I've spent the last month testing and demolishing a bunch of new-design thermal PCBs from SinkPAD, and have come to the conclusion that this is a solid solution versus traditional dielectric PCBs commonly used for mounting LEDs. There are many pros, and a few cons, and I will address these in my review of their product, written below.

We will start with the good stuff first, the Pros. The SinkPAD Direct Thermal Pathway PCB is made from solid aluminum or copper (as of the time of this writing I had yet to test any copper PCB), so it's very good at thermal transfer. This helps make it easy to solder; versus a traditional dielectric board, the solder took to the SinkPAD in roughly half the time. This also comes in handy for reflow work and rework, as mounting and un-mounting an LED from the board is quick thanks to the PCB being constructed out of high-conductivity aluminum and copper. Repairing any mistakes takes minimal time and effort, a must for any prototype designer or hobbyist. The solder resist is also very solid, during my reflow cycling test I never once saw a solder bridge form, nor had any shorts. The same solder resist is quite durable against thermal shock as well. I torched it until it was smoking and crackling, near-black, and with no problems I was able to mount an LED to it and light it right up, and the remainder of the pad transferred heat exactly as it should. This durability is exactly what the military and police forces could use for LED-assisted weapons solutions, such as barrel or grip-mounted lights, or IR night-vision equipment. The aluminum boards are light-weight and stiff, very difficult to bend, even with a pair of clamps and pliers and my full weight applied.

Now for the cons. Due to how the thermal pathway is manufactured, there's an indentation on the back of the board. This means you need to use more thermal paste/epoxy, and you need to be more careful not to introduce air bubbles and gaps. On the aluminum boards, there is no solder pad on the back side, which would help greatly since solders tend to be more conductive than thermal pastes and adhesives. The copper board likely wouldn't need it, since copper is easy to solder. Speaking of copper, there are a distinct lack of copper options for many of their PCB choices. While this is understandable (many of these LEDs simply don't need it) the ability to have broader choice in materials would be nice. My final bad note is the difference between prototype boards I have versus some of the production boards. An older X-Lamp XR-E board had four screw holes for improved mounting, and they were placed so that most screws that could fit those holes would not have the heads short out on the contact pads. These holes are nonexistent on the star and disc boards. The star have their electrical contact points too close to the indents at the outside to allow screws to be attached there, but the circular boards look like they might have a better chance.

Overall, this is a solid piece of thermal management tech for LEDs. The ease of use and durability should appeal to a wide variety of LED consumers, from hobbyists, designers, and engineers to police, military, and even more groups of people and industries. Most of the cons are personal nitpicks and aren't exactly game-breaking important, and the pros certainly outweigh any con I've been able to notice. Highly recommended.

I finally put the MK-R to its first official use (and quite possibly its only use!)

Both now serve as the lighting for my freebie fish tank I acquired earlier today.

HD video of it in action.

36w, 18w per diode. Overdriven and still going strong.

I finally got the right boards personally delivered to me. It was quite funny, exchanging tiny baggies of what any person at least ten feet away would assume were drugs right in the middle of a Del Taco parking lot. Then watching an accident happen not fifteen feet from us, between bicyclist and car.

Anyways, I just shot a little run of the MK-R, both of them, driven at 18w each. Note how they obliterate the Cree XR-E to the left, driven at 1.2-1.3w or so (3.7V rated Vf @ 350mA.)

I'm going to go step outside to get a night shot. Updates later in this journal post, in the comments.

Finally got around to doing a night test of the MK-R.

I went out onto my patio, and put it right beside my 100w incan that typically lights the porch.

And here's the result. As you can see, absolutely no contest. Fluoro equivalent to 100w incan is a ~26w bulb, so we're looking at around 25% the power consumption of an equivalent CFL (LED driven at 6w) and way, way more light.

Still unable to drive full power. SinkPad mistakenly sent me XM-L boards, not MK-R.

I managed to get some engineering samples of the Cree MKR LED announced on /. a couple weeks or so back.

