Cheap Chinese RGB LED strip light question - Page 1
Forum section: electronics / beginners

author: snipe
author_rank: Newbie
timestamp: November 26, 2020, 04:06:40 pm
content: Hello,I hardly know anything about electronics and would like to use LED strips to light my aquarium.I ordered this,https://www.ebay.co.uk/itm/RGB-LED-Strip-Lights-5M-10M-15M-Remote-Control-for-Room-Bedroom-TV-Party-Decor/393004836841?ssPageName=STRK%3AMEBIDX%3AIT&var=661925797205&_trksid=p2057872.m2749.l2649I'm not sure what I've ordered, but it appears that there are is a cable with three ends and each of the three, 5m strip lights connects to one of the ends.The aquarium is cylindrical, so the light with be circular. I'm guessing I'll need to cut up the strips with scissors and stick them to a 65cm disc like this,Then connect the strips with these,https://www.ebay.co.uk/itm/WOW-10-X-PCB-5050-RGB-10mm-4Pin-LED-Strip-lights-Wire-Connector-Adapter-Cable/252144006954?epid=4027560775&hash=item3ab4f4372a:g:SRsAAOSw14xWMcSeThis is my intended layout to scale,Will I need to use heat sinks as the Chinese LED strips are only £1 a meter and I'm assuming they'll last at least 6 months at a time, or am I wrong?Am I risking a house fire with this set up or am I good to go?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 26, 2020, 04:38:32 pm
content: LED lifetime decreases with increased temperature.You did not state from what material you made the disk.If you make it out of metal, then your LED's probably have plenty of cooling.If you're still afraid of fires, you can put in a thermal fuse or two.The most likely part to start burning your house down is probably the power supply and not the LED's themselves.

author: John_doe
author_rank: Regular Contributor
timestamp: November 27, 2020, 12:56:12 am
content: If you think that is cheap then you have no idea what cheap meansI bought a 5M RGB 5050 30L/M reel (like yours) from AliExpress for $2.82 USD shipped, and it wasn't even a sale. The IR control+remote would've been around $1-1.5 more and the power supply... Well, that depends heavily on the quality of it.As for your questions: I've never bought these solderless connectors but looking at the pictures it looks like they'll work, but if they don't sit flush with the surface maybe it will be a mechanical weak point for the adhesive (I'm just guessing, I have no experience).You don't have to use a heatsink at all if you set your brightness low enough. This is easy to test, simply put your hand on the segments and if it's too hot lower the brightness. You can also try it on the reel to get an idea (the reel will heat a little more than the spread out segments with the same brightness setting).You may not even need so many segments. Maybe fewer will give you a sufficient light level. Experiment.As for your wiring diagram: It will work but will not give a uniform light as the end furthest from the connector will be very dimly lit. I don't know how to solve this problem with only the solderless connectors that you have purchased. If there are solderless splitters, it would be much better.One more thing, it looks like your 3-way splitter is female and so are the solderless connectors, so you'll need more male headers. I don't know what pitch they use, but 2.54mm pitch headers cost pennies.

author: cdev
author_rank: Super Contributor
timestamp: November 27, 2020, 01:23:16 am
content: Keep it dry and protect yourself against electrocution, also you could fashion the strips into a spiral, perhaps. I'd try to avoid cutting and splicing them. Maybe you could arrange them like a pinwheel.Preventing water damage and electric shock is important. I'd put them behind some plexiglas behind their own enclosure of some kind that keeps them dry.

author: John_doe
author_rank: Regular Contributor
timestamp: November 27, 2020, 02:01:59 am
content: cdev, these strips work on 12VDC, so the only electrocution risk is if the PSU shorts output to mains which, to be fair, is not uncommon with cheap Chinese power supplies, but rare in high-quality ones. If it does happen though, you'd know about it because the led strip will stop working.As for the not splicing idea, I would advise against it, as voltage drop on the tracks is a real issue, especially with cheap strips which use thin copper tracks:

author: snipe
author_rank: Newbie
timestamp: November 27, 2020, 12:45:36 pm
content: Quote from: Doctorandus_P on November 26, 2020, 04:38:32 pmI've found aluminium sheets on ebay that are 60cm squares. They can cut the shape I need for free. The thicknesses are,1.0 mm (£16 shipped)1.5 mm (£17 shipped)2.0 mm (£20 shipped)3.0 mm (£27 shipped)4.0 mm (£34 shipped)I want the light unit to be lightweight. What is the minimum thickness advisable that will provide adequate cooling for 15 metres of LED strip laid 1cm apart?Quote from: Doctorandus_P on November 26, 2020, 04:38:32 pmThanks, I'll replace the power supply ASAP as I've seen them for sale for £2. They must be really low quality and dangerous. Can I use a branded secondhand laptop PSU? What type should I buy or can I use any one?

