Tech In Plain Sight: Incandescent Bulbs

While they are dying out, you can still find incandescent bulbs. While these were once totally common, they’ve been largely replaced by LEDs and other lighting technology. However, you still see a number of them in special applications or older gear. If you are above a certain age, you might be surprised that youngsters may have never seen a standard incandescent lightbulb. Even so, the new bulbs are compatible with the old ones, so — mechanically, at least — the bulbs don’t look different on the outside.

You might have learned in school that Thomas Edison invented the light bulb, but the truth is much stranger (public domain)

It has been known for a long time that passing a current through a wire creates a glow. The problem is, the wire — the filament — would burn up quickly. The answer would be a combination of the right filament material and using an evacuated bulb to prevent the filament degrading. But it took over a century to get a commercially successful lightbulb.

We were all taught in school that Thomas Edison invented the light bulb, but the truth is much more complicated. You can go back to 1761 when Ebenezer Kinnersley first caused a wire to glow. Of course, wires would quickly burn up in the air. By the early 19th century, limelight was fairly common in theaters. Limelight — also known as the Drummond light — heated a piece of calcium oxide using a gas torch — not electric, but technically incandescence. Ships at sea and forts in the U.S. Civil War used limelights to illuminate targets and, supposedly, to blind enemy troops at night. Check out the video below to see what a limelight looks like.

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OpenWRT, But On An Unsupported Router

Everyone likes something cheap, and when that cheap thing is a router that’s supported by OpenWRT, it sounds like a win. [Hennung Paul] ordered a Wavlink WL-WN586X3 for the princely sum of 39 Euros, but was disappointed to find his device a rev. 2 board rather than the rev.1 board supported by the Linux distribution. Toss it on the failed projects pile and move on? Not at all, he hacked together a working OpenWRT for the device.

It’s fair to say that a majority of Hackaday readers will  have familiarity with Linux, but that’s something which runs on a sliding scale from “Uses Ubuntu a bit” all the way to “Is at one with the kernel”. We’d rate ourselves somewhere around halfway along that scale in terms of having an in-depth knowledge of userland and a working knowledge of some of the internals which make the operating system tick even if we’re apprehensive about tinkering at that level. [Henning] has no such  limitations, and proceeds to take the manufacturer’s distribution, itself a heavily modified OpenWRT, and make it his own. Booting over tFTP we’re used to, and we’re particularly impressed to see him using a Raspberry Pi as a surrogate host for the desoldered Flash chip over SPI.

It’s a long path he takes to get the thing working and we’re not sure we could follow it all, but we hope that the result will be a new device added to OpenWRT’s already extensive support list. It’s sometimes a shock to find this distro is now over two decades old.

Open Source Lemontron 3D Printer Is Ready To Build

In this era of cheap turn-key machines, the idea of actually building your own desktop 3D printer might seem odd to some. But if you’re looking for a challenge, and want to end up with a printer that legitimately sets itself apart from what they’re stocking on Amazon these days, then take a look at the Lemontron.

We’ve been keeping tabs on the development of this open source 3D printer for some time now, and just before Christmas, the files finally were released for anyone who wants to try putting one together themselves. There’s currently no formal kit available, but once you’ve printed out all the parts, there’s a very nice bill of materials you can find on the website which will tell you everything you need to complete the assembly — and critically — where you can get it.

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