Minimalistic multichip DIY LED build

[JeffBoyRD]

Originally Posted by Lassef

Yes - I have used 1:33 as refractive index of water. That's an estimate, because temperature and wavelengths affect the index. The basis for the calculations in water are taken from here.

There is not a scientifically precise tool but I hope it gives a little bit more than just guesswork

Sincerely Lasse

New version from #2481

Thanks. Now from what I see, this calculation deals with the outside of the cone of light and its angle from the source point and its refraction in the water and its reflection out of the water. What about the light from the LED that strikes the water perpendicular or with an inflection of 0 degrees from 90 degrees? Will that not still produce the same cone structure? I am by no means a physicist or mathematician, just trying to understand and better prepare. Thanks again.

[Lassef]

The calculation shows how the water's refractive index makes the cone narrower when it breaks the water surface. The water surface will thus function as a small lens. The calculation is intended for use for point sources with lens (e.g. LEDs).

It's easy to calculate a cone of light in one media of you know the spread angle. This model was developed to calculate how large the cone becomes when it has passed into another media - water.

The model does not account for how much light is reflected and it was not the target either.

Sincerely Lasse

[sfsuphysics]

If you wanted to get really specific you could use known published values for the wavelengths we'll typically use
400nm is about 1.35
465nm is about 1.345
480nm is about 1.344
700nm is about 1.336

However you're calculation of 1.33 is off by no more than a hundreth and is more than sufficient for the purposes here. Turbulance in the water surface which would be impossible to account for would affect the bending more than the index of refraction differences.

[slipknot23]

what would be good for a ap12 ??? thanks hope some one can help

[ReefUrchin]

Okay, so I checked drivers for the LEDs and I am very sad over the choices. With that said, and my bottle of anti-depressent pills, is there a driver of "any" sorts that can drive 3 100w LED chips in series? I am being very stubborn about running one driver but havnt found anything. Kind of hoping someone has run across an option of some sort.

Also, when are these company's going to realize we need to have more watts per driver?

[dwolson2]

what meanwell driver would i use to drive 2 50W leds, that can be dimmed by the apex(0-10V)

[jg210302]

Has anyone used the cheap drivers from ac/rc for the 100 Watt multichips? I purchased one for testing to see if I would even like the 100 watt chips. I was doing some testing with the LED running full power for about 2 hours and noticed the driver got very warm.

Is anyone else having this experience?

[Lassef]

Yes I have one giving 3 A. It is hot - yes but it works. I have built it into one of their aluminum boxes. No fan - has worked for a long time, but gets warm - about 40 C.

Sincerely Lasse

[jg210302]

Originally Posted by Lassef

Yes I have one giving 3 A. It is hot - yes but it works. I have built it into one of their aluminum boxes. No fan - has worked for a long time, but gets warm - about 40 C.

Sincerely Lasse

Thanks Lasse! I think I will mount it to an aluminum plate and cool it...

[Lassef]

Originally Posted by dwolson2

what meanwell driver would i use to drive 2 50W leds, that can be dimmed by the apex(0-10V)

There is differnet types of 50 wats out there. I need a link to the chip so I can see the spec. Normally - 50 watts - 30-36 V and 1.7 - 1.8 A

You need to connect them im paralell mode and its wise to connect (in serie) a 2 A fuse to each chip.

This can work HLG-120H-36B - it gives 3.4 A - in paralell mode 1.7 at each leg (2 legs)

Sincerely Lasse

[dwolson2]

Originally Posted by Lassef

There is differnet types of 50 wats out there. I need a link to the chip so I can see the spec. Normally - 50 watts - 30-36 V and 1.7 - 1.8 A

You need to connect them im paralell mode and its wise to connect (in serie) a 2 A fuse to each chip.

This can work HLG-120H-36B - it gives 3.4 A - in paralell mode 1.7 at each leg (2 legs)

Sincerely Lasse

I can link it, but incase it gets taken down:
•50W high power LED
•Beam angle: 120 degrees
•Forward current: 1500mA
•Forward voltage: 30-35V
•Luminous: 4000-4500LM
•LED colors: White
•Color temperature: 30,000K

Sorry no ebay links allowed~dc
Thank you

[mcgyvr]

Does epistar/epileds or whatever publish the multi chip led packages thermal resistance (junction to ambient) ?? They should...
That's how you would properly size the heat sink/forced air cooling.
Maybe someone that contacts ac-rc could find that out.