author: tunk
author_rank: Super Contributor
timestamp: November 27, 2020, 01:16:51 pm
content: From the listing each 5m reel is 36W - so I guess thatyou really don't need 15m. Also, 108W is a lot todissipate - would guess that none of the sheets willhandle that. The strips run at 12V and most laptop PSUsare 17-19V, so unless you find a 12V PSU, they will notwork.

author: snipe
author_rank: Newbie
timestamp: December 03, 2020, 04:06:25 pm
content: 15m of LED is probably is overkill, but better to have and not need. I might want to keep light loving corals in the future.I ordered the 4mm thick aluminium sheet and a temperature gun.The 5050 leds are 3.5cm apart on the strip and I'm leaving a 1cm gap between strips.I'm thinking the 4mm thick, 600mm x 600mm sheet will cool LED better than a row of aluminium profiles which appear to usually be only 1mm to 1.5mm thick.

author: jmelson
author_rank: Super Contributor
timestamp: December 03, 2020, 04:16:54 pm
content: Quote from: tunk on November 27, 2020, 01:16:51 pm36 W??!!?? Yikes. Now, I know these are RGB with resistors, so that cuts efficiency. I have made fluorescent retrofits in my kitchen with high efficency white LEDs and no resistors. I have 3 of these units with 20 LEDs in series, running at 350 mA with a commercial lighting regulator. The LEDs draw about 19 - 20 W, and are about as bright as a "40 W" fluorescent tube. So, I think you need to test out a section of the LEDs and find out how much light you get. Don't want to BLIND the poor fish!Now, dumping 36 W into a 60 cm aluminum disc that only has cooling on one side, it is going to get warm. You might have to put heat sink fins on the top side. But, maybe with far less power, heating will not be a problem. Maybe some of the heat will go into the water, which may be just fine for tropicals. Another issue will be water condensing on the light, especially when it is turned off.Jon

author: snipe
author_rank: Newbie
timestamp: December 04, 2020, 03:18:04 pm
content: I already had a metre of this strip and taped it temporarily to the side of my aquarium to test it. It wasn't bright and ran quite cool to the touch without a heatsink.I think I will need 15m of this strip to punch light down to the bottom of the aquarium. It's 76cm deep. I still think the 4mm aluminium sheet is overkill.It'll be interesting to see the results with the temp gun. It's been 10 days since I ordered the LEDs and I still haven't received them. The eBay listing states it's also in London, but it's obviously coming from China. I wouldn't have ordered it from China as I don't want to wait that long.I was tricked

author: CJay
author_rank: Super Contributor
timestamp: December 04, 2020, 03:29:04 pm
content: Not necessarily tricked, a lot of these guys are China based but drop ship from UK warehouses and it does estimate a 10 day delivery time so it's possible it's held up somewhere.It might also be on it's way from China...

author: snipe
author_rank: Newbie
timestamp: December 11, 2020, 05:00:27 pm
content: I have it up and running with all 15m of strip. It's not that bright.The 4mm metal sheet is showing 80f from the temp gun. Room temp is 72f.

author: snipe
author_rank: Newbie
timestamp: March 09, 2021, 12:59:03 pm
content: I've run this lighting for 3 months and it's not bright enough.I'm not getting enough light to the plants at the bottom of my aquarium.I've been looking at the individually controlled LEDs on eBay. They can support 144 LEDs per metre instead of the 30 5050 LEDs per metre that I'm using.I spaced out my strip lights (1cm of strip light and 1cm of spacing). By not spacing, I can double the current output.I'm running 108w of LED so that would be 216w if I didn't space them.If I used IC LEDs at 144 LEDs per metre, I could light this x5.That's 216w x 5 = 1,080w.What on Earth would I need to buy to run this that I don't have already? 0_o

author: CJay
author_rank: Super Contributor
timestamp: March 09, 2021, 01:56:05 pm
content: Quote from: snipe on March 09, 2021, 12:59:03 pmThe rule of thumb for growing plants in an aquarium is around half a watt per litre (varies according to depth, type of plant)https://www.aquariumgardens.co.uk/lighting-guide-26-w.asp1080W is a *huge* aquarium, maybe take a step back and reconsider your LED and positioning choices.

author: snipe
author_rank: Newbie
timestamp: March 09, 2021, 02:26:43 pm
content: I'm dead set on 1,080w of RGB IC LEDs and would like advice on what I need to buy to run it please.It was easy before with no knowledge as I just bought the kit. There are no kits that I've seen on eBay for 30 metres of 144 LED per metre IC controlled strips.I'm not even using the IC feature. I just want 144 LEDs per meter