KItchen undercounter lights with XMLs and nanjg105c, AC/DC adapter 5V?

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Mon, 10/20/2014 - 08:43
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vex_zg
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KItchen undercounter lights with XMLs and nanjg105c, AC/DC adapter 5V?

So, I was thinking to make this kitchen undercabinet lightning using the above, and use an 3-5V adapter. I can program the nanjg105c to a few modes if necessary.

I’m not sure about the AC/DC adapter – I can’t find one around 3.5-4.5V and sufficient power (they are normally up to 1A, and I’d like to have around 5-7A, can I use more easily available 5V adapters and reduce the load and heating on the emitters with PWM?

will they survive 5V while being PWMed? what about the atiny13A ?

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Mon, 10/20/2014 - 10:50
Hikelite
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You could try getting a MeanWell from China if Nanjg 105C is not a must/personal DIY must.
Output: 9~34V 1.75A 60W
AC/DC LED Driver
http://www.ebay.com/itm/Mean-Well-MW-9-34V-1-75A-60W-AC-DC-LED-Driver-LP...

It is preferred to use LEDs in series to you can use a buck driver. Paralleling LEDs from a linear driver is not desirable.
Keep in mind that generally LEDs are not even driver to they max rated current for efficiency and lifespan reasons that is there are so many 1A or 1.75A power supplies, and for the reason many 3535 LED are stll rated max 1.5A current, except for the new XP-L which is 3A of course.

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Mon, 10/20/2014 - 15:25
vex_zg
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Hikelite wrote:

You could try getting a MeanWell from China if Nanjg 105C is not a must/personal DIY must.
Output: 9~34V 1.75A 60W
AC/DC LED Driver
http://www.ebay.com/itm/Mean-Well-MW-9-34V-1-75A-60W-AC-DC-LED-Driver-LPC-60-1750-TUV-Class-2-IP67-UL-/380474612109

It is preferred to use LEDs in series to you can use a buck driver. Paralleling LEDs from a linear driver is not desirable.
Keep in mind that generally LEDs are not even driver to they max rated current for efficiency and lifespan reasons that is there are so many 1A or 1.75A power supplies, and for the reason many 3535 LED are stll rated max 1.5A current, except for the new XP-L which is 3A of course.

i was thinking about nanjg105c because I can write my own firmware, but I need not invent “hot water” if there’s a decent dimmable solution

so what about 6pc of 3535 LEDs, i.e.

http://www.ebay.com/itm/Hight-Quality-CREE-3W-3535-Pure-White-Light-LED-Emitter-Bead-12mm-PCB-300LM-New-/251568869453?pt=Lamps_US&hash=item3a92ac504d

connected in series in triplets, that’s cca 1800lumen totally, distributed across cca 230cm of kitchen counter, cca 20W

and dimmer such as this one

http://www.dx.com/p/single-channel-led-dimmer-controller-111145#.VEVZsvm...

plus some sufficient 12 AC DC converter

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Tue, 10/21/2014 - 01:27
texaspyro
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Ah yes, the subtle wonders of kitchen under-counter lights:

http://budgetlightforum.com/node/16245

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Tue, 10/21/2014 - 03:54
Hikelite
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The only thing I would advise you strongly is about the LEDs. You would not want 6500K in the kitchen which can be green or purple, but mostly you don't want low CRI. I am saying this because I like to cook and it can look real bad to look at carrots, bell peppers (green red yellow) and meat looking rather spoiled (bad) than delicious/appetizing. Or let's say you have some herbs right on the counter or flowers there under low CRI or 6500K will look bad. I had this problem before with food looking unattractive due to bad light source.
I would suggest nothing higher than 4500K and whatever it is should be high CRI.

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Tue, 10/21/2014 - 05:18
vex_zg
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Hikelite wrote:

The only thing I would advise you strongly is about the LEDs. You would not want 6500K in the kitchen which can be green or purple, but mostly you don’t want low CRI. I am saying this because I like to cook and it can look real bad to look at carrots, bell peppers (green red yellow) and meat looking rather spoiled (bad) than delicious/appetizing. Or let’s say you have some herbs right on the counter or flowers there under low CRI or 6500K will look bad. I had this problem before with food looking unattractive due to bad light source.
I would suggest nothing higher than 4500K and whatever it is should be high CRI.

thanks.

I did some more research and I was thinking about this 12V XML T6 EZW (easy white)
it’s convenient becuase it’s multiple die emitter connected in series internally, so you can run it straight from 12V adapter (which are more common and cheaply dimmable)

http://www.fasttech.com/product/1570604-cree-xm-l-t6-ezw-10w-860lm-warm-...

it says warm white 3000-3200k, I don’t know how warm it is, hope it’s not yellow.

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Tue, 10/21/2014 - 05:20
vex_zg
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texaspyro wrote:
Ah yes, the subtle wonders of kitchen under-counter lights:

http://budgetlightforum.com/node/16245

thanks, lot of reading there.

