Minimalistic multichip DIY LED build
- Thread starter maglofster
- Start date
I have seen a lot of posts regarding the lenses for the 50-60W chips... but how do you attach the whole assembly together? I read somewhere not to use superglue. I have 2 50W that I want to attach 90° lenses (reflector and lens are separate), but cant seem to find where or how to make them stay put.
Lassef
Member
You are welcome to post (in english) at the swedish forum. most people in Sweden understand english very well. If you use google - remember we speak backwards compared with you. That´s one of the reasons why my post sometimes is difficult to understand for you. And google can also help you to find threads in english about 5 channel Dream Chip. And rather near to you 
Sincerely Lasse
Sincerely Lasse
Lassef
Member
I use two component Epoxy. Do not take too much and be careful when you glue the reflector base to the chip
Sincerely Lasse
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The manufacturers generally recommend using high temperature silicone - a number of the sellers of multichips carry a very nice to use super-clear version. Kafuter K-705 is one of them. It's an alcohol cure silicone, so it smells different and has somewhat different properties than the acetic acid types we are used to.
Hey,
I've been lurking in this thread for a while, and have a couple of builds I'm thinking of incorporating these chips into, but would like some advice before setting out to buy anything.
The first build I'm working on is a Fluval Edge reef. The tank is 6 gallons, with the dimmensions 16.9" L X 10.25" D X 8.75" H. The opening where the LEDs must fit (including the heatsink) is 4" x 6.5". Most people who mod the tank add 6 3W LEDs for 18W total, I was thinking about doing 2 10W LEDs? As far as heat is concerned, could I put 2 of the 10W on one 6.5" x 4" heatsink, with a fan on top? If not, what about a single 20W? the height isn't too restricted, so I could put a thick heatsink, or a larger fan if necessary.
As far as drivers are concerned, I don't need them to dim as far as personal preference goes, but if they will need to be toned back because of light intensity, I am willing to go that route also.
Any help would be appreciated, and I thank those of you who have shared your knowledge with the rest of us.
I've been lurking in this thread for a while, and have a couple of builds I'm thinking of incorporating these chips into, but would like some advice before setting out to buy anything.
The first build I'm working on is a Fluval Edge reef. The tank is 6 gallons, with the dimmensions 16.9" L X 10.25" D X 8.75" H. The opening where the LEDs must fit (including the heatsink) is 4" x 6.5". Most people who mod the tank add 6 3W LEDs for 18W total, I was thinking about doing 2 10W LEDs? As far as heat is concerned, could I put 2 of the 10W on one 6.5" x 4" heatsink, with a fan on top? If not, what about a single 20W? the height isn't too restricted, so I could put a thick heatsink, or a larger fan if necessary.
As far as drivers are concerned, I don't need them to dim as far as personal preference goes, but if they will need to be toned back because of light intensity, I am willing to go that route also.
Any help would be appreciated, and I thank those of you who have shared your knowledge with the rest of us.
jooce01: Check out the dell poweredge heatsinks for your build, they are very low profile.. search ebay for W2406 for an example of the type I'm talking about. They're made to handle 120+ watts so you could put a small quiet fan with it and be fine.
A single 20w would be my personal inclination, maybe with a 3w 420nm or two for company. Probably a hybrid type, with a mix of blue and 10000k, although that might be a bit on the blue side for you, I think they have about a 15000-16000k look. You may have to get 2 x 10w (white/blue) and blend to get the color you want, but honestly, good luck finding small dimmable drivers. And you DO want dimmable, 20w will probably cook most corals without some acclimation.
A single 20w would be my personal inclination, maybe with a 3w 420nm or two for company. Probably a hybrid type, with a mix of blue and 10000k, although that might be a bit on the blue side for you, I think they have about a 15000-16000k look. You may have to get 2 x 10w (white/blue) and blend to get the color you want, but honestly, good luck finding small dimmable drivers. And you DO want dimmable, 20w will probably cook most corals without some acclimation.
