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LED DIY

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Barbara Turner said:
I'm using a

10 - Cool white 10w Cobs
10 - Full Spectrum10w Cobs
5 - Green 10w Cobs

You can see them glued down to the Aluminium profile with thermal adhesive paste.
I wired them in series in batches of 5
I'm then using 5 boost converters that allow me to run constant current or constant voltage these are run off 2 x 24v laptop power supplies
These are swiched on and off with a 4 channel sonoff controller that allows me to turn them on and off via my phone, It also set up schedule and controls CO2

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Good build i can see the controller box has led driver correct me if im wrong. Is the driver rated for 10w leds. As i can see you have 25 leds and 5 driver that tells me each driver is rated for 5 /10w leds. The problem i see is the profile you are using. Its not good enough as these wont even be good for a 3w leds. The heat spread is minimal. Hence why leds cant go over 5w they heat up and fry.
 
mow said said:
Hence why leds cant go over 5w they heat up and fry.
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The small Alu channel profile Is glued with adhesive paste and riveted to a 5mm x 1m x 200mm sheet of aluminium.
It only gets up to about 40 degrees with everything running flat out.
It could possibly do with a collection of heat sinks along the top and painting a darker colour.

But at the minute I don't ever run it flat out, the tank is only 1.2m long and only been set up for about a month.
Be a good way to turn everything green.

Be nice to borrow a PAR meter and find out how much light I actually have.
 
Barbara Turner said:
The small Alu channel profile Is glued with adhesive paste and riveted to a 5mm x 1m x 200mm sheet of aluminium.
It only gets up to about 40 degrees with everything running flat out.
It could possibly do with a collection of heat sinks along the top and painting a darker colour.

But at the minute I don't ever run it flat out, the tank is only 1.2m long and only been set up for about a month.
Be a good way to turn everything green.

Be nice to borrow a PAR meter and find out how much light I actually have.
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You have to spread the heat across rememebr you have 130 watts per channel and those are 10w led chips. If you run them 100% you will run into trouble i can gurantee you. Also they wont last long with the aluminiumn heat sinks you have, by this i mean if they have a life span of 50000 hours and they are running hot all the time they will only last 10000 hours and they will give up. And yes i would love to have a par meter too but they are not cheap devices. What i do is calculate lumens per litre and its worked for me.

My 1w leds are 100-110 lumens .
72w is my fixure that i am using
100(lumens)x72w= 7200
7200 lumens devided by 160litre which is my tank volume = 45 lumens per litre.20180511_163722.jpg
This is from tropica and it worked for me.
 
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Barbara Turner said:
I'm using a

10 - Cool white 10w Cobs
10 - Full Spectrum10w Cobs
5 - Green 10w Cobs

You can see them glued down to the Aluminium profile with thermal adhesive paste.
I wired them in series in batches of 5
I'm then using 5 boost converters that allow me to run constant current or constant voltage these are run off 2 x 24v laptop power supplies
These are swiched on and off with a 4 channel sonoff controller that allows me to turn them on and off via my phone, It also set up schedule and controls CO2

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You might find this an interesting video. skip it to 25.30 minute.. This guy explaines it very good what to look out for and how drivers work using these 10 watt HP cob leds and run them properly. He uses a very cheap available PT4115 driver.. He doesn't explain the dim function. But this is rather easy with connecting PIN 8 from the PT chip to the TC420 mosfet Gate Pin.. 🙂
 
@mow said, do you what happens if I wire up everything according to your diagram and connect 24V directly to it without the TC420??
 
rebel said:
@mow said, do you what happens if I wire up everything according to your diagram and connect 24V directly to it without the TC420??
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You will need a 24v driver ofcorse. If you plan to build 100w then again 150w 24v driver is needed. Led driver is a must!!!!
Buy a tc420 its only 15 quid and its worth it.
 
No problem if you need any help just come back to the this and leave a comment. And please do post your build if you can.😉
 
@lazybones51 , thats great that you have a heat sink ready to go. Make sure you water proof your electronics also .

@mow said , thanks for all your tips. By the way, where did you get a 4 foot sink? I havent found such a large heat sink .Thinking of linking up 2 foot ones.
 
rebel said:
@lazybones51 , thats great that you have a heat sink ready to go. Make sure you water proof your electronics also .

@mow said , thanks for all your tips. By the way, where did you get a 4 foot sink? I havent found such a large heat sink .Thinking of linking up 2 foot ones.
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What is your tank measurements and what is your plan for it. High tech , medium or low. Reason i am asking because if you want a low tech then you might not need all these fancy stuff and go with leds + drivers , no resistors or lm317.
 
lazybones51 said:
Yes it is, from the brief look I had online it seems that large heatsinks are expensive! Has anybody looked at encasing the electronics in some form of resin for water protection?
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Water protection? I used a perspex sheet cut to size. Very cheap also it was around less than 10 quid online. No need for resin
 
@mow said , My tank will be a 4 footer. It will be high tech and I need to hang the light high above the tank potentially. At least 60cm above the tank. My plan is to use 45 degree lenses.

I am also up to the challenge of such a build but I need it to be very neat like yours as it will be a display tank. I am very finicky with colour rendition and don't know exactly what I like. I think I will like a purple tinted crisp white look. Probably more heavy on the blues.
 
lazybones51 said:
Yes it is, from the brief look I had online it seems that large heatsinks are expensive! Has anybody looked at encasing the electronics in some form of resin for water protection?
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Never heard of any options. I just use the spray-on water proofing for electronics.
 
ian_m said:
I have used sprays like this to moisture proof electronics.
https://uk.rs-online.com/web/p/electronics-varnishes-lacquers/8232646/

Need to be careful around any connectors and wire attachments as the lacquer will prevent connectors connecting and will crack and fall off around wires.

To moisture proof connectors and wires use non corrosive silicone (or hot glue).
https://uk.rs-online.com/web/p/silicone-sealants/0494118/

Notice I use the words moisture proof, not water proof !!!
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You might find stuff like that in regular automotive shops as rustbuster.. Epoxy resin spray to apply over rust without further ado.. It brings an air tight waterproof epoxy coat over the rust or anything else that it is sprayed upon. And sold by Conrad Electronics i see..
https://www.conrad-electronic.co.uk/ce/en/product/829564/Brunox----EPOXY----BR040EP----400-ml

But actualy a regular 2 component epoxy would even be eaiser to apply with a brush and than you decide the layer thicknes.. As long as the components aren't mixed it is indefinitely shelf live if stored dark. Just need a little weight scale to mix 100/50 or 100/60 parts in small amounts. I already have it for 5 years on the shelf and still using it.. Mater a fact 2 days ago, it still is ok.. (so the 1 year shelf life on the bottle is commercial bs).. 🙂 And it has about 45 minutes work time, it slowly cures, in 20 minutes it will be a thick syrup, still able to apply it, but it wont run so much anymore..
 
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I havent used any waterproof sprays on my unit. Its been more than a year and nothing. As long as you use a sheet on top of the wiring you will be safe. I used a black perspex sheet the measurements are in page one. You can use any colour you wish even clear acrylic sheet will do. Perspex is acrylic, easy and simple no need to buy sprays but it's up to you. You think twinstar or chihiros use any sprays i
 
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