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Discussion Starter #1
EDIT: For those of you coming to this thread for the first time, please take the time to read all those who made comments following. There really is a great deal of information that everyone should know before using Eagle Eye LED lights, and most of what you need to know is provided not be me, but the folks who make posts that follow this one.


For years, we've been using little battery operated LED pucks to act as spots for our graveyard. However, as we get older, the daily routine of going out and turning them on and off has become a bit less exciting. Oh wait, it never was exciting. So, we've been experimenting with various ideas on wiring our LED spots. Many of those ideas came from fellow haunters here on the forum. One of the approaches we've tried came when we stumbled across Eagle Eyes while looking for LED lights online. (We've not seen this idea out there before; but to be honest, we can’t imagine why not. So, if this is repeating well-known info, our apologies. We still think it’s cool.)

Car hobbyists often use 12-volt LED running lights called Eagle Eyes to add either extra light for driving or extra light to impress. The lights are small, cheap, usually waterproof, put out a nice amount of light, and come in different colors. However, our initial purchase of what we thought was going to be a great idea for spot lighting didn't go quite as planned.


Eagle Eyes would make great spots for highlighting graves and other props if they didn't heat up so easily when plugged into a 12-volt adapter plug. From our experience, cooler colors like green and blue didn't warm up too badly with 12-volts pumping through them, but the yellow lights we bought could actually burn your fingers after being on only 30 minutes.

eaglelights02.jpg

We bought quite a few lights and adapters for experimenting with and we think we have a solution to the Eagle Eyes overheating. We use a 9-volt adapter plug. Now, I admit, I’m not a good electrician. I don’t understand how amperages, volts, impedance, and all that stuff works. (But you knew that the moment you saw the wiring I did for my proof of concept test.) Even at 9 volts, a single yellow light hooked up to 9-volt adapter heated up after an hour, but I figured if I hooked up a whole bunch of lights to the adapter that might change.

eaglelights03.jpg

Sure enough, when I hooked up five of the lights to the adapter, none of them heated up, even after running for four hours. Even the yellow lights stayed cool. And the amount of light output was still exactly what I wanted. My partner, who is much more savvy about the electrical side of our props, will do the real wiring for the Eagle Eyes, the junction box, and the RCA cords they will hook up to. What you see here was simply my attempt to prove it could work, and it does… really well, in my opinion. One light placed a few feet away from a tombstone can make reading it easy. And yet, it's virtually invisible as lighting sources go.

eaglelights01.jpg

We haven’t proved the aspects of longevity and water tightness in the field. That will come next year at Halloween. Still, for now, Eagle Eyes look very promising. Here are links to one of the places I purchased both the adapter and the Eagle Eyes. https://tinyurl.com/ybgl7umg and https://tinyurl.com/yceybznc
 

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The reason that 5 of them didn't heat up is lack of current. Your 9v adapter is only rated for 1 amp, those LED's will draw 1/2 amp each. So 5 of them connected to a power source that can only supply 1 amp will dim each LED to less than full brightness. If they still work and are bright enough for your purpose then all is good!
 

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I want you to feel how hot that wall wart gets. That's where your heat problems could appear.

I would definitely check the rated current draw of those LED's. If you look around online, you can find wall warts rated for a few more amps each. That way, you don't burn stuff out.

Another thing to consider, is those laptop power supplies that put out the same voltage, but usually rated at much more current draw.
 

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Discussion Starter #5
The reason that 5 of them didn't heat up is lack of current. Your 9v adapter is only rated for 1 amp, those LED's will draw 1/2 amp each. So 5 of them connected to a power source that can only supply 1 amp will dim each LED to less than full brightness. If they still work and are bright enough for your purpose then all is good!
Thanks for the explanation. I thought it had something to do with that, only since I don't know much about electricity, I figured if I kept splitting the full juice in pieces by adding more lights, that might be the outcome. Which leads me to a question hoping for an answer from one who knows. The Eagle Eyes are actually rated for 12 volts. They're supposed to be hooked up to a 12 volt battery. But I figure 12 volt AC and 12 volt DC might not be exactly the same beast. The lights, work very well on the nine volt adapter. Does keeping them on a nine volt adapter doanything to keep them cooler, or could I get the same effect by using a 12 volt adapter that was rated for 1 amp and having 5 lights? I'm totally ignorant about these things, but figure it doesn't hurt to learn. Thanks.
 

