Here goes. First off, parts list:

555 Timer x 1
Diode (1N4148) x 2
100K ohm Potentiometer x 1
0.1uF Capacitor x 3
10K ohm Resistor x 1
LM317 Voltage Regulator x 1
470 ohm Resistor x 1
3.3K ohm Resistor x 1
PCB x 1 (I'll leave size up to you)
Wire

Top side



Botom side



All parts are available from Radioshack. I made sure of that. You can also get all these parts online at places like Digikey and Mouser for a lot cheaper, especially if you have to build multiple. If you really want to get adventurous, you could build this using a 556 timer for dual control in the same chip. This is what I will probably end up using. I'll post pics for anyone interested when I get it done.

Okay so I'm a bit confused. What is the purpose of the shiny?

Thats the solder side of the board. You create traces by soldering the pads together. Think of it as a DIY pcb.

Oh I meant what is the point of the whole thing? Is this a driver? Are you guys trying to replace buckpucks? If so how many LEDs do you think you can run in a string? How many of these could you power off of one 32v converter?

Read the rest of the thread. It explains a lot.

Are you saying I can't buy the cliffnotes version?

nice build. Thanks.

Ok, "Evilnotes" version, just for you Marteen.

Buckpucks don't seem to be capable of what they advertize. They seem to be inconsistent beyond 6 LEDs, with some having luck (myself included) and some blowing pucks left and right. So the search was on....

Zingtaw was kind enough to point us to a Meanwell power supply that he thought might work, but wanted to get our opinion. To cut a long story short, it's a line voltage supply (no DC power supply needed) with two models that can support 30 or 60 watts, with different max voltage models. They are capable of dimming, but you have to jump through hoops to do it. The circuit I posted earlier is one of the ways to accomplish dimming control.

Edit: Evil, you beat me this time.
Cliff notes?!? You're in LED gradschool now, there's no such thing as cliff notes

Thanks Evil for the quick work.
This looks straight forward. I'm interested in a 556. When you have some pictures of that, could you send me some via email? I hate viewing pictures (esp. ones with detail) in a thread like this and would rather download them an view in something else. I can PM you my email when you are ready.

Thanks Evil!
hmmm... well it would figure something like this would go up the day after I ordered my buckpucks. Oh well let's hope they work. Any idea what the potential for this would be? I'm thinking of really large arrays that before we were talking about having to use like 12 buckpucks with multiple PS. If this works how big of an array do you think it could support?

npain-

LED gradschool! I just wanted to go to technical college!

Is this big enough?
http://www.meanwell.com/search/clg-150/default.htm

They have a 260w under develoment

It depends on what drive current you want to run the LEDs at. The example in the datasheet for the ELN-60 shows a driver running 24 LEDs (6x4) at 600-700mA. If you want to run at 1000mA, it would drop to 12 LEDs. The 48v version could run 13 LEDs in series, or 26 (13x2) at just under 700mA.

You will be fine with the Buckpucks for the setup you are running, and they are less hassle to get them to do what you want. Plus, they are tiny compared to this thing (8" long). This driver is a good second solution, and great for those of us running big arrays.

Hopefully I'll get an answer back from Powergate tomorrow. Heh, I'll get one one way or another. I can be persistent/irritating when I want to.

Yeah I just noticed in the specs how big these things were! These buckpucks are teeny tiny in comparison.

This thread is unfolding nicely. I'm definitely excited to see what kinds of LED arrays you guys create with these LED power supplies. Hopefully it helps to reduce the costs of setup on larger LED arrays... I have a 29 gallon now, but next year I would like to get (up to) a 90 gallon, so power (i.e. the ability to drive lots of LED's and be stable) and the ability to upgrade are important. pictures and schematics

These are looking pretty cool. If you can deal with only running the array at 700mA, you can start getting into some pretty big series-parallel arrays.

In my infinite wisdom last night, I forgot to add the wire that actually goes out to the driver for dimming. I will be adding the wire and taking pictures when I get home this afternoon. I will be testing the unit today though.

Test ran beautifully. Very smooth and linear transition from 0-100%. Only thing I saw was that you get to about 98/99% duty cycle before the end of the pot travel. Not a big deal, but something to note.

