# Custom LED emergency lights



## Kuryakin (Mar 7, 2010)

Folks, got an interesting application here. We're in the process of restoring a WWI artillery battery in Lewes DE. 
We are doing our level best to make this place as original as possible. However, being a public building, we also need to make it code compliant. 
Emergency lighting is the topic. Right now, we have the typical 6v lead acid incandescent line powered flavor on the walls. I want to get rid of them. 
The corridor in this place is 420 feet long, and has a cable chase down the length of it! I had a bright idea (pun intended) that we could drill small holes in the cable chase covers and have something like Cree XPE on a star mount every 15 feet or so, and powered by the power pack of above emergency lights, but hidden behind the covers. To see what I'm talking about, see:
http://www.facebook.com/fortmileshistoricsite?ref=nf#!/photo.php?pid=3478504&id=173215562763
So, I am looking for suggestions here, on which LED to use, should I use a lens, and any other ideas anyone might have. Now, also keep in mind, we don't have a lot of money, and most of this is being funded from our own pockets. (fund raising is another aspect we're working on). 
I was simply thinking about driving 6-7 of these, with resistors, from our existing power packs, minus the lamp heads, each. We have something like 8 of these in place now. 
Whatcha all think?

J.


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## Burgess (Mar 7, 2010)

Hmmm . . . .


I'm wondering --

did yer' UserName spring from _*The Man From U.N.C.L.E.*_ ?


Guess i'm showing my age here. (56)


_


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## Evilsizer (Mar 7, 2010)

are you looking for maximum run time with a decent amount of light or are you looking for maximum light not worrying about run time?

i was messing around with this LED,
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16656
does put out a nice amount of like, i would guess to say like a flood light. were you looking for something like a flood light or spot light?


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## nein166 (Mar 8, 2010)

Kuryakin said:


> Folks, got an interesting application here. We're in the process of restoring a WWI artillery battery in Lewes DE.
> We are doing our level best to make this place as original as possible...
> ...I was simply thinking about driving 6-7 of these, with resistors, from our existing power packs, minus the lamp heads, each. We have something like 8 of these in place now.
> Whatcha all think?
> ...


Its great that your trying to make things look original and I hope some modified emergency lighting boxes can pass an inspection. The shame is having to still use the Lead Acid, you'll be replacing them too often. I know from experience, in the commercial building I work in we inspect about 120 emergency lights once a month and replace the batteries in at least 3 units a month. Mine is a 12V 2 cell system and maybe they fail because they are charged in series. Just make sure that power pack is accessible in case.

Your wire chase looks like its covered in MDF or Masonite, that's not going to help with cooling LEDs. Perhaps you could mount the stars on a metal plate and screw the plate to the back of the wood board Drill your hole to 1" since the light radiates out in 120 degrees and the wider the hole the more light can spread. Then you can find a brass handle that won't look too out of place like this one. Mount the handle over the hole and LED. The handle can look like its for removing the board for access and the LED will not be seen, but when it lights up it can downlight the floor and wash the panel from light reflected off the backside of the handle. Of course if the hole is higher in the board the wider flood you will get across the floor.

As far as running the LED with a resistor, that's not the best course to take but it can work if you use the right resistor.
I think you want as much light as you can get from the LED right.
So with a 6v Battery source and a 3.5v LED pulling 1A you want a 2.7ohm resistor. BUT the resistor will also be consuming 2.7Watts 
These will get you close to total output of the LED and handle the power
http://www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=10089
Certainly the cheapest way and it will work just not the best.

You can check resistor calculations here and remember 1amp is 1000ma
http://led.linear1.org/led.wiz
http://metku.net/index.html?path=mods/ledcalc/index_eng

If you have some funding you could get drivers for each LED and the lights would run brighter for longer. 
With a resistor the LED will fade gradually from the start as battery voltage drops.

