Led driver advice

[joekellner]

Hi guys.my friend is diy-ing some leds. a similar question to my last thread but he is using different leds.

he is going to use these drivers http://www.ebay.co.uk/itm/121042265301?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648

He Is wondering how many leds these drivers will safely drive.

http://www.ebay.com/itm/321014243296

http://www.ebay.com/itm/170962465950

http://www.ebay.com/itm/390267410768

Prob easiest to have only one colour of leds on each driver and to allow dimming of each colour to acheive the best look to suit him.

And finally what wire would he need to link it all up and solder?

Any help would be appreciated. thanks in advance.

[TheFishMan65]

Well the maximum output voltage is 30 volts. Most LEDs are running around 3 volts so about 10 LEDs. I am not sure that is the best driver, but according to the specs it will work.

[TropTrea]

Looking at the power it is an adjustable voltage driver and not a current driver. So I would not even consider it. Then with the selection of XM-L LED's these are basicly 10 watt LED's running at 300ma and 3.3 Volts each. This would limit you to only three LED's per power supply.

You want a current limiting Power Supply. Depending on how many driver your using select one from this listing to match the Curent of the LED's for the XP-E I would run them at 1050 ma and the XM-L's just under 3000 ma. A good ratio between these two would be 6 XP-E Royal Blues per each XM-L White.

<http://www.meanwell.com/webnet/search/search_ps.aspx?power=Button21>

[TheFishMan65]

Trop,

I am confused. They say they can limit the current in about the last paragraph of the description. They say 3 amps output so where is 300ma coming from? 30 volts output how can that limit to only 3. It actually sounds like these do almost everything and ELN does. I am not sure what the third pot does and it only goes to 30 volts and needs a power supply.

After thinking about it I am not sure these are that bad. I am not sure of the current exchange rate, but even at 2X that would be $5 and not a bad price.

[iddly]

Just to say thank you for the Advice on Using the driver and leds,
The problem is in the UK we do not have the mass DIY led following that you have in the US,
So any advice on a Cheap UK Meanwell driver that can be dimmed would be great.
Would like to use these LM2596 DC-DC Step-down as they are cheap and look very easy to use.
One Question is Can they easily be dimmed using a separate Dimmer and not the onboard pots, and is this done at the AC uk 240Volt side or the Led output side.
Will be running XML at 2Amp as Cree recommends that on the Bin Spec.
looking at using CPU Ali Blocks hopefully without fans joined(bolted and heatpasted) on an ali strip. Thank you in advance....Max(iddly)

[iddly]

Just to say thank you for the Advice on Using the driver and leds,
The problem is in the UK we do not have the mass DIY led following that you have in the US,
So any advice on a Cheap UK Meanwell driver that can be dimmed would be great.
Would like to use these LM2596 DC-DC Step-down as they are cheap and look very easy to use.
One Question is Can they easily be dimmed using a separate Dimmer and not the onboard pots, and is this done at the AC uk 240Volt side or the Led output side.
Will be running XML at 2Amp as Cree recommends that on the Bin Spec.
looking at using CPU Ali Blocks hopefully without fans joined(bolted and heatpasted) on an ali strip. Thank you in advance....Max(iddly)

[TropTrea]

Sorry I still cannot recommend these drivers.

The 10 Watt LED's run at 3000MA and can draw up to 3.7 Volts. This limits him to 3 LED's for each of these. Now add the fact he also needs a 35 Watt power supply for these drivers you end up with 4 of these $5.00 units plus a power supply totaling almost what a meanwell will cost you.

Next you have the 3 Watt XP-E that run at 900 ma and will draw between 3.3 and 3.7 volts each. So with the 30 volt max you now looking at a max of 8 of these LED's on each of these drivers.

Next there is no ability to hook these to any form of a controler for dimming. With the meanwell drivers there are many options here dependent on what type of dimming you prefer to use.

My recomendation would be something like the HVG-150-48 which could drive 12 of the 10 Watt LED's without an issue. Also the HLNH-40-42 would work good with the 3 Watt Royal Blue LED's.

Now I keeping in mind that in the UK standard house power is 220 Volt 50 cycle if I recall correctly.

[TheFishMan65]

Trop,

I agree these may not be the best choice - especially since he wants dimming,

BUt you still have me confused (so please spell it out :)). Where are you getting this "The 10 Watt LED's run at 3000MA and can draw up to 3.7 Volts. This limits him to 3 LED's for each of these."

If you are willing to use an outside power supply you might also consider the Meanwell LDDs.