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Discussion Starter #6
I want you to feel how hot that wall wart gets. That's where your heat problems could appear.
Pardon my lack of vocabulary knowledge, but is the wall wart the adapter part of the plug I'm using that takes the 110 volts down to 9 volts? If it is, that never gets hot no matter what I do in the way of lights.

I would definitely check the rated current draw of those LED's. If you look around online, you can find wall warts rated for a few more amps each. That way, you don't burn stuff out.
I have to admit that I get really confused over volts and amps. The lights are rated for 12-volt DC current as they're basically just car lights hooked up to a car battery. However, once my lights overheated using a 12-volt AC adapter plug, I went out on the net trying to find a reason. A bunch of sites had people complaining about how hot the lights got on 12-volt current. So, I tried finding a 9-volt adapter to see if lowering the voltage output would change things. It sort of did, but then I'm thinking J-Man is right about the current being divided up.

Almost everywhere that talks about Eagle Eye LEDs refers to the 12-volt aspect of them. That's the only electrical info I could find on the site that sold them to me, but I did finally find an automotive article that said the Eagle Eyes they put in their car used only .12 amps of power. If that's the case, I just kept splitting the power until it stopped overheating the lamps but still lit them up. I guess... because I really suck at electrical stuff. But I am trying to learn, because I really want to wire some LED candles, I know at some point I'm going to have to learn about resistors and the whole nine yards. Besides, I also want to make a fountain similar to the one you made a few years back, so learning how not to kill myself around electricity and water might be a good thing.

So thanks for the help. I appreciate whatever comes my way from folks who know more than I.
 

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Thanks for the explanation. I thought it had something to do with that, only since I don't know much about electricity, I figured if I kept splitting the full juice in pieces by adding more lights, that might be the outcome. Which leads me to a question hoping for an answer from one who knows. The Eagle Eyes are actually rated for 12 volts. They're supposed to be hooked up to a 12 volt battery. But I figure 12 volt AC and 12 volt DC might not be exactly the same beast. The lights, work very well on the nine volt adapter. Does keeping them on a nine volt adapter doanything to keep them cooler, or could I get the same effect by using a 12 volt adapter that was rated for 1 amp and having 5 lights? I'm totally ignorant about these things, but figure it doesn't hurt to learn. Thanks.
Well first off, LED's with no current limiting resistors will operate somewhere between 2 and 3 volts DC depending on the color. Any LED that is sold for automotive use already has resistors built in to handle 14VDC which is what a car's charging system typically puts out. The reason your LED's work with 9V is due to the resistors still allowing enough current to light them. If you were to use voltage higher than 14V, the LED's would likely burn out. Now a bit about amps (current). Think of electricity as water thru a garden hose. The amount of water coming out of the hose is current (amps). The pressure that's pushing that water is voltage. The higher the pressure, the more water you'll get out of the hose. Same with voltage, it's the pressure pushing the current (amps). That's why standard 120V AC house electricity is so dangerous. Most people who don't understand electricity think it's voltage that can kill you but it's actually the amperage, and it doesn't take much. 1 amp is enough to kill you IF there is sufficient voltage to push it, and 120V is plenty of "push". That's why a car battery is not able to electrocute you, it has tons of amps, but no "push" because it's only 12V. On the flip side, have you ever been shocked from a spark plug lead on a lawn mower or your car? It's a pretty good jolt because it's around 10,000 volts but it's not dangerous because there's no amperage. Back to power adapters (wall warts), the amperage rating is the max current that it can output. If you connect a device(s) that draw more than the power supply can handle, they usually just shut down via an internal cutoff. Using a power supply that has a higher amp rating than what your device needs is fine, the device will only draw what it needs. Voltage on the other hand is usually critical and should be matched to what the device specifies. Hopefully this gives you a bit of knowledge on the voltage/amperage topic.
 

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BTW, your "eagle eyes" will operate cooler on 9V than they will on 12V. Like I said, if they're bright enough for your purpose using 9V, then by all means, use 9V.
 

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Discussion Starter #9
BTW, your "eagle eyes" will operate cooler on 9V than they will on 12V. Like I said, if they're bright enough for your purpose using 9V, then by all means, use 9V.
Thank you so much for your explanations. It does help make it clearer to me how the voltage and amperage are going to effect my lighting. Considering that I want one light for each tombstone, I think I'll stick with the cooler running 9-volt power adapter, but one that has 2 amps so I can add more lights to the graveyard running off just one adapter. Now if that sounds right to you, then I actually understand what you're telling me.

