TheFishMan65
New member
bhammer,
What do you man by LED power factor?
Looks good otherwise, but make sure you have dimmable drivers.
What do you man by LED power factor?
Looks good otherwise, but make sure you have dimmable drivers.
DIY LEDs - The write-up
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TheFishMan65
New member
OK, I would have just put it in as the current maybe calculated a percentage of math. Since the driver have a power factor and it can vary some it confused me.
4 strings of cool white at a maximum of 1.5 amps but dimmed to 75%
4 * 1.5 * 75% = 4.5 amps the supply only give 3.9
4 strings of cool white at a maximum of 1.5 amps but dimmed to 75%
4 * 1.5 * 75% = 4.5 amps the supply only give 3.9
bmwaaron
New member
What are the advantages or disadvantages to running a Higher voltage series circuit vs a parallel circuit?
Do the Higher voltages pose more problems?
For instance what would be the advantages vs disadvantages of running a Inventronics EUC-150S700DT vs a Meanwell HLG 185?
I would think for simplicity you would run the constant current driver to run 60 LEDS vs running 5 parallel strings
What am I missing here?
Do the Higher voltages pose more problems?
For instance what would be the advantages vs disadvantages of running a Inventronics EUC-150S700DT vs a Meanwell HLG 185?
I would think for simplicity you would run the constant current driver to run 60 LEDS vs running 5 parallel strings
What am I missing here?
bhammer
Addicted User
From what I have read, it is only the higher voltges and the dangers of working with it. There are a couple folks that are going with a high voltage power supply.
Gold Stripe
New member
Death.
48v wont stop your heart if you hit it but 100+ will. High voltage can and has been used successfully but you have to be the type of person that is extra careful and tripple checks everything every time. You also have to go the extra mile of completely insulating all connections against incidental contact especially since you are using it over water. If you want to put in the time and effort to do it right it is a great way to go but for most of us average joes it just isnt worth the risk.
48v wont stop your heart if you hit it but 100+ will. High voltage can and has been used successfully but you have to be the type of person that is extra careful and tripple checks everything every time. You also have to go the extra mile of completely insulating all connections against incidental contact especially since you are using it over water. If you want to put in the time and effort to do it right it is a great way to go but for most of us average joes it just isnt worth the risk.
DC grabs you differently than AC as well. Because DC doesn't pulse like AC does it grabs you harder. The current considered a bigger factor in the danger though. I have been working on a 24v fire alarm system lately and the current is so low that unless your hands are sweaty you can't feel it. If it was bumped up to 1000mA like we use it could really hurt.
Going parallel with I driver that has a lower voltage and higher current handling is much better for us. Even 48v DC at 1A could do more damage than 120v AC at 1A.
Going parallel with I driver that has a lower voltage and higher current handling is much better for us. Even 48v DC at 1A could do more damage than 120v AC at 1A.
bhammer
Addicted User
I see that folks are using fuses to protect series / parallel strings. Has using resistors to protect been talked about? What are the advantages or disadvantages of doing so? Maybe I don't understand it, but my thought would be that if you run a resistor for each LED at just below the max rated current, you would protect them.
I know that would be a lot of resistors to solder. And there is probably a loss of power for the resistors.
I don't remember it being talked about in the threads and if it has, just point me to the thread number.
I know that would be a lot of resistors to solder. And there is probably a loss of power for the resistors.
I don't remember it being talked about in the threads and if it has, just point me to the thread number.
kcress
New member
I cover that in this post and also jcgd's misconception about big current verses little current.
Check this out:
http://www.reefcentral.com/forums/showpost.php?p=18472743&postcount=21
Okay, okay. You are right, but I don't think I'm completely wrong. It is the current that does the damage, but with the typical resistance of a human body you need a high voltage to get the high current.
I believe your number of 50 000ohms is very loose. It can be up to hundreds of thousands of ohms and down as low as a few dozen ohms and you are leaving out the fact that the resistance has many variables. Dirt, oil, sweat (a fantastic conductor), etc.
That writeup is for the most part very accurate, but for someone to assume they have a resistance of 50 000ohms is a mistake.
Now, break the skin and your resistance drops to very low numbers. Have open cuts and you are in trouble
5A will hurt very badly. But you can be killed by as little as 1A or less depending on all the factors.
A guy at work took 347v AC a few months back. According to your numbers of 50 000ohms he would have received only 6.94mA. He shouldn't have felt a tingle, but he has massive burns on his hands, he locked up solid and the only reason it let him go was because gravity let him fall straight back onto the floor, pulling his hands off the wire. The tool grabbed two phases across his chest. He got lucky.
*I would edit my previous post as I did a very bad and misleading job on it but I don't know how. The edit button isn't present.
