Here's a lamp I bought today for the par38 bulb. I assume that most sockets will work with that bulb? Anyways here's a photo of it with a regular bulb to show what it looks like.

Should work fine! Looks great over your tank.

I looked everywhere and this is the only adjustable lamp I could find that had a screw off cover. I'm not sure how much the par38 weighs but this fixture seems very secure after tightening the screws. If anyone is interested in the fixture, office depot sells them for $11.

i belive the T in lm317T means it can handle up to 1.5 amps.. the then the two others are 1 500mA and then like 250Ma or something.. T is good..

in part due to the mixed / negative response i got to the idea of grounding the metal casing holding the leds/heatsink, i've explored other safety options.

i've learned about the technique of 'double insulation' used in many appliances without a ground wire, and so i'm planning a way to provide similar insulation with an acrylic enclosure to hold the heatsink, then attaching that to the metal casing which will hold it all.

just wanted to toss out the idea to anyone who may also be looking. the purpose is to provide a layer of security in case there is a short to the heatsink and the heatsink becomes charged.

Hey Redfishsc,

I have Meanwell drivers too. I know ACL and ACn are outputs but not sure which one is positive or negative. Could you please help me on that one ? Thanks in advance !

Considering I've purchased all the parts of the project already, this might be a too late but anyways : do you see any problem running all white and blue leds at 1000ma ?

ACL= AC "live" (the hot)

ACN= AC "neutral".







They are rated to run at this I'm pretty sure, so long as you are talking about Cree XRE.

I am putting an LEDs in my biocube 14 hood. Couple of questions. First, should I use 10 or 12 LEDs? and should I get optics for them or not? Thanks.

I just called LEDSUPPLY and they said that I would be better off getting the 700mA buckpuck drivers than the 1mA because if it overheats it would lose a lot of efficiency and with only a 8X5 heatsink it could overheat. What do you guys think?

Clean, peel, stick. After a few heat cycles, they will get stickier and cure.


That's a lot of area to light. My recommendation would be a 9x6 array (2" on center between LEDs, 3" between rows) with 60 degree optics.


Do not connect the left most pin on the LM317 to both center and outer pins on the pot. Center only. This is most likely your problem.


It will be a considerable upgrade in light. Think of it like putting a metal halode over the tank.


Is the tension on the joints adjustable? You may need to play with that, as the PAR38's are a lot heavier than the standard bulbs.


Considering the heatsinking capacity we normally have, it's no problem at all.


12, and no optics. If you haven't already, read through Waterproof's build, as well as the many other BC14 builds. There is a sticky for LED projects here in the Lighting forum.

I don't quite follow. I only have the left and center pin connected together (via the resistors). The rightmost pin only has DC voltage in. It sounds like you are saying I have all 3 pins connected somehow.

Are you referring to the left and center pins of the pot, perchance?

How much do the par38's weigh?

The light fixture works perfectly, once you tighten up the screw all the way it's really secure. I actually hung two older type cameras from it last night and it didn't budge an inch.

Sorry, I wasn't very clear there. Yes, the pins on the pot were what I was refering to.

Ok.... corrected the pot. Still getting 2.5 to 15v, give or take a decimal.

Is it possible that I have the input and output prongs on the LM317 swapped, or is there no polarity?

Or something.

Looking at the calculators, it almost looks as if the 470-ohm resistor is being bypassed and only the 1K and pot are doing any resistance. If R1=1K and R2=10K, voltage output is around 14v. Toss in a few more decimals for 5% tolerance.... and maybe this is it?????

Provided that you have it wired up exactly like the picture you posted earlier (besides the pot not being wired properly), you are fine. The 1K and 470 ohm resistor are in series and will look like 1470 ohms to the circuit. There is polarity to the LM317. You have it pictured correctly. Pin 1 (all the way to the left with the back of the tab facing away from you) is ADJ. Pin 2 (middle) is VOUT. Pin 3 (right) is VIN.

Man.... so where do I go from here?

Not sure yet. Gonna hit RS tonight and get the parts (no time this weekend ). Can you take a picture of the top and bottom side of the pcb? Maybe I can spot something obvious.

Ok, I can try to do that tomorrow. Tonight I'm working on a pile of grad work.

The first thing you'll notice is my unattractive solder work, but I've inspected it fairly well for any shorts or loose connections.



Is there anyone who has actually gotten 10v out of this rig with a typical 12v wall wart? I know Artnsx seemed to but I can't recall since he had P models and couldn't use the dimmer.