If you're shaking your head thinking, "no, he doesn't get it," then I might need a bit more help. At any rate, I am grateful for your help and advice. I figure if I can get lighting under my belt, then all those wonderful toys you sell won't be far behind. :)
 

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You are correct, more available amps (more current) will allow more load (more lights). BTW, all the controllers I offer are really quite simple to use. I provide detailed PDF files with color pictures that walk you through everything. I've had lots of people with zero experience successfully use my boards. Plus I'm retired so I'm almost always available via email to answer any questions or problems.
 

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Note: These calculations are VASTLY simplified, and are used for illustration only. It treats the Eagle Eye lights as if they were a purely resistive load. They are not! I do not know the internal construction of the Eagle Eyes you are using... They may contain a single LED chip and a resistor, they may contain multiple LED chips in any of a number of arrangements... I don't know... But the calculations below will still give some idea of what is going on...

I looked up Eagle Eye LED lights. They are typically rated at 12V and 9W each. That means they usually draw about 0.75A of current each, or they are effectively a 16Ω load.

When you run a 16Ω load on a 9V power supply, it will draw about 0.56A of current (9V/16Ω) which means it is now dissapating about 5W instead of 9W. Nearly half-power... so, yes, they will run cooler.

5 of these lights running on a 9V power supply are going to TRY to draw 2.8A of current (5 x 0.56A). Since your power supply is only capable of providing 1A of current, the current gets divided up among the 5 lights (about 0.2A each). This means your Eagle Eyes are only dissipating about 1.8W each. This is why they are staying relatively cool.

This is ONLY safe if the power supply you are using has built-in over-current protection. If you tried this with a power supply that does NOT have built-in over-current protection, you would likely overheat and burn out your power supply. This is why you were cautioned to check how hot your power supply was getting.

You were very lucky that your chosen power supply apparently DOES have current-limiting. Not all do...
 

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Discussion Starter #12
Note: These calculations are VASTLY simplified, and are used for illustration only. It treats the Eagle Eye lights as if they were a purely resistive load. They are not!

This is ONLY safe if the power supply you are using has built-in over-current protection. If you tried this with a power supply that does NOT have built-in over-current protection, you would likely overheat and burn out your power supply. This is why you were cautioned to check how hot your power supply was getting.

You were very lucky that your chosen power supply apparently DOES have current-limiting. Not all do...
Thanks for the post, jimdkc. When I finally get around to setting up the lights, I will sit with them to make sure the power supply doesn't get hot. Adding ohms to the mix tends to confuse me even further, but that's par for the course. What I appreciate is so many being willing to ensure we don't burn down our house while lighting up our graveyard. There is just too much irony in that happening, so I'm really grateful for every response.

I will take your calculations and see if I can find power supplies that match the amperage needed for the light sets we create.
 

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The specs for the eagle eyes link you posted state the wattage at 3.5W on 12V, not 9W. Using 12V that would be .29 amps (290ma). Using 9V, it will be less.
 

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The specs for the eagle eyes link you posted state the wattage at 3.5W on 12V, not 9W. Using 12V that would be .29 amps (290ma). Using 9V, it will be less.
Thanks for doing the math, J-Man. I was getting very confused by what I was finding online. From what I was reading of people installing them, they weren't drawing anywhere near .50 amps. I've found articles online about people using the lights in tricking out trucks and they said "the small bubble lens in front throws a fairly wide pattern and each LED uses a meager 0.12 amps." Another user of the lights on Amazon said they were pulling "0.106 amps so at 12 volts that is 1.27 watts power consumption each." As I mentioned, I get very confused by much of this. Partly because the numbers seem to be all over the place. But, mostly because I'm not quite sure what to divide into what, or any of the math that runs hand and hand with electrical props. But it's starting to make more sense to me. Part of it is learning the terms, but part of it is also finding explanations that jive with what I was finding for results.

The numbers you gave me explain why my power supply might not have heated up even with 5 lights on it. The lights might have been pulling a bit more than the power supply was rated for, but not by much. I figure now if I get myself a 9V 2 amp power supply, I can safely add seven lights to the system. With one set for my Pet Semetery and two sets for the larger graveyard, I will be able to pull off my master plan... world domination through Halloween props.

Thanks again. And that thank you is for everyone contributing. You've all been a great deal of help.
 