There was a very minor change to the layout of the pcb, but all it is is the movement of one end of the 10K ohm resistor, and adding the two wires to connect to the driver. I'll take fresh pictures when I get home and post them asap.

Cool. Any word from powergate?

No

Just got off the phone with Powergate. We could have a problem.

Turns out that Meanwell USA does not regularly stock the ELN30/60-XX-P (digital dimming control), but stocks tons of the standard, non-dimming versions. They were willing to modify the standard unit to accept dimming control, but wanted a 1-2 lead time (which I could deal with), and another $20 on top of the original price!!!! OMGWTFBBQ!!!! Powergate is looking into if the increase in cost is a one time deal for the modifications, or whether this is what the price will be all the time. Standard lead time on volume of the drivers with dimming is 10-12 weeks. If Powergate saw enough interest and demand, they would stock the units for us, but I'm sure they would need to see consistent sales to a certain volume to do that.

Hopefully I'll get a call back today or Monday to see if this is going to look a little better. If the driver works, I'm sure we could get a group buy together to get a bunch of these in, and maybe if there is sufficient volume, the lead time will shorten to something a little more practical.

Stay tuned.

That is a bummer....bigtime

Lets see what Monday brings.

Anyone can advise how we can order ?
I go to their site but I think cannot order online.
I am in Singapore.

ok.Finally find Singapore distributor

Cheers

Hopefully you don't have the same trouble finding the dimmable version.

Phew, I thought I was goin a little crazy there wondering why you only had main power wires to the PWM driver. I was like, "ummm where's the output?" I thought you made some kind of new mythical circuit



And what happens when you go over 98/99%? Does it fold over on itself and drop the drive way back down?

No. At 98% of the pot travel, it's at 100% duty cycle and stays there through the remainder of the pot travel.

Still got to get the new pictures for you guys, but it will be kinda moot if we can't get the dimmable drivers.

Any update on Meanwell PS?

Nope. Tried calling twice, and no response. I'll try again tomorrow.

I have two that were shipped. they should be here late this week, or early next week. I will let you know how it works out, if all the other components arrive also. I am planning to see how running ~24 LEDs in two strings, and then each string running on their own powersupply/driver to see the difference. I will just dial down the constant current when using one supply per string.

How did you manage to get the adjustable ones? Powergate (and Meanwell USA) don't stock them. Just the non-adjustable versions.

I assume I am getting the non-adjustable, not great, but for the money if it works, I will be happy. I will let you know when they arrive. If we do plan to push of a group purchase, I will commit to buying a couple. The ones I ordered were special order, because I am unable to return, but based on all the info, I am sure they are not adjustable. We shall see. I am enjoying the journey either way.

Ok I have been following this thread. For the electrically challenged is this Meanwell the way to go? I am look at running all white 3 watt Crees. I only need 8 LEDs for this project. I will need dimmability. Would my best bet be just to go with 2 buckpucks and putting four on each? The size doesn't matter to me. But if I need to create a board to dim the meanwell that is probably out of my skill level. Dimmability is the most important function for me as this will be required for my tiny nano. But if I upgrade and do something else I will want them to run full blast.

If you need something brain-dead easy to hook up and is dimmable, go with the Buckpucks. The Meanwell drivers will require you to get your hands dirty with electronics to be able to dim them (provided we can get them).

I got off the phone with Powergate, and the saga continues. Seems like for small orders out of California, they hand modify them to add the dimming control, and they add the $20-ish dollars on top of the cost, no matter what. ~$50 isn't too bad for a line voltage 60W driver I guess. It just now makes it less atractive cost wise to a Buckpuck setup. Lets see how this works out. Two different scenarios to drive 24 LEDs (12 white, 12 blue)

Buckpuck:
4 x 1000mA Buckpucks $79.96 ($19.99 each)
1 x 24v 4.2A power supply $14.95
Total - $94.91 + shipping

Meanwell:
2 x ELN-60-48 $100 (assuming $50 each)
2 x Dimmers $20 (assuming you can build them for $10 each ordering online)
Total - $120 + shipping

Is the $20 worth it? If we can get the drivers for the $30-ish cost that the standard ones are, it's totally worth it.