[TheFishMan65]

Trop,

I agree these may not be the best choice - especially since he wants dimming,

But you still have me confused (so please spell it out :)). Where are you getting this "The 10 Watt LED's run at 3000MA and can draw up to 3.7 Volts. This limits him to 3 LED's for each of these."

If you are willing to use an outside power supply you might also consider the Meanwell LDDs.

[TropTrea]

Trop,

I agree these may not be the best choice - especially since he wants dimming,

But you still have me confused (so please spell it out :)). Where are you getting this "The 10 Watt LED's run at 3000MA and can draw up to 3.7 Volts. This limits him to 3 LED's for each of these."

If you are willing to use an outside power supply you might also consider the Meanwell LDDs.

For his white LED's he is linking to the CREE XM-L led's. These are Cree's newer 10 Watt LED's.

Per Cree's data sheet on these LED's they run at 3000ma and 3.35Volts for actually 10.05 Watts. They also list max voltage at 3.5 Volts. I have run theses LED's and with a 3000ma driver found that they were actualy pulling between 3.42 and 3.62 volts. So they were actualy running at 10.26 to 10.86 watts. By reducing to 2800 ma I found the voltages dropped to 3.14 to 3.36 volts meaning they were running at 8.79 to 9.40 Watts.

There was also a thread about 3 months ago in an electroncs site where someone ran these LED's with a current limiting supply at 3000ma and found that the voltage drop between LED's ranged from 3.4 to 3.7 volts after they were on for three hours. On an initial cold start they ranged from 3.2 to 3.5 volts. The voltage rise is actualy the opposite effect that I would have expected.

While everyone does not run there LED's at maximium current this is normaly for an effeciency reason. On some lower cost LED's you can get more light running 2 LED's at 350ma compared to one at 1000ma. However the XM-L show very much flatter effecieny curve. Basicly you can compare one running at 3,000ma to two that are running at 1,300 ma. So you save 15% power running two XM-L rater than one rather than saving 43% running older design LED's.

As far as most effecient driver selecton is concerned there is one big piece missing from this puzzle. That is how many of each of these LED's will Joe be using? If this is a small tank where he is going to use only 4 Whites and 16 to 24 Royal Blues his selections are much simp0ler than someone running a large tank wth say 40 Whites, and 160 to 240 Royal Blues.

[iddly]

Thank you Trop, and any body else supporting this THREAD.
Will be lighting a 5x2x2 foot tank.
Only want to run all the leds at 75percent of there maximum output,
Also i do want to dim the leds and pos later ad a dawn to dusk control unit.
I would like to keep the setup simple.
Our Meanwell drivers seem to be very differant from the ones used in the states.
i do not mind using the LM2596 driver, but if there is no way of dimming,
Then what UK meanwell or similar driver would you guys recommend.
Hope to Order and build the unit as soon as i can nail down the correct parts.
Max

[TheFishMan65]

Thank Dennis, but I think you missed what I am not understanding. Why only three LEDs? Wait I think I have it, but I can't find it right now. Was there wattage limit on these drivers. I seem to recall 35 watts but I am not seeing it now.

[iddly]

Any advice on using this driver and thank you so far.

Mean Well
LPF-60D-24
for the the Cree XML - XPE
how many leds and better this driver or the LM2596 DC-DC Step-down..
http://www.ebay.co.uk/itm/1210422653...84.m1423.l2648
if so how many leds of each ??
as hope to start build asap...thank you max

[iddly]

Any advice on using this driver and thank you so far.

Mean Well LPF-60D-24
for the the Cree XML - XPE
how many leds and is it better this driver or the LM2596 DC-DC Step-down..
http://www.ebay.co.uk/itm/1210422653...84.m1423.l2648
Want to be able to dim leds also.
if so how many leds of each ??
as hope to order and start build asap...Thank you max

[Dave Thebrewguy]

Trop,

I agree these may not be the best choice - especially since he wants dimming,

BUt you still have me confused (so please spell it out :)). Where are you getting this "The 10 Watt LED's run at 3000MA and can draw up to 3.7 Volts. This limits him to 3 LED's for each of these."

If you are willing to use an outside power supply you might also consider the Meanwell LDDs.

I'm missing something too. It looks like this driver can put out 3A (3000mA) at up to 30V. Even at 3.7V each, that's up to 8 XM-L per driver. That may be pushing your luck with a 29.6V string, but 7 XM-l should be fine.
I wouldn't use this driver, I'd suspect it's a matter of "you get what you pay for," but YMMV. You'll still need a power supply for it since the input is only up to 35VDC. I'd want to put the full 35V into it if you expect to get anything close to 30V out of it. Going with 7LEDs would probably allow the use of a 32V power supply.
The Meanwells are a much better choice. I haven't used that model but it should power 6 XM-L and won't need a seperate power supply.