Thank you for the fast reply Tom!
I'll have to look more into that heat sink when I get home, I can't seem to find the dimensions online anywhere, but I'm at work with what basically amounts to dial-up internet.
As far as the blue-ness goes, I love a nice blue light, but the tank is a surprise gift for my mom. I'm building it, and my sister (another reefer) is going to maintain it (they live together). I can't really ask her how she feels about the blue light without giving away that I'm building this for her. She will more than likely just be keeping some softies and zoa's in the tank, so lighting doesn't need to be all that strong.
As far as drivers go, can I get a driver that is made to power say 3 20W, and just use it to power 1?
From what I've read 20000k in LED won't look the same in 20000k of MH (what I'm familiar with). So is there any good way of determining what will give a nice blend of blue/white? You recommended 16-ish K, so something like this:
http://www.ebay.com/itm/20W-16000K-...ultDomain_0&hash=item336f0c5cd1#ht_1626wt_892
Thanks again Tom, greatly appreciated.
So after looking around for a while, I can't seem to find the dimensions of that heat sink. But I was thinking that I could just get one of Mean Well's ELN-60-27D dimmable driver correct? The 20W would fall within it's range of 13.5-27V, and I've seen that Lasse suggests basically this same driver just different higher voltage models.
I also found http://www.ebay.com/itm/60x150x25mm...597?pt=LH_DefaultDomain_0&hash=item2ec0a96d15 a while back, the dimensions would fit inside of the hood, I just don't know if it would provide enough heat transfer to handle a 20W bulb. Like I said I can always throw a 60mm fan or bigger on top of it to facilitate cooling.
Thanks in advance
I also found http://www.ebay.com/itm/60x150x25mm...597?pt=LH_DefaultDomain_0&hash=item2ec0a96d15 a while back, the dimensions would fit inside of the hood, I just don't know if it would provide enough heat transfer to handle a 20W bulb. Like I said I can always throw a 60mm fan or bigger on top of it to facilitate cooling.
Thanks in advance
Lassef
Member
It depends. The 20 watt I use (AC-RC) has a FV of 10-11 V and then the driver does not work. 2 x 20 watts of AC-RC type in a daisy chain works well. Other types of 20 watts may have higher FV and therefore will work with this driver.
A driver that works with only one AC-RC type of 20 watt chip is ELN-30-15D
Sincerely Lasse
Thank you Lasse, that was exactly what I needed to know.
What do you think about that heat sink I linked, would it be able to cool a single 20W chip?
Jooce: I can get you the dimensions, I have one on the shelf here... 7" overall length, 2.75" wide and 1" thick, the section with the three heatpipes and extra fins is 3.5" or so and the part with the heatsink base is also 3.5" long. It may be too long overall to fit in an Edge, not really sure the dims of what you have there.
I would recommend a hybrid type, search ebay for "hybrid panel 20w" - there are 2 listings, one is for 10000k + 453 blue and the other is 20500k + 453 blue. I'd say the first will be about 15-16000k and the second more like 20000k as compared to halides. I haven't used either personally but I do have a chip that is 50/50 10000k / 453 and it's about 12000k.
I would recommend a hybrid type, search ebay for "hybrid panel 20w" - there are 2 listings, one is for 10000k + 453 blue and the other is 20500k + 453 blue. I'd say the first will be about 15-16000k and the second more like 20000k as compared to halides. I haven't used either personally but I do have a chip that is 50/50 10000k / 453 and it's about 12000k.
Lassef
Member
I would have preferred that the flanges had gone the other way. when they had been able to fit a 60 mm fan and two "roof" so that the air is blown out to the edges. You can use a square tube with a hole and a fan. This is large but you can use the basic idea with a tube 25*50 mm and 50 mm fan. This works well for around 50 - 60 watt as you see
Sincerely Lasse
Sincerely Lasse
Mike31154
New member
Hi
I have ordered
One set of 5 of these
http://www.ebay.in/itm/290739819764?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
4 of these
http://www.ebay.in/itm/221116650656?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
2 of these
http://www.ebay.in/itm/200798805322?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
And the power supply is
12V 10Amp 120W DC Switching Switch Power Supply Driver
I was thinking of connecting the blues and whites with individual dimmers
So please can someone guide me how should i set up the leds with the power supply.
