zingtaw

LED MeanWell power supply?

833 posts in this topic

Looks like a good option for those just wishing to build a big on/off array

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Help me, I'm a bit slow when it comes to electronics. I'm ready to build a DIY LED for a planted tank and was happy to see this driver. There is a wiring diagram for the ELN-30-24 (24v at 1.25a)

 

http://www.meanwell.com/search/eln-30/ELN-30-spec.pdf

 

... it shows two strings of 6 leds with LED specifications of Vf=3.0-3.5 If=600-700ma

 

Will this not work as shown with two strings of 6 - 3w LEDs driven at 700ma? I'm not up on my LED specs, but aren't those typical specs for a 3w Luxeon or Seoul LED?

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You will be fine with that setup.

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You will be fine with that setup.

That seems like a pretty good setup then, $30+ for a power supply/driver that can handle 12 3w LEDs. I'll wait to see how the others make out with this.

 

One more question though, on Mean Well's diagram they show wires across the parallel strings of LEDs. Is this the way you would actually wire them? What is the purpose of that, does it help balance the load?

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This is the first driver that I have seen take this approach to wiring parallel strings, and I can only assume it is for load equalizing. For basic duties, this driver seems great, and at a great price. It's limitations hold it back from becoming the ultimate driver.

 

EDIT: After taking a second look at the datasheet, we might be in better shape with this driver. The limitation of -25%-3% current adjust seems to be limited by the internal adjustment pot. If you take a look at the top of page 3, the graph shows full current adjust with the use of an external voltage source or pwm signal. I might order one of these to experiment with.

Edited by evilc66

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The limitation of -25%-3% current adjust seems to be limited by the internal adjustment pot. If you take a look at the top of page 3, the graph shows full current adjust with the use of an external voltage source or pwm signal. I might order one of these to experiment with.

 

It's interesting that it uses a 1-10V control signal. Logic is usually 5V max.

 

The PWM might be a good way to go.

 

Also interesting that the circuit diagrams show the parallel strings interconnected after every LED. Must be for better current equalization.

Edited by schudini

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I put in a call to Powergate, and they are going to help look into the confusion on the datasheet. They way it's worded it really does seem like the internal pot limits the max current, and the external control does 0-100% dimming. If this is the case, this driver is going to rock.

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I put in a call to Powergate, and they are going to help look into the confusion on the datasheet. They way it's worded it really does seem like the internal pot limits the max current, and the external control does 0-100% dimming. If this is the case, this driver is going to rock.

 

I read it as the internal pot adjust it +3 to -25, and the optional PWM did 0-100% for dimming. But now it has become a bit confusing. Please keep us posted.

 

FYI, I had called mean well directly on another issue on Monday, and found their engineer quite helpful. Their number is 510-683-8886. They are in cali, I couldn't find a 800 #.

Edited by npain316

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Good news everyone!

 

We are starting to get closer to finding out how good this driver is (feature wise at least). I called Meanwell a little while ago and had a good long conversation with one of the tech engineers about exactly what this driver was capable of.

 

First, my fears of this being a constant voltage supply as well as a constant current supply have been put to rest. This driver will support down to a single white/blue LED in series (some drivers with higher current output will still have to have LEDs in parallel, but thats ok), on all versions. This is cool. The constant voltage end of things is still a mystery, but it seems like it doesn't apply in this application.

 

Next up is the current adjust. The internal pot is there for max current settings. This will allow drivers like the ELN-30-48 to be adjusted down to 1000ma (full -25% adjustment) for safe operation with most 3W LEDs. There is an external connection for dimming control, but it seems like you have to define if you want digital or analog input at the time when you order. This will adjust from 5/15% (depending on analog or digital input) to 100% brightness. This is awesome. One of the issues is the analog input though. It requires an external voltage source. It can be done in many ways including a 10v wall wart power supply, or making a small linear one that can be located close to the driver. The digital version may be little easier, as 5v power supplies are a little easier to find, and you can make a simple pwm driver with a 555 timer.

 

I still didn't get any indication as to how the external dimming is connected to the unit though. I will probably be ordering one of these tomorrow to test. You can't beat the price on these, even though there are some issues, but they are easy to overcome.

 

EDIT: I must be blind. The dimming input is part of the output harness. It's four wires; LED+, LED-, Dim+, Dim-.

Edited by evilc66

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Great Info, I am glad you confirmed what I thought when I saw this item. I appreciate this thread staying alive. Did you have any conversation about the way they show the wiring of the LEDs? The grid layout would appear to allow one LED to "die" and the others to stay on. As I am planning out my implementation of my LED setup, I want to take into consideration the best way to wire up the LEDs. Thanks again for helping investigate this.

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I forgot to ask about that. Maybe I'll call them back tomorrow.

 

The LED array wiring would not suffer froma typical series-parallel setup. I'm sure that the way they have it wired is for load ballancing and for redundancy, like you mentioned.

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Is there a particular area of the power supply you wanted photos of or just an overall shot of the innards? It would take me just a few minutes to get some shots of the interior.

 

Re: Solaris I5 power supply

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Anything and everything you can get!

