# Help with t10 LED's for homemade underwater fish light :)



## acearcher (Apr 10, 2013)

Hello, 

New here and am looking for some help on how to best wire some T10 wedge LED's.

Basically I am looking to wire between 5-10 T10 wedge LED bulbs, where each bulb has 28 individual LED's on it. After wiring these together i will be putting them into a watertight glass jar and submerging them 1-4 feet in fresh water in order to attract baitfish (and therefore bigger fish) at night. These will be running of a 12v boat battery for 3-5 hours at a time for occasional use.

I have been playing around with 5 of the bulbs and have soldered them together in parallel. To do this I basically determined which wire on the wedge was the positive one and then soldered those together and soldered the negatives all together, ran 12v power to those points and voila "let there be much light".

I intend to add in a in-line fuse holder on the hot line with a small automotive type fuse as well. The lights work fine and are all at maximum brightness. 

However, I am a complete nublet when it comes to this stuff so i have no idea if wiring them in this fashion is the correct way to do it!!!

I'm not terribly concerned if this will cause the LED bulbs too burn out a little more quickly than normal, but wouldn't want them burning out after 10 hours of use either. 

To be honest i am not experienced in this area... so any discussion of ohm's laws, and theorys of relative resistance/conductivity etc are going to be wasted on me. 

If i need to change my setup (and or add to it) please give it to me in as simple (dumbed down) version as you can 

Thanks so much in advance for any assistance you experts can render.


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## acearcher (Apr 11, 2013)

Here are a couple of pictures showing where i am at now.


It's still pretty rough around the edges but want to work out the bugs before it gets all the finishing touches.












The second picture really does not do it justice, it's exceedingly bright (to the point of hurting your eyes is you stare at it)

In any case, my main question remains will i be okay with having this wired in this parallel fashion, or am i missing anything vital?


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## acearcher (Apr 11, 2013)

Also out of curiosity how would i go about wiring these in series if i wanted to go that route. I tried to do so at first and with every additional bulb i attached the lights became dimmer and dimmer until there was no light output at 4 bulbs. 

Again this would be running of a 12v car battery.

specs on the lights are as follows.

Socket Type: T10 Voltage: DC 12V LED Quantity: 28pcs 3020 SMD LED Light Color: White Power: about 2W Color Temperature: 5000-6000K Lifespan: 50,000 Hours Lighting Angle: 360 Degree Total Height: About 35mm Diameter: About 10 mm


again thanks for any comments you can throw my way on if i am fine with the parallel setup or should i wire these in series (and if so how to do it)


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## AnAppleSnail (Apr 11, 2013)

You've got the electrical stuff handled pretty well. LEDs can heat up, though. How many watts is each (Electrical watts, not 'replacement incandescent' watts) bulb? We're looking for a number between 2 and 10, most likely. That's about how much heat is warming up that jar, and LEDs don't like high heat. Run it in a sink of water for an hour, then take it out, turn it off, and feel for the LEDs to be hot. If not, you're set.


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## acearcher (Apr 11, 2013)

Here is the information on the bulbs from where i purchased them.

*T10 168 194 W5w White 28 SMD LED Wedge Light Bulb Lamp 12v*

Socket Type: T10 Voltage: DC 12V LED Quantity: 28pcs 3020 SMD LED Light Color: White Power: about 2W Color Temperature: 5000-6000K Lifespan: 50,000 Hours Lighting Angle: 360 Degree Total Height: About 35mm Diameter: About 10 mm

So am not sure if the W5w means they are 5w or if the 2w listed next to the power is the correct number.

doing the sink test now will report findings. Im hoping that being submerged in water will help get rid of any heat buildup pretty quickly.


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## mds82 (Apr 11, 2013)

Just another idea, but if you cut a piece of aluminum into a circle you could glue that to the top frst. Then you could use a single XP-G LED or something similar and light up the whole glass. The aluminum and the top of the glass would act as the heatsink. You would just need a small LED Driver, such as the Bucktoot - http://www.ledsupply.com/bucktoot.php It takes 12v input


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## acearcher (Apr 11, 2013)

Okay so completed the 1+ hour soak test while running and there was no real heat coming from the bulbs (they felt very very mildly warm i would guess they would have been somewhere around 85-90 degrees) so i guess that these are going to be good for some extended field testing session's soon  

Would the single XP-G LED provide a similar amount of light to the 5 bulbs with the 28 LED's in each bulb? The reason i am doing this is that i have looked into purchasing commercial made submersible LED lights and they are all far beyond my budgetary means. but they all seem to be priced on the number of LED's contained within the unit. ie. most with 100-150 leds cost around 130-140$. 2-300 led's are around the 200$ mark etc. Thats the main reason that i went with the multiple LED / Multi directional Bulbs (also one of the more popular commercial models seems to use this setup) With the setup that i am doing i am able to use about 150 led's on the 5 bulbs (28 each bulb) and have that easily fit inside the small mason jar while retaining plenty of room for about 10 oz's of lead weight to sink the whole setup.


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## VegasF6 (Apr 12, 2013)

It seems to me what you are doing will work fine. As stated, electrically you are already wiring them correctly. Your question about wiring them in series, well you just can't do that without higher voltage to start with. These are already a pretty low end product so i can't imagine going to any sort of extremes to try and protect them. Maybe submerging the leds in distilled water or mineral oil first would keep them marginally cooler, but I don't expect it would make a significant change in thier life. 
Curious how water or oil inside would effect the buoyancy? I have to imagine with oil it would be buoyant and with water, more or less neutrally buoyant?