[TropTrea]

The LM 2596 Chip has a max power rating of 30 Watts not mentioned in the add. It only says you need to heat sink it if your going over 15 Watts. If your running 3 Amps that means a max of 10 volts or no more than 3 LED's, if you run at 2 Amps then you can you can go to 15 Volts or 4 Chips. if you run at 1 Amp then you can go to 30 Volts and the 8 Chips like your thinking. But you have to watch the Wattage rating on drivers which is equaly important as there current and voltage range.

[TheFishMan65]

Thanks TropTrea I figured I was missing something.

[TheFishMan65]

iddly, the links don't work. I looked at the datasheet for the LPF and I can't see anything wrong with that driver.

[Dave Thebrewguy]

The LM 2596 Chip has a max power rating of 30 Watts not mentioned in the add. .
I figured that might have been the case but I wasn't able to find the info. Thanks for pointing it out.

[iddly]

Sorry Guys the link is dead as i bought the Drivers as recommended, Thank you..

[TropTrea]

I little pointer on how select my drivers.

1. I calculate the actual wattage I need on the string of LED's that I intend to use them on and then add 10% more to assure I will not be usining the driver at its max.

2. I determine the current I want to run the LED's at maximium power. Then I search the available drivers available with that wattage and current.

3. I double check that the input power of the drivers matches my available power. Note some require a DC input, some run from 90 to 180 volts AC, others require 180 to 480 volts ac. Keep in mind that if you take one running on DC it will require an added AC to DC power supply which can cost considerably more than having it built into the driver. On a large build with many low wattage LED's the added DC power can be a cost saver but but on some other builds it can more than double the total driver cost.

4. I review the options as far as matching the dimming circuitry to haow I want to dim them if I want to dim them. There are usualy three options here, 0-10 volt dimming, 1 to 10,000K ohms dimming, and pulse width modulation dimming.

3. I will check the case to determine if it is rated for high humidity applications and or cooling requirements.

In the past I have used maxwell as well meanwell drivers with no problems. I have had problems though with some other brand names.

[Reef Developer]

I little pointer on how select my drivers.

1. I calculate the actual wattage I need on the string of LED's that I intend to use them on and then add 10% more to assure I will not be usining the driver at its max.

2. I determine the current I want to run the LED's at maximium power. Then I search the available drivers available with that wattage and current.

3. I double check that the input power of the drivers matches my available power. Note some require a DC input, some run from 90 to 180 volts AC, others require 180 to 480 volts ac. Keep in mind that if you take one running on DC it will require an added AC to DC power supply which can cost considerably more than having it built into the driver. On a large build with many low wattage LED's the added DC power can be a cost saver but but on some other builds it can more than double the total driver cost.

4. I review the options as far as matching the dimming circuitry to haow I want to dim them if I want to dim them. There are usualy three options here, 0-10 volt dimming, 1 to 10,000K ohms dimming, and pulse width modulation dimming.

3. I will check the case to determine if it is rated for high humidity applications and or cooling requirements.

In the past I have used maxwell as well meanwell drivers with no problems. I have had problems though with some other brand names.

Dennis;

I'm designing an LED build for my new nano. Been reading up on LEDs and drivers and have a couple questions, if you could kindly answer them;


Where do you search for/find drivers, anywhere besides RapidLED and LED groupbuy.com?
To keep is simple, I'm going to use a driver that accepts AC. When a driver states something like 100-200vac, does the input voltage have any bearing on the output voltage, or is the incoming V normalized to 120?
In terms of the dimming options you clearly layed out, wich one is cheapest/easiest? I know 0-10k needs a POT and voltage supply. What about PWM?
What does someone do when they want to use the new XM-L at up to 3kMA but also is going to have a couple violets and royal blues? Use a lower current driver AND higher current driver? In my case, for my 12g nano I'm going to have about 3 cool whites, 6 blues, an 2 violets. Could I use this for my lower mA LEDs? http://www.superbrightleds.com/moreinfo/led-drivers/700ma-constant-current-led-driver/1323/3045/


Sorry for the sidetrack.....tia. Kevin

[TropTrea]

Yes on the dats sheet of the device they do not list a total wattage rating. However if you to the chip spec sheet you see that at 3 amps the list a max of 12 volts, and at 1 Amp they list a max 35 Volts. Using Ohms law this gives a max of about 35 to 36 watts in either situation.

Without knowing the internal components of this module it is very hard to know the exact rating and there absense of giving one would make me nervious using this modle beyound the 35 watt range. It does claim you can use it for voltage outputs of up to 40 folts though with the correct component as low Amperages and proper cooling.