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The digital version may be little easier, as 5v power supplies are a little easier to find, and you can make a simple pwm driver with a 555 timer.

 

Huh? Any info for us non-EE folks to get and idea of a "pwm driver with a 555 timer"?

I'm excited that this looks so promising. Heck I'm excited to see evilc this excited.

I think I will be ordering one or two tomorrow w/ the digital input.

 

 

Thanks Evilc

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Wow this is shaking out nicely. I was gonna start ordering my LED and driver parts next week, but I think I might hold off just a bit longer till this settles down. Integrated affordable driver/power supply would really make my day :)

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Huh? Any info for us non-EE folks to get and idea of a "pwm driver with a 555 timer"?

I'm excited that this looks so promising. Heck I'm excited to see evilc this excited.

I think I will be ordering one or two tomorrow w/ the digital input.

 

 

Thanks Evilc

 

www.dprg.org/tutorials/2005-11a/index.html - **Brought to my attention that this isn't the best circuit. Try this one. It's the same design as the one I build in a few posts.

 

This is a pretty simple circuit for a pwm output. Your output voltage will be determined by the source voltage. The datasheet states 10v peak, but the engineer I talked to said 5v, which is much more common logic level. I will confirm this today. Usable frequency range is in the 100Hz-3KHz range. Try and keep the frequency low to avoid unnecessary noise, but go with whatever parts are easy to get. You should be able to get everything from Radioshack. The default values in the schematic on that page are easy to find, and will get you a 144Hz frequency.

 

The other option is the analog route. 10v power supplies aren't common, but 12v is. Low power 10v linear regulators are pretty cheap from Digikey or Mouser, or even an LM317 set to 10v would work (another Radioshack obtainable part). Pair that up with a 10K ohm pot and you are in business.

Edited by evilc66

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If using two power supplies (one for blue and one for whites), would you need this set up for each potential meter. I think so, but could you use the same power source(12v divided)?

 

Nick

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If you are going to dim them equally, you would only need one. If you were to dim them seperately, you would build two of the pwm circuits, but can still only use one power supply.

 

I'm trying to order one today. Powergate is still trying to find out the different part numbers for the digital and analog input versions. I also still need to call on how the LEDs are connected together.

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If you are going to dim them equally, you would only need one. If you were to dim them seperately, you would build two of the pwm circuits, but can still only use one power supply.

 

Are you saying we can dim two // strands independantly from the same PS? I though there was only one set of output wires per power supply. If true, this makes them even more bad a$$!

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Isnt there any simpler PWM circuits out there? I cant believe no one makes something we can just hook a pot up to and have fixed frequency PWM control.

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Are you saying we can dim two // strands independantly from the same PS? I though there was only one set of output wires per power supply. If true, this makes them even more bad a$$!

 

By same power supply, I ment the power supply driving the 555 timer circuit, not the LED power supply.

 

Isnt there any simpler PWM circuits out there? I cant believe no one makes something we can just hook a pot up to and have fixed frequency PWM control.

 

How much simpler do you need? It's about $5 worth of parts (online, about $12 at Radioshack). The biggest issue with making a "canned" device, is that it is hard to cover all the bases. You can build this circuit any way you like to get the frequenct you want, the size of the components you want, the cost you want, the potentiometer you want, etc....

 

There are literally less than a dozen parts that anyone with basic soldering skills can solder up and get working in about an hour. Do you guys want me to make them for you? It's not hard.

 

I'll build one tonight, providing Radioshack has all the parts in stock.

Edited by evilc66

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There are literally less than a dozen parts that anyone with basic soldering skills can solder up and get working in about an hour. Do you guys want me to make them for you? It's not hard.

Understood on the powersupplies. That almost sounded too go to be true.

 

As for the PWM:

For me its understanding the scematics, its like hieroglyphics. Sqwiggle line here, sqwiggle line there, upside down triagle of lines. If I saw one assembled on pcb, top and bottom, I probaby could figure it out and it would make sense of the hieroglyphics too!

 

Building one for us is a great gesture. Let me see one done and I'll decide if understand it then.

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I got all the parts just s little bit ago. Shouldn't take too long to build one up.

 

On the driver front, had my second talk with Meanwell, and the pwm voltage does have to be 10v. Not the end of the world, but adds a few more part to the equation. I'm still trying to get clarification from Powergate as to the exact part numbers to order.

 

Also, the way they show the parallel string connections, it is a way to prevent taking down the entire string of LEDs if one fails. This isn't to say that it should be left like that indefinitely, as the voltage drop now changes, and could change performance. You can still wire the LEDs in parallel in the normal way without issue.

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Got it built already. Ended up taking a little over 30 minutes for me, but your mileage may vary. I ended up adding an LM317 voltage regulator set to 10v. This will allow you to use any power supply from 12-32v. I would suggest only 12v supplies, as they are common, and will not create any unnecessary heat. It should be minimal as the current for adjust circuit is low, even though you could be burning off 22v.

 

I will test it tomorrow at work when I have an oscilloscope handy.

 

I'll post pictures and a full parts list here in a little bit.

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