Needless to say, I was thoroughly impressed. I ran 12V @ 200mA, 500mA, and 1250mA. You know how us geeks/nerds say do not look into laser with remaining eye? You don't HAVE any eyes left with the new MK-R, even at a measly 200mA of direct current at 12V. At 1250 mA, I only needed half a second before the diode packaging began to melt the green PCB, the heatsink was absolutely ineffective. Be prepared to use metal SMD-mount boards for these diodes, because that cheap green board used for most SMD LEDs simply will not cut it. Pushing 15w in a 7mm x 7mm package, you need serious heat dissipation capabilities. Also, DO NOT HOLD THE DIODE WHEN DRIVING AT 200mA! You will blister yourself.

I no longer have my light meter, as I would use that to check flux levels and lumen levels, but needless to say, you drop a quad of very-efficient nearly 4-watt diodes into a single tight array like this, and the world is going to light up before your eyes. I would love to see one of these in a Mag-Lite. At 200mA, 500mA, and 1250mA, you would have all the light you need. Remember that commercial where the kids with the flashlight are using new Energizer batteries and it looks like they're suddenly using a 1,000,000 candlepower light? It's even better than that.

Just one of these would light up my entire 15' x 24' living room, quite possibly more, with wonderful light levels. I could see this sitting in the center of my ceiling. Two bedrooms, two bathrooms, living room, kitchen, dining room. Seven rooms, 105w operating power with all in operation. I could leave my whole home lit up for the same cost of a single 100w incandescent light bulb, which barely lights one room. Oh wait, I forgot the porch and patio. Make that 135w operating power. And in reality, even at 500mA drive current, I think that's more than enough light for an area roughly 25' x 25'. Still beating the pants off of equivalent incandescent or fluorescent. It's the end of them, and I already have the belief that these will truly smash HID systems.

I want single-color versions of these. Cree, if you're reading/listening, you have technology in your hands right now to take over an entire segment of the optoelectronic market. You dropped out of said market (and a couple of others) when you quit making 660nm diodes, and you could really take this class of diode to great heights if you could specialize single-wavelength versions of this.

So I just popped 175K on my '98 Taurus. I'm quite pleased with this vehicle. The AC is dead, and I've only had to replace the transmission once at 125K, when the planetary gear chewed itself to shit going to Washington back in 2008.

Any other gearheads reading this journal? What're you driving, and what're you pushing mileage-wise?

Took me a while, but after more careful digging, I've figured out what is happening. Last.fm is indeed lying. They are not listening to your media players. They are listening to your sound card output. Disabling sounds in Skype will disable every Skype event log except for two - updates to mood/music playing, and any time you make a skype call. Those to events trigger Last.fm logging. In the log, there's no real identifying information. What can be gleaned, though, is how long you made that call.

"If you choose to download the Last.fm software, it will monitor all the music you listen to on your computer (even if you are not online). It will then send this information to Last.fm via Audioscrobbler. This information will then be integrated into Last.fm to enhance the depth of your record collection and the accuracy of your profile.

The Last.fm software cannot and will not collect and transfer any other information from your computer other than as described above."

That is a flat-out LIE. And you're not even told about the integration with Skype when you install Last.fm's Audioscrobbler. You have to find out yourself by looking through log files, or go back to an obscure 2006 Skype Blog post.

This was most fun!

That'll teach me to cut my nails too short!

After a little tiff with some angry man over on Reddit, I had to go conduct a few experiments of my own regarding the effectiveness of green light on photosynthesis.

To get to the meat of it all, between ~450 - 1800 umol, green light tends to drive photosynthesis more efficiently than red and blue light, especially in plants with much thicker leaves, like actual trees, succulents, cacti, etc. A tiny bit higher than 1800 umol, and your ROI drops rapidly as you've pretty much hit saturation of the chloroplasts, for all ranges of light. The law of Diminishing Returns comes to bite us in the butt, and no wavelength is ultimately more efficient than any other, and in fact, you begin reaching damaging levels of photon saturation which can burn a plant.

