Meanwell LDD driver: for those who want to dim to 0 using Arduino

[sfsuphysics]

I thought you reduced the voltage not the amperage for the dimming.

When you're dealing with drivers that fix the current and let the voltage match like with LEDs you're actually lowering the current, the voltage will lower as a net result. The trigger signal to the driver that says "lower voltage" is voltage based though.

That said the LDD dim via pulse width modulation (PWM) which doesn't do either to dim, it has 100% current and voltage... just pulses it very rapidly, which gets the same effect as dimming, our eyes just don't notice the pulsing and we see it as dimmer or brighter. Which is why you probably shouldn't use an LDD 1000 on an LED that has a max current rating of 700mA even if you plan on running it at 70% or less.

 

[sfsuphysics]

One thing I noticed with the Meanwell powersupplies (at least the SP series ones I bought) is the fan on them is quite loud... almost reminiscent of those tiny Northbridge motherboard coolers .. tiny but ran fast to move air and made an annoying whining sound. It's not quite as high pitched, but definitely has that sound of a CD-rom drive spinning very fast. I plan on building a case for the PS, removing the internal fan on the PS, and putting a 92mm fan or so on the case that does the same thing.

 

[O2Surplus]

One thing I noticed with the Meanwell powersupplies (at least the SP series ones I bought) is the fan on them is quite loud... almost reminiscent of those tiny Northbridge motherboard coolers .. tiny but ran fast to move air and made an annoying whining sound. It's not quite as high pitched, but definitely has that sound of a CD-rom drive spinning very fast. I plan on building a case for the PS, removing the internal fan on the PS, and putting a 92mm fan or so on the case that does the same thing.

That's a great idea! I don't know why MeanWell uses such noisy fans in their supplies? You'd think "quiet power" would be a good selling point?

 

[joshlawless]

also how many of the luxeon m's with one 1000ldd run?
http://shop.stevesleds.com/Philips-Luxeon-M-ROYAL-BLUE-12-Watt-LEDs-Luxeon-M-RB.htm

Depends on the input voltage you give the LDDs. They can accept up to 56, and can output about (input-4) volts. Divide the output voltage by the forward voltage of the LEDs you have in mind, and ROUND DOWN. That's the number you can run.

With a 48V power supply, you can run ((48-4)/11.4)=3.85 rounded down to 3.

If you tweak the 48V power supply to output closer to 50 (doable), then you could run 4 (right at the bleeding edge).

 

[sfsuphysics]

That's a great idea! I don't know why MeanWell uses such noisy fans in their supplies? You'd think "quiet power" would be a good selling point?

The worst thing is I think the fan speed is voltage regulated not power regulated. When I plugged it in with no load just to test it that it worked, the fan was hardly noticeable and I thought to myself "awesome quiet as quiet should be" so I put the PS outside of my fishroom (so humid air wouldn't get sucked into it constantly) wired everything up, and plugged in it... and *WHIRRRRRRRRRRRRRRRRRRRRRRRRR* ***!? Even with a single string of LEDs at 10% power (maybe 3 watts worth of pull? on a PS rated for 320 watts) still sounds like I'm burning a CD.

Needless to say the wife objected to being able to hear the sound up the stairs.

 

[Giga]

Is there a limit how far these can be from the leds? Becuase my fixture is thin and I want to mount those about 3-4 feet away in a box

?

 

[O2Surplus]

?

3' or 4' isn't going to matter. The driver will push the same amount of current regardless of the small voltage drop incurred on the wire do to the added resistance. I've got some Leds mounted over 10' away from my Ldd's and they're still being driven at the expected current level.

 

[Giga]

Sweet!

 

[habeeb]

No- the outputs can't be tied together. The LED outputs have to remain electrically isolated from each other for the LDD's to work properly.

hi guys,

had a question on this..

I notice some are using large amounts of LDD drivers. I notice the meanwell AC-DC power supply, usually only include 3 slots for output. how can we even use a 600 watt power supply when you can only then hook a max of 3 LDD drivers to it ???

so if it has 3 slots for power outputs, you can only put 3 LDD drivers on one power supply? you have to buy multiple power supplies for say 7 LDD drivers?

 

[joshlawless]

so if it has 3 slots for power outputs, you can only put 3 LDD drivers on one power supply? you have to buy multiple power supplies for say 7 LDD drivers?

You can connect multiple LDDs to each output of the power supply -- the number of outputs is not limiting.

 

[nemosworld]

hi guys,

had a question on this..

I notice some are using large amounts of LDD drivers. I notice the meanwell AC-DC power supply, usually only include 3 slots for output. how can we even use a 600 watt power supply when you can only then hook a max of 3 LDD drivers to it ???

so if it has 3 slots for power outputs, you can only put 3 LDD drivers on one power supply? you have to buy multiple power supplies for say 7 LDD drivers?

if you read back through this thread, you will notice most if not all of the members in this thread are using custom pcb's to mount their ldd's, the boards designed range from 4-up to 6 up, i believe they was a 3-up as well.
all of these connect to one power source.

 

[habeeb]

You can connect multiple LDDs to each output of the power supply -- the number of outputs is not limiting.

thanks.. so can I make my comment more specific maybe while looking dumb, but saving me from blowing something up, or potentially ruining something.

