DIY LEDs - The write-up

[TheFishMan65]

Air should circulate around the whole thing IMO. The LEDs can get warm too.
you confused kcress with the 6x16 which is only the layout.

And I am going against the grain here, but I think you could get buy with fewer LEDs. 24-30 per side. I have 48 XR-E and 500 ma mix of 40 and 60 degree lenses 18 inches above the tank and I am burning a monti cap on the floor (38 or inches below the lights).

 

[James77]

Air should circulate around the whole thing IMO. The LEDs can get warm too.
you confused kcress with the 6x16 which is only the layout.

And I am going against the grain here, but I think you could get buy with fewer LEDs. 24-30 per side. I have 48 XR-E and 500 ma mix of 40 and 60 degree lenses 18 inches above the tank and I am burning a monti cap on the floor (38 or inches below the lights).

Thanks Fishman.....

Cooling the entire thing is actually far easier than what I was planning, so I'll go that route. Im going with that many LEDs because I am shying away form having the fixture raised anymore than 12" off the top of the tank. I also want to completely avoid any spotlight effect, but Im guessing Im pretty safe from that. Powerful little things to be burning that coral on the sand bed.

 

[TheFishMan65]

Oh yeah - don't use square tubing use something the air can get to all sides.

 

[James77]

Yes...its 1/8" thick x 1" wide by 1/2" high aluminum C-channel.

 

[TheFishMan65]

That sound good. You made an earlier comment about blowing air through it so I wondered.

 

[kcress]

Yes me was confused.:fun5::fun5: 12 should work.

As Fish noted you want some air moving past the fronts of the LEDs as one aging process is the plastic dome thingy that covers the LED. With some air flow around them this is greatly dim-minished.

 

[Algaenot]

I've been experimenting a little with the NWs. It doesn't take many NWs to generate a lot of yellow. In my tank it gave a muddy look to the water.

 

[James77]

Yes me was confused.:fun5::fun5: 12 should work.

As Fish noted you want some air moving past the fronts of the LEDs as one aging process is the plastic dome thingy that covers the LED. With some air flow around them this is greatly dim-minished.

I was originally just going to make the flow go over the C channels themselvs, but I'll just vent the entire fixture now.

 

[James77]

I've been experimenting a little with the NWs. It doesn't take many NWs to generate a lot of yellow. In my tank it gave a muddy look to the water.

I thought i had read they were a far better color, I must have mixed it p with another.....I've done so much reading on this, and there is only so much room in my head. Great to have caught that now, I almost ordered them today........

 

[patmack]

I thought i had read they were a far better color, I must have mixed it p with another.....I've done so much reading on this, and there is only so much room in my head. Great to have caught that now, I almost ordered them today........

I hear that!
Kinda surprised rapid didn't tell you about the NWs..?

 

[kcress]

I my opinion you really should use some NWs They provide some red that's completely lacking in CWs. Just keep in mind a little goes a long ways - a really long ways. So use one for every six or eight CWs if you can.

If running parallel strings you need to keep the counts the same in paralleled strings.

So if you're running twelve LEDs in a string, run one or maybe two NW in each string. Use the same count in each. For instance use two in each string. They can be anywhere in the strings but each string needs the same count.

 

[cmbspd]

Just used a kill-a-watt to test two DIY led arrays that run fine in terms of producing light. Both are pretty standard builds based on info from this and related threads (thanks)- 12 Cree leds each, mostly RB & CW with a couple NW, connected to Meanwell drivers (running at ~900mA). One of the arrays uses about 34 watts, the other is reading ~54 and I can't figure out why. I switched the drivers and still get the same result for the same array so that I assume the issue is with the leds and their connections. Any ideas on why one array is consuming about 60% more power than it should?

The two arrays might differ in the ratio of colors, but they are all 3W leds and I don't see why color would matter (other than efficiency of converting the 3W to light). The arrays were built at the same time using the same gauge wire, solder, etc.

Could it be heat? The higher consumption array is on aluminum u channel rather than a proper heat sink...but it reads the same power usage just after it turns on as after it has been running for a while so heat doesn't seem likely either.

Could there be a little current leaking through the ground wire from a bad solder? I'll check that tonight, but I thought that such a situation would just short the unit.

Thanks for any ideas.

 

[TheFishMan65]

Check the current through each string. Does each array have the same number and type of each LEDs.

On NW I would try and look at some fixture. I think I read somewhere that we here on RC on the only folks that still recommend CW so check out some other sites. But by all means look at some what is right for me is probably not right for you.

 

[GEORGEDOPE]

On the subject of optics. You can get different angles for the led's which I understand totally. But when it comes to Carclo Optics, whats the difference between Ripple and Frosted and what degrees are the wide and medium? Is that info anywhere?

 

[patmack]

I saw a data sheet on the carclo optics somewhere... Google it and I bet you can find them. The way I understand it the ripple lenses concentrate the light in the center and the frosted give more even output. I think the wides are still pretty naarrow- maybe 38 degrees.

 

[James77]

For my 2 MeanWell HLG-185-42B Drivers running 4 strings of 12 each, I assume it is no different than running parallel with any other driver.....I need to use a fuse and resistor on each channel, correct?

Also does some type of power distribution terminal or block exist? It would be for going from the positive lead from the driver into a block, so I can run the 4 strings and their resistors and fuses neatly.

 

[TheFishMan65]

Sound like the correct wiring. Look up terminal blocks - I think that is what you are looking for.

 

[patmack]

I got some terminal strips from radio shack that look like they will work pretty well.

 

[James77]

Sound like the correct wiring. Look up terminal blocks - I think that is what you are looking for.

Can you run multiple wires off one single terminal block? I want to go from 1 wire to 4 wires, without using a wire nut.

 

[TheFishMan65]

Yes run a wire connecting for of the terminals or look for metal jumpers that match you terminal block.