Multi-way Capacitor Replacement Without The Pain

Anyone who’s worked with older tube-based equipment will be familiar with the type of vintage electrolytic capacitor which integrated several capacitors into one can. Long obsolete, they can be bought as reproduction, but unfortunately at an eye-watering price. [D-Lab Electronics] introduces us to a solution using a very useful kit, that it’s worth sharing.

The piece of equipment in the video below the break is a rather lovely Heathkit oscillator, following the familiar phase shift model with a light bulb in its feedback loop. It’s a piece of test equipment that produces a low-distortion sine wave output, and would still be of use to an audio engineer today. He replaces the capacitor with two modern ones on a multi-cap board from [W8AOR], who sells a variety of these kits for different configurations.

We’ve done this very repair more than once, and it has usually involved wiring, heatshrink sleeving, hot glue, and cable ties, looking very messy indeed. It’s not that often that a kit catches our eye as this one has, but we know we’ll be finding it useful here some time in the future. Meanwhile if you’d like to know why this oscillator has a light bulb, take a look at our piece on distortion.

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Navigate Burning Man With Ease With This Custom Tool

When setting up a city in the desert, the team behind Burning Man does its best to lay things out in an ordered fashion. Even still, getting around at ground level can be a challenge at times, and it’s easy to get lost. To help get around easier, [Zach] developed a nifty GPS device built specifically for navigating the ephemeral clock-like city.

The device is built for a few simple purposes. It shows where you are, it helps you navigate somewhere you’ve been before, and it helps you navigate to portable toilets. It’s set up to be usable both on bike and on foot, the typical ways of getting around the playa. Since Black Rock City is fairly simple, it uses an arrow to point to a desired waypoint, and is capable of storing up to five points of interest. It’s built using a cheap GNSS receiver and transflective LCD screen, and a Pi Pico is the brains of the operation.

The value of the device is obvious, particularly when exploring deeper areas of the playa, or after the road signs have been removed or structures have been taken down or burnt to ashes. We’ve seen some other great projects from the desert festival before, too. If you’ve got your own playa-spec hacks, don’t hesitate to let us know!

Eliminate That Pesky Power-Only USB Cable With This Cable Tester

Ever wondered why your Arduino wasn’t programming, only to find out that the cable doesn’t have any data conductors? Worry not, [Spencer Maroukis] has got you covered with the USB Sleuth Cable Tester!

The cable tester is a beautiful black circular PCB, with USB ports of nearly every type on the edges. It works partially through passive detection with LEDs and otherwise through active detection of things like the orientation with an STM32 powered by a coin cell battery. But it gets better: There are disconnect switches and exposed pads to test some of the conductors with a digital multimeter!

It may not be necessary for all of us, but one thing is clear: When you needed a good USB cable, you wished you had this to actually test it. The design is open-source too, which is definitely nice if you want one for yourself.

Meanwhile this isn’t the first USB cable tester we’ve seen here.

A Concrete Solution To Balance And Protect Camera Gear

Knocking over expensive camera equipment is an unfortunate occupational hazard when filming projects in a workshop. [Dane Kouttron] wanted to stop sacrificing lights to the cause, so he came up with a practical use for a weeble: A self-stabilizing monopod.

Inspired by a giant scale weeble built by [Colin Furze], [Dane] first did the math to determine the parameters for the build. It’s all about achieving torque equilibrium with a hemisphere of concrete, and [Dane] walks us through the equations, arriving at the conclusion that a 2 lb. camera on 4 foot pole, one needs a hemisphere with a mass of 28 lbs. and a radius of just under 4 inches. To achieve this weight in the given volume would require extra dense concrete with steel shot added.

After some CAD work and 3D printing the 4-part mold was assembled, with RTV silicone sealant acting as both adhesive between the parts and mold release agent. [Dane] first did a test mold with concrete he had laying around. With success achieved, he pursued the real mix but had issues with an error in the concrete-water ratio and the difficulty of mixing in the steel shot. On the second attempt he managed to extract a functional hemisphere from the mold, with the pole held in position during curing by a 3D printed bracket.

The hemisphere bottom of the hemisphere has a flat spot to keep it stable when bumped lightly. [Dane] added a Manfroto quick-release mount to the end of the pole to allow easy attachment of lights and cameras. It might be a bit hefty to carry around, but it’s takes up less floor space than a tripod and is sure to save [Dane] from expensive bumps-turned-crashes.

Camera cranes, small and large, are another great tool for workshop cinematography. For sheer overkill it would be hard to beat an 8-axis workshop-sized motion control robot.

Robot Can Read Braille Much Faster Than Humans With New Sensor

Braille is a method of physical writing used to allow humans to read by touch — most commonly used as a substitute for printed text by those who may be visually impaired. Both displaying Braille and reading it is difficult to do with machines, but there has been a development in the latter area. A research team has trained a robot to read Braille at a speed far exceeding humans.

The robot was developed by a team at the University of Cambridge. Rather than trying to read Braille by touch, it instead uses a camera and an image recognition algorithm to do the job. Their solution is a bit ironic in a way, given the purpose Braille was created for. The robot can quickly sweep across a Braille display, working at a rate of up to 315 words per minute at 87% accuracy. That’s roughly twice as fast as a human reading Braille, with a similar level of accuracy. Some nifty de-blurring algorithms were needed to achieve this speed from the camera’s video feed.

We’ve also seen some impressive development on the other side of all those little bumps, with two Braille devices taking home awards during the final Hackaday Prize in 2023.
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Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean

Polynesian cultures have a remarkable navigational tradition. It stands as a testament to human ingenuity and an intimate understanding of nature. Where Western cultures developed maps and tools to plot courses around the world, the Polynesian tradition is more about using human senses and pattern-finding skills to figure out where one is, and where one might be going.

Today, we’ll delve into the unique techniques of Polynesian navigation, exploring how keen observation of the natural world enabled pioneers to roam far and wide across the breadth of the Pacific.

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Flat-Pack Multi-Tool Has Many Dimensions

Sometimes, you just have to see whether something can be done. Such is the case with [ToolTechGeek]’s flat-pack metal multi-tool build. Can an entire multi-tool be made with only flat pieces of laser-cut metal and fasteners? It would seem so, yes. And quite nicely, too, as you’ll see in the video after the break.

[ToolTechGeek] started by designing all the parts in Inkscape, and then made a few 3D printed versions to check fitment before committing to laser-cut metal. Once they had the pieces cut, everything came together nicely except for a few tabs that connect some of the parts together. These just had to be filed down a bit.

So now, [ToolTechGeek] has a handy set of pliers, flat- and Phillips-head screwdrivers, a knife, and a bottle opener all in one place. Although the pliers don’t have teeth, they still do a fine job of removing nuts and the like. Be sure to check out the final product and see it get put to the test.

No use for such a thing? Maybe you’d prefer an NFC multi-tool.

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