Minimalistic multichip DIY LED build

[TropTrea]

An LED is a diode and a diode has not a linear relationship between voltage and current as the resistance is large in the beginning and at a given voltage (FV) it will be very low.

As an example: Cree's XM-L LED.

At a voltage of 2.8 V, the current is 400 mA. At 3 V, the current is 1100 mA and at 3.2 V, the current is 2100 mA. At a difference of 0.4 V, the current increases by almost 1700 mA or more than 5 times.

As it is amperage that burns down our chips, it's much wiser (and safer) to use a source that provides a constant current and varying voltages after the load.

I'm not saying it is not possible with a constant voltage source, but it requires a lot more knowledge and fine-tuning especially if you are close to the chips FV.


Sincerely Lasse

Yes for our application with the high output diodes this is especialy true. It is even more impoetant since we are working in a low voltage range. However there are some comercial applications where the Voltage regulation is a much cheaper route and even considering the higher potential of burning out LED's. In these applications Zener Diodes are usualy used to regulate the voltage well below the threshold of the LED's.

As you mentioned earlier just expanding on the XM-L LED
Voltage Current Wattage
2.8 400 1.12 Watts
3.0 1.1 Amp 3.3 Watts
3.2 2.1 Amps 6.7 Watts
We can roughly project that then that
3.4 Volts 4.1 Amps 14 Watts
3.6 Volts 8.1 Amps 29 Watts
The safe max for this LED on long term use is only 5 Watts. So with a small change of .2 Volts you are more than doubling the Wattage beyound the safe range.

Now As said there are applications where this is not as muchh of an issue an example is in some signage use. Here you may have 30 LED's wired in series with a pulsing power supply that is generating a 33% power cycle with 85 volts. This is putting 2.83 Volts across each LED only 1/3 of the time. This allows cooling to occur 2/3 of the time.

The biggest destroyer of LED's is actualy heat. The higher the Power the LED is consiuming the more heat that is generated and heat slowly builds up. If you look at effeciency rating on LED's they at not more effecient at higher currents which shows that the ratio of heat to light increases as the current goes up.

If someone wanted to do an experiment on LED's at higher current and there life spans it could easly be done. Theywould find that that a some majic point usualy the lfe spans would start decreasing drasticly like to less than 50% by a change in voltage of only a few hundreds of a volt. But unless you wanted to simply blow up a hundred LED's it is best to just the manfacturers word and observe their limits.

 

[TropTrea]

Hey Lasse!

I have a question regarding multi-chips.

I have a 6' 180gallon and have three arrays over the tank. Each array has 2 X 20W white, 4X 10W actinic (white 10X + blue 450nm), and 2X 10W 460nm chips. The 20W are 1:1 with a driver, and the 10W are 2:1 to a driver ran in series.

I am using the Sure electronics PWM 10/20w drivers and running them all off a 24V 14.6a power supply.

Specs are as follows:

White:
DC Forward Voltage (VF): 15 ~ 17 Vdc
DC Forward Current (IF): 1200mA ~ 1300mA

Actinic:
10W Actinic:
DC Forward Voltage (VF): 9.0V-11.0V DC
DC Forward Current (IF): 900-1000mA

Blue:
Forward Voltage :10- 11V
Forward Current : 1000mA

Now, the Sure drivers are 1500MaH. Will this be an issue later down the road? Am I putting too much current through the 10W LEDs causing them to overheat? If so, how can I lower the current while still using the same power supply and drivers? If I have to, I will order lower-current drivers from Sure. I currently have 15 total drivers wired to the Power supply.

[\QUOTE]

On a personal note I'd run this completly differently.

Whites 6 Chips each rated at 20 Watts for a total of 120 Watts so I would put them all on a Meanwell HLG-150h-48B. This would allow you to run them up to 16 Volts @1.57 Amps each for up to 25 Watts each. in a serries parrellel combination.