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Tue, 10/21/2014 - 06:10
Hikelite
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vex_zg wrote:
Hikelite wrote:

The only thing I would advise you strongly is about the LEDs. You would not want 6500K in the kitchen which can be green or purple, but mostly you don't want low CRI. I am saying this because I like to cook and it can look real bad to look at carrots, bell peppers (green red yellow) and meat looking rather spoiled (bad) than delicious/appetizing. Or let's say you have some herbs right on the counter or flowers there under low CRI or 6500K will look bad. I had this problem before with food looking unattractive due to bad light source.
I would suggest nothing higher than 4500K and whatever it is should be high CRI.

thanks. I did some more research and I was thinking about this 12V XML T6 EZW (easy white) it's convenient becuase it's multiple die emitter connected in series internally, so you can run it straight from 12V adapter (which are more common and cheaply dimmable) http://www.fasttech.com/product/1570604-cree-xm-l-t6-ezw-10w-860lm-warm-... it says warm white 3000-3200k, I don't know how warm it is, hope it's not yellow.
The 3000K would be a bit yellowish, would be nice to get a 3500K-3700K, I doubt you can get that since there are many 3000K LEDs in general.The T6 is quite a low bin for XM-L EZW, you have U2 U3 U4 U5 U6 V2, all higher bins.
T6 us rated 280lumens at 350mA @ 12V  and rated to be drivable up to max 1000mA where you will get about 890lumens max, (based on the graph from the datasheets, showing 350mA as being 100% and 1000A as being 220% percent)
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Tue, 10/21/2014 - 07:01
vex_zg
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Hikelite wrote:

vex_zg wrote:
Hikelite wrote:

The only thing I would advise you strongly is about the LEDs. You would not want 6500K in the kitchen which can be green or purple, but mostly you don’t want low CRI. I am saying this because I like to cook and it can look real bad to look at carrots, bell peppers (green red yellow) and meat looking rather spoiled (bad) than delicious/appetizing. Or let’s say you have some herbs right on the counter or flowers there under low CRI or 6500K will look bad. I had this problem before with food looking unattractive due to bad light source.
I would suggest nothing higher than 4500K and whatever it is should be high CRI.

thanks. I did some more research and I was thinking about this 12V XML T6 EZW (easy white) it’s convenient becuase it’s multiple die emitter connected in series internally, so you can run it straight from 12V adapter (which are more common and cheaply dimmable) http://www.fasttech.com/product/1570604-cree-xm-l-t6-ezw-10w-860lm-warm-... it says warm white 3000-3200k, I don’t know how warm it is, hope it’s not yellow.
The 3000K would be a bit yellowish, would be nice to get a 3500K-3700K, I doubt you can get that since there are many 3000K LEDs in general.The T6 is quite a low bin for XM-L EZW, you have U2 U3 U4 U5 U6 V2, all higher bins.
T6 us rated 280lumens at 350mA @ 12V  and rated to be drivable up to max 1000mA where you will get about 890lumens max, (based on the graph from the datasheets, showing 350mA as being 100% and 1000A as being 220% percent)

i can’t find ezw in any other bin than this one

http://www.fasttech.com/products/0/10001903/1570600-cree-xm-l-t6-ezw-10w...

It’s not critical for this to be efficient to the maximum, the goal is to have decent CRI and tint, and enough light.

I plan to have 2-3 of these per meter of counter, I did some test with my flashlights, it should be enough light. Currently The same area is lit by 6× 20W halogens, and it’s enough.

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Tue, 10/21/2014 - 07:51
Hikelite
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The XM-L EZW are typical 82CRI for 3000k-2700K (meaning around there, more or less) unless they are specified to be higher CRI, which in this care they are not.
BTW you halogens are 3200K, so you would have a sense how those will look warm-wise.

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Tue, 10/21/2014 - 08:21
vex_zg
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A bit on the warmer side is preferable to colder tint.

what about something like this? it’s easier to mount, no lens/colimator needed ?

http://www.fasttech.com/products/2206/10008174/1786903-10-8w-1000lm-2800...

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Tue, 10/21/2014 - 08:55
Hikelite
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vex_zg wrote:
A bit on the warmer side is preferable to colder tint. what about something like this? it's easier to mount, no lens/colimator needed ? http://www.fasttech.com/products/2206/10008174/1786903-10-8w-1000lm-2800...

Should be nice for what you need shape-wise, CRI unknown (probably not great), kind of high range of temperature, I mean 2800K to 3300K.
You can only try it Because other solution are quite clear to get 3535 and put them all in series  (like this or this)
They are quite diffuse anyway at 120deg, optics will only make it narrower (like 10, 25, 45 or 60deg). Only thing you would need to care about is actual physical protection for any LED (getting hit, dust, oil splashes) if it is the case.

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Fri, 06/26/2015 - 21:10
hank
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I asked at LEDSupply and found this driver is OK to put inside a junction box:
http://www.ledsupply.com/power-supplies/magtech-12vdc-constant-voltage-4...

— which means all the electrical wire nuts can be inside the box, as our inspector wants to see them (we’re in earthquake country, things get shaken and stirred unpredictably, I can’t argue with the rule about keeping wiring where it’ll be somewhat safer):

I’m looking at commercially built LED undercounter lights — not “budget” the way I think of homebuilding, but not scary to the spouse and architect and contractor who are going to tear out the kitchen and replace it with something. So far, these (again LEDSupply — because I can understand their pages. Not an endorsement — I haven’t bought anything yet!

http://www.ledsupply.com/led-strips/high-density-led-flex-strips
or
http://www.ledsupply.com/led-strips/luxstrip-high-power-led-strip-lighting
or, most likely, as they look finished and reassuringly unexposed for kitchen undercounter placement near water:
http://www.ledsupply.com/led-strips/linear-led-fixture-lvl2

And besides, I’d probably learn enough to build my own for the shed, and maybe the living room, after going through this once with prebuilt stuff. I hope ….

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