DIY LEDs - The write-up
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Discustopia
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Current draw creates heat - the worse the connection, the more heat and loss created.
OR
Good clean connections and properly sized wires keep it cool and increase efficiency.
That quote means that the amount of current the LED can handle is based on how well you keep it cool. the Cree XR-E should be kept under 1000mA. Less mA, less heat. To keep it working well, you need to keep it at or slightly above room temperature, or at least stable. If it heats up too much the life of the LED will be shorter. The solder point is how the heat is dissipated and then through the starboard (if mounted).
Louis Governo
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Thanks. However, I don't understand how it could use the solder points to heat sink since they are isolated from the starboard. I also didn't know there was any other kind of solder joint other than "right" and "wrong" (cold joint).
I'll try and tackle what the Meanwell can do, as much as I know. All of the information below is my understanding from reading this thread and multiple others on nano-reef. I have to give special thanks to evil66 as he is a master at this.
First, I don't think there is any difference between the cool white and royal blue. Both are 3W, have a forward voltage of ~3.6v, and take a max current of 1000mA. However, I've read that the royal blue (and white to a lesser extent) are best run at a slightly lower current. Say 700mA. This extends the life of both types of LED with only a slight decrease in light output. This means that both colors could be on the same driver. But, most people don't so they can dimm them by color and turn them on at different times to simulate sunrise/sunset. I'll try and get confirmation on this.
The Meanwell, specifically that in the group buy ELN-60-48P, is a line voltage constant current source. It provides a constant 1.3A (-25%,+3%) to the LED load on it. It can handle up to 48V max on the load. And the P means it is externally dimmable with an analog signal. The line voltage part means it just plugs into the wall (90 - 240v), no additional power supply is needed. The max constant current is changeable by an internal potentiometer -25% or +3%. This means it can output from 1A to 1.4A or so.
LEDs have a current requirement and a forward voltage. For the Cree XR-E that is ~1A and 3.6v (on average). In series, voltage adds and current is the same. Thus, the Meanwell can power up to 13 XR-E in series at 1A (with the max current at -25%).
It can also run two parallel strings of 13 LEDs at 700mA per string with the max current set to +3%. Current divides in parallel so a total of 1.4A is being provided but each string gets 700mA.
A word of caution with parallel strings of LEDs. This is a recipe for disaster. If you aren't comfortable building this next item, don't run LED strings in parallel. What happens is if one LED in one string dies, then that string shorts and all of the current is sent through the other string. This either kills part or all of the LEDs in the other string or it severely limits the life of the LEDs in the second string. The higher current will work but it will also heat up the LEDs a lot. That is how they die.
But, you can do parallel strings as long as you build in a current mirror. Evil66 found and posted this in the Meanwell thread on nano-reef. Basically it forces the same current in both strands. If one strand shorts then it shorts the other strand too. The Meanwell thread:circumventing the filters is generally frowned upon
Finally, the Meanwell is externally dimmable with an analog signal. The meanwell thread on nano-reef also has this information towards the end. Basically, you create a small circuit with three parts and a 12v power supply and you have dimming.
Another positive is that the meanwell does not need additional cooling.
However, I guess they are 8" long so much larger then a buckpuck. Also, some people reported the max current output could be varied more then the spec -25%,+3%. You should always use a multimeter to see what's going on before loading it with $5 LEDs.
Whew. :twitch:
First, I don't think there is any difference between the cool white and royal blue. Both are 3W, have a forward voltage of ~3.6v, and take a max current of 1000mA. However, I've read that the royal blue (and white to a lesser extent) are best run at a slightly lower current. Say 700mA. This extends the life of both types of LED with only a slight decrease in light output. This means that both colors could be on the same driver. But, most people don't so they can dimm them by color and turn them on at different times to simulate sunrise/sunset. I'll try and get confirmation on this.
The Meanwell, specifically that in the group buy ELN-60-48P, is a line voltage constant current source. It provides a constant 1.3A (-25%,+3%) to the LED load on it. It can handle up to 48V max on the load. And the P means it is externally dimmable with an analog signal. The line voltage part means it just plugs into the wall (90 - 240v), no additional power supply is needed. The max constant current is changeable by an internal potentiometer -25% or +3%. This means it can output from 1A to 1.4A or so.
LEDs have a current requirement and a forward voltage. For the Cree XR-E that is ~1A and 3.6v (on average). In series, voltage adds and current is the same. Thus, the Meanwell can power up to 13 XR-E in series at 1A (with the max current at -25%).
It can also run two parallel strings of 13 LEDs at 700mA per string with the max current set to +3%. Current divides in parallel so a total of 1.4A is being provided but each string gets 700mA.
A word of caution with parallel strings of LEDs. This is a recipe for disaster. If you aren't comfortable building this next item, don't run LED strings in parallel. What happens is if one LED in one string dies, then that string shorts and all of the current is sent through the other string. This either kills part or all of the LEDs in the other string or it severely limits the life of the LEDs in the second string. The higher current will work but it will also heat up the LEDs a lot. That is how they die.
