Looking for DIY kits for LED fixtures

What kind of angle of the 'beam' are you looking for? And why reflectors anyway?

joe

Reflectors? So I can direct the beams to my liking. But, since you asked the question, the square LEDs that I've seen project a pretty large pattern... typically 140 - 160 degrees in both planes. I'd like to be able to control the lighted area rather than lighting the whole backyard or neighborhood.

I'd like for the lights to have a flatter vertical, but wide horizontal beam. Maybe 45 - 60 degrees vertical and around 120 degrees horizontal.

I've thought about making my own reflectors from acrylic panels covered with aluminum foil, or from polished or painted sheet metal panels. I'd prefer to buy the parts rather than resorting to manufacturing them.

Dave M

I made my own, so I guess I can't be of much help. :P

Tim

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Caution: A few years ago, whilst climbing over a pile, I stepped on a loose piece of paper and did a flying split... left me so sore I went to the doc to make sure I hadn't sprung my artificial hip joint :-( ...Jim Thompson

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Deal extreme at

has a whole range of bare LEDs and various hardware, reflectors, drivers, etc. Yes its cheap Chinese, so you have to be a bit careful about what you read vs what you get.

--
Regards, 

Adrian Jansen           adrianjansen at internode dot on dot net 
Note reply address is invalid, convert address above to machine form.

Also be very careful about the power voltages. Many things on DX are

220 only. I looked at strip LED lights once and decided to not buy them. They offer various pieces but little info on how they go together and how well they work for any given application. How do you say Caveat Emptor in Chinese?

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Rick

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

D'oh!

I wouldn't suggest reaching for that light, to break your fall; it's built from uninsulated copper clad (2oz), one side is AC line + 100VDC, the other the ground return for the LED chains. Hence it's also mounted beyond normal hands' reach..

Other side of the lab looks as good, though sadly lacking in bench space,

Though not in screen space:

Tim

--
Seven Transistor Labs 
Electrical Engineering Consultation 
Website: http://seventransistorlabs.com

You can buy them pre-manufactured in most hardware stores now. They look like a typical halogen yard lamp but inside there's a square LED chip array covered with yellow phosphor.

The only reason to build your own would be for running at odd voltages. Phillips and CREE make some nice LED components. Manufacturers are finally converging on standard package heights so many of the late model power LEDs may all use the same model of lens.

Lots of lenses:

You can also buy generic linear lenses if you're on a budget and don't need much focusing. They're just an 'M' shaped strip of plastic that you cut to size and place over your LEDs.

Most modern LEDs require precision PCB mounting. You'll need to buy the PCBs if you can't make them.

LED lights are very simple -- no need for any kit -- just an interesting/lively weekend afternoon. To create the intense light needed for outdoor purposes, the LEDs need to be connected in parallel. Each LED has to have a dropping/current limiting resistor, the value of which is calculated easily from the nominal current/ voltage values obtained from the LED datasheet. The power supply could be a simple linear one. One of our products is commercial lights -- typically 40 white-light LED lights consuming 1 A of current. One could also use light-weight reactive power supplies for LED lights that plug directly into the wall sockets. Hope that helps.

That wastes a lot of power. If you put many LEDs in series, and use a constant-current power supply, there will be only one low-value resistor for the supply to sense the current. I made one unit myself, 10 while LEDs in series, running about 300 mA.

I later built two units to replace kitchen fluorescents in a suspended ceiling. these have 20 1W LEDs, all in series, and a commercial off-line power supply.

Jon

Here's how I built mine - no kit needed.

1 piece of flat aluminum bar and 2 pieces of aluminum L channel. End view:

------- -------- | _____________ | | |_____________| | | ^bar^ | | |< L channel | |

You can screw the L channels to the bar, or use epoxy. The auto parts store sells epoxy that works well with aluminum. The square LED modules mount with #2 hardware.

Ed

You would never be able to make anything that would do what you want more cheaply than by buying something off the shelf. They typically consist of small plastic individual reflectors around each LED emitter with the emitters all bolted onto an aluminium heatsink. Modern lighting engineers are control freaks so you can get several variants of the reflector pattern for the same basic light emitter unit.

Some of the units sold for stage lighting would probably do what you want after a bit of careful weather proofing.

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Regards, 
Martin Brown

Yes, these are used for growing weed - I don't know the area very well - you google/ebay "grow lights."

Or you can pretty easily put one together yourself. But it's a project, but I'll describe the basics. Silicone the 10W white leds (about $1 apiece) to a

1/8 in. sheet of aluminum. Use teflon coated 14 wire. Silicone any bare wire with clear DAP Silicone and a caulking gun. (5$ a tube.) Silicone around led contacts. Buy a 12V power supply on ebay from china - 15A is $

You're probably right about the cost, but that isn't my primary concern. I've looked at the outdoor spotlights and area lighting fixtures, but haven't found anything that is described well enough for me to be comfortable with ordering them in quantity. After a bit more research and thought, I think my best solution is to make several fixtures similar to parking lot lighting fixtures and mount them on strategically located poles. That way, the light is directed more directly onto the area and I don't have to worry about focused reflectors or lenses. That kind of fixture doesn't need a shaped reflector... only a weatherproof enclosure, which I can build easily.

Thanks to all who replied.

Dave M