I hope you can achieve your goals in this project, I sure wish I could rebuild the emergency lighting in the place I work, LiPo cells, Multiple LEDs, a reliable battery charger and constant current regulation, it sure would make one night of the month much easier.


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## Kuryakin (Mar 8, 2010)

Ayep!!



Burgess said:


> Hmmm . . . .
> 
> 
> I'm wondering --
> ...


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## Kuryakin (Mar 8, 2010)

Max light, if they stay on for 15 minutes, I'm happy. I think I want a flood, we're trying to light up that corridor so the people can find their way out. Having no windows, the place is a total cave with the power off. 



Evilsizer said:


> are you looking for maximum run time with a decent amount of light or are you looking for maximum light not worrying about run time?
> 
> i was messing around with this LED,
> http://www.goldmine-elec-products.com/prodinfo.asp?number=G16656
> does put out a nice amount of like, i would guess to say like a flood light. were you looking for something like a flood light or spot light?


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## Kuryakin (Mar 8, 2010)

For us, being efficient is a non issue, these are emergency lights, after all! 

Yes, the covers are MDF, and yes, the LEDs will be mounted on a metal plate behind them. That's not a worry. 

Holes, not too worried. Given these will be FAR more hidden than what we have now, we'll live with the holes. We can also counter bore the back side to get the LED closer to the front to minimize the hole size and still spread the light. The nice thing about this, we really don't need to get too exotic to be functional. My goal is NOT to satisfy the electronics and LED geek in me, it's to have functional, well hidden emergency lighting, as cheaply as I can do it. 

As far as battery life goes, lead acid batteries probably last as long as anything else does, as far as dying due to loss of capacity. 

Let me look at your stuff, and noodle on this, thanks!!



nein166 said:


> Its great that your trying to make things look original and I hope some modified emergency lighting boxes can pass an inspection. The shame is having to still use the Lead Acid, you'll be replacing them too often. I know from experience, in the commercial building I work in we inspect about 120 emergency lights once a month and replace the batteries in at least 3 units a month. Mine is a 12V 2 cell system and maybe they fail because they are charged in series. Just make sure that power pack is accessible in case.
> 
> Your wire chase looks like its covered in MDF or Masonite, that's not going to help with cooling LEDs. Perhaps you could mount the stars on a metal plate and screw the plate to the back of the wood board Drill your hole to 1" since the light radiates out in 120 degrees and the wider the hole the more light can spread. Then you can find a brass handle that won't look too out of place like this one. Mount the handle over the hole and LED. The handle can look like its for removing the board for access and the LED will not be seen, but when it lights up it can downlight the floor and wash the panel from light reflected off the backside of the handle. Of course if the hole is higher in the board the wider flood you will get across the floor.
> 
> ...


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## bshanahan14rulz (Mar 8, 2010)

My school uses strips of like, 20 superflux-style LEDs every few feet in the hallways. They are on constantly and have flicker to them, so I'm assuming they are running half of the AC or on a bridged rectifier when the power is fine. Haven't had a power failure yet, so I don't know if they are used for that, but I can't see why not...
The newer ones are nice tint, not harsh blue.


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## Kuryakin (Mar 8, 2010)

I was thinking of a fairly powerful LED every 10-15 feet or so. Strips don't exactly hide too well. A 1-3 watter poking out of a small hole seems like a better idea. Flicker? Only time they'll be on is on batteries, and last I checked, 60Hz batteries are tough to come by. <G>



bshanahan14rulz said:


> My school uses strips of like, 20 superflux-style LEDs every few feet in the hallways. They are on constantly and have flicker to them, so I'm assuming they are running half of the AC or on a bridged rectifier when the power is fine. Haven't had a power failure yet, so I don't know if they are used for that, but I can't see why not...
> The newer ones are nice tint, not harsh blue.


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## Ken_McE (Mar 8, 2010)

Kuryakin said:


> Right now, we have the typical 6v lead acid incandescent line powered flavor on the walls. I want to get rid of them.



