DIY LEDs - The write-up

[stugray]

ReefEnabler,

" If anybody knows how to interface with DMX dimming I'd be interested to know."

DMX-512 is RS485 serial at 250 Kbaud so it's really just a simple 8 bit serial protocol.

You could control these with a PC serial port and a converter:

http://www.electronics-lab.com/blog/?tag=rs485

Someone would just need to find, or write, the driver software to comply with the protocol.

Stu

[stugray]

Here is a power supply that is $1 per Watt:

http://parts.digikey.com/1/parts/727...-36-c0700.html

It might seem expensive at $50, but can drive ~9 LEDs per string.

Stu

[goofyreefer]

Soundwave... I was just wondering how your setup is doing? any problems? blown LED's?

[ReefEnabler]

Originally posted by stugray
ReefEnabler,

" If anybody knows how to interface with DMX dimming I'd be interested to know."

DMX-512 is RS485 serial at 250 Kbaud so it's really just a simple 8 bit serial protocol.

You could control these with a PC serial port and a converter:

http://www.electronics-lab.com/blog/?tag=rs485

Someone would just need to find, or write, the driver software to comply with the protocol.

Stu

Thanks Stu. BTW I haven't forgotten about the Rabbit 4010 PWM project Its just that having a kid, and setting up the reef itself kind reordered some priorities for a while

Once I get these LEDs going I want to try get back into the rest of it. Have you had any progress with the code to dim smoothly??

[stugray]

ReefEnabler,

"Have you had any progress with the code to dim smoothly??"

The code works just fine but the daughter-board layout wasnt finalized yet ( remember I was still experimenting with which Opto coupler was best ).
However I am gearing up for diving back into it.
I have ALL of the parts in hand.

With getting back from 2 months in Cocoa Beach, Fla. and working 3rd shifts for a few weeks, it messes with the plans.

My current plan is to make a tank controller that is meant for JUST the hood and power control for the Display.
It will have 4-12VDC current control channels for fans, night lights, and LEDs, and ~6 AC power controls for lights, pumps, etc.
It is ALL enet controlled.

I can add more PWM channels, but they would have to be software controlled rather than hardware.
The RCM4010 only has 4 hardware controlled PWM channels.

Stu

[barderer]

can someone explain to me why we are hooking up the LEDs in a series as opposed to parallel? What are the advantages of each method?

Thanks

[Pufferlips]

Hello all… Long time reader, first time poster here. I figured it is time to cut my teeth on the forum.

I have a DIY system I am trying to build a lighting system for and decided to go LED since I love the LED’s on my current system.

I am doing 20x20x16 Acrylic rimless reef tank and was wondering what would some of you choose for lighting it up? I want to keep the light about 6-8 inches above the water (which is 3/8-1/2 of an inch from the top)

I’ll want to keep mainly SPS’s and probably an anemone or two.


Thank you all in advance, and I am glad I finally joined.

[Soundwave]

Goofy, the setup is going great. I screwed up somehow and killed my green monti cap that was growing so well. It totally bleached out and no other coral was affected. I'm so lost as to why that happened. I just reloaded my phosban and boom, the next day is showed signs of bleaching and today, dead. bummer.

My optics showed up today and I plan on starting the work tomorrow night.

I found a use for my new drill and I am going to completely re-do my rock work in the tank. I'm going with pillars and caves instead of my "fruit stand" style of setup where the rocks have been piled against the back glass for the past two and some change years. I will post pictures at some point but I will be a busy bee for the next week.

[kcress]

Originally posted by IamBIGGUN
I was thinking of driving them at 4 volts and 1000 mA for the whites and 3.6volts and 1000 mA for the blues so at what point is it too much for the driver?

Thanks,
Kevin

When you exceed the controller's allowed current or the controller's temperature due to poor cooling for it.

[kcress]

Originally posted by barderer
can someone explain to me why we are hooking up the LEDs in a series as opposed to parallel? What are the advantages of each method?

Thanks

Have you read this thread in its entirety? I kinda thought we were pretty clear on this - above.

There are numerous reasons.

[kcress]

Originally posted by Pufferlips
I am doing 20x20x16 Acrylic rimless reef tank and was wondering what would some of you choose for lighting it up?

