they point on paintings, plants, ect. I heard turquise is nice for plants...maybe a differant string of red for the bedrooms and bathrooms (4 in series).

 

[Darell]

Hmmm. Free electricity, you say? Yes, there certainly is some voltage there - I've zapped myself before, so I know it's true. Veeeeeery, interesting.

 

[Darell]

Well, when I rode my bicycle down there this afternoon in the sunshine, they hand plenty in stock.

You probalby don't ride your bike too much these days in Alaska do you?

 

[**DONOTDELETE**]

An led that might work wonderful for you is Nichias NSPWF50BS. It is actually a flat led with a viewing angle of 110/80 This led using the same chip and phosphor as all Nichia leds but is packaged in a way to get a very wide beam. Its somewhere around .3 cd for the typical ones. You can order these online at www.nichia.com

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Mike:
You might want to consider the rectangular wide angle white LEDs that Paul who used to do the whiteleds.net site was selling. I think he still has some available. His e-mail is [email protected]

They make a nice area light. You could string 3 or 4 in series and put however many you want in each room. This is a nice cheap solution ($1.75 each). These are just as bright as the standard 20 degree Nichia LEDs that everybody uses, except that the light is spread over a very wide angle. The light is very white.<HR></BLOCKQUOTE>

 

[**DONOTDELETE**]

I would try Nichia Part number NSPWF50BS. It is a flat leds with a very large viewing angle 110 degrees or 80 degrees depending on the way you view the led. Its currently around .3 cd. You can order these online at www.nicihia.com