Thanks
As Lasse mentions, using a constant voltage power supply can be tricky & risky. Having said that, my build uses similar components with respect to chips, power supply & dimmer. I have a total of 27 ten watt multichips and am running them in parallel using two power supplies on separate timers. Each of my chips is mounted on a heatsink with fan which makes for a lot of wiring, but it's a solution that provides subsantial weight savings over mounting them on a large heatsink. I've been running my fixture since April, so about 6 months with no issues other than a fan failure which was easily repaired, no damage to LED.
The two 12 volt power supplies are adjusted down to 10 volts output to keep them at or below the maximum forward voltage of the LEDs. The 8 amp dimmers further reduce the voltage and I run the chips at 8 volts or less to reduce the risk of burn out & subsequent increased current to remaining LEDs.
Based on my personal experience & if you keep the voltage out of the power supply at or below 10 volts, you might want to go ahead with what you have. You will need to hook up the LEDs in parallel and make sure you get appropriate heatsinks. A fuse in line with each LED would also help in the event one shorts or burns out. This will prevent the remaining LEDs from overcurrent.
If you wish to know more about my build, I have a DIY post on a canadian forum under the same user name. Below is a photo of the heatsinks I've used. A lot of soldering to hook up all 27 LEDs plus each fan, but the entire fixture weighs in at only about 12 lbs.
A couple of the photos are older & I've made a few modifications since. One of the more important & time consuming changes was to rewire all the fans. Initially I had soldered the fan leads to the LED tabs, meaning each (12 volt) fan ran at the same voltage being fed to the LED. Problem with that was, that when the lights came on in the morning at low voltage (3 to 4 volts), most of the fans would not start. This is fine since the LEDs don't produce much heat at such a low voltage/current, but not ideal for when I'm not around to kick start the fan with my finger. So I finally bit the bullet & ran another set of wires from each power supply to directly feed the fans with 10 volts. No problems with start up at that voltage and the fans actually run quieter at the higher voltage. Some of them would produce an irritating whine at slower speeds. Now I can just set the voltage to 6 volts for the whites, 8 volts for the blues & go on vacation knowing the fans will start up reliably.
Might want to order a couple of extra LEDs & heatsink/fans for spare parts. An extra power supply would not be a bad idea either.
I see what you mean, having the flanges run length wise instead of width. That would make sense to distribute heat along the entire piece of metal. Looking around some more I found http://www.ebay.com/itm/160x80x26-8...052?pt=LH_DefaultDomain_0&hash=item416496beac which has flanges that run the length of the heatsink, plus it is bigger while still fitting into the space available.
Just curious if it is worth the extra $12.23, I know it is a small price to pay for better cooling, just curious how much better the cooling really would be.
Thanks again for your input, and before I go buying either I'll have to look around locally for the tubing you're talking about.
Lassef
Member
The AC-RC type of 20 watts chip manage 50 - 60 degree C at the backplate. They are in reality 2.5 watts invidual LED.
Whatever you chose - we want to see pictures of your built in this trhead
Sincerely Lasse
ReefUrchin
New member
Okay, after a little hiatus bird dogging this MH fixture the lady is holding out on, I am back to planing my LEDs. If the MH does not pan, I am thinking, for now, to get things going, a 100w 20k chip and a 50w AC-RC chip, which runs at another 100w full tilt, so, that equals 200w worth of power. I plan to put the chips next to each other. Now, I do have my heatsinks which are 16" x 9 3/8" with a base of 1/4" thick (see pic). Will these be enough to dissipate 200w of heat (if i run them both at full, which I doubt I would) or should I fall back and punt?