Cool avatar, btw!
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LED gurus, ive been thinking of going LED for a while, but never really found a reason to until now.

the available space is 16"x14"x12" roughly. i cant really remember the exact height.
the heatsink i found is anodized black, fins are on the outter side of the fins leaving the center flat. there are different size available. the biggest is around 4"x6-7"

i would be using LEDs and LED drivers from deal extreme. i dont really care for the dimming capability as this is only for a frag tank. so the sunrise and sunset fnction is not needed as well. also with those drivers i can just connect AC power direct to it and will provide constant power and current to the LEDs
http://www.dealextreme.com/details.dx/sku.13691

the questions i have is which LED should i use from deal extreme. from evil's first post. he suggests to use Q5 stars as they give off the most light. ive found 3 different white Q5 led and want to know which one is best

http://www.dealextreme.com/details.dx/sku.11023
http://www.dealextreme.com/details.dx/sku.11022
http://www.dealextreme.com/details.dx/sku.2394

i cant seem to find any royal blue LED, or any blue cree leds for that matter. evil said xr-e is the best blue led, but most of the xr-e led are white. this is the only blue led i found on deal extreme
http://www.dealextreme.com/details.dx/sku.11015

how many LEDs and what kind of lens should i use? is 10 LED enough for the available size?

also i remembered evil have a group buy on LEDs, but it seems like it just ended, evil, will you ship internationally? when will the next group buy happen?

any other suggestions would be greatly appreciated.

You can get all the LED's from nanotuners.com, or at least just the blue ones.

They also have the VERY handy and useful Berquist thermal pads which are great for gluing the LED's to the heatsink. Well worth it.

SVR2 to reduce to 1A ?

Btw, I thought SVR1 is to vary the output voltage? eg..slightly above 48V maybe 50V++ (assume 48D series)

if else fails then i would have no choice to order out of the country, but i rather not since shipping be crazy

My bad, I forgot you lived in Hong Kong...

SVR2 controls the maximum current output. By default from the factory, they should be set at ~1.3A. In a constant current mode (which you will be running when LEDs are connected) SVR1 will do nothing.



Contact Chris/Nick and see if he can get you a quote for shipping. May not be as bad as you think.

As far as what you need for that area, a 4x4 array should work out fine. No need for optics at ~12". I'd still recommend dimmable drivers. It's not for dawn/dusk effects, but for acclimation and setting the appropriate light output for the tank inhabitants. LEDs can be powerful little critters.

I ordered the 20k 60 degree par38 last night! I can't wait to see how it covers the picotope.

Should work pretty well. Just remember, it's a very different look.

How so? I wasn't aware it would be any different, except for the coverage.

I was talking about the use of a spotlight more than your choice in optics. The shadows are considerably more dramatic. It's very... "Japanese". Not sure how else to describe it. Personally, I like it. It takes some people a little getting used to when coming from your typical T5/PC lighting scheme where there is light everywhere from every angle.

Oh ok, cool. I thought you meant the 60 degree optics were going to be a lot different.

I've really liked the looks of the par38 spotlight effect from the photo's I've seen and I'm sure I'll like it even better in person. The ada mini cube that reefbuilders showed using the par38 sold me on it.

If I like it enough I plan on buying the same lamp fixture (if it even works with the bulb) and putting them side by side. Would a 12k mix well with a 20k if you kind of crisscross them?

I do the same thing on my 40B. It's 20K, 12K, 20K, 12K, from left to right. You notice warmer and cooler colors, but nothing really stands out.

Jake at Reef Builders absolutely loves that lamp. I have talked with him a few times on the phone and he just can't get enough. The teardown pictures he did last week were really nice.

You never want a ground on a DC system. I work with High DC volts and we constantly monitor for DC grounds as they are serious trouble. The case ground is for AC safety.

Ok, some good news and some "no news".


No news....the 10v LM317 circuit, same issue (haven't made any changes) but pics will come so Evil can see what on earth I've done wrong.

Good news.

Other than the dimmer switch, the array works fine. I found a 5v cell phone charger, tested it and it gives 5.4 volts, so I used that for the dimmer input.

The Meanwell lit them up nicely .


Then someone suggested using a 9v battery for a temporary input to see what they look like at nearly-full blast. Tested the battery at 9.7v.

Worked like a charm. I forgot to hook up the meter to see what current was running through the LED's but since I had the SRV2 turned counter clockwise, it should be fine.

So I'm setting it aside waiting for 1 replacement blue LED for the one I roasted over the weekend, and waiting to get the real-deal dimmer circuit working so I can dim them with a pot.



Evil, I can't thank you enough for your help!!!!!!!!!!!!!!!!

More news to come at 11.

Here is a pic of the face of the PCB. I forgot to get a pic of the back w/soldering. I'll take that later tonight.

Anything look wrong here?

LM317 prongs are spread out for ease of soldering on back. This helped a lot.

Black goes to pot, green goes to Dim+, red is voltage input. Dim-, Pot. -, and DC wall wart - all connected as ground and soldered on the back (back right hand side).

Oh, and I happen to just now find a true 9v power supply. Says specifically on the back in big letters "regulated" whereas the other old 9v supplies I found in our shop do not say "regulated" and all throw off (without a load) anywhere from 11.8 to 18v.

This one, without a load, is showing 9.2v, so I'll just use this puppy.


So, a couple of questions.

