Superflux (piranha/UFO/etc) LEDs - Page 1
Forum section: electronics / projects

author: richard.cs
author_rank: Super Contributor
timestamp: March 10, 2015, 11:38:05 am
content: Hi All,I'm thinking of making up some floodlights with Big Clive's boardshttp://bigclive.com/flud.htmDoes anyone have any reccomendations for LED suppliers? I'm looking for a sensible balance between price and quality, the very cheapest on ebay are presumably awful (experiences anyone?) but I'm going for bulk light output so neither the last few % of efficiency or perfect reliability are that important to me. I'm after a few hundred in white, lead times are unimportant.Or have these been superceeded anyway, might I be better buying a few reels of LED strip and sticking it to an aluminium plate? I've made a few lights like that and the results are fairly impressive but I quite like the form factor of the floodlight PCBs.

author: Kjelt
author_rank: Super Contributor
timestamp: March 10, 2015, 12:04:20 pm
content: If you keep the current for the leds below around 200mA (so +/- 500mW each) you do not have to use aluminium pcb as long as you get rid of the heat somehow (so IP66 enclosures for outdoor will be a small problem unless the enclosure can radiate a bit of heat itself).The current generation of T8 ledtubes use standard pcbs with max 200mA current (medium power leds).Power leds >1W need aluminium heatplate and cooling.

author: mark03
author_rank: Frequent Contributor
timestamp: March 10, 2015, 03:16:43 pm
content: IMO the problem with the "Pirahna"-style LEDs is that there is almost no industrial use for them anymore---everyone moved on to surface-mount parts a long time ago. Because the remaining market is principally hobbyists, the available offerings are going to be dominated by cheap crap or worse. I am sure good parts are out there, but you may have trouble finding them.Solution: Use surface-mount parts from a reputable supplier. Using parts that the major players are still spec'ing in huge quantities offers you a certain amount of protection.

author: richard.cs
author_rank: Super Contributor
timestamp: March 10, 2015, 04:06:40 pm
content: Quote from: mark03 on March 10, 2015, 03:16:43 pmPoint taken. The only reason I'm after that style is because I can buy for low cost (£3 each, £2 postage) a PCB in a form factor convinient to me. I could of course spin my own to take 3528 smt LEDs but that is considerably more effort. I'll not rule it out though, it seems do-able as a fairly simple 1-layer board.

author: DanielS
author_rank: Frequent Contributor
timestamp: March 10, 2015, 05:07:56 pm
content: Quote from: richard.cs on March 10, 2015, 04:06:40 pmI would still consider going double layer for a LED PCB of non-trivial power simply to use the top (or bottom) layer's ground plane as a heat sink/spreader.

author: sleemanj
author_rank: Super Contributor
timestamp: March 10, 2015, 10:40:52 pm
content: Quote from: mark03 on March 10, 2015, 03:16:43 pmIf my own sales of them are anything to go by, even hobbiests have little use for them.Every couple of months somebody will want 10, invariably in a mix of colours, and invariably, they never come back for more.I think that they might still be used in some automotive brake lights maybe.

author: Corporate666
author_rank: Unknown
timestamp: March 11, 2015, 02:22:42 am
content: I used to use tens of thousands of these LED's...The ones to go for are the Cree, CP44 I think the product # is. They are significantly brighter than competing parts and competitively priced. Not sure if they do white, I'm guessing so, I've used the red and yellow.I don't like that PCB at all. It's a mistake to think that just because an LED is through hole, that it doesn't require any heat sinking or that it can be densely packed into an array in an enclosed housing.I have a PCB with about the same density of those 7.62mm LED's and it gets *hot* and must be mounted onto an aluminum heat sink to be able to run continuously.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 11, 2015, 02:44:59 am
content: Why don't you consider the direct-to-heatsink types, like ebay 390876125031 ?Even the lowly 10W ones are far too bright to look at directly.

author: Corporate666
author_rank: Unknown
timestamp: March 11, 2015, 04:38:24 am
content: Just checked - the white part from Cree is CP41B.They come in 60 and 90 degree versions - Verical has them at $0.20/ea.

author: Kjelt
author_rank: Super Contributor
timestamp: March 11, 2015, 08:33:32 am
content: I would go for smt it is the way to go, leds are cheaper and get the R&D momentum at the moment sp future safe, and you can make it on a one sided pcb so you can stick the other side to any housing or cooling plate if you wish.