I'm really considering going with a setup like this for my new tank in progress (120G long).. Put a 50 or 100W in a couple cannon style pendants.
Anxiously awaiting results on the "dream chips" and their availability dates..

[mcgyvr]

Also running LEDs in parallel with only a fuse for protection is not something I would be recommending here. Its just a bad idea especially if you are running them close to their limits already.. Some fuses take quite a bit of extra current/time before they blow. So if you must... look for the fuse that is "fast acting" and has the quickest time curve.. But I wouldn't do it at all IMO. Just because it works sometimes doesn't mean its right. Series strings are your "safest" bet. My "dream multi chip" would be multi channel with only series strings.


The proper way though would be to use a current mirror circuit or some sort of active LED protection IC.
http://ledsmagazine.com/features/6/2/2

[mcgyvr]

Originally Posted by mcgyvr

Does epistar/epileds or whatever publish the multi chip led packages thermal resistance (junction to ambient)

Sorry meant junction to case thermal resistance..

[dwolson2]

I could use some advice please. Before I start, I have a 4'long, 24"deep by 28 tall 135gal tank.
I currently have, unassembled, the following set up, minus the 50W chips:

What my question is, should I put 2-50W chips on the end, or should I not use the multi puck's, sell them(for about 160$), and do 2-100's on the end, and the reds/greens/UV's on the center, as well as a strip of blues or whites to adjust the color output?

What I would like as my end goal. I would like to be able to fine tune the blue/white color to get a 20K look(as in 20k on metal halides)

I am thinking about ordering 30K 50/100w, leds, but I would like a good link to either one so I can get the look I am looking for.
Thank you

[Lassef]

Originally Posted by mcgyvr

Also running LEDs in parallel with only a fuse for protection is not something I would be recommending here. Its just a bad idea especially if you are running them close to their limits already.. Some fuses take quite a bit of extra current/time before they blow. So if you must... look for the fuse that is "fast acting" and has the quickest time curve.. But I wouldn't do it at all IMO. Just because it works sometimes doesn't mean its right. Series strings are your "safest" bet. My "dream multi chip" would be multi channel with only series strings.


The proper way though would be to use a current mirror circuit or some sort of active LED protection IC.
http://ledsmagazine.com/features/6/2/2

The problem with chip´s at higher watt´s and daisy chains is that its few (if any) drivers that manage 60 - 72 V (two 50 or 100 watt´s in a daisy chain)

The paralell is the only option if you want to run 2 or 3 with the same driver.

However - its a risk and I agree with you that it is not wise - but what to do?

@ dwolson2 With 1.5 A - it was not a wise recomendation from me

This is better HLG-120H-42B - will give 1450 mA to each leg. A fast fuse at 1.6 A is wise also

Sincerely Lasse

[mcgyvr]

Originally Posted by Lassef

The problem with chip´s at higher watt´s and daisy chains is that its few (if any) drivers that manage 60 - 72 V (two 50 or 100 watt´s in a daisy chain)

The paralell is the only option if you want to run 2 or 3 with the same driver.

However - its a risk and I agree with you that it is not wise - but what to do?


Sincerely Lasse

The reason is safety organizations (UL/IEC/EN) classify 60VDC and under as SELV circuits (safety extra low voltage) so all the drivers stay below that for safety/certification reasons. Once you go over 60VDC the risk of human shocks is greatly increased.

What to do?... Use a current mirror circuit as I showed in that link (illustration #4). plain and simple and much safer than fuses alone.

Or just spend the extra couple bucks on another driver and never run them in parallel. Its just people trying to be cheap that want to run parallel strings.

[dwolson2]

Originally Posted by Lassef

The problem with chip´s at higher watt´s and daisy chains is that its few (if any) drivers that manage 60 - 72 V (two 50 or 100 watt´s in a daisy chain)

The paralell is the only option if you want to run 2 or 3 with the same driver.

However - its a risk and I agree with you that it is not wise - but what to do?