I am sure we could come up with a new design using a decent lighting class led such as the XP-G and a more efficient power supply too, but it seems what you have is already working for you. I expect a single XP-G driven hard could put out more light than the current setup, or close. Your current 140 leds, maybe 3 lumens each, 520 raw lumens not figuring any losses. Cree states "up to 493 [email protected] 4.9W." But the XP-G will be more directional, and will require some drive circuitry.


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## AnAppleSnail (Apr 12, 2013)

acearcher said:


> Would the single XP-G LED provide a similar amount of light to the 5 bulbs with the 28 LED's in each bulb? The reason i am doing this is that i have looked into purchasing commercial made submersible LED lights and they are all far beyond my budgetary means. but they all seem to be priced on the number of LED's contained within the unit. ie. most with 100-150 leds cost around 130-140$. 2-300 led's are around the 200$ mark etc. Thats the main reason that i went with the multiple LED / Multi directional Bulbs (also one of the more popular commercial models seems to use this setup)



A single XP-G will give you around 500 lumens of light at reasonable power levels. For your 12v battery, you could use three of them in series ($20 in LED bits, with some math to figure out the other parts) and get 1500 lumens. Your homebuilt stuff will probably work better than the 'professional' gigging lights I've seen. And as you know, the price point can't be beat!


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## acearcher (Apr 12, 2013)

VegasF6 said:


> Curious how water or oil inside would effect the buoyancy? I have to imagine with oil it would be buoyant and with water, more or less neutrally buoyant?



Wait are you saying i could fill the jar with either distilled water (which i have) or mineral oil? and still run the lights? wouldn't that cause them to short out? It currently is taking about 9 ounces of lead weight to hold these under water when they are all put together in the mason jar. I don't mind using the weights but if these started out neutral buoyant they would take a lot less weight to sink.

I am fairly certain that i saw something about these lights not being waterproof.


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## VegasF6 (Apr 12, 2013)

Believe it or not, water doesn't conduct electricity. It's the impurities in water that do that. So yes. It will effect the optical qualities, but I don't see that being a factor in your case.
I would assume if you chose mineral oil it would actually float, but I don't really know.


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## AnAppleSnail (Apr 12, 2013)

acearcher said:


> Wait are you saying i could fill the jar with either distilled water (which i have) or mineral oil? and still run the lights? wouldn't that cause them to short out? It currently is taking about 9 ounces of lead weight to hold these under water when they are all put together in the mason jar. I don't mind using the weights but if these started out neutral buoyant they would take a lot less weight to sink.
> 
> I am fairly certain that i saw something about these lights not being waterproof.



Low voltage stuff won't short out easily. One way to measure impurities in water is to measure resistance, and you get a figure that's really ohms per meter. If your smallest bits are 2mm apart, you could calculate the power lost to resistance. But water can do strange things to circuits, including delaminating the layers of the chip.

I could build an intrinsically-waterproof LED device made of parts that can be immersed for months (In reasonably fresh water). A prebuilt assembly could have some surprising reactions to water, and if it swells up wires may pop loose. Corrosion can become a problem, too. It sounds to me like flooding this jar is a solution looking for a problem.

If you really want to mess with it, fill her up with epoxy and see what happens. This ("Potting") also makes things waterproof.


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## VegasF6 (Apr 12, 2013)

Good point with things swelling up. I don't think corrosion could be a problem though could it? If anything, just the opposite. Or at least with mineral oil since it protects the components from oxygen. 
Can metals corrode in distilled water? 

Incidentally, apparently even perfectly distilled water will conduct to some point, but the resistance is so high as to not be much of a concern. (or so a little more research says)
Anyone ever see any of these videos of workers washing high voltage lines from a helicopter?
http://www.youtube.com/watch?v=lcjhjna9jZE


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## AnAppleSnail (Apr 12, 2013)

VegasF6 said:


> Good point with things swelling up. I don't think corrosion could be a problem though could it? If anything, just the opposite. Or at least with mineral oil since it protects the components from oxygen.
> Can metals corrode in distilled water?



Anything on the stuff you soak will increase the conductivity of the water. Washing everything with isopropyl alcohol gets old fast . Also, the mason jar lid may provide electrolytes.

Corrosion "should" only attack the outsides of things. But a loose solder joint can be attacked more effectively and shows results just as well as a cut wire. Metals can corrode under all kinds of conditions with voltage on them. Calling water in a container with dozens of materials inside is more about "How closely am I looking?" Stuff comes off electronics in water. Plastics, resins, plasticizers, maybe solder paste, flux, and fingerprints. After that, you're just waiting on what fails first. Dry electronics are happier than wet ones.


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## VegasF6 (Apr 12, 2013)

Those are all great points, thanks for bringing them to our attention!

I have to say though, I have LED buggy whips that are encased in oil. Leds, a little phenolic resin board and some SMD resistors. They have been working trouble free for years. Been to the warehouse that assembles them too, and let me tell you, it ain't exactly a clean room up to Intel standards 

And of course there are people who submerge mother boards in oil. So while there may be hazards, in practice it seems the risks are minimal. I suppose it depends on what final results you are looking for. Lucky these aren't being sent to space, lol.

Actually I have project on the back burner with an RGB led sequencing in baby oil which probably is even less pure, what with the added "fragrance" if I ever actually complete it I will document the results.


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## acearcher (Apr 12, 2013)

wow, good stuff to learn guys, and i greatly appreciate the feedback you have given! I took a closer look at using the mineral oil and although it might work good, cost would keep me away from it. (would cost about 2$ in mineral oil to fill the mason jar vs 25cents in lead)

Im going to do a bit of field testing with this and if all works good i think im gonna build a couple more lights using some clear pvc pipe and some larger g4 type leds I figure i could put in 4-5 of the 102 or 120 led pure white g4 tower types and have 2500 or so lumens...  that will light stuff up like nobody's business. 

Again thanks for your feedback guys!


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