Atinics 12 Chips each tated at 10 Watts again for a total of 120 Watts. I would use the same type driver but would run 4 LED's in Serries with 3 Parrellel circuits. This would mean your running up to 12 Volts @ 1.04 Amps giving you a max of 1.25 Watts per LED.

Finaly for your 6 Blue LED's at 10 Watts each and a 60 Watt total I would go with HLG-80H-42B. This would allow you two strings each running 14 Volts@0.975 Amps or 13 Watts per LED.

The nice thing about these drivers are.
1. You can internaly adjust the max current, to assure you do not overpower your LED's
2. They are fairly unicersal to use either stand alone or basicly any controller.
3. You have three channels here one for each color to allow you to mix and match per your color taste.

 

[TropTrea]

We have a saying here in Sweden: It is possible to skin a cat in many ways.

I chose 10 W multi chip when I built my first LED design just because it was not possible to obtain white 3 watt LED at 10,000 to 16,000 K. I did not want to make use of the large chips (30 - 100 W) because I wanted the opportunity to vary my light over the aquarium.

However, you are wrong when you say that the large chips do not provide an evenly distributed light. They provide a good distribution of light and with the help of lenses you can get a good penetration. The Dream Chip developed (with 5 separate channels) provides the best of both worlds - variation, penetration and uniform distribution of light.

It is clear that you can achieve this with the help of 3 watt LED as well but I do prefer to work with multiple chips.

There are two different mindsets, so you must decide what path you should follow. I do not think it will be cheaper to multi chip; you should invest in quality there too.

Sincerely Lasse</SPAN>

Only one additional thing to keep in mind. And that is that they now have 10 Watt single chip LED's. It would not surprise me if within a year or two we will be seing single chips up to 25 Watt.

My plans for my next build will be using the 10 Watt single chip LED's. Hopefully by then they will be available in all colors.

 

[Lassef]

Hey Lasse!

I have a question regarding multi-chips.

I have a 6' 180gallon and have three arrays over the tank. Each array has 2 X 20W white, 4X 10W actinic (white 10X + blue 450nm), and 2X 10W 460nm chips. The 20W are 1:1 with a driver, and the 10W are 2:1 to a driver ran in series.

I am using the Sure electronics PWM 10/20w drivers and running them all off a 24V 14.6a power supply.

Specs are as follows:

White:
DC Forward Voltage (VF): 15 ~ 17 Vdc
DC Forward Current (IF): 1200mA ~ 1300mA

Actinic:
10W Actinic:
DC Forward Voltage (VF): 9.0V-11.0V DC
DC Forward Current (IF): 900-1000mA

Blue:
Forward Voltage :10- 11V
Forward Current : 1000mA

Now, the Sure drivers are 1500MaH. Will this be an issue later down the road? Am I putting too much current through the 10W LEDs causing them to overheat? If so, how can I lower the current while still using the same power supply and drivers? If I have to, I will order lower-current drivers from Sure. I currently have 15 total drivers wired to the Power supply.

Hi

I think that you can have some problems here. But I´m not sure how to solve it. I have contact my electronic guru - I hope he can answer here in the thread.

Until further notice, it may be wise not to operate 10 watt chip higher than 60%. Because its a PWM drive, the current will not go down but the effect will be the same to the chip.

Sincerely Lasse

 

[ReefUrchin]

reefurchin use google translate to read it

I tried that and I get:

The blue equagfhrge gets to the maximum gjhduir and fkjfkjt does the ddkdlk good to know.

Now, that is not that bad as I was able to at one time understand 10% broken english from Russian friends, but, maybe I am getting lazy because that site was a chore to read translated :lmao: . I will say though, it noce to have that link to have a look at the other side of the pond. No real complaints here.

Hey Lasse!

I have a question regarding multi-chips.

I have a 6' 180gallon ................................

The real question is, do you have any pictures of it running? We need more of those also :dance: .

 

[ReefUrchin]

Only one additional thing to keep in mind. And that is that they now have 10 Watt single chip LED's. It would not surprise me if within a year or two we will be seing single chips up to 25 Watt.