Agreed. 6 volts is too limited.



> should I use a lens,


You want the light to disperse a lot. Maybe as much as possible. You may actually want a diffuser rather than a lense.




> and any other ideas anyone might have. .


There is another way you might consider. Buy 420 feet of cool white LED ropelight and run it in a straight line down the hall. I've done this in some of my properties. It will be a touch dim, down right around the border of where you switch from color to black and white vision, but it will also be tremendously even and will not blind anyone who looks the wrong way. Sadly, ropelight is going for around $1.50/ft, which would put this hallway around the $ 630 range for just the lights.

I don't know what it would cost to paint the lower side walls with GID paint, never tried it myself. Running the fluorescents would charge them up automatically. It would have low maintenance and high reliability.



> I was simply thinking about driving 6-7 of these, with resistors, from our existing power packs, minus the lamp heads, each. We have something like 8 of these in place now. Whatcha all think?



420 divided by seven equals one light every 60 feet. Not satisfactory for a public facility





> Max light, if they stay on for 15 minutes, I'm happy.



Code will probably want 90 minutes.


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## Kuryakin (Mar 8, 2010)

Rope lights are not up for consideration, as they don't look period correct. Fluorescent paint is out for the same reason. 

If I was using some of the Cree stars, the output as I am planning should be lots. 

I was talking about 6-7 per pack. We have 8 power packs, so, not worried about the output. As I see it, something like $200 total for all the LEDs and resistors. Peeking through a shallow hole is about as inconspicuous as I think we can get. Something on the order of one Cree star every 10 feet or less. Given the output of these things, should be plenty. Code here varies, depending on the building. Occupancy won't be all that high, and with 4 exits, emptying the building should be pretty quick. Or I can simply install larger batteries! 



Ken_McE said:


> Agreed. 6 volts is too limited.
> 
> You want the light to disperse a lot. Maybe as much as possible. You may actually want a diffuser rather than a lense.
> 
> ...


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## Kuryakin (Mar 9, 2010)

*Candidate LEDs for my custom emergency light project.*

Opinions on these, please! You guys seem to know the junk from the good stuff.
Keep in mind, my criteria here is to get enough output, 100lm or more, and to do it as cheaply as possible. Efficiency is secondary. So, here goes:

http://cgi.ebay.com/NEW-10x-White-H...emQQptZLH_DefaultDomain_0?hash=item3efd35c9c4

http://cgi.ebay.com/6pcs-White-High...emQQptZLH_DefaultDomain_0?hash=item335ab14e0e

http://cgi.ebay.com/5x-White-High-P...emQQptZLH_DefaultDomain_0?hash=item53dffa2a64

Whatcha all think?


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## DM51 (Mar 9, 2010)

*Re: Candidate LEDs for my custom emergency light project.*

You do not need a new thread for this. I'm merging it with your existing one.


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## spencer (Mar 9, 2010)

Keep in mind you will need heatsinking for every LED. The star they come on won't be sufficient. A chunk of Al on each one should be sufficient.


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## Kuryakin (Mar 9, 2010)

Got that. If I use these, there'll be an aluminum plate on the back for mounting/heat sinking, and to mount the LED to the right depth in the chase cover. 



spencer said:


> Keep in mind you will need heatsinking for every LED. The star they come on won't be sufficient. A chunk of Al on each one should be sufficient.


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## nein166 (Mar 10, 2010)

*Re: Candidate LEDs for my custom emergency light project.*



Kuryakin said:


> http://cgi.ebay.com/6pcs-White-High...emQQptZLH_DefaultDomain_0?hash=item335ab14e0e
> http://cgi.ebay.com/5x-White-High-P...emQQptZLH_DefaultDomain_0?hash=item53dffa2a64



Thats the best deal, you'll get 6 for each light.
I didn't realize you wanted 6 LEDs per emergency light thats going to be plenty of light.