Now, there are multiple food crops that have an optimal light requirement below 500 umol. Multiple types of lettuce grow very well with ~200 umol, for an example. For that purpose, LED lights using red and blue light do well more than simply suffice. For rooting cuttings, red and blue light works very well. Fruiting plants typically require much more light, Jalapenos like it around 1500 umol. I've grown nice-sized jalapenos, bigger than what I'll find in most supermarkets, under a red and blue only panel, but I suspect I might be able to do a bit better with some focused green light. I'll do that when I get one made with equivalent specs.

Of course, getting to that intensity for larger plants will likely require me going solid white with a carefully-tuned color temperature. I have seen units now that on equal power draw with their HID counterparts are beating them by roughly 20%. However, these still require either EXTREMELY LARGE or very exotic cooling systems for anything over 300w and in a reasonably small package, and are not totally feasible for either green house or consumer gardening, this will likely be stuck in the parking light/street light arena for a while.

I have seen the benefits of green light, but there isn't MUCH additional benefit versus splitting up into different LED modules so you can get the light deeper into the canopy with the red/blue units. Perhaps for those doing bonsai, or growing cacti, and possibly underwater corals/plants, there is a good use, I can see it. Well, at least I'm sure of why an HPS works rather well despite having a very 'poor' spectral output. It's more than just the 660-680nm + IR that it dumps in massive quantities, it is also the green light having its own effective role.

Kinda goes totally against the conventional knowledge that red and blue are the most efficient, eh?

So Jorge Cervantes did a Reddit AMA. And he went on to say LED is not as good as CFL or HID.

As you see in the response to that post, I didn't let that slide, at all.

Don't dare talk shit about my profession when you're totally uninformed about the subject.

http://www.youtube.com/watch?v=9ZTikdxj8AI&feature=youtu.be

Finally, I have a copy of the video from the filming session done at the end of last year. Sorry that took so long to acquire!

It was great getting to watch (albeit remotely) the filming session.
Got any questions?

Trying to figure out a way to go modular. I think the company I'm working with has a piece that I could modify into a modular plug and play system for my horticultural panels, so I can simply warranty repair with a swap out. It is going to take a fair amount of modification, however.

http://i.imgur.com/kGmNh.jpg

http://i.imgur.com/tY6C5.jpg

Can't show much more than that, unfortunately.

Looks like my tech is gaining some attention - the BBC's program "CountryFile" will be at the UK facilities for filming Monday.

This should be rather interesting. Shame I'm here in the USA - I guess I'll have to settle for a mere mention on the program instead of being physically present to explain things.

So my side porn shop job has these LED-lit display cases for Lelo vibrators. Of course, being an LED nut, I pay more attention to those cases than I really should.

That paid off. A couple of weeks ago, I had noticed issues with the display cases flickering on occasion. Yesterday, I could smell electronics burning, and my first instinct was to go check the Lelo Displays and their wall-wart power supplies.

At first touch, I got burned. So I kicked the warts out of the wall plug, waited a few minutes, and opened up the transformer housing.

This is what I saw.

The entire output side of the boards (bottom of the picture) are totally fucked. Resistors burned to a white ash, diodes burned black, capacitors bulged, transformer wrapping coming unglued from the heat.

Now, the design of the circuit is just fine, and the components appear to be quality. The major flaw I see is that this is 12V 1A being pushed down 20 feet of thin thin copper wire (WITH insulation, the wires are about 1mm thick.) DC hates being pushed any considerable distance (exception being HVDC) and this leads me to believe these power supplies were inadequately tested. We tried powering 6 meters of LED strips on DC back at the research facility in the UK, we measured 23.6V input at the beginning of the chain and 10V at the end, causing huge resistive losses and making heat sinks almost intolerably hot to touch. Lesson learned, don't drive DC power down any long length of wire, especially low voltage DC. I believe this is what caused the failure in these power supplies, and the fact that the failures are in the same area (on the DC output side of the board, essentially) would give extra strength to my theory.

That porn store should be happy they have me. I just saved them from a potentially expensive fire.