If you happen to be in the market for a small artificial sun, you may be interested to know that for about $1300, you can get a tennis-ball-sized LED array that outputs 120,000 lumens.
How much is 120,000 lumens? Well, it’s a lot—systems of an equivalent brightness are generally sold as parking lot lights, and your average domestic light bulb only produces somewhere in the region of 1000 lumens. (As an aside: if lumens are an unfamiliar metric, they’re a measure of luminous flux—or, in less technical terms, a measure of how much light is generated by the light source you’re measuring. Confusingly, old-style incandescent light bulbs used to be rated in Watts. Incandescent bulbs that generated 1000 lumens were rated somewhere between 90W and 120W. Today’s LED versions use a lot less power to achieve the same brightness.)
So this is clearly a very, very bright light. The only problem is that creating this much light also requires a lot of power—the array draws up to 1.5 kW—and generates a load of heat. YouTuber Matthew Perks sets out to address the latter problem in a new video on his channel DIY Perks. The video catalogues his attempt to build a cooling system for the LED array, one that cools the light effectively enough to allow sustained operation while also remaining relatively portable.
He settles on a hexagonal water-cooling system based around a central coolant reservoir. The hexagonal design allows the reservoir to double as a cooling system for the LED’s six voltage regulator boards, each of which is thermally coupled to the reservoir’s exterior. The LED itself, meanwhile, is mounted on a custom-built water block. From the reservoir, the water flows through this block and then into one of six large copper radiators, each of which is cooled by three PC fans.
The LED array is powered by a portable lithium battery, which also powers some on-board electronics: sensors to monitor the coolant flow rate and temperature, along with an Arduino to monitor them. The final touches are two lenses to focus the LED’s light.
Once the first lens is on, Perks is delighted to see that the light is powerful enough on its own to light a single match. Now, if you’ve spent the last decade watching YouTube legend Styropyro—yes, he of the 400 car batteries—setting fire to things with lasers, this might seem underwhelming, but it’s still pretty wild. As Perks explains, while the system generates plenty of heat, the LED itself outputs virtually no infra-red light, so it’s just the sheer overwhelming amount of visible light that generates enough heat to light the match.
Anyway, once that little experiment is done, Perks attaches the second lens and takes the finished device, which looks not unlike an oversized steampunk CPU cooler, out into the forest to confuse the local wildlife. Happily, the finished design works a treat. If anything, it’s the battery that looks like being a problem: it dies after 15 minutes, but before it does, its internal temperature is starting to get alarmingly high. The LED’s temperature, meanwhile, remains within safe operating margins, which is a pretty impressive result for a home-built cooling system.
And if that’s not a big enough vote of confidence, then there’s also this: one of the most popular comments is from, yes, Styropyro, who is no stranger to absurdly powerful lights himself and who says, “This is an incredibly well done light!” Game recognize game, and all that.