But if you notice these leds can not be powered at 1000ma just up to 750ma. But due to higher forward voltage of these LEDs you can use the same 3.3 ohm resistor
And remember every LED needs its own resistor and this is going to drain your battery faster. For every 3W LED you'll have 1.6W burnt up in the resistor. So with 6 LED+resistor pairs thats 27W, and if I'm right your battery is 6V 4A/hours. I think the battery would have 24W/hours, So you should get about 30 minutes of bright light tapering off until the battery is drained and the LEDs dim down. The LEDs could dim out quick once the battery voltage dips below 6v due to all LEDs voltage sensitivity.


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## Kuryakin (Mar 10, 2010)

*Re: Candidate LEDs for my custom emergency light project.*

Yep, 4 AH is what we have here. Yes, I realize the resistors are going to consume about as much energy as the LEDs themselves, but that's OK. A driver would substantially drive up the cost, but not reallly get us much on function. I was actually thinking of underdriving these a bit, as LEDs get more efficient at lower power, hence the idea of driving 3 watters instead of slightly overdriving 1 watters. But, I'll connect a few and see how they look, and adjust accordingly, resistors are cheap. 
Thanks. 




nein166 said:


> Thats the best deal, you'll get 6 for each light.
> I didn't realize you wanted 6 LEDs per emergency light thats going to be plenty of light.
> 
> But if you notice these leds can not be powered at 1000ma just up to 750ma. But due to higher forward voltage of these LEDs you can use the same 3.3 ohm resistor
> And remember every LED needs its own resistor and this is going to drain your battery faster. For every 3W LED you'll have 1.6W burnt up in the resistor. So with 6 LED+resistor pairs thats 27W, and if I'm right your battery is 6V 4A/hours. I think the battery would have 24W/hours, So you should get about 30 minutes of bright light tapering off until the battery is drained and the LEDs dim down. The LEDs could dim out quick once the battery voltage dips below 6v due to all LEDs voltage sensitivity.


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## Kuryakin (Mar 15, 2010)

*Re: Candidate LEDs for my custom emergency light project.*

Drat! I was hoping for a bit more feedback. Oh well. I'll order a bunch and try 'em out!



Kuryakin said:


> Opinions on these, please! You guys seem to know the junk from the good stuff.
> Keep in mind, my criteria here is to get enough output, 100lm or more, and to do it as cheaply as possible. Efficiency is secondary. So, here goes:
> 
> http://cgi.ebay.com/NEW-10x-White-H...emQQptZLH_DefaultDomain_0?hash=item3efd35c9c4
> ...


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## Kuryakin (May 29, 2010)

Got it just about done! We have 31 3 watt LEDs down the corridor powered from off the shelf emergency light power packs. Just ditched the heads, put a 4.7 ohm 5 watt resistor in series with each LED, wired 4-6 LEDs to each power pack. Looks GREAT! And virtually invisible when off. To see:
http://www.facebook.com/fortmileshi...l&subj=173215562763&aid=-1&id=100000695359604



Kuryakin said:


> Folks, got an interesting application here. We're in the process of restoring a WWI artillery battery in Lewes DE.
> We are doing our level best to make this place as original as possible. However, being a public building, we also need to make it code compliant.
> Emergency lighting is the topic. Right now, we have the typical 6v lead acid incandescent line powered flavor on the walls. I want to get rid of them.
> The corridor in this place is 420 feet long, and has a cable chase down the length of it! I had a bright idea (pun intended) that we could drill small holes in the cable chase covers and have something like Cree XPE on a star mount every 15 feet or so, and powered by the power pack of above emergency lights, but hidden behind the covers. To see what I'm talking about, see:
> ...


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## Walterk (May 29, 2010)

For reference:






This picture is found at: http://dmcleish.com/MauiHome/ 
Loaned from the website of CPF member Gizmo.


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## Evilsizer (May 29, 2010)

looking good!


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