DIY LEDs - The write-up

[The Grim Reefer]

Nice Grim. I'm in the early stages of designing a system myself and am gravitating toward using channel as well. In my case, I was planning on using the channel as a heatsink and mounting the stars on the flat profile (opposite of the way you used it) thereby making the vertical profiles act as fins. Like you I also plan on using a mix of warm and cool whites to get that 'bump' in the 500nm + range. Well done.

Thing is the legs will act as cooling veins pointed up or down. What I like about mounting the LED's inside is I could just leave the wires running from LED to LED and they are protected. Another reason I did it like this is no optics so the channels act as reflectors and keep the light from the front and rear channels from being shot out of the tank.

It is hard to see from the pictures but I also tilted the first and last channel in slightly so the light is more focused into the tank rather than the front and rear glass. I get really good spread from these. The edge of the front channel is about 3 1/2" from front glass and the PAR is only about 4% less than the center of the tank

 

[TheFishMan65]

Grim, I hope I am not becoming a pain. BUT

1) You say that you measured inside the slot. I read this as you are seeing the star and measuring as close to the center as you can get on the heatsink.

2) You say you had it resting on the table

I picture something like this minus the acrylic:

I would think this would be much better than real life temperatures.
1) Any heat produced has a straight path up and out
2) Nothing is holding the heat in.

I am not great on heat dissipation so maybe you are right, but just throwing this out there.

 

[The Grim Reefer]

Grim; You have that exactly backwards. :hmm5: There can be NO condensation in that case. It would have to be warm moist air drawn into a cool place...

According to what I read unless you move enough air to completely evacuate the moist air it will still cause condensation. Could be wrong but in either case it appears that level of cooling isn't needed. I still might have done it that way if I had not mounted the drivers above the fixture. I want to use a couple fans blowing air in over the two banks of drivers and the heat sinks. Cooling the drivers is never a bad idea. The canopy will be tall enough I can pull in the air down low and vent it out at the top. Should get good circulation. I am considering doing something more elaborate. Having two fans which come on with the lights and two low speed fans that will run 24/7 just to keep humidity from building up over night.

 

[The Grim Reefer]

Grim, I hope I am not becoming a pain. BUT

1) You say that you measured inside the slot. I read this as you are seeing the star and measuring as close to the center as you can get on the heatsink.

2) You say you had it resting on the table

I picture something like this minus the acrylic:

I would think this would be much better than real life temperatures.
1) Any heat produced has a straight path up and out
2) Nothing is holding the heat in.

I am not great on heat dissipation so maybe you are right, but just throwing this out there.

Becoming a pain? Read the T5 thread some time, you aren't even in the same time zone as pain :celeb3:

The measurements were taken from the second channel in from an LED at the middle of the channel, and XPG. the reason I did it like that is I had drilled small holes in the side of that channel to hold the clips I thought I would need to hold on the acrylic. I was able to feed the thermal couple through the hole. The table only covered 30" of the 44" channel but it is a padded card table so I am pretty sure the amount of heat being trapped is comparable.

As far as which way will better dissipate heat I have no doubt having the legs pointed up with no acrylic would be better but I really doubt it is going to make a big difference. If I were using optics and spacing the LED's a couple inches apart I would either run air up the channels or mount the LED's like you plan.

Another thing I would do is instead of mounting the channels to a steel cross member would be to bolt the channels to each other using 1/4" spacers to provide a small air gap between the channels

 

[laverda]

I've also made a request for a price on the HLG-100-48B.
One question. The adjustable current range on the HLG's does not go below 1A.
Is that a problem for running the LED's at 750mA? or don't I understand yet?

George I got a call back today, and they told me that none of the HLGs are dimmable. The HLG-240-20A is $109 in small quantities. The HLG-120-54 in not available yet. Maybe dimmable versions will be available in the future.

There was a dimmer mentioned a few pages back that may be suitable for dimming after the driver. I am going to have to research it more.

 

[The Grim Reefer]

I just measured the temperature on the backs of the channels, one with and one without the acrylic shields. The acrylic maybe added a degree to the back of the channel. No way to measure at the LED without tearing it apart.

 

[Obi-dad]

Obi-dad, since you appear to have more temperature experience than most do you think Grim is going to be in trouble? I know they say temperature will shorten LED life. And you are saying the lens gets the hottest. That means Grim has trapped all the heat in the channel with the shield. I did not notice fans blowing through the channel so let's assume they are not there.