The next peice of the puzzle is to find out if they can be made at the factory dimmable, and what costs are associated with that. Powergate said they can expedite from the factory in one week, but at a cost I'm sure.

Stay tuned.

Thanks for the update.

I bought 12 pwm led drivers from sure-electronics for $6, good for 22v at 700ma about 6 months ago. they worked great but they have been burning out one by one. The max I run them at is 600ma at 18v(4 rebels) and I am out of back-ups. I also built my owm currunt contllers from transistors, but the heat is crazy. Then I tried lm3410 which work great, and they are cheap, http://www.newark.com/national-semiconduct...r-ic/dp/78M7736
but you would have to build a surface mount board and reflow oven. I was thinking about buc pucks, but for the price, its not worth it just to have them fry. Is their a low cost, worry solution?
And I was wondering about these power supplies? at 0 pwm, is the output cut-off? at 1% pwm do the leds blink(like the ones from sure-electronics)? What's the warrenty ?
I love my LEDs, I never had my corals grow so good, but its getting to be a full time job designing, building and maintaining these!

We aren't sure what the response will be at low pwm frequencies, but according to the datasheet, turn on is at 15%. How it reacts below that is an unknown.

What does pwm stand for? Is this something similar to duty cycle?

PWM=Pulse Width Modulation. It's a square wave signal that has a fixed frequency (period), and you change the amount of on time and off time in that period. It's used for things like motor control and dimming to simulate using analog devices like a potentiometer for the same functions.

This might explain things a little better.

Too bad.
After 2 emails and one call finally manage to get the distributor for Meanwell in Singapore.
But same as you they to not stock ELN series here in Singapore.
It is under indent basis.And I think it is expensive.I am quote USD 45 for ELN60-24/48

Thats pretty high for just the standard version. I found a site in Australia that will order the dimmable versions for a decent price, but they still have a 6-10 week lead time on them.

I received the two I ordered last night, they are not dimmable, I am still waiting on more LEDs, and I will be hooking these up this weekend. Evil, any idea how to make them dimmable? If PowerGate can do it, I would assume the board probably already has the connections to make it dimmable. Welcome your thoughts.

Having never seen them, I have no idea how they could be modified. One of the first differences will be the output cord, as your model has two wires, and the dimmable has four.

Any chance of you snapping some pictures of the drivers? Maybe some of the internals?

Here are 3 pictures of the guts, One from the bottom of the PCB (I circled the two Dim solder joints. One from the AC in side and One from the LED out/ Dim side.

Seems like there are parts missing leading back to the IC. Could be a somple mod if we can find out what parts are truely missing. This might be an alternative. I thought the units were potted and this was going to be near impossible.

Hmm. Gears turning

STAND BACK EVERYONE!

It's when you smell smoke that you need to run

I have now done some experimentation with these, First I connected 12 LEDs (6 cree White and 6 cree Royals) in series to one EN60-48v. I turned the internal Potentiometer that adjust current down all the way. Should be -25% so ~ 1000ma. This setup was dimmer than I thought it should be. I have not hooked up a multimeter to measure the actual current however, so I decided to connect two 12 LED strings in parallel- so a total of 24 (12white, 12 Royals), and turned the current to the max on the internal potentiometer, this produced a significant amount more output. I have decided for now to stay with one supply pushing the two strings of 12 LEDs. I probably could bump up the number of LEDs by 1 per string, and I might do that. I also might put a multimeter on it to see what current it is pulling with one string on a single EN60-48 and then adjust to ~1000ma.

I would suggest using the multimeter to verify the current. They may put a pot on that will dial it down beyond the suggested -25% on the data sheet. Likewise when you crank it all the way up. You may do some damage to the PS by doing this. My powersupply that I use to drive my buckpucks is like this.

I had a little time, so I hooked up the multimeter and as was stated above, the current was higher than specified. Full pot = ~1.6 amps, so I dialed it back to 1.4 amps for running two 12 led strings in parallel. This is a little higher than spec, but I thought I would try it. Also for note the minimum current when adjusting the Pot, was 300ma or so. If anyone uses this device, they will need to use a multimeter to dial in the proper current. At this point I am happy with the device.