Moonlight LED's are too bright

[Eman79]

Hi All,

I have installed a 350mA moonlight driver with 2 "moonlight" blue LED's in PARALLEL and it is just way too bright. I've added a small shield, but it is still too bright for my taste and for what I think the fish would "expect" at night. Any ideas on how to further reduce the brightness? I'm no electrical engineer, but in parallel, I believe that each bulb should be only seeing 175mA. The driver is not a dimmable model.

TIA.

[Wifi]

Try covering more with shield or something black and use a paper hole punch or something equvilant to allow the amount of light that you want. Holes can be off centered than placed directly under LEDs.

[kcress]

Originally Posted by Eman79

Hi All,

I have installed a 350mA moonlight driver with 2 "moonlight" blue LED's in PARALLEL and it is just way too bright. I've added a small shield, but it is still too bright for my taste and for what I think the fish would "expect" at night. Any ideas on how to further reduce the brightness? I'm no electrical engineer, but in parallel, I believe that each bulb should be only seeing 175mA. The driver is not a dimmable model.

TIA.

That's not going to help.

You really need to be down around 20mA to have the brightness you seek. Hi power LEDs are really lousy for moonlights. Much better are regular gum-drop LEDs.

Another thing to consider is one LED shining in one place like the center or an end. That way you get some effect and the fish can move out of the "beam" if they want. If you have fixed coral you probably just need to go dimmer.

[Yaryman]

Not going to help you, but I had to turn my LED moon lights off at 9pm as they were too bright for the fish.

I'm using this LED setup I purchased on Ebay.

The information display now kind of serves as a moon light.

[10reefman]

try the leds in series

[ghellin]

Originally Posted by 10reefman

try the leds in series

This would double the current light and make them twice as bright on his non dimmable driver.

Go with the gum drop LEDs at 20mA kcress is right.

[Rhodophyta]

Or maybe it's the tank is too small, not the light's too bright (wishful thinking) What about raising the light? One of the public aquariums experimenting with spawning corals, had a board above the tank with seven nails. The light was lifted to a higher nail each day and then when it reached the top, a lower nail each day after that.

[Eman79]

Yes, it's too bad. My main blue LED's were on a dimmable driver that would never completely turn off. The faint glow was a PERFECT moonlight. I added LED's to rectify the problem of the LED's blinking below 50% power, and as a side effect, they now turn completely off (like they are supposed to anyway.) I was hoping that I could add some kind of resistance to the circuit, but if the recommendation is 20mA, it doesn't sound like that is an option. Looks like I will be spending some more $$$, and NOT be recommending the moonlight kits from RAPID any time soon.

[CBRzilla]

Here is a document I wrote on how to make the RapidLED 350mA drivers dimmable. Using the components I put in my brother-in-laws (100 ohm resistor and 1k pot) I got his driver to be adjustable between 10mA and the full 350mA.

http://dl.dropbox.com/u/54538354/Moo...driver_mod.pdf

Enjoy!

[CBRzilla]

Dropbox has been failing as a document host site! Here is a new link to where I keep the instructions now

https://sites.google.com/site/projec...0ma_driver_mod

[mcgyvr]

LED's should never be put in parallel.. does it work..yes sometimes it does.. Is it wrong.. yes it is..
You cannot guarantee that they will share current equally.

[kcress]

Eman79; Whoa.. You don't have to spend hardly anything to get nice moonlight.

Get some old wallwart, a couple of gum drop (T-1, T1-3/4) style LEDs in any of the dozens of colors available, and a couple of resistors and you're in business. You don't need expensive current control for moonlight.

[CBRzilla]

Originally Posted by kcress

Eman79; Whoa.. You don't have to spend hardly anything to get nice moonlight.

Get some old wallwart, a couple of gum drop (T-1, T1-3/4) style LEDs in any of the dozens of colors available, and a couple of resistors and you're in business.

The moonlight driver is only $10... $18 and it comes with CREE LEDs

If you happen to have an old wall wart laying around this could work fine. In fact you can turn an old wall wart into a current driver for around $3 I'd guess off the top of my head... Sounds like another project/instruction I could put together!

The issue I have with driving LEDs with a voltage source is that LEDs are extremely sensitive to over voltage (they draw current at an exponential rate to the voltage applied) and since wall warts aren't usually regulated very tightly, the LEDs won't last along as if you used a current regulator (unless you have a better one which would cost more than $10 anyway)

[mcgyvr]

Originally Posted by CBRzilla

The moonlight driver is only $10... $18 and it comes with CREE LEDs

If you happen to have an old wall wart laying around this could work fine. In fact you can turn an old wall wart into a current driver for around $3 I'd guess off the top of my head... Sounds like another project/instruction I could put together!

The issue I have with driving LEDs with a voltage source is that LEDs are extremely sensitive to over voltage (they draw current at an exponential rate to the voltage applied) and since wall warts aren't usually regulated very tightly, the LEDs won't last along as if you used a current regulator (unless you have a better one which would cost more than $10 anyway)

he said resistors. So current limiting is taken care of.

[CBRzilla]

Originally Posted by mcgyvr

he said resistors. So current limiting is taken care of.

Yes, resistors are a form of uncontrolled current limiting, I was just making the argument that a current limiting driver is not an expensive solution (unless you are getting a high output regulated one, in that case a regular wall wart wouldn't work anyway), in fact the wall wart I bought for my WiFi reef controller i just built cost more than rapidLEDs moonlight driver!

[mcgyvr]

Originally Posted by CBRzilla

Yes, resistors are a form of uncontrolled current limiting,

"uncontrolled" ... Ohms law would disagree.

but hey..go ahead and spend the money then mod the driver because its WAY too powerful by adding a pot or whatever.

I'll just stick with a couple 10 cent leds and a couple 5 cent resistors and heck everyone has an unused "free" wallwart around somewhere.

Another simple device for a simple constant current supply (up to 1000mA or so) from a wallwart supply is an LM317 IC and a resistor.

Don't get me wrong thats a good little driver but just a waste for a moonlight.

[triggreef]

get a kit from steves leds on sale for $25. then you can dim it and have any color you want to. with a remote control. lol

[CBRzilla]

Originally Posted by triggreef

get a kit from steves leds on sale for $25. then you can dim it and have any color you want to. with a remote control. lol

Now what fun is that! Lol

[CBRzilla]

Originally Posted by mcgyvr

"uncontrolled" ... Ohms law would disagree.

I'll just stick with a couple 10 cent leds and a couple 5 cent resistors and heck everyone has an unused "free" wallwart around somewhere.

Another simple device for a simple constant current supply (up to 1000mA or so) from a wallwart supply is an LM317 IC and a resistor.

Don't get me wrong thats a good little driver but just a waste for a moonlight.

Uncontrolled because it's a fixed resistance value, so no control if the voltage changes either from inconsistent led voltages or an led failure, for example if one led fails short, then all the other LEDs current spikes way up and fail very shortly after. I've had this problem with some of my first led builds (even picking resistors that limited the current to half the led ratings I was still seeing failures), learned the hard way that current regulators are a better choice for long term leds (all my resistor with a wall wart lights are cooked while my first current regulated led light is still going strong)

But this is an argument that could go on forever since there are pros and cons that can be argued for both... I definitely agree with you on the moonlight driver being way too much though. Normal gumdrop LEDs are plenty bright enough for a moonlight!

[becon776]

I have odyssea fixture (hey its what i could afford lol) and after one day the leds are blinking like xmas lights replaced all the bulbs because that was sellers idea for a fix. Seems like a ballast problem idea?

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