I was wanting to use a ( not sure if I can say, I think there banned here ) a setup that has 2 drivers it, with dimming knobs, and a fan connector..... Can I hook as many of these up to one output I want? or can I only hook 1 unit up to each output..


I get that you can hook up more then one driver to a output now, but is that dependent on only being able to hook up one "electronic board" to each output, and your stuck with how many or little drivers each board has on it??


Thanks

 

[n2585722]

You can hook up as many boards as you want as long as the load current is less than the max current of the output .

 

[O2Surplus]

thanks.. so can I make my comment more specific maybe while looking dumb, but saving me from blowing something up, or potentially ruining something.

I was wanting to use a ( not sure if I can say, I think there banned here ) a setup that has 2 drivers it, with dimming knobs, and a fan connector..... Can I hook as many of these up to one output I want? or can I only hook 1 unit up to each output..


I get that you can hook up more then one driver to a output now, but is that dependent on only being able to hook up one "electronic board" to each output, and your stuck with how many or little drivers each board has on it??


Thanks

The only real limit you must pay attention to is the maximum current/ wattage rating of your power supply. The rest of your build will just require some creativity on your part. There are a myriad of ways to wire up a DIY led lighting system. Do yourself a favor and spend some time looking at some of the other DIY led threads that are posted here on the forum. There's bound to be more than one that will show some inspired wiring tricks. I'm familiar with the " 2 drivers it, with dimming knobs, and a fan connector" that you're planning to use. Since they're all intended to mount to the (not mentioned here) DIY Heat sink, you could- for example, "daisy chain"all of them together, and only run a single wire pair back to your power supply. That's just one way- there's plenty of other examples out there, if you look.

 

[Meldrath]

Anyone have 3 or 4 - 4up boards with pull down resisters for sale? I'm in the DFW area.

 

[Sacohen]

Great thread going here.
I'm trying to read through it all, but there is a lot. I'm on page 24 of 68 so I still have a while to go.

I have a couple of questions.
I found someone who started this project and then abandoned it for a ready made lights so I'm going to buy his drivers and PCB, but he says that new features have been added to the 4 chip PCB since it first was designed.

All I can see so far in the addition of a socket for the driver to go in rather then soldiering it to the board.
Is there more to it than just that?

This is my proposed build.

My build is going to be 72 LED's
Six channels broken down like this...

12 = Blue

12 = Royal Blue

6 = 10K (Warm White)
6 = 6500 (Cool White)

8 = Violet
6 = Ultra Violet

6 = Green
6 = Cyan

6 = Pink
4 = Red

All of my strings will have 12 LED's on them except 1 which will have 14 LED's.

My questions are...
Is 14 Led's to much for one driver?
What size PS would I need for this?

 

[joshlawless]

Is there more to it than just that?

Depending on when your breakout boards were made, the new features may include 1) a pull-down resistor (this causes the lights to dim to 0% when the control/dimming signal is removed, rather than jump to 100%) and 2) jumpers to control whether or not the pull-down resistors are active (primarily for people who won't use a control signal to dim their LEDs)

Is 14 Led's to much for one driver?

Determining how many LEDs you can run on one driver (e.g., one Mean Well LDD-H driver) involves just a little bit of math. Each LED has a "forward voltage" for the current at which you plan to run it. So, if you're using an LDD-1000 (1000 mA current) to run a string of LEDs, look up the forward voltage for those LEDs at that 1000 mA current. (Somewhere between 2.5 to 3.5 volts, for most LEDs).
Add up the forward voltages of all the LEDs in the string -- this is your total forward voltage for the string. Your driver (e.g., the Mean Well LDD) needs to be able to ouput this much voltage BASED ON the input voltage you provide it. So, if you provide the driver with 48 V, it will output between 44 and 45 V. As long as your total forward voltage is less than 44 V, your string will be fine.

What size PS would I need for this?

For each string of LEDs, multiply the total forward voltage by the operating current in Amps (e.g., 40 total forward volts for string 1, running at 1.0 amps or 1000 mA) to get the approximate wattage of that string (40W in our example). Add up all the wattages for all the strings, then add a safety factor of at least 25%. This would be the minimum wattage power supply you would need, with a voltage high enough to provide the necessary forward voltage to each string (e.g., in our example, you'll need a 48V power supply).

Mean Well makes an inexpensive line of power supplies (SE series) in a variety of wattages (SE-600-48 is 600W, 48V).

 

[Sacohen]

Thanks Josh.
I'm looking at Bridgelux which say they have a forward voltage of 3.7V @700mA.

What would that be at 1000mA or 1A?

I am planning on using the LDD-1000H drivers.

If I estimate 1000mA would be 4v (just a guess right now until I hear back on what it would be) that would be 56V.

I guess the PS can't really be determined until I know the forward voltage at 1000mA instead of 700ma.

 

[dre7606]

If the led is rated at 3.7@700ma u do not want to overdrive it...the led it is meant to operate at the 700ma at a max

 

[Sacohen]

So if the 700H is rated for 2-52V @ 700.00mA then 14 lights @ 3.7 forward voltage (totaling 51.8) would be cutting it to close. :debi:

Damn