My plans for my next build will be using the 10 Watt single chip LED's. Hopefully by then they will be available in all colors.

That would just basically be tomato/tomoto, right? The real issue is spectral issues, but, tis an interesting note to ones self.

 

[JACOXVIII]

"See here, post 51 and 55

Sincerely Lasse "


the one in the post has heat pipe the one i linked does not i looked it up and there is a +10*c hotter with my linked heat sink
what about http://www.arctic.ac/en/p/detail?sArticle=23.?
I'm looking at building 6+ of these for a friends pet store so i need to keep the price down
after looking at the one at post 51 i think i will try and find a deal on those units

 

[Lassef]

ok..so last time you told me to use the ELN-60-48 (p or d) and it is possible to connect 4 pieces 10 watt LED in series to each driver. can you please post me from where i can buy them from ebay!? At first im going to run a test run with 3 leds. is there another driver available rather than the ELN 60-48. can you please PM if itd not possible to post advertising here? thanks

The ELN 60 - 48 (D or P) manage 3 - 4 10 watt of the AC-RC type. There a few good drivers to the 10 watts of this type. If you live in Europe or have a voltage of 185 - 295 V in your grid you probably can use meanwell driver LCM-60. According to the spec - it is possible to run 1- 6 pcs 10 watts in a serier (900 mA). I have not tested this but I have several drivers of an other Brand that is rather similar to this driver.


@ JACOXVIII: I think it is necessary to use a cooler with heatpipes to run this chip up towards 150-200 watts. A graphic card cooler like one of these woork well also

sincerely Lasse

 

[DetroitReefer]

On a personal note I'd run this completely differently.

Whites 6 Chips each rated at 20 Watts for a total of 120 Watts so I would put them all on a Meanwell HLG-150h-48B. This would allow you to run them up to 16 Volts @1.57 Amps each for up to 25 Watts each. in a series parallel combination.

Actinics 12 Chips each rated at 10 Watts again for a total of 120 Watts. I would use the same type driver but would run 4 LED's in Series with 3 Parallel circuits. This would mean your running up to 12 Volts @ 1.04 Amps giving you a max of 1.25 Watts per LED.

Finally for your 6 Blue LED's at 10 Watts each and a 60 Watt total I would go with HLG-80H-42B. This would allow you two strings each running 14 Volts@0.975 Amps or 13 Watts per LED.

The nice thing about these drivers are.
1. You can internaly adjust the max current, to assure you do not overpower your LED's
2. They are fairly unicersal to use either stand alone or basicly any controller.
3. You have three channels here one for each color to allow you to mix and match per your color taste.

I have taken this into advisement.

The idea behind the multiple drivers was that I can control left/right lighting as well as individual intensities. If I drop to only 3 drivers, I lose all real unique control. I have a 72MhZ microprocessor that is doing all the dimming/storm simulations/sunrise/sunset patterns as well as controlling the powerheads within the tank. The microprocessor is hooked into a TLC5940NT chip to control the PWM dimmers.

I tried that and I get:

The real question is, do you have any pictures of it running? We need more of those also :dance: .

You want to see the tank or the lighting?

 

[otterinaround]

Can we refer to you as the YODA of LED??? Brilliant thread!

 

[ReefUrchin]

You want to see the tank or the lighting?

Both working together please, and your summary of how it looks and what you might do next time for power to reach the bottom and how the blending is working for you.

 

[fishguy597]

I'd like to start off with wow what a ton of info. I wish this could be broken down into sections ; tank size, how much light, what led wattage , how to match up a driver, etc.
I made it to page 25 and my head is spinning lol.

Here is what I'm looking to do. I have an 84"x24"x24" inch tank. So according to the formula earlier 84x24/16=126 126x3w= 378w needed.Will this be enough for sps? I currently have 2*400w mh with another 100w in actinic.

