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Topic: Powering 50 Watts of Leds with Arduino (Read 4443 times) previous topic - next topic

Erod998

Hello. I am building a LED Light for my aquarium. I have a few questions first.
These are the LEDS I'm buying.
http://www.ebay.com/itm/5pcs-10W-Pure-White-800-900Lm-High-Power-Bright-LED-Bulb-Lamp-Light-10Watt-9-12V-/331021461675?pt=LH_DefaultDomain_0&hash=item4d126aa8ab

Ok, when I power these, do I wire then parallel or series?
Next, how would I power them? What kind of driver would I need to buy? I need it to run off a standard wall plug. (110-120)
Now, is it possible to use an arduino and a pot to dim the less when I want?
Thanks guys, if you need any more info just let me know.

Simpson_Jr

#1
Feb 10, 2014, 04:16 pm Last Edit: Feb 10, 2014, 04:19 pm by Simpson_Jr Reason: 1
For safety reasons I'd try to find a power supply capable of handling twice the power you need. A supply just being able to handle 50 watts may overheat and cause problems, it more or less is  like driving your car at top speed continuously.

Whether you wire'm parallel or in series shouldn't matter much.

Advantage of wiring 'm in series is that you will need to limit current once, disadvantage is the need of a 60volt power-supply.

Parallel makes it possible to use 12 volts, but... you'll need to limit current for each led individually.  Your leds apparently can take 1 amp. Wiring all anodes + cathodes (true parallel) and using a 5 amp limiting-circuit unfortunately isn't a good idea. There's a lot of chance 1 of the leds will pass much more current as the rest and once it breaks down, the other ones will follow soon. That may take a while..., but can easily reduce the lifetime of your leds from  50.000 hours to less as 500.

Here's an... instructable on how to power high power leds & limit current, in step 8 there's a circuit i've used in combination with an arduino several time, but other ways of limiting current exist as well.

Whether you wire'm in series or "parallel", limiting current is most important.

Using a potentiometer to dim leds is possible,  every arduino has at least 6 pins to read analog (pot) values and it also has at least 6 PWM-pins that you can use to dim leds. They're quite easy to use if you read a bit about the analogRead()- and analogWrite()-function.


ArduinoGuy18

#2
Feb 10, 2014, 04:42 pm Last Edit: Feb 10, 2014, 04:52 pm by ArduinoGuy18 Reason: 1
It will be nice to have a small SMPS like this http://www.ebay.com/itm/New-12V-DC-2A-5A-8-5A-10A-12-5A-15A-20A-30A-Regulated-Switching-Power-Supply-/190852157998?pt=US_Lighting_Parts_and_Accessories&var=&hash=item2c6facd22e  And you can easy control them whit Arduino , but i suggest to put those high power LEDs on a heat sink.

fungus


For safety reasons I'd try to find a power supply capable of handling twice the power you need. A supply just being able to handle 50 watts may overheat and cause problems, it more or less is  like driving your car at top speed continuously.


Not just the power supply. Those LEDs are going to burn up if you run them at 10W with less then perfect heatsinking.

A 700mA driver is a much safer bet.

PS: You'll still need a big heatsink. There's no way you can use them as-is.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

drab

im doing the same thing and this is what im doing...im running 150 watts worth of them using an uno and a high power driver from spark fun....i have mine wired up in a parallel series circuit...i.e..i have 4 leds wired in series and two sets of four wired in parallel and seems to be working fine...what size tank do you have first off and to be  honest 10 watt leds are way to much for corals it will cook them like crazy....and for simplicity id go to amazon and look up led strips you can get a 16m strip of them for dirt cheap and those are great for using with arduino.....if you want to talk more im me on here and ill help you out as most answers you will get here are going to be vague at best

CrossRoads

Ideally one would use a constant current driver for high power LEDs:
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

fungus


10 watt leds are way to much for corals it will cook them like crazy....and for simplicity id go to amazon and look up led strips you can get a 16m strip of them for dirt cheap and those are great for using with arduino.....


Good idea.

Big LEDs are a pain to work with. A few meters of LED strip gives out a lot of light and is much simpler to drive.


if you want to talk more im me on here and ill help you out as most answers you will get here are going to be vague at best


Yep. We can tell you how to hook up some LEDs but we have no idea what's really needed for an aquarium.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

drab

#7
Feb 10, 2014, 08:45 pm Last Edit: Feb 10, 2014, 08:48 pm by drab Reason: 1
and also if you use the fade function with the arduino you can control the brightness of the leds without using a pot...btw depending on tank size the biggest led i would use is a 3w led nothing biiger than 5w and those are still a pain to power....

Erod998

#8
Feb 10, 2014, 10:28 pm Last Edit: Feb 10, 2014, 11:15 pm by Erod998 Reason: 1
Ok, I have decided not to buy those crazy powerful LEDs, after all you guys informed me of. Also, I don't expect ya to know what's needed for an aquarium, that's what the fish forums are for, lol. Ok, I have now decided to purchase a led strip off eBay.
http://www.ebay.com/itm/150926886392
I will be buying white and blue.
On to my next question. I want to power 2 different strips, at different times. I want some white less on during the day, and a few blue ones on at night. How would this all hook up to the arduino? Also, is it possible to hook a pot into it for dimming? And could someone post the code? Sorry for all these noob questions. I stopped doing stuff with eletrconics about 3 years ago and now I'm getting back into it! Thanks everyone!

drab

erod.....those are pretty good and like i said im me so we can exchange emails and ill help you with it im too busy to sit here and type it all out right now i know what you are wanting to do as i have it pretty much built myself and coded out and all also the fish forums wont help you that much either been there done that...

Erod998

Sweeeet! Thanks for helping me out! Just sent my email your way  8)

Simpson_Jr

One small thing I would like to advise you is to test your project before using it and to be very sure it works like you want.
Fish/plants are quite sensitive and they won't like it when a small error would cause non-24hrs days.

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