DIY High Power LED Retrofit

[deepdvnarq]

I see, I saw the picture of a 24 Volt 1amp plug... but now since you said you have a 5amp one thats fine.

 

Im still trying to find some 24 Volt adapters, Frys electronics selection was crap.. im still lookiing can you help?

 

Hmm looks like http://www.powerstream.com/12-volt.htm has some.

 

Ordered a 24 Volt 2.5 amp for 40$ shipped

try http://www.mpja.com/ they have plenty of power supplies and other goodies too.

 

Wuz up WP!

[Waterproof]

you ordered the 9x5? Small Less than 1 Foot?

 

I did the Large less than 1-foot (8.5" x 5"). Another person got a 6" length, and it fit fine as well.

[Darklyte24]

great thanks

[Waterproof]

Wuz up WP!

Hey man. Did you dump anything into the 3gal yet? I checked out your vid. I have the same problem trying to capture vid of the blue leds. They get blasted out. The color rendition just doesn't come through.

[deepdvnarq]

Hey man. Did you dump anything into the 3gal yet? I checked out your vid. I have the same problem trying to capture vid of the blue leds. They get blasted out. The color rendition just doesn't come through.

just those green shrooms and the two neon gobies seen doing their flyby while taking the video. i might make it a sexy tank with zoas and palys or maybe i'll remove the shrooms and make it a GSP biotope. dont know yet. and you? anything new? i start my conversion in my bc 14 real soon.

[Waterproof]

just those green shrooms and the two neon gobies seen doing their flyby while taking the video. i might make it a sexy tank with zoas and palys or maybe i'll remove the shrooms and make it a GSP biotope. dont know yet. and you? anything new? i start my conversion in my bc 14 real soon.

I added an orange ricordea, a green favia, and a green millepora - all small frags.

My calcium & carbonate demand is a little rediculous right now. I'm adding 20ml of 2 part solution daily. My next purchase has to be dosing pumps! The good news is that the mille, my first SPS, is doing really well.

[Darklyte24]

You said you have a 24 volt 5 amp power supply.

 

2 pucks connected in parallel.

Both getting 24 volts.

1 has 5 LEDs 24/5 = 4.8 volts 2nd puck 24/6 = 4 volts.

wont that blow the LEDs? or is the POT good enough to limit the voltage?

[thelovablebum]

You said you have a 24 volt 5 amp power supply.

 

2 pucks connected in parallel.

Both getting 24 volts.

1 has 5 LEDs 24/5 = 4.8 volts 2nd puck 24/6 = 4 volts.

wont that blow the LEDs? or is the POT good enough to limit the voltage?

 

Buckpucks are constant current drivers, your looking at constant voltage.

 

The POT controls how many amps are going to the led.

[Darklyte24]

Negative theloveablebum,

 

buckpucks give constant current, therefore it STAYs constant, the pot adjusts the voltage.

I tested it with my DMM.

[Waterproof]

You said you have a 24 volt 5 amp power supply.

 

2 pucks connected in parallel.

Both getting 24 volts.

1 has 5 LEDs 24/5 = 4.8 volts 2nd puck 24/6 = 4 volts.

wont that blow the LEDs? or is the POT good enough to limit the voltage?

 

With LEDs, they will only use the voltage that they need. Excessive current, however, will fry an LED, which is why we use the buckpucks. The drivers regulate the current to each LED run in series. The pots, as you stated, vary the voltage to the LED, thereby effectively dimming the unit.

 

Keep in mind that each buckpuck requires 2v to run properly. Therefore, 6 LEDs = (24v - 2v)/6 = 3.67v each. On the 5 LED leg, the LEDs will only pull what they need (~3.7v), leaving a little voltage to spare.

 

With a 24v power supply and a buckpuck, I can run 1, 2, 3, 4, 5, or 6 LEDs.

[Darklyte24]

Components like LED's use only current they need or what you feed to it. You have to apply the correct voltage.