1) For the pot--- do I just put this inline on the + side of the DC ps? Input the 1st terminal, with middle terminal going to the dim+ on the meanwell? I did this and it certainly dimmed them, but I'm not sure if this is the "right" way.

2) Strange issue. When I am putting in 9.2v, with or without the pot, I am only reading 0.20 amps through the LED's. Dimming it doesn't shut them off completely but cuts it down to around 50mA. I cannot tell by looking at them what "full power" looks like. They are quite bright at 200mA, but I think they could go brighter. I've never seen them at 1000 mA. SRV2 is maxed out counter-clockwise. Something just doesn't seem right.

What's going on here?

Nanotuners sure is fast, my light was already shipped out!

1) One outer pin to PS+, other outer pin to PS-, center pin to DIM+, DIM- to PS-.

2) Where and how are you measuring the current?

1) Thanks, will do that. Can the Dim- and PS- be soldered to the center pin together?

2) Measuring current after final LED in line. Alligator clip the - multimeter terminal to the wire coming from - pole on LED..............clip the + terminal of multimeter to alligator clip to voltage -. If I swap terminals on the multimeter it just changes the reading from + to -. Stays at 200mA (this is without the pot even attached, so it's getting a full 9.14 volts).

I've triple check everything to make sure my polarity isn't reversed somewhere. I'm not even sure that could cause the low current. I resoldered a couple LED's that looked like they *might* have had some solder barely touching the aluminum on the side, as I got a little heavy handed with the solder. I'm confident there's no shorts and all LED's light up equal.

1) You mean the outer pin on the pot right? Center pin goes to DIM+

2) You are hooking the meter up correctly it seems. You have the meter in the 10A mode and the fuse in the meter is good right? Many multimeters will have two current modes. Low current (upt to about 200-250mA) and high current (up to 10A).

1) Yes. My bad.

2) Correct on all points, although I can't promise anything about the fuse. Unless a fuse can partially blow, it's fine b/c I'm definitely getting a reading. This is a new mulit, although it's a $25 Lowes model. Set to 10A, with the + terminal plugged into the correct jack,

Spoke to someone at Nanotuners about the current issue. He suggested messing around, with the Meanwell running, with the SRV2 and SRV1. I have not touched the SRV1. I severely doubt that the SRV2 on the lowest setting would give me 200mA with 9v of input dimming. I'm not comfortable messing with that, and I'm not even sure what can be profited by messing with the voltage if my issue is a strangely low current.


I also checked the heatsink to see if I was getting any stray voltage or current with the unit on. Plugged the negative terminal in a ground outlet, touched the heatsink with the + terminal, and got absolutely no current (even on low current setting) and the voltage gave me a few decimal points of "noise" but nothing substantial, a few tenths of a volt maybe.

Nick/Chris contacted me on that one. I had a feeling you were the one they were talking about. I'm going to try and get a test rig set up so I can do a little compare and contrast.

yeah that's me

FWIW, I can put a 9v battery to the LED and it lights up about 5X brighter than it does running at 200mA, so I'm certain there's only 200mA going through them (or something similar).

Running 7 LEDS. I am getting 20.7v at 200mA with it running. Dimmer input is 9.14v.



What are you going to be looking for on your end? And is there anything else i can do on my end?

I will recreate what you are running, and see if I get the same results. If I do, then I see what is needed to correct it. Not much you can do at this time.

hmmm. then not much I'll do got a lot of studying to do. I can solder up the dimmer pot though.

Here is a shot of my heatsink with the LED's at 200mA. Notice the dead one. Replacement is coming in the mail from nanotuners.

I'm hoping I don't have much trouble removing the dead LED since the thermal pad hasn't had much heat to it. Maybe lacquer thinner would debond it.

HAHAHA i think the LED is not lighting up because its not wired up.. hahahaha.. or maybe from your 9V battery testing.. looks good but..

xcracer, the last one was excommunicated. It will, within a day or two, be burned at the stake.

I can't say for sure that this will work since all I know of soldering is what I did this and last week, lol, but here's what worked for me.

First, what wattage soldering iron are you using? I'm lucky enough to have one at the shop that's around 100W and has a "fine tip".


Second, are you using rosin core solder? Are you at least 60/40 or maybe 63/37?

Third, do you have any flux paste?



What I did:

Cut, strip, and twist all the wire ends.

Use a wood clamp (or any small vise type clamp) to hold the wire, pointing DOWN (so the solder will drip off the end if you get too heavy, rather than run down onto the insulation)..

Once the wire is in the clamp, give it a small amount of flux. A toothpick works well for this.

Tin the tip of the iron. Touch it to the wire and heat the wire for a second or two and touch the solder to the wire near the solder iron.

When I did this, the solder would wick into the wire where it's twisted like sponge. I had no problems at all soldering up the LEDs.

What type of wire are you using? Is it copper?

Fairly certain.
http://shop.willyselectronics.com/browse.c...awg/2,1008.html