Grim. can you measure the inside temperature of those channels?

Thanks all

Just to make sure we are talking about the same thing, by 'lens' I am referring to the tiny silicone (I think) one that is covering the LED die, not the lenses that people are mounting over the LED.

 

[TheFishMan65]

Thanks Grim, I guess I over reacted and I am glad it is not a problem.

Obidad - I was using lens (in this case) with the description that you were using.

 

[skippyreef]

Need some advice on an easy way to use my Osram SA DIM to dim my ballast. It is a 10V signal amplifier. I would like to be able to connect it to a terminal rail or something and then use the screws to connect the wires on each ballast to receive the dimming signal.

 

[skippyreef]

The LBF AP and the EVG AP are external devices connected to the PL dimming channel with a telephone 6p6c connector. There is one thing to consider; on one of the plugs (L1L2 or L3L4) at the PL you have two dim channels. If you plug one LGF AP or EVG AP at one of these plugs without a splitter you will lose one cannel unused.

To your question; yes you can connect an Osram Dim SA to a LBF AP and then all drivers on the Dim SA to control them. But"¦

My aim was to dim the whites and blues separately and also one chain for moonlighting. So I did it this way; I use an EVG-AP 2F. This one is using two channels from the PL (no splitter required) to operate the whites and blues separately and one EVG-AP 1F on a splitter (there I use the second channel for a Tunze pump) to operate the separate day and moonlighting chain.

The advantage of the EVG APs is they have relays on board to switch the main power to the drivers on and off. This means that in the 12 hours where the lights are off there is no power going to the drivers at all.

To do it this way is a personal choice. I did it because I think it is safer if something is switched off from the main supply and secondly and more important that I save money because here we are billed also for mW.:furious: That means also for the energy a TV, DVD, microwave, etc. is using in stand-by mod. My biggest motivation to build a LED rig was economy, so this is one more step to get it as efficient as possible.

I hope I could help you somehow

Monty

I received the SA DIM yesterday. Will need to pick your brain some now

 

[King_Richard]

Hello everyone, excellent thread. So I'm new to this forum but been keeping saltwater tanks for sometime now. Recently built up 60g tank with a 50g sump and it's now time to light it properly. Currently only using regular 6700k flourescents but have used pc's in the past before t5's were mainstream.

I've read the entire thread and I'm new to led's but understand electronics to be comfortable enough in building a setup. However, have a couple questions:

I remember when I started keeping coral a while back that our actinics were mostly to simulate the depth that some of the corals are found naturally and that it was more for pleasing our eyes when viewing them, but i have found that

most people are using more actinics than whites so, why is this?

I want to start out small since I'm currently a college student and veteran so needless to say I don't have a alot of $$$ to throw around on the lighting and plan to slowly build it up. I like the fact that soundwave only used 48 led's. And I would like to keep mine to a minimum also. My tank is 24x24x25h and I prefer to have no more than 24 led's total but will be starting out with 12.

Is it alright that I only use 12xpg's to begin with and no blue's?

I have a rockwall that I made so plan on directing most of the light over the wall where the majority of the coral will be going.

Lastly, I'm having a hard time finding reflectors for these xpg's and I like the idea of the 60 degree optics but can't find them.

 

[kcress]

King_Richard; Let me the first to welcome you to RC.

If you've read this entire thread.. Then you are no longer "new to LEDs". :lmao:

Blue.. It's all about personal choice. You can certainly run just XPGs. There are some posts around with that or with only a few blues added in. I would lean to less blue than most builds I see.

 

[wld1783]

George I got a call back today, and they told me that none of the HLGs are dimmable. The HLG-240-20A is $109 in small quantities. The HLG-120-54 in not available yet. Maybe dimmable versions will be available in the future.

There was a dimmer mentioned a few pages back that may be suitable for dimming after the driver. I am going to have to research it more.

laverda

Have you looked into the CLG 150-48A at 3.2A you can run 4 parallel strings of twelve and have room for one open circuit. It's manually dimmable through an internal potential meter. The HLG should have the same option according to Mean Well.

Personally I like to run my LEDs between 70-80% rated current. I'm very happy with this driver on my 48 LED fixture.

Only down side is its manual.

