diy LED Lumina 5.2 Purchase help.

[oreo57]

also if channels 2 and 3 are 1500 mh, then why Im I only using a 1000mh driver?

There are no ldd drivers higher than 1000mA that can handle more voltage than 36V mostly..

2 Lumia's in series is At, roughly 36V ..Voltages add in series. Running all in parallel allows you to use the LDD1500-L.

Just remeber, sometime what you can run something at is not always what you should run something at..

 

[banthonyb71]

So stay with the 100h drivers unless I want to run my leds at 1500mh in which case it is not recommended?

 

[oreo57]

So stay with the 100h drivers unless I want to run my leds at 1500mh in which case it is not recommended?

your choice will depend more on how you set them up. Putting 2 chips in series and you can't use ldd-ls (36v maax BUT since they lose voltage to get 36v out you need 38(9) (2-3V "loss" across the LDD) power supply

If you run ALL in parallel you can use LDD1500-L's
The difference is loss of light output but loss of heating as well. Technically most LED's are more efficient at lower drive currents (more lumens/watt) at the cost of gross output (loss of Watts so to speak).
A made up example:
at 700mA a 3v LED has an output of 120 lumens/watt
at 1000mA a 3.4v LED (voltage increases thus increasing amp draw) has an output efficieny of 100lumens/watt

diode A 252 lumens
diode b 340 lumens IT should be 408 if it kept the same "efficiency" as diode a

But diode a runs cooler..

Note: diode a and b are the same diode at different currents.. Couldn't think of a better way to do this fast.
Note 2: It is not "quite" this simple but good enough.

 

[perkint]

To put it simply - one LED at 1000mA will output less light and more heat than two of exactly the same LEDs at 500mA. So you get more light per watt. And, if you want to be picky (as I usually do) you need less cooling as you have less heat and the fact that things are cooler actually improves the amount of light per watt, again

Tim

 

[banthonyb71]

what is ldd-ls?

 

[oreo57]

what is ldd-ls?

Ldd-l 's...
http://www.meanwell.com/search/LDD-L/LDD-L-spec.pdf

@ series Ldd-H (higher voltage)
Ldd-L
Which really has a few different "forms" See spec sheet.. pg2 for the higher Amp ones.

you have to be careful since their wiring configurations can differ..

Some boards can only do LDD-H's ect..

There not as "neat" but no reason you can't just use "W" versions of each.. which have simple "wires" than pins for board mounting..

 

[mkj]

LOL. talk about over thinking things. If you ordered what I suggested on first page your lights would be built by now. Quote form Einstein " the easiest, quickest way, is always the right way, even if there are other way to do it". (just like my love making)

Either of the two ways parallel or serial will adjust from 100% to 0%. I use serial and have all special lightning and whatever. I use 4 Lumias on 2 PS with 2 boards, 6 700 LDDs and 4 1000 LDDs + reafangel for controller. All ordered form same place except reefangel (one shipping cost). No problems and takes less than 5 minutes to put together. no need to overthink and make yourself confused about which way is best "there is no best".

Goof luck with your build whichever way you decide to do it. :spin1:

Lets see if this thread can hit 100 replies for no reason.

 

[banthonyb71]

If you ordered what I suggested on first page your lights would be built by now.

Lets see if this thread can hit 100 replies for no reason.

bro, you are waay off base here. for one, if you look at the last few posts, people have been trying to help me understand voltage, amps, series parrallel. great info for me to know regaurdless of what drivers I choose.

You on the other hand are implying that I should just listen to you and not ask questions. Why? because I know you? What makes your advice any different from the next person that suggested something totally different? See thats what some of you experienced guys dont quite understand on these forums when dealing with newbies.

You give a person a piece of advice and he doesn't follow it, but follows the next guy's. You get offended, sarcastic. as if this new person should magically know your way is best over the next persons??

Really no need to get sarcastic...but since you did...let me see if I can try that game.

Let's start by counting how many times you said "I think" when suggesting what I should do.

The 250watt will be fine with two 5.2s but I think the amps may be a problem with trying to use three Lumias on that PS. The one set of LDDs will be doing 4.1amps if maxed (3X700 + 2X1000), which is fine for that PS but add a second set of LDDs and amps go over that PS I think.

I think with two sets of boards/LDDs you need to double that 4.1 amps to 8.2 amps which is over that PS you quoted but Im not sure if amps doubles or not with second board/LDDs on the same PS.

Personally I would use the 250 watt PS on two but I would get a second PS when/if order the third Lumia. Or, order the 500 watt that has 10.4amps. Overkill for two Lumias but good for three I think.

read http://www.reefcentral.com/forums/showthread.php?t=2372156 . Aqualund built a large one using many Lumias

Now bro, I appreciate your advice. I really do..and I'm not sure if what you said is right or wrong.....but my mother once told me, if you stop to ask for directions and the person says "I think it's....." or It's this way but I'm not sure." Kicks rocks and go ask the next person"!!

Just saying.

So please bro..I already know what drivers, boards etc. still haven't picked out a PS but nobody is over thinking anything just trying to understand as much as possible and I'd appreciate you not detouring help away.