We're all just learning here. I'm not sure anybody has a clear recipe yet. I sure wouldn't want to suggest anything in particular at this point. I think you will need to read this whole thread thru and thru. When you reach an understanding of what's here you will then feel confident enough to try something.

Start with the excellent top project that Soundwave provided. Scale it to what your needs are.

[fernandokng]

Kcress - I read the whole thread, but I'm not the most technical person, so I must have missed this as well.

Can you help me understand this a little bit better as well? thanks.

Originally posted by kcress
Have you read this thread in its entirety? I kinda thought we were pretty clear on this - above.

There are numerous reasons.

[tahiriqbal]

Ok Guys if I do this way I can have them run from 2 x 200 watts LED drivers (not power supply)



Or if I driver them from 4 x 100 watts LED drivers (not power supply then it will look like this.


Any comments am I still on the wrong path?

[ReefEnabler]

fernandokng,

1) at the bottom of the page, click "show printable version"
2) once that loads, click "Show all 463 posts from this thread on one page" (this is on the top right near the page numbers and prev next

3) Press Ctrl+F
4) Type "Parallel"
5) hit "next" until you get a post that explains it.

Searching in this way brought me to the answer you want in about 10 seconds. Theres more said on the subject, just search for it in this thread. This method of searching a whole thread has always been better for me than using the RC search or google with keywords (If I know something is in fact in the thread)

This always sounds logical..... unfortunately it's kind of hard to explain but if you have two branches of 6 LEDs in parallel and each branch requires say 1 Amp you would have to supply two Amps to the circuit. The Buck Puck is a constant current source so it will divide it's 1 Amp into the two branches so it will only supply 500 mA to each branch. I hope this makes sense.

There is another problem with parallel circuit in that if you could supply two Amps to the circuit and if an LED fails and the circuit is opened on one branch the current has to go somewhere so it flows in the other branch. That means 2 Amps will be flowing though that other branch resulting in a big cloud of smoke.

[fernandokng]

Ryan - that is clever! Thanks. Learn something new everyday

[Konadog]

This thread has been nominated for "April's Thread of the Month". Please take a moment to read each of the nominees and vote.

Vote for Thread of the Month

[bebereef]

Voted!
Like i wrote earlier, this is TOTM for sure!

[Soundwave]

Sweet! Vote!

[lilmonster]

I voted for you.

[kcress]

Originally posted by ReefEnabler
fernandokng,

1) at the bottom of the page, click "show printable version"
2) once that loads, click "Show all 463 posts from this thread on one page" (this is on the top right near the page numbers and prev next

3) Press Ctrl+F
4) Type "Parallel"
5) hit "next" until you get a post that explains it.

Searching in this way brought me to the answer you want in about 10 seconds. Theres more said on the subject, just search for it in this thread. This method of searching a whole thread has always been better for me than using the RC search or google with keywords (If I know something is in fact in the thread)

Thanks a bunch for this Ryan!
I never knew this..

[ReefEnabler]

Hopefully this 'secret' doesn't spread too fast and we crash RC by all opening entire threads from now on j/k

actually its a pain in the behind to actually read a thread like that, but handy for searching, especially if you're scanning a big thread for a picture you recall.

[kcress]

tahiriqbal; You need to read that same passage ReefEnabler just put up.. I don't think you're understanding the hazard of parallel LEDs especially high power LEDs.

If you build any of those diagrams you risk major failures on a regular basis. The more strings in parallel the more likely you will hook up an unmatched group. That group will either hog current or shunt current to the other strings overloading them.

Very likely some of those strings would give poor performance from the minute you turned that on. You would see really bright strings and dim strings. (poor performance) The bright ones would be rapidly degrading the dim ones would be waiting their turn to fail.

You also run the risk of a fire with HPLEDs and that much drive spread over parallel chains.

To do it correctly - use a driver per chain .

[EBOLII]

Soundwave now another week has passed what is your tank evaluation?

[fernandokng]

The way Soundwave LEDs are set up, they are in series - so if one blows out, the full row of LEDs shuts off, but saving the other bulbs from burning out.

How do you replace the bulb if the LED is permantly expoxied to the Heatsink?

[ReefEnabler]

You shouldn't use epoxy under the whole surface of the star mount, there should be thermal grease under most of the center.

If using epoxy I'd suggest it only go around the edges, and then it would be easy to just slip a razor blade around the parimeter and pop it off, and another would fit right in there.