Its the high voltage or if you go beyond the rated current, that can blow the LED.

[Waterproof]

Components like LED's use only current they need or what you feed to it. You have to apply the correct voltage.

Its the high voltage or if you go beyond the rated current, that can blow the LED.

 

Negative, Ghostwriter. I've hooked up a single LED to an 18.5v power supply using a buckpuck driver. Read up on the buckpucks:

http://ledsupply.com/wired-buckpuck.php

 

They only regulate current. Excess voltage from a power supply won't hurt the LED.

 

 

Unlike standard power supplies, which deliver a fixed voltage to the output, the BuckPuck is designed to deliver a fixed current. The output voltage will vary as required to maintain the specified output current with differing forward drop voltages of LED junctions.

[Darklyte24]

you sure about that?

 

I just tried it and it burned a LED

 

12 volts going into the buckpuck, connected a digital meter to the output and it read 12 volts plugged in the LED and it burned out. its pretty simple, 12 volts going into a device that only uses 3.5 volts will burn it out.

 

When it says "the output voltage will vary as required" they mean what you put in.

 

Now if it would regulate voltage as well as the current thats a different story.

but as the buckpuck says, it only regulates current.

 

So before you give out bad information, you want to really try it yourself before telling people so they dont go blowing up 6$ leds..

 

I dont mind because i have more than enough.

[Waterproof]

I just tried it and it burned a LED

 

So before you give out bad information, you want to really try it yourself before telling people so they dont go blowing up 6$ leds..

Dude, I can only tell you what I've personally tried, and what I've been told, and what I've read. I wish evilc66 would chime in on this. I'll tell you what...I'll take a photo of me using a 18.5v 1.5A power supply and a 700mA buckpuck to drive a single Cree XR-E LED. Sound good? Based on what you're saying, this should deliver 18.5v and 700mA to my single LED, which would certainly blow it. Right?

 

I'll do this once I'm home from work and post the results.

 

Here's another story...when I was soldering my LEDs, I would take the buckpuck connected to my 24v power supply (+/-) and touch the leads to my LED array to test the connections. I started w/ 1 LED, then 2, then 3, etc, etc, until I had all 6 soldered in series. I never experienced a problem. No blown/fried LEDs.

 

Are you sure you're providing DC output? Is the buckpuck wired correctly? It sucks you fried an LED, but it's not the result of my info.

[Darklyte24]

your power supply is probably regulated, or the LEDs have a regulator built in?

If you look at the specs of the LEDs, max voltage is 3.7 volts, 1 AMP. try giving 1 LED 18.5 volts see what happens.

 

My guess is you have something different or wired differently.

[coralcor]

i pan on doing this to my red sea max once i get some $

[evilc66]

Darklyte24, you have everything back-asswards here.

 

LEDs are current driven devices and therefore need constant current to operate within safe tollerances. The voltage of the device has to change as the LED heats up. A buck driver like the Buckpuck will do everything within its power to keep that current rock steady, and will adjust the output voltage to meet those requirements. It does this by switching the circuit on and off at a high frequency, causing the inductor that is part of the circuit to fluctuate. Depending on the frequency, the inductor will assume an average current output as it's switched to give you the desired current. A driver like a Buckpuck will be able to regulate current on any number of LEDs (1-6) using any power supply that is greater than the forward voltage of the string of LEDs. You could (and I have) run one LED on the 32v power supply (max input voltage of the Buckpuck. If you have cooked an LED, you have either connected something incorrectly, or the driver is faulty, as it should have caused zero issues.

[Waterproof]

evilc66, thanks for the more technical explanation.

 

I ran the test like I said I would. From the attached pic, you should be able to see all the equipment used. It's a 19v 2.4A power supply with a 700mA buckpuck and a Cree XR-E cool white LED.

 

 

Any questions? Like I said, my info is good.

[Darklyte24]

Thanks i tried with a new LED, so the first one that burned out must have been bad?.. lucky me.

the rest im using are good.