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Hey you're welcome! Here's two easy formulas for amps/volts/watts. You'll always know the voltage for the application, so if you know the watts or amps you can calc the third.
Watts ÷ volts = amps
Amps x volts = watts
 

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BTW, just a heads up on power supplies, make sure it's regulated or switching. Always check a new power supply with a meter and NO load to verify the voltage. If it's regulated or switching, the stated voltage should match with no load (or very close to it, usually no more than 1/4 volt over). Unregulated power supplies will output a much higher voltage until the load equals the rated amperage which is not what you want. On the flip side of that, when the load exceeds the rated amperage of a non-regulated supply, the voltage will drop below the stated number.
 

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Didn't mean to confuse! I had to calculate ohms to estimate current draw at the lower voltage.

Also, I didn't see where your Eagle Eyes were 3.5 watts. Most of the ones I found online were 9 watts!

Good luck!
 

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The ones I bought from ebay were rated at 9w per LED. But when I actually tested them with a multimeter, they only draw 0.07 amps at 12v on my regulated power supply. That works out to 0.84W. Looks like the real specifications are varying all over the place.

I advise everyone to test the lights before wiring everything together, just to make sure you wont have problems (fires!) later on.

One single 0.84W blue LED is easily bright enough for one prop. A green LED of the same power will be much brighter (because of the sensitivity of the human eye), while red would appear dimmer. I might try a few purple ones next year in my display.
 

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Discussion Starter #19
Looks like the real specifications are varying all over the place.

I advise everyone to test the lights before wiring everything together, just to make sure you wont have problems (fires!) later on.
I have yet to read of anyone testing them that says they're actually up to spec. They seem to all be less than what they are rated, but we'll be testing ours before the wiring begins just to be safe. We talked a friend with a multimeter into helping us out with the project.

The one thing that they all seem to have in common is that they don't draw nearly as much as any spot light I've ever used, and because they're so small, they hide really well compared to an old fashioned flood light. I will be adding a bunch to the haunt next year, but I am struggling with which way I want to go. Using yellow across the graveyard will give the area a nice candlelit feel that we can augment with some flickering lights, but we played around with color spots this year and I have to admit that at some point the Disneyesque look of a haunted graveyard on color overdrive sort of started to appeal to me. We're not haunters out to scare anyone, so the color just seemed to make it even less intimidating and more enjoyable for the youngest kids.

One single 0.84W blue LED is easily bright enough for one prop. A green LED of the same power will be much brighter (because of the sensitivity of the human eye), while red would appear dimmer. I might try a few purple ones next year in my display.
I have been hoping to track down some purple ones without much success. I guess I better wander over to Ebay and start looking. :)
 

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Discussion Starter #20
Didn't mean to confuse! I had to calculate ohms to estimate current draw at the lower voltage.

Also, I didn't see where your Eagle Eyes were 3.5 watts. Most of the ones I found online were 9 watts!

Good luck!
I am beginning to realize that what I thought was comparative to an "all these lights are the same" sort of product, are actually all over the board. And even the specs don't seem to help me as much as you gents have. The 12-volt Eagle Eye that I bought with the most information on it said in its specs:

Brightness: 70 to 90 LM Rated
Rated Working voltage: DC 12V
Rated Working current: 0.5A
Rated Power consumption: 3.5W each Pcs

But those current and power consumption stats don't match J-man's suggested formulas, and the multimeter reading by our friend didn't match any of them either. The newest lights I'm going to purchase are like Korax's choice, 9 watt. They list as a 9W 12V 18MM LED Eagle Eye Light. But in their specs it says:

Brightness: in Between 70-90 lm (or so strict symmetric)
Voltage: DC 12V
Rated working current: 300 mA (Less than or equal to)

Again, the math doesn't seem to work out quite right. A nine watt bulb needs a greater working current than 300 mA, right? It actually would be more akin to the .75 jimdkc posted, right? And yes, even Korax's actual measurements of the lights on a multimeter don't seem to jive with those specs.

So, another question to those of you who know more than I. When I'm working with this, it seems to me, that as long as the lights are rated for 12-volt DC and I'm using a 9-volt adapter, my voltage needs aren't really an issue as far as safety. It is how many amps I have available compared to the lights I want to run that is the issue. Run too many lights without enough amps and I heat up the wall wart...yeah, I learned a new word... and that is where my house bursting into flames becomes a possibility. Is that basically correct? If not, where did I mess up in my thinking?

Eventually, with your help, we are going to have such a well lit graveyard that I can't wait for another 316 days. :)
 
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