[Steven] had one of those musical gift cards laying around, and thought he might as well reuse the piezo speaker inside it. Without a particular project in mind, he soldered an LED to the piezo and tapped on it, which caused the LED to illuminate as expected. He started to wonder what quantity of force would be required to light the LED, and if it could be done by a raindrop.
He first tested his theory in the shower, and as you can see in the video below it actually worked, though the light was dim and sporadic as you might imagine. He eventually discovered that for optimal lighting, the piezo worked best when struck by single droplets falling with pauses in between, from a minimum height of 4 feet. To achieve a water flow within those specifications, he built a rain funnel so that he can control the droplet frequency and intensity.
It seems to work pretty well from what we can see. Off the top of our heads we can’t seem to come up with any practical applications of the water powered LED, but it is an interesting set of experiments nonetheless.
Have an idea to use this setup that we totally missed? Let us know in the comments!
Here’s a Blade Runner umbrella build that is done just a little bit too right. It delivers a double-dose of geekery with its lightsaber-gone-rain-protector look but where we think it crosses the line is at the built-in audio system. When you turn it on it plays recordings of popular lines from Blade Runner, something that might not fly in public. But the quality is in a different galaxy compared to the dollar store illuminated umbrella that we looked at last year.
[Erv’ Plecter] replaced the central support rod for the umbrella with a clear polycarbonate tube. An optic cable snakes through the hollow tube, illuminated by a Luxeon LED in the handle. The custom PCB and 900 mAh battery are both housed there as well. Take a look at (and listen to) the demo after the break. We’ll need to add this to our future projects list right after that Lightsaber movie replica build.
[Adam] wanted a stereo that could stand up to rain and keep sand out. He ended up building this beach stereo out of a cooler. The cooler’s already made to be water tight. He cut holes in the front and back for marine speakers and added a water-tight bezel and cover for the controls on the deck. Inside you’ll find a marine battery to power the unit. Now he and his friends can rock-out even in poor weather thanks to this portable and rugged unit.
[andrew] sent us this proof of concept. Based off of the Spiech Clear view screen, used in marine applications, it uses a spinning disk to keep a part of your vision free of water droplets. While you may not be too impressed by watching the video initially, keep in mind that this was a quick prototype. With some planning and a little work, this could be moved to a more convenient location and run by a side mounted motor. It could even be made to be removable for fair weather. It probably doesn’t do so well with mud though.