[evilc66]

Glad everyone is playing nice now

[deepdvnarq]

hey Wp!,

i got a few questions for you. do you know how high the posts are where you mounted your brackets? also the space between the brakets in millimeters? just off the tp of your head. i hate for you to take the top apart. i want to install fans beneath the heatsink. thanks bud. my power supply should be here on tuesday and i almost got all the tapping done. I'm working on my 37 gal fixture too. that's alot of freaking tapping! lol if you have a good guesstimate for those mesasurements, that will be real cool. thanks again.

 

ps hows your kid?

Deep

[Waterproof]

hey Wp!,

do you know how high the posts are where you mounted your brackets?

also the space between the brakets in millimeters? i want to install fans beneath the heatsink.

 

I'm working on my 37 gal fixture too. that's alot of freaking tapping!

ps hows your kid?

Ahhh, these are going to be complete guesses. I think the posts are about 1" high. The space between my brackets is maybe 2-2.5". I used 1" wide aluminum strips and drilled them in the middle. You could drill them off-center and shift each outward, giving you a little more than 3" (I'd suspect). I'd go with a thinner fan. Silenx makes an 80x80x15mm. This might be tight in terms of width. You could go w/ two of the 40x40x10mm fans, but they don't move much air. Is there anyway you could grind down some of the fins? If you could grind down an area so the fans are sunk into the heatsink, then you'd have plenty of room. I've assumed you don't plan to drill the top of the hood, which means you'd need enough clearance to allow proper circulation in the fan. If, however, you are planning to drill the top, then a 25mm thick fan would probably be fine. I have a couple of the stock 50mm biocube fans you can have. As you know, they are loud. Acousticpc.com has a bunch of low noise options other than silenx.

 

http://www.acousticpc.com/index_quiet_computer_fans.html

 

I'll take a better look tonight and let you know what I find out. Dude, between the eclipse, the 12gal, and the 37gal, you've got your hands full! I don't want to even think about all that tapping. If I do this again, I think I'll try the self-tapping screws.

 

The baby's great. I think he's trying to break my will through sleep deprivation! On a positive side, I've stopped blowing all my money of my hobbies since I have no time for them!

[deepdvnarq]

I'll take a better look tonight and let you know what I find out. Dude, between the eclipse, the 12gal, and the 37gal, you've got your hands full! I don't want to even think about all that tapping. If I do this again, I think I'll try the self-tapping screws.

 

The baby's great. I think he's trying to break my will through sleep deprivation! On a positive side, I've stopped blowing all my money of my hobbies since I have no time for them!

thanks WP

that was plenty of info. i'm going to put 2 to 4 40 mm x 10mm fans between the brackets blowing onto the heatsink or i still might do it how you did it on yours. the stock fans are only 50mm! i almost ordered the wrong size. i'll decide by today which ay it'll be. sleep deprivation....hahaha, just wait at least one to two years before deciding to have another one or you will know to definition of sleep deprivation (my two kids are only a year and 1 month apart). thank God i'm not into the sleep thing that much. i'll take some pics of how i do my fans and post them here. (got to figure out on how to post more pics. i have to go back and erase pics from my other posts.)

thanks again WP

Deep

[Waterproof]

thanks WP

that was plenty of info. i'm going to put 2 to 4 40 mm x 10mm fans between the brackets blowing onto the heatsink or i still might do it how you did it on yours. the stock fans are only 50mm! i almost ordered the wrong size.

Well, I guess I was a bit too optimistic. The posts are 0.75" high. Also, my mounting brackets are only 1.5" apart. The plastic posts are about 2.5" apart. Instead of making your mounting brackets so they go longways, you could run them front to back which would give you a good area in the middle to work with. I think two 40mm fans would be plenty. You don't need a ton of flow. Getting the flow out of the hood is more important.

[deepdvnarq]

Thanks WP. that's was awesome of you to do that extra work. so a 10 mm thick fan would work great. i'll send you pics when i get it done.