 

[banthonyb71]

for every one who has offered advice, Idefix, Perkint, Jedi, Mkj and everyone else including those who helped outside this thread AquAlund, Oreo. Please understand it is not a lack of taking advice as to the reason this thread is still open as Mkj suggested.
I think it would be foolish to try not to understand something as much as possible.

hopefully nobody has been pushed off to answer but another question.

(again, this has nothing to do with the power supply Im going to purchase. I understand I know 180 watt PS is not enough0 but just for understanding

on LED GB website. they state" We have taken the original Lumia 5.1 and expanded on it by adding a range of High End CREE LEDs. These CREE LEDs produce more light for less power. For instance, you can power 2 of the CREE Lumia 5.2 with only 5 LDD drivers and 1 180w power supply.

If all 5 channels equals 4.1 amp then why are they suggesting 3.75 amp PS? is 400mh or so not enough to make a difference?

 

[Idefixes]

on LED GB website. they state" We have taken the original Lumia 5.1 and expanded on it by adding a range of High End CREE LEDs. These CREE LEDs produce more light for less power. For instance, you can power 2 of the CREE Lumia 5.2 with only 5 LDD drivers and 1 180w power supply.

If all 5 channels equals 4.1 amp then why are they suggesting 3.75 amp PS? is 400mh or so not enough to make a difference?

Maybe they use a 5 LDD700H route => 5x 700ma=3.5Amp, but then you don't obtain 70W per lumia.

Marc

 

[perkint]

5 channels is 4.1A on the output. Assuming 3 x 700mA and 2 x 1000mA. But that is about 70W. So two is 140W. How much current this will draw from your PSU depends on the voltage of the PSU. If you ran the two in parallel from a 24V supply (10 LDDs) or two in series from a 36V supply (5 LDDs and PSU adjusted to 39V) then you would be using less than 150W total so drawing just over 6A from 24V and just over 4A from a 36V.

Tim

 

[Idefixes]

5 channels is 4.1A on the output. Assuming 3 x 700mA and 2 x 1000mA. But that is about 70W. So two is 140W. How much current this will draw from your PSU depends on the voltage of the PSU. If you ran the two in parallel from a 24V supply (10 LDDs) or two in series from a 36V supply (5 LDDs and PSU adjusted to 39V) then you would be using less than 150W total so drawing just over 6A from 24V and just over 4A from a 36V.

Tim

Perkint in LGB assumption they use to Lumia in serie as they said

you can power 2 of the CREE Lumia 5.2 with only 5 LDD drivers

so power supply output doesn't be lower as 2x18Vf+3v(LDD)=>39V. If they had parralleling them on PSU 10LDD were needed and then Voltage needed will be 18Vf+3V(LDD)= 21V. A 24V PSU will needed and as 5 ldd are in parallel => 4.1+4.1=8.2Ax24V=>196W. Yes if they are not used at 100% rating lower power can go but it's IMO not a safe way to act. SMPS have a lost between 10 and 20% power so for 8.1A needed PSU must be rated at min 8.1x1.2= 9.72A. If you select PSU at 21V => 9.72x21=204W for 2 lumia in parallel à 100%

Marc

 

[oreo57]

on LED GB website. they state" We have taken the original Lumia 5.1 and expanded on it by adding a range of High End CREE LEDs. These CREE LEDs produce more light for less power. For instance, you can power 2 of the CREE Lumia 5.2 with only 5 LDD drivers and 1 180w power supply.

If all 5 channels equals 4.1 amp then why are they suggesting 3.75 amp PS? is 400mh or so not enough to make a difference?

Maybe they use a 5 LDD700H route => 5x 700ma=3.5Amp, but then you don't obtain 70W per lumia.

Marc

Because the "actual" watts (amps) is based on the actual drive current x the actual voltage.

LED's are not static devices. As voltage across them increases amp draw increases.

@ 500ma the voltage may be3.25V
@ 700mA 3.5V
@ at 1500ma 3.6V

W/ 5 in series:
8.12W
12.25W
27W respectively

W/ a 24V ps you would need it rated at
.33A (7.92W)
.51A (12.24W)
1.125 (27W)

The theoretical (or max) may be 5 but the "actual" (based on the actual voltages at the selected drive current) is quite different.

since a single chip is 5 parallel rows you just add the actual calculated from each row.

Simple adding Ldd amps is sort of a rule of thumb.. Only met when the actual LED series string voltage equals the actual power supply voltage (of course w/ the 2-3V "loss" of an ldd this is not really possible anyways)
AFAICT..

 

[perkint]

A 24V PSU will needed and as 5 ldd are in parallel => 4.1+4.1=8.2Ax24V=>196W. Yes if they are not used at 100% rating lower power can go but it's IMO not a safe way to act. SMPS have a lost between 10 and 20% power so for 8.1A needed PSU must be rated at min 8.1x1.2= 9.72A. If you select PSU at 21V => 9.72x21=204W for 2 lumia in parallel à 100%

As oreo57 said, it doesn't work like that. Even at 100% across all channels a lumia 5.2 will not draw 4.1A if running thru LDDs on a single PSU as some strings are lower voltage and therefore will not be pulling the same current from the PSU as the LDD is outputting to the LEDs.

