DIY: Steve's LED's module

[soramsu]

It's in a string of 7:

(+) -- (O) -- (O) -- (X) -- (O) -- (O) -- (X) -- (O) -- (-)

Where the "X's" are the dim LEDS. If there was a bad solder joint I would think it would affect all the LEDs, rather than just 2 randomly in the middle. I'll double check it though. As far as the power supply, having just 1 driver connected and dimming it works fine, which is less of a load than having 2 connected. The 2 connected work fine as long as they're at the same dimming level. But if one is turned all the way up, and the other turned down, it buzzes. The drivers are connected to two different 24V outputs on the PSU. I'd assume there's not any kind of matching requirements between the two outputs, but I have no information on the power supply

 

[TheFishMan65]

Yeah, I think you have bad LEDs. I didn't think they would be parallel (typo above - sorry).

Doesn't sound like such a great power supply either. Resistors might help, but I don't know what the problem is.

 

[Daniel G]

Ive been running my fixture with 24 of his leds for around 3-4 months now and they all are doing good. I see no problem with them. Also, I don't dim them. For drivers I'm using some i bought on e bay.

 

[soramsu]

So here's and update and my final impressions of working with this system. Still working through the power supply problem. Even after connecting all the drivers, the ps will still give out a high pitched noise. Steve said the dimmer LEDs were b/c occasionally he'll get a few that have a higher forward voltage. :strange: However, he did offer to replace any of them for free of charge.

My newest problem is using his 0-10V wiring harness with the system. When both channels are turned on to the harness, the lights will flicker. I contacted Steve, and he said it's a known problem. Said it's because it's from interference from the RKE ALC, and the harness. He suggested making sure it wasn't near any other electronics, etc.

The wiring between the two is nowhere near any other wires or electronics. I think the problem has to be on the side between the harness and the drivers. The harness is outputting a pwm signal to the drivers. That seems more likely to be affected by, and possibly create, noise issues. I've separated the two signals as much as I can from each other and the drivers. Unfortunately, the layout of the drivers doesn't give a great way to do this easily or very well. Steve said that he's working on a fix for this and said I'd get it for free. No info on when and what it is.

Anyway, I enjoy electronics projects, but at this point I just want some lights. :headwally: I'm definitely going to replace that part of the setup with meanwells.

So, my final thoughts are this. For the LEDs, and if you understand the tradeoffs (which have been beaten to death here...haha), I think it's a decent option. It is nice being able to order the heatsink + leds already mounted and soldered up, saving quite a bit of time. I also like the heatsink/fan design. It's clean, and easy to install. The fans are virtually quiet. Once in my canopy, I didn't hear them at all. They also give really good airflow through the heatsink.

As for the drivers and such, I'd probably go with an alternative right off the bat. I don't think an extra $100-$200 is worth all the trouble, when you're already talking about saving a whole lot more.

 

[soramsu]

Just thought I'd post an update on how this whole thing turned out. I did try running Meanwell drivers with the setup. However, I ran into an issue where most of the Meanwells I got didn't output any current. I never figured out this problem. Not sure if I just got some bad drivers or what. Also, with the Meanwells, I didn't like the fact that it required > .9 volts to turn on from the dimming circuit. Anything under .9 volts, they wouldn't completely turn off. There's apparently some stray current with these that doesn't get taken care of. So even at a setting of 0 from the dimmer, the lights are really dimly lit. To work around this I was going to just turn power off to them, but when I did that they do a quick ramp up to max intensity, flash, then turn off. So, I dropped the idea of using Meanwells for these reasons.

I decided to dig into the flickering problem some more, in hopes of using Steve's drivers. I did some probing with an o-scope to find the source of the problem, and I had my own arduino board (what he's using for his dimming harness) that I programmed to convert the 0-10V to a PWM signal. I discovered that with as little as a 4mV swing from the 0-10V signal, with the code he had, it would cause a change in the PWM signal. This was more visible at lower dimming levels, as the pulse width is smaller. So, I wrote some code to filter this noise out, and it worked. He had said he had seen this occasionally, but didn't have a fix for this noise problem as of yet.

I got back with Steve, gave him my code, and it's now part of of the harnesses he's sending out. In the process of all my probing/debug, I managed to fry a couple of the drivers. He ended up replacing all my drivers, reprogramming my harness with my new code, and also taking care of replacing the original power supply that had the buzzing problem, and replacing the LEDs that had a higher forward voltage that showed as being less bright when dimmed than the others.

At this point I'm satisfied with the end result. It was definitely a lot of trouble to get to this point. The biggest issue was the flickering, but that seems to be solved, and hopefully the work I did here will benefit others who buy his systems.

 

[AC2020x]

Cool, just wanted to say thanks soramsu for being a guinea pig for this. I am new to reef tanks though I've been into saltwater for about 2 years and i'm looking to make the change to a reef tank. Because I know little about lighting I figured i'd just skip T5's and MH lighting and go right to LED's since they seem to be the best most efficient way to go. When I found steve's LED's I thought this was great since how cheap they are and because I know little about lighting and LED's. However, after reading this thread and your experience with his set-up I think i'd rather take the time and extra money, learn what I'm doing, and do it the right way so I know what I'm doing. Not that i'm saying going with Steve is the wrong way, but you never know what your gonna get when you have someone else do a DIY project for you. Plus, this way, if I do it all myself, I will understand and learn what i'm doing better instead of letting someone else do it and me not understanding it.

This is just my 2 cents on the whole situation.... Plus you know what your getting for sure when you go with CREE's which is always a plus.