What watt light is better to go with and why 50 or 100w? I think it's the 100w for light penetration. I have been leaning on going with the super actinic with a 10k supplement.I would also like to have a dawn/dusk that make the corals pop and I'm not quit sure wich way to go as far as thats concerned.
I guess I need to figure out what light to go with first before figuring out what driver to use, even though I know I want dimming capabilites. Ifigure the meanwell driver is what would work but not sure of what specs to use.
If someone could point me in the right direction that would be great.

 

[Lassef]

@DetroitReefer : I have talk to my "electronic guru" and he has not a quick fix to this problem either. He agree with me that it should be wise not to exceed 60 % for the 10 watts. Some PWM dims has a construction which in practice gives a current adjustment. It is difficult to know if your drives have this construction but if you can measure that the current is varying with dim level it should probably work.

In the long run, both He and me thinks that it is better to replace your Sure drives to those that provide up to 1000 mA.

I fully understand why you prefer this solution - it provides full control of your lighting. At some of my solutions, I have max 2 multichip on one drive - just to be in full control. I also let the "sun" rise at one end of the aquarium.

Sincerely Lasse

 

[Lassef]

@fishguy597: With respect to light penetration both 50 and 100 watts (with lenses) should work. If you want an opportunity to vary the light maybe 6-8 pieces of 50 watts is a good choice. If you also choose chips with 45 mil LED you can "overdrive" them up to 125 watts if you need to. Examples 1, 2, 3 and 4

Sincerely Lasse

 

[marspeed]

@DetroitReefer : I have talk to my "electronic guru" and he has not a quick fix to this problem either.

the boards have a resistor that determines the current down load document
le-ll 14113 from sure electronics that should give him a hint


marc

 

[Lassef]

the boards have a resistor that determines the current down load document
le-ll 14113 from sure electronics that should give him a hint


marc

Thank´s for the information

If you have a solution to the problem - feel free to post it.


Sincerely

Lasse

 

[thermoJoe]

Whoa, finally got through all 108 pages...it only took a week and a half. What an amazing amount of info. I thank maglofster, Lassef, mr.wilson, ronreef, et al. for providing so much feedback (sorry, I know there have been many more than this posting valuable info, and I'm sure I've missed some important contributors, my apologies).

After about 10 pgs of initial reading, I order some 60W multichips from AC-RC, as well as MW drives, etc. It only took 1.5 days for the multichips to get from Hong Kong to NY, but there they sat for 9 days...Looks like they're on the move finally and I should be getting them this week.

I'll post pics once assembled. Going for the "steam punk" pendant look (well, poor boy pendant at least).

Looking forward to more posts of the dream chip (aka 5 channel multichip) ("missed it by that much")

Thanks All!

 

[007Bond]

WOW...1st post after 108 pages congrats Joe !

 

[thermoJoe]

Lol, yes. Most questions are usually already answered. In this thread even ones you have not thought of yet.

 

[rcoleman]

Hello, my name is Rick, and I'm getting back into the hobby after 20 years. A lot has changed, especially in the lighting area. After reading 108 pages of posts, I would like to thank maglofster, Lassef, mr.wilson, ronreef, and everyone else for providing so much information.....uh, too much information!

I just ordered a 60x24x25 reef tank, it's not going to be here for about 3 weeks, so I have some time to work on lights. I will be building the stand and canopy. I'm going for mostly corals and inverts and a few fish. Needless to say, i would like good healthy GROWING corals this time around.

Could someone give me a recommendation as to the best overall lighting for a tank of this size? I would really like to get this right the first time and not waste a lot of money on lights that don't grow coral. Obviously the Dream Chip would be awesome if I could get some, but it looks like I'll have to wait a while for that. Since I'm setting this up from scratch I could go ahead and build one set of lights to get started. I've got a feeling you can suggest the proper mix of hybrid chips and the correct dimmable drivers, heat sinks, etc. that will get me going down the proper track. I'm a total noob when it comes to electronics, so I'm at your mercy to tell me what I need to get and if it's all compatible or not. This appears to be a really great time to be getting back into the hobby. Thanks in advance.

Rick.