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bmwaaron
New member
Sounds good.. I guess Ill stick with the meanwell drivers and using parallel circuits.
Second question:
Do you have to match voltage of the Meanwells exactly or can you go over. Example is if I wanted to drive 11 LED's that have a forward voltage of 3.6 on a 48volt driver would I be OK since my forward voltage requirement is actually 39.6v ?
Second question:
Do you have to match voltage of the Meanwells exactly or can you go over. Example is if I wanted to drive 11 LED's that have a forward voltage of 3.6 on a 48volt driver would I be OK since my forward voltage requirement is actually 39.6v ?
Ive read bits of this thread, and several others. I'm getting ready to order leds soon. I plan to do a linear design using channel. 60 leds, 5 rows of 12. Over a 75, 48x20x18. Im trying to make a final decision on colour and layout.
Im thinking something like this:24 Royal blue, 12 Cool white, 12 Neutral white, 10 blue, 2 red.
RB RB RB RB RB RB RB RB RB RB RB RB
CW NW CW NW CW NW CW NW CW NW CW NW
B B B R B B B B R B B B
NW CW NW CW NW CW NW CW NW CW NW CW
RB RB RB RB RB RB RB RB RB RB RB RB
With RB, NW, CW dimable seperatly, an the R/B sting dimable.
Im wondering about banding issues, possibly either going no optics, and having the fixture only a couple inches off the tank, or maybe 60 or 80s on everything except no optics on the center rail. I have no preference on fixture location.
Im thinking something like this:24 Royal blue, 12 Cool white, 12 Neutral white, 10 blue, 2 red.
RB RB RB RB RB RB RB RB RB RB RB RB
CW NW CW NW CW NW CW NW CW NW CW NW
B B B R B B B B R B B B
NW CW NW CW NW CW NW CW NW CW NW CW
RB RB RB RB RB RB RB RB RB RB RB RB
With RB, NW, CW dimable seperatly, an the R/B sting dimable.
Im wondering about banding issues, possibly either going no optics, and having the fixture only a couple inches off the tank, or maybe 60 or 80s on everything except no optics on the center rail. I have no preference on fixture location.
bmwaaron
New member
Does this work?
39 Cree RB XPE
3 parallel strings of 13
1 HLG 150H 54w
The maximum amp output of the 54W is 2.8 amps so if I ran 3 strings that would be a maximum of 933 ma. I would be dimming with a profilux.
The HLG is only going to put out enough voltage to meet the forward voltage
requirement correct?
Would I be safer going with the HLG 120 48W which outputs 2.5 amps that would give me 833 ma?
39 Cree RB XPE
3 parallel strings of 13
1 HLG 150H 54w
The maximum amp output of the 54W is 2.8 amps so if I ran 3 strings that would be a maximum of 933 ma. I would be dimming with a profilux.
The HLG is only going to put out enough voltage to meet the forward voltage
requirement correct?
Would I be safer going with the HLG 120 48W which outputs 2.5 amps that would give me 833 ma?
tonythefish
New member
I am running 120 leds on a 180
bmwaaron
New member
How do you like your color?
I'm adding LED's as a supplement right now then if I like them I will make a complete fixture. I'm still holding out a little for the XL-M's
The reason for the change is that for some reason with T5's I get lighter color and not a deep color like I get with MH's.
This doesn't seem to be something I'm doing because another friend with the same light fixture that switched from MH's notices the same thing. I'm hoping LED's will give me deep rich color and not so much pastel.
You will be safer with the 150-54. You're not using up the max voltage so you might end up with 1000mA per string or even more, instead of 933mA
(carefull with firing up the driver)
With the 120-48 you're getting close - or even over its max output voltage.
13 LEDs makes 3.6V per LED while 3.9 is the max Vf for the XP-E RB.
To go with 12 Leds per string would be safer.
Recommended by Meanwell is to stay within 60/90% of the drivers' maximum output. I don't think 92 or 93% would cause any seriuos problems, but the driver will have a hard time managing the current when all the voltage is used up by the LEDs.
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brassmonkyballs
BMB
my experience has been and continues to be that the XPEs and XPG run no where close to those voltages. In fact they tend to run 3.1 to 3.2V and the rare outlier pushing 3.3V. On my most recent build I showed I was measuring 31V on the 10 series and 34V on the 11 series. This with the HLG 120-42 and the 185-42. I am running the 185-42 at 1A-1.1A per string and the 120-42 at 850-900ma. I am absolutely confident I can run 13 on the 42V version.
Maybe its just me but the last 3 builds I've done are running this way which includes a RB only supplement light with 28 RBs wired in 2 strings of 14 off an ELN-60-48......
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