If you ran a single 3W LED from an LDD1000 on a 48V PSU it would only draw 63mA from the supply! Well, plus a bit for the LDD, but nowhere near 1000mA!

Tim

 

[Idefixes]

As oreo57 said, it doesn't work like that. Even at 100% across all channels a lumia 5.2 will not draw 4.1A if running thru LDDs on a single PSU as some strings are lower voltage and therefore will not be pulling the same current from the PSU as the LDD is outputting to the LEDs.

If you ran a single 3W LED from an LDD1000 on a 48V PSU it would only draw 63mA from the supply! Well, plus a bit for the LDD, but nowhere near 1000mA!

Tim

For sure time but when you dimension the system imo the better thing is to do is to consider the system maximum rating and not a hypothetique using point instead of you can have bad surprise. Vf i use are vf LGB one at full led amp rating. LDD are constant current source so if you use a LDD700H (@100% PWM) on a led it will push 650mA through this. It's clear if the led is alone power consumption will be 0.65xVf @ 650mA only. I am aware with all your math and know what you stated but for dimensionning the system, consideringhis max rating will allow more safety marge in.I see number of smps (even meanwell) brake down even with use under half power : many time resistor burned, sometimes inductor, many other time heat dry or brake down low quality electrolytics...

Marc

 

[oreo57]

For sure time but when you dimension the system imo the better thing is to do is to consider the system maximum rating and not a hypothetique using point instead of you can have bad surprise. Vf i use are vf LGB one at full led amp rating. LDD are constant current source so if you use a LDD700H (@100% PWM) on a led it will push 650mA through this. It's clear if the led is alone power consumption will be 0.65xVf @ 650mA only. I am aware with all your math and know what you stated but for dimensioning the system, considering his max rating will allow more safety marge in.I see number of smps (even meanwell) brake down even with use under half power : many time resistor burned, sometimes inductor, many other time heat dry or brake down low quality electrolytics...

Marc

your points are valid BUT you have to consider "real" maximum vs "theoretical" maximum.
As an example my "rule of thumb".. Just add driver mA's and size the power supply accordingly. Problem is this could be well over 50% higher than the REAL maximum..

As to low quality electrolytics, personally, nothing will prevent their breakdown. It will only marginally extend their life.. "Capacitor rot" is still alive and well.
I believe they now have it down to a science in order to do the "planned obsolescence"..

My personal conspiracy theory. They know exactly where to place the "cheap" ones in order to kill the product in x amount of time..

 

[perkint]

For sure time but when you dimension the system imo the better thing is to do is to consider the system maximum rating and not a hypothetique using point instead of you can have bad surprise. Vf i use are vf LGB one at full led amp rating. LDD are constant current source so if you use a LDD700H (@100% PWM) on a led it will push 650mA through this. It's clear if the led is alone power consumption will be 0.65xVf @ 650mA only. I am aware with all your math and know what you stated but for dimensionning the system, consideringhis max rating will allow more safety marge in.I see number of smps (even meanwell) brake down even with use under half power : many time resistor burned, sometimes inductor, many other time heat dry or brake down low quality electrolytics

I think i know what you mean, but i don't understand this bit: "Vf i use are vf LGB one at full led amp rating". Specifically LGB?

But, i think i now understand what you are saying. Correct me if i misunderstand, but i think you mean, for an increased safety factor you would design the system around the maximum it would be possible to draw, if (for example) you decided to add a few more LEDs to the strings. Not the maximum the config you intend to build will use. If that is what you mean, i wouldn't argue against it if someone wanted to do that, so long as they were doing it deliberately and knowing that they were over engineering for extra safety measures allowing for future expansion.

In fact, the build i am (slowly!) working on involves the same 350W PSU linked earlier, for a design (currently) with a max power of about 150W!!

Tim

 

[banthonyb71]

Thank you. So how did you guys learn this stuff? Do you have a background in electronics? Did anyone learn just from doing LED lights?


My final question related to power supply. does the voltage of the power supply always have to match voltage of chips? say if you had 48 watt power supply, you would always have to wire leds to come a close to 48 volts? or can it be under 48?

 

[oreo57]

Did anyone learn just from doing LED lights?

I did. It is amazing the things you teach yourself so you don't burn down your house..
Or watch smoking things consume your checkbook.

My final question related to power supply. does the voltage of the power supply always have to match voltage of chips? say if you had 48 watt power supply, you would always have to wire leds to come a close to 48 volts? or can it be under 48?

Well it depends on the drivers for one.. but w/ LDD's and related types.. No you just need the voltage for the LED's and the plus 2-3V for the LDD's. any extra is err extra.

Matching increases power supply efficiency but not really necessary. That said you really don't want one 3V led on a 48V power supply.

different ones look different but the principal of efficiency is to fall in the sweet spot.. if you can.
Running say different strings w/ different voltages is err. difficult to do unless you aim for watts..

A computer power supply. Principal remains the same..

 

[banthonyb71]

looks like around 50% max efficiency a?