But, you can do parallel strings as long as you build in a current mirror. Evil66 found and posted this in the Meanwell thread on nano-reef. Basically it forces the same current in both strands. If one strand shorts then it shorts the other strand too. The Meanwell thread:circumventing the filters is generally frowned upon
Finally, the Meanwell is externally dimmable with an analog signal. The meanwell thread on nano-reef also has this information towards the end. Basically, you create a small circuit with three parts and a 12v power supply and you have dimming.
Another positive is that the meanwell does not need additional cooling.
However, I guess they are 8" long so much larger then a buckpuck. Also, some people reported the max current output could be varied more then the spec -25%,+3%. You should always use a multimeter to see what's going on before loading it with $5 LEDs.
Whew. :twitch:
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The bottom of the LED is the solder point I'm talking about, not the ones from the starboard to our wires. The heat exits the LED through its base solder, into the star board, and then hopefully into your heatsink through thermal paste or epoxy.
850mA would be good. From what I read that helps extend the life of the LED with very minimal intensity decrease. I'm planning to run mine around 700mA with the meanwells (parallel strands of 13 on a driver, I must be crazy).
850mA would be good. From what I read that helps extend the life of the LED with very minimal intensity decrease. I'm planning to run mine around 700mA with the meanwells (parallel strands of 13 on a driver, I must be crazy).
Louis Governo
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Thanks Eric, that makes more sense on the solder points. I don't even need to worry about that since they come already mounted. Do you know how many meanwells the RMK-ALC will dim individually? I am guessing 2 but I don't know what a lunar pod port is. http://www.digitalaquatics.com/saltwater/RKM-ALC
I have confirmation that you can run any color combo of the Cree XR-E (with same specs of course) on a single driver.
Louis - Just make sure that the LED/starboard mount are in turn mounted to a heatsink.
As I see it you can dim two sets with the two 0-10v DC ports on the RMK-ALC. A single port can dim multiple meanwells the same amount. The meanwell just takes in a given voltage on the dimming input. It is a pretty sweet module for the RKL or RKE. Sadly, one doesn't exist for my RK2.
Louis - Just make sure that the LED/starboard mount are in turn mounted to a heatsink.
As I see it you can dim two sets with the two 0-10v DC ports on the RMK-ALC. A single port can dim multiple meanwells the same amount. The meanwell just takes in a given voltage on the dimming input. It is a pretty sweet module for the RKL or RKE. Sadly, one doesn't exist for my RK2.
Ahah! The luner Pod is an accessory. http://www.digitalaquatics.com/saltwater/LUNAR_POD Basically moonlights from Digital Aquatics.
edit: fixed link.
edit: fixed link.
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melev
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GEORGEDOPE
New member
Could you plug the cord from the power supply into a controller to control dimming of the lights. Like a Profilux Plus II. Or does the dimming device need to be between the driver and LED's?
Neither.
You can plug the line in of the Meanwell into a controller but would only control whether the light is on or off with either line voltage or none. The dimming is a separate input to the Meanwell that takes 0-10v DC. 10v DC is full brightness. 0v DC is fully dimmed. With the appropriate controller port you could control dimming. But, you would need a second port for on/off.
This is approximately the same for BuckPucks. However, the dimming on a BuckPuck is a potentiometer which would be more difficult to use with a controller.
You can plug the line in of the Meanwell into a controller but would only control whether the light is on or off with either line voltage or none. The dimming is a separate input to the Meanwell that takes 0-10v DC. 10v DC is full brightness. 0v DC is fully dimmed. With the appropriate controller port you could control dimming. But, you would need a second port for on/off.
This is approximately the same for BuckPucks. However, the dimming on a BuckPuck is a potentiometer which would be more difficult to use with a controller.
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ReefEnabler
Premium Member
profilux does support dimming 1-10v interfaces, although I'm not sure how you'd interface with the cables. they basically use a telephone line and this 'dimming interface'
The basic model Profilux has 2 ports.
Thats 2 analog outs 1-10v for each port, a total of 4 analog outs.
Also included in those ports is 1 relay out for each analog out, a total of 4 relay outs.
Those relays are use to shut off the dimming device, because 1-10v never completely shuts off the lights, you will need those outputs to completely shutoff the unit.
I am ordering LEDs from that group buy, about 100 of them.
Going use 1 port, 2 analog outs for the whites and blues dimming.
Then using the relay outs to switch the power off.
This what your going to need. Scroll down to see the English version.
http://www.aquariumcomputer.com/Download/Manual_EVG-AP2_V400.pdf
EVG-AP2 is rated at 16 amps at 250 (8 amps at 125v). Its a dual output port.
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Qdaddy
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Are there any pictures or build threads relating to this. It would be very helpful for us electronically challenged people. Also maybe a summary of what's changed from the beginning instructions, if anything has. There's been so much discussion back and forth, that its hard to tell if there was a consensus change from the original post.
This thread was automatically split due to performance issues. You can find the rest of the thread here: http://reefcentral.com/forums/showthread.php?threadid=1630589
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