@ dwolson2 With 1.5 A - it was not a wise recomendation from me

This is better HLG-120H-42B - will give 1450 mA to each leg. A fast fuse at 1.6 A is wise also

Sincerely Lasse

Do you think I would be better to just run 2 drivers then? I don't mind. Also see the post before, I would like to hear your opinion on it. Thanks Lasse!

[Lassef]

@mcgyvr: Thanks for the link. By my self, I would never run paralell but there is a lot of people asking for solutions of this. Yours is a good one. another guy I know runs paralell (the starter of this thread ) but he use 45 mil chip. he run them in paralell but as normal 50 watt´s. They are able to manage over 100 W. Therefore - if one break - the other manage the dubble current.

@dwolson: I would run two drivers. Not only because of daisy chain/paralell question but also that you will have better control if you use dimable drivers.

Sincerely Lasse

[ClemQuat]

Originally Posted by ReefUrchin

Okay, so I checked drivers for the LEDs and I am very sad over the choices. With that said, and my bottle of anti-depressent pills, is there a driver of "any" sorts that can drive 3 100w LED chips in series? I am being very stubborn about running one driver but havnt found anything. Kind of hoping someone has run across an option of some sort.

Also, when are these company's going to realize we need to have more watts per driver?

Meanwell has several drivers for higher power LED's have can dim

Check out the HLG, HVG, HLN, LPF and HLP series drivers. Id link to their site, but I dont think thats allowed.. Just Google, 'Meanwell LED power supply' and youll find it.

[dwolson2]

Originally Posted by Lassef

@dwolson: I would run two drivers. Not only because of daisy chain/paralell question but also that you will have better control if you use dimable drivers.

Sincerely Lasse

Noted about the drivers, did you see this post? what do you think?

Originally Posted by dwolson2

I could use some advice please. Before I start, I have a 4'long, 24"deep by 28 tall 135gal tank.
I currently have, unassembled, the following set up, minus the 50W chips:

What my question is, should I put 2-50W chips on the end, or should I not use the multi puck's, sell them(for about 160$), and do 2-100's on the end, and the reds/greens/UV's on the center, as well as a strip of blues or whites to adjust the color output?

What I would like as my end goal. I would like to be able to fine tune the blue/white color to get a 20K look(as in 20k on metal halides)

I am thinking about ordering 30K 50/100w, leds, but I would like a good link to either one so I can get the look I am looking for.
Thank you

[Lassef]

@dwolson2: I have few experiences with the "3 watts" LED system with different colours.

Regarding your choice of 30 K chip - I do not know, I've never shopped there. Personally, I would probably prefer two pieces Epistar 60W Actinic Blue Hybrid 45 mil LED. You can run them with 2.1 A up to 4.2 A and then gives from 60 watts to nearly 150 watts. I know that this chip provides a good bluish tint. With those chips, you can start with 60 watts and then increase if it is not good enough. Then you can keep your small LED and try to set up so that you will be satisfied.

Sincerely Lasse

[JACOXVIII]

in the center section it looks like you have all of your white up front and most of the color in the back.
i think you will have a bad color separation from front to back

Originally Posted by dwolson2

Noted about the drivers, did you see this post? what do you think?

[dwolson2]

Originally Posted by Lassef

@dwolson2: I have few experiences with the "3 watts" LED system with different colours.

Regarding your choice of 30 K chip - I do not know, I've never shopped there. Personally, I would probably prefer two pieces Epistar 60W Actinic Blue Hybrid 45 mil LED. You can run them with 2.1 A up to 4.2 A and then gives from 60 watts to nearly 150 watts. I know that this chip provides a good bluish tint. With those chips, you can start with 60 watts and then increase if it is not good enough. Then you can keep your small LED and try to set up so that you will be satisfied.

Sincerely Lasse

Thanks! I will go with that one then. If you don't mind, could you let me know which driver to use with them? I am really horrible about picking out drivers. Sorry

Originally Posted by JACOXVIII

in the center section it looks like you have all of your white up front and most of the color in the back.
i think you will have a bad color separation from front to back

Ok, I haven't built the rig yet, I will mix them up a bit so I won't have the separation. Thanks for the input!

[dwolson2]

@Lassef
was this your video? http://www.youtube.com/watch?v=fSPnD...ture=endscreen Did you have to set the driver? The eln60-48d you have to set the trim pot on the inside for the 3w leds. Do you have to do that with the multi chips?