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Help making an LED lamp Answered

Alright, I want to make an LED grow light for my plants because the window I want to put them in doesn't get enough sun.

I need quite a bit of light for this application and it will have to be on for a significant part of every day so LED is a must.

I've been looking at the prices and it seems like the most economical option is to buy some LEDs off ebay, buy a driver... maybe some resistors... then mock up some kind of heat sink to connect them to.

I was considering about 10-20 ten watt on chip LEDs. This light is going to be in a room I'm in a lot so I don't want to go with any funky colors. I'd like to just use daylight spectrum LEDs. Something around 6500k.

Anyway, I'm thinking it makes the most sense to get one big driver to run all the LEDs rather than one driver for each. That just seems cheaper and frankly more interesting.

But I need help understanding how to wire the whole thing together and understanding whether I need resistors etc.

So I'm looking for some general help figuring out what to buy and then how to wire it all together.

Thanks :)

Discussions

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WillE2

3 years ago

Well, it totally works. I have a 9000 lumen, 100 watt grow light now. The thing is like the SUN! :D Which was the point.

Now my pepper plants can grow. I'm trying to play around with some perennial crop plants that can be grown indoors. So I have some peppers and I'm thinking about putting in some black velvet blackberries. I also have a fairly extensive spice garden. All inside. My home is like a green house at this point. Every window is covered with plants. And the last big window basically gets no sun so... giant grow light.

Total cost 80 bucks give or take.

What I want to figure out is how to do this with the little LEDs you buy from china because those things hilariously cheap.

You can buy 100 of them for like 10 dollars. Maybe another 20-30 for the driver... and the frame should be something between free and 10 dollars.

The bit I keep having a hard time with is working out how to do the wiring so I don't short out the LEDs or nearly as bad don't supply enough power.

The little LEDs tend to have a max voltage of about 3.5 volts and a max current of something like 300 ma.

So how do you rig up 100 of them? You can't go over 3.5 volts and I worry if I put the current up that that will fry the LED.

Is voltage the only thing I have to worry about or do I have to current regulate as well?

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maxsbl

3 years ago

It depends on the plant but, with LEDs the reduced heat output promotes faster growth. It sounds like you're interested in building your own grow light. This website probably has what you need. They also sell some high quality cheaper LED grow lights. www.superbrightleds.com

LED grow light.PNG
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robo10302

3 years ago

I don't know if this would help but don't the plants need actual sunlight even for the heat? It would suck if those little guys started dying, Ok so heres how you wire it. I suppose you're going to get a strip of leds and they usually run around 12v, next you would need a led controller circuit which is really cheap just search up a 12v led circuit driver but make sure you read the specifications set by the manufacturer, and at last you would need a power supply of 2-3 amps. You can buy it all from amazon or eBay if you have any particular parts in mind after searching ill be glad to help you out in detail. :)

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WillE2

3 years ago

Also, I'm seeing a lot of people selling lenses for these LEDs... is that needed or is that for another application I don't need to worry about?

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ProbleeWillE2

Reply 3 years ago

I have been wanting to build a grow also. I wanted full spectrum and it's like by the time I buy all the stuff it would be cheaper to buy a led grow light. If all you want is white light you may want to check in to buying a 50 watt fixture or 100 watt fixture. From eBay, I just bought a 50 watt, 6500k, 4500-5000lm PIR outdoor fixture for $30 with free shipping. I know that takes all the fun out. I'll probably take it apart and learn about heat sinks and power supplies. I want to build one too. I'm struggling not to buy the 300 watt full spectrum led grow light for $117 w/free shipping. Good luck

Rob

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WillE2Problee

Reply 3 years ago

Well, I went through some designs. I even got so far as to work out how I would build the heatsink/LED holder. I was going to cut up a big sheet of aluminum to make a big LED holder with the whole thing being a big passively cooled heat sink.

But then I started going over a few things and I realized that the only way to get a good price on LEDs was to buy them directly from China. Which all thins being equal would be fine only the shipping was estimated to be like 4 weeks or something. On top of that, I often have buyer's remorse from ebay. I prefer Amazon because there is typically less nonsense. I don't mind Ebay from US sellers... you can often literally call them on the phone and work things out if there is an issue. But the Chinese ones all very much buyer beware.

Anyway, so I started looking at other things and I found this:

http://www.amazon.com/gp/product/B00NW6KSA6?psc=1&...

Now keep in mind, each one has a built in heatsink and driver. These bulbs handle normal AC power out of the wall with no additional electronics required. So they're super simple. I bought 10 pairs of fittings for these bulbs for about 10 dollars.

The price per bulb is 6.70 USD each. Which is pretty good if you go over the stats. I'm thinking I'm going to use something between 4 and 6 of them in a row as my main grow light. Which leaves me with between 6 and 4 bulbs after that which can be used for other things.

It is just simpler this way. The one thing I was stressing out about with the previous concept was the heatsink. I was really worried that I would go through all this trouble of cutting up this aluminum sheet, welding it together, and then having it not be able to dissipate the heat. So, I apparently don't have to worry about that with these bulbs.

All told, I'm spending more than I wanted to but this is way easier, I know it will work, and I have some extra bulbs that I can use in other projects.

The next project I could do with the spare bulbs is a planted fish tank. I've always wanted one of those.

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ProbleeWillE2

Reply 3 years ago

I laugh, with you that is. I am on my 3rd redesign. My first attempt was a box to hold cfls. I built a nice box and bought 200 watt cfls and all the hardware. I gave up on cfls and was going to use cob leds and last night I ran across this video and have now decided to call Cree and get the low down on these new blue leds. That looks like a lotta light for not much power. I believe they are the technology the guys won the Nobel prize for. They don't seem all that expensive. I can't figure out why the xlt leds on ebay don't come with the lens.

Happy Trails......

Rob

http://www.cree.com/LED-Components-and-Modules/Pro...

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p...

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WillE2Problee

Reply 3 years ago

My issue with that is that I'm putting this in my living room. That's where my plants are... So odd lights are going to be distracting. I want something that is similar to sunlight.

Anyway, I've already bought the damned things so we'll see what happens.

I'm thinking about doing a planted tank as well. so that was another project that I decided to spin into this given that I'm getting at least 4 more bulbs than I actually need.