I finally got around to testing the ELN 60-48D and found it perfect for two parallel strings of 12. At 1.3 amps (I measured 1.5) it is too powerful for a single string of 12 at 10Vdc. I did not fry my LEDs as it was full power for only a couple of seconds. Two of these should power a 48 LED fixture perfectly provided no open circuits.

Bill

 

[King_Richard]

King_Richard; Let me the first to welcome you to RC.

If you've read this entire thread.. Then you are no longer "new to LEDs". :lmao:

Blue.. It's all about personal choice. You can certainly run just XPGs. There are some posts around with that or with only a few blues added in. I would lean to less blue than most builds I see.

Thanks for the welcome, and I won't feel fimilar with it until I start working with them. But man it was alot of reading and I definitely feel overloaded with info.

Another thing I was thinking, I don't have the lights yet but should be ordering them within the next few days, would a half inch pvc or one inch pvc fit over the stars and leds?

I see some of the lenses out there, but not the degree's I think I'll need but if I can use pvc tubes to reflect some of the light down than I wouldn't degrade the outputs by running them through a frosted lense. I would just have to come up with something reflective to put in the pvc and possibly give the reflective material a cone shape. I don't know just thinking of ways to keep the light from spilling out of the tank.

 

[wfournier]

Thanks for the welcome, and I won't feel fimilar with it until I start working with them. But man it was alot of reading and I definitely feel overloaded with info.

Another thing I was thinking, I don't have the lights yet but should be ordering them within the next few days, would a half inch pvc or one inch pvc fit over the stars and leds?

I see some of the lenses out there, but not the degree's I think I'll need but if I can use pvc tubes to reflect some of the light down than I wouldn't degrade the outputs by running them through a frosted lense. I would just have to come up with something reflective to put in the pvc and possibly give the reflective material a cone shape. I don't know just thinking of ways to keep the light from spilling out of the tank.

Regarding your previous post, sure you could start with just the white LEDs, however unless a more efficient Blue LED comes out I would not do 12 XP-Gs. I have a setup with 8 XP-E cool white and 8 XP-E royal blue and I would say that it is a little on the warm side from what most people seem to prefer. Using the XP-Gs will make it even warmer. I might do 8 XP-Gs and 16 blues, but that is just me. Are you planning on being able to dim the different colors?

As far as the optics, what angle are you looking for? The PVC might work, but will be FAR less efficient than the frosted optics you mention. The 60 degree optics from ETG seem like they could be a promising option. I have not had a chance to try them yet but should have some here soon to play with.

 

[TheFishMan65]

King Richard,

12 XPG migt be a little low on light. The current recommendation is 1 per 10-20 square inches of surface. Now XPG are a little brighter, but not twice. Start with 12 and see.

I only throw this out for thought. The PVC my limit the air flow around the LEDs. Yes lenses to, but they are made for them. With 12 LED you are going to be running fairly hot. I don't know if the PVC will create a heat issue.

 

[zangmann]

First off, thanks to all the contributes of this thread i now have my 24 RB LED supplement strips setup, the tank really glows!

All the greens and reds and yellows really stick out, but it seems I have lost all my beautiful purple and blues! What can I add to get these to pop? Can I add some other color LEDs or a few whites?

I was thinking of going with a 3:1 ratio RB/CW as a test, will this give me the results I am looking for?

Thanks again for everyone's help!

 

[MontyJack]

Need some advice on an easy way to use my Osram SA DIM to dim my ballast. It is a 10V signal amplifier. I would like to be able to connect it to a terminal rail or something and then use the screws to connect the wires on each ballast to receive the dimming signal.

Hi, I need some more info what you have there?
I'm right that you have a PL2 and now one DIM SA? What else do you have? How many drivers? Do you have a EVG AP or a LGF AP?

 

[skippyreef]

I have the pl2 and lgp set up. I am not using any of the dim channels on the pl2. I have 16 drivers 12 of which are dimmable.

 

[GEORGEDOPE]

George I got a call back today, and they told me that none of the HLGs are dimmable. The HLG-240-20A is $109 in small quantities. The HLG-120-54 in not available yet. Maybe dimmable versions will be available in the future.

There was a dimmer mentioned a few pages back that may be suitable for dimming after the driver. I am going to have to research it more.

I got a call back from Meanwell yesterday. The only HLG available now is the 240 which is not dimmable. All the other HLG's will not be available for at least 3 months and they will all come in a dimmable model. I got a price of about $90 for the HLG-150-54. But 1 of these would replace 4 of the ELN-60-48.