What is the best LED type for interior lighting?

 I am wanting to improve the light quality in my sailboat. I would like to build fixtures and controls myself and this looks like a good place for DIY ideas.

I have a mix of light bulbs and none are serving all that well. All are 12VDC. All lighting will be powered from the 12V house batteries. The best light I have comes from halogen 20 watt bulbs but they generate too much heat and consume too much power. LED replacement bulbs I have tried so far are not so great for interior light quality and cost aprox $40 to $50 USD each and I have 10 fixtures with both red and white bulbs plus 5 reading lights. Total replacement cost could be aprox $1000 USD. Then the other problem is the light is a bright point and can be a bit blinding if your look in the direction of the fixture. I am thinking of wash lights for most lighting and keeping the reading lights for...  well, for reading. I do have an acceptable LED for the reading lights but always on the look out for a better one. 

I have been on aircraft that used all LED interior lighting and it was the best LED lighting I have ever seen. The systems used a combination of white LED dome lights and RGB side wall wash lighting. The wash lights could be tuned to an impressive range of color including very pleasant white. So I know it is at least possible get really good light from LED's. Downside to this is it's expensive and designed for 28VDC from aircraft power. The controller was a dedicated cabin interior control module and computer.

The other requirement for the boats interior lighting is to have red light for use while underway at night to help keep the night vision. Red LED's I have used for this are very harsh and poor quality for getting around in the cabin.

I would like to try RGB LED's for a wash lighting system that will give either white or red. Preferably with both variable and dim-able so it can be tuned or programed as desired. The control modules I have found so far make a lot of claims for their multi-color capabilities but not about their steady on white light quality. Again I am interested in white and red lighting however if a large variation of colors is a side effect that can be turned on for fun thats fine but not needed.

I would be happy to document my project and post it here if I find a good DIY solution. So far I have found a couple of RGB controls here and may try one but I would like to hear about the white light quality before I start buying parts.

My homework for now will be to calculate an actual quantity of light needed and how many controls I would need/want. 

Thanks for your ideas.

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LED lighting can be a bit too blue and hot, but there are warm white LEDs available now, they might be worth a try, otherwise Luxeon or Cree are probably the best LED makers to use - their LEDs are repeatable in colour and sensitivity and efficient. It sounds like you know what you want, and you want a quality job, I can't recommend LEDs off Ebay for that. I have some wash light strips from Osram that are nice, but they aren't suitable for your application.

viking42 (author)  steveastrouk7 years ago
For my application I will need to build several fixtures and have separate controllers for each. Eventually I will want controls for port and starboard in the main cabin, port and starboard in the V-berth, quarter berth, head and galley. So I would like the simplest controller. I would be OK with an ON-OFF-ON switch (red, off,  white) and a small knob for a dimmer. It would be nice to have a fine tune for adjusting color quality of the red and white light, but the fine tune can be tiny trim pots inside the case. When wandering into the boat I need to be able to hit a switch and get red or white light and not have to fuss with dialing in a color.

 I guess I could build two strips of RGB LED's into the fixture and tune each to the color I want and have on off and dim. But, could I also have two controllers each tuned to the light I want and drive one RGB LED strip?

Can anyone refer me to the simplest RGB controller that could give one color of light and be dimming?

Thanks again

Got to be an off-the-shelf device to do what you want ?
viking42 (author)  steveastrouk7 years ago
 Off the shelf item not required. I should have asked for reference to simple kit or plans. I am wondering if I am overlooking something simple as far as controlling RGB LED's. The controller kits/plans I have found so far all have a programable or pre-programed chips. Is it necessary to build a complex circuit for what I am wanting for lighting or can it be done with a switch and a few trim pots? 

Done for a lot of lamps, using a "switch and a few trim pots" is not very efficient, you really need to use  a load of adjustable voltage regulators, like LM317. For a lot of LEDs that might take a lot of current, you'll need a lot of power dissipation in the regulator. Different LED colours (even in RGB modules) take different forward voltages. You'd be better running in constant current mode, and for multiple channels that starts to get complicated. Here's a typical trimmable current source. You need three per RGB system, and you probably need one set for every 10 LEDs - they need to be placed in series with these units.

One on/off switch would to each RGB system.,
trimmable current source.JPG
viking42 (author)  steveastrouk7 years ago
 So my latest thought then, taking efficiency into account, is to get a kit using a programable chip. My question for that is how programable is it? How hard would it be to program it with a dial that would select my specific light settings? For instance off, red low, red med, red high, white low, white med, white high. Or some such arrangement. Again the idea being to have all light switches throughout the boat to be the same with red and white light.

There is a kit mentioned on this site that has a knob that rotates though a number of pre-programed settings. I'll have to go find it again. I have also seen it on other sites.

I have never programed a chip so there will be a learning curve for that but I can read schematics and solder.

What are your thoughts(or anyone else's thoughts) on programming these chips? 

1.) Get some LEDs to audition/
2.) Put together my driver.
3.) Play with LEDs, see if you like the colour rendering etc.
4.) Design driver to suit LED selected
Its not QUITE all, because you may as well make the things "switch mode" as use energy wasting linear electronics. I'd be looking at dimmable LED drivers, and THEN use the chip to control them.