Hopefully you guys can help me out on this one, I might have gotten in a little over my head. I don't know much about electrical engineering, but am usually pretty decent at researching enough to piece things together.

I have an outdoor lighting project. I have to make some custom LED lights that will be fixed to stone walls. Off the shelf units weren't cutting it, and is why a DIY solution is in order.

For simplicity's sake, I'm going to just focus this thread on ONE of the walls, so 12 lights total.

Right now, I am looking at either using a 5w or 10w LED chip. Either this:
http://www.ledsupply.com/leds/cree-xlamp-xpg2-high-power-led
Or this:
http://www.ledsupply.com/leds/cree-xlamp-xm-l2-leds
I think 10w will be overkill, but I need to purchase some and test which will give me the amount of luminosity I need.

I need these lights to be app controlled to turn them on and off and dim them. I need to do this all the cheapest and easiest way possible. I can solder components, and I am building custom housings for all of these so that part isn't the issue. I am just a little lost on which drivers/controllers will be sufficient.

Talking to a friend, if I was to use the 10w LEDs above, we discussed using a 24V power supply and two of these http://www.ebay.com/itm/300-3000mA-...a473db983:g:wRUAAOSwo8hTopLs&autorefresh=true 1 per 6 leds. However, I don't think this is the best or easiest way to go about this.

Hopefully you guys have some insight. Like I said, I'm a little lost on this whole subject. Thanks in advance!

 

That looks about right. I'm not certain that the linked controller can reach the voltage you need for 6 LEDs in series, on a 24V supply. It might, but it's hard to tell. So you might need 3, for 3 strings of 4 LEDs each.

Don't put the LEDs in parallel unless you give each one its own controller.

 

You say the commercial fixtures "weren't cutting it"- in what respect are they inadequate?

The E-bay LED drivers could do the job, by far the simplest solution to meet your requirements.

Your hardest task is managing the thermal and environmental design problems.
Driving them with the correct current is the easy part.

Left unprotected, the system would last a few months at best before failing in an outdoor application.
You will need to design your heat sink to manage the substantial heat produced, this is also a bit harder than you might anticipate. You need to make sure your environmental isolation does not isolate your heat sink from cooling...

Then there is that app control thing... again, tons of work that is already done in a commercial product.

This project sounds like a ton of work and frustration to me, I would try desperately to find a commercial solution, otherwise you are really doing a difficult product design effort. cost / benefit = not attractive

 

You say the commercial fixtures "weren't cutting it"- in what respect are they inadequate?

The E-bay LED drivers could do the job, by far the simplest solution to meet your requirements.

Your hardest task is managing the thermal and environmental design problems.
Driving them with the correct current is the easy part.

Left unprotected, the system would last a few months at best before failing in an outdoor application.
You will need to design your heat sink to manage the substantial heat produced, this is also a bit harder than you might anticipate. You need to make sure your environmental isolation does not isolate your heat sink from cooling...

Then there is that app control thing... again, tons of work that is already done in a commercial product.

This project sounds like a ton of work and frustration to me, I would try desperately to find a commercial solution, otherwise you are really doing a difficult product design effort. cost / benefit = not attractive

Let me rephrase that. Off the shelf lighting units won't cut it. The current in wall lights are more for aesthetics, rather than for lighting up an area. The housings I am making are aluminum and I'm going to use the actual housing as heatsink. They're designed in such a way to throw light out across the wall and at an angle across the patio. Everything will be weather sealed, the mechanical aspect is the easiest part for me as that's what I am used to.

For the lighting, I would rather buy off the shelf controllers and drivers. I just want to make the actual light itself.

Getting into this project, I was assuming there was something along the lines of this https://www.amazon.com/Controller-C...89295167&sr=8-19&keywords=wifi+led+controller That could handle what I needed to do.

Sorry if how I phrased it was confusing.

 

The Mi Light looks nice, it's not a current regulator, it assumes that you are connecting LED strips that have current limiting resistors built-in.
You could use this if you included current limiting power resistors in your lights.

For example- the Cree XLED Vf 3.05V @ 1500 ma.

Connect 6 LED's in series- Vf total is 18.3V

24V -18.3V = 5.7 Volts.

5.7V /1.5A = 3.8 ohms.

5.7V * 1.5 A = 8.55 Watts

A 3.8 ohm, 10 watt resistor is what you need, not a common beast, but doable.

Note that of the 36 watts feeding this setup, 8.55 watts got straight to heat, not very efficient, but simple.
You might be tempted to add more LED's in series here, but this makes the circuit very sensitive to voltage changes and variations in LED Vf.
It's a compromise, the fewer LED's, the more stable and predictable, but more wasteful of power.

 

Hopefully you guys can help me out on this one, I might have gotten in a little over my head. I don't know much about electrical engineering, but am usually pretty decent at researching enough to piece things together.

I have an outdoor lighting project. I have to make some custom LED lights that will be fixed to stone walls. Off the shelf units weren't cutting it, and is why a DIY solution is in order.

For simplicity's sake, I'm going to just focus this thread on ONE of the walls, so 12 lights total.

Right now, I am looking at either using a 5w or 10w LED chip. Either this:
http://www.ledsupply.com/leds/cree-xlamp-xpg2-high-power-led
Or this:
http://www.ledsupply.com/leds/cree-xlamp-xm-l2-leds
I think 10w will be overkill, but I need to purchase some and test which will give me the amount of luminosity I need.

I need these lights to be app controlled to turn them on and off and dim them. I need to do this all the cheapest and easiest way possible. I can solder components, and I am building custom housings for all of these so that part isn't the issue. I am just a little lost on which drivers/controllers will be sufficient.

Talking to a friend, if I was to use the 10w LEDs above, we discussed using a 24V power supply and two of these http://www.ebay.com/itm/300-3000mA-...a473db983:g:wRUAAOSwo8hTopLs&autorefresh=true 1 per 6 leds. However, I don't think this is the best or easiest way to go about this.

Hopefully you guys have some insight. Like I said, I'm a little lost on this whole subject. Thanks in advance!

A current limited power source is best. Let the voltage across each LED fall where it will. Second choice is a voltage regulated supply with a limiting resistor. Worse choice, but it works, is just a power supply, eight 3 V LEDs running at 24 V supply. I have been running a 10 W LED at my bench for years off of just a wall wart power supply. Slightly under rated on power. The LED is rated at 9 to 12 V at up to 1.5 Amp. I am running itb at9 V and about 400 mA. Brightness is less than maximum but it works such as it is.
Precise calculations on the current limiting resistor? No. Anything close will work.