Tidy Board Rework Uses Flex PCBs, No Wires

December 17, 2019 by Donald Papp 26 Comments

PCB rework for the purpose of fixing unfortunate design problems tends to involve certain things: thin wires (probably blue) to taped or glued down components, and maybe some areas of scraped-off soldermask. What are not usually involved are flexible PCBs, but [Paul Bryson] shows us exactly how flex PCBs can be used to pull off tricky rework tasks.

It all started when [Paul] had a run of expensive PCBs with a repeated error; a design mistake that occurred in several places in the board. Fixing with a bunch of flying wires leading to some glued-on components just wasn’t his idea of tidy. A more attractive fix would be to make a small PCB that could be soldered in place of several of the ICs on the board, but this idea had a few problems: the space available into which to cram a fix wasn’t always the same, and the footprints of the ICs to be replaced were too small to accommodate a PCB with castellated mounting holes as pads anyway.

It’s about then that he got a visit from the Good Idea Fairy, recalling that fab houses have recently offered “flex” PCBs at a reasonable cost. By mounting the replacement parts on a flex PCB, the board-level connection could reside on the other end of an extension. Solder one end directly to the board, and the whole flexible thing could be bent around or under on a case-by-case basis, and secured in whatever way made sense. Soldering the pads of the flex board to the pads on the PCB was a bit tricky, but easy enough to pull off reliably with a bit of practice. A bonus was that the flex PCB is transparent, so solder bridges are easy to spot. He even mocked up a solution for QFP packages that allows easy pin access.

Flex PCBs being available to hobbyists and individuals brings out fresh ideas and new twists on old ones, which is why we held a Flexible PCB Design Contest earlier this year. Repairs were definitely represented as applications, but not to the extent that [Paul] has shown. Nice work!

Journey Through The Inner Workings Of A PCB

December 10, 2019 by Kerry Scharfglass 20 Comments

Most electronics we deal with day to day are comprised of circuit boards. No surprise there, right? But how do they work? This might seem like a simple question but we’ve all been in the place where those weird green or black sheets are little slices of magic. [Teddy Tablante] at Branch Eduction put together a lovingly crafted ~~walkthrough~~ flythrough video of how PCB(A)s work that’s definitely worth your time.

[Teddy]’s video focuses on unraveling the mysteries of the PCBA by peeling back the layers of a smartphone. Starting from the full assembly he separates components from circuit board and descends from there, highlighting the manufacturing methods and purpose behind what you see.

What really stands out here is the animation; at each step [Teddy] has modeled the relevant components and rendered them on the PCBA in 3D. Instead of relying solely on hard to understand blurry X-ray images and 2D scans of PCBAs he illustrates their relationships in space, an especially important element in understanding what’s going on underneath the solder mask. Even if you think you know it all we bet there’s a pearl of knowledge to discover; this writer learned that VIA is an acronym!

If you don’t like clicking links you can find the video embedded after the break. Credit to friend of the Hackaday [Mike Harrison] for acting as the best recommendation algorithm and finding this gem.

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Drive A Plasma Ball With An ATV Ignition Coil And A 555

December 9, 2019 by Gerrit Coetzee 7 Comments

[Discrete Electronics Guy] sends in his short tutorial on building a high voltage power supply from simple things.

The circuit is a classic, but we love the resourcefulness shown. The ignition coil comes from a three wheeler, the primary power supply is a ATX supply from a computer and the oscillator is powered by a 9V battery. We do wonder whose vehicle stopped working though.

He gives a great explanation of how the circuit works and was constructed and then moves on to build his own Plasma bulb. Despite expecting something more complicated the end result was achieved by putting a lightbulb on a stick. Fantastic. The circuitry was nearly packaged into a takeaway food container and the entire construction was called complete.

All in all it shows what someone can accomplish if they’re resourceful and understand the basics. However, it’s probably that you don’t electroBoom yourself to death if you can avoid it.

Secret C64 Program Found On A Christian Rock Band’s Vinyl Record

November 24, 2019 by Sharon Lin 29 Comments

How often do you find Easter eggs in old vinyl records?

It sure was a surprise for [Robin Harbron] when he learned about a Commodore 64 program hidden on one of the sides of a record from the 1985 album of Christian rock band Prodigal. The host of the YouTube channel 8-Bit Show and Tell shows the “C-64” etching on one side of the vinyl, which he picked up after finding out online that the record contained the hidden program.

The run-out groove on records is typically an endless groove that keeps the record player from running off the record (unless there is an auto-return feature, which just replays the record). On side one of the vinyl, the run-out groove looks normal, but on side two, it’s a little thicker and contains some hidden audio. Recording the audio onto a cassette and loading it onto a dataset reveals a short C64 program.

The process is a little more troublesome that that, but after a few tries [Harbron] reveals a secret message, courtesy of Albert Einstein and Jesus Christ. It’s not the most impressive program ever written, but it’s pretty cool that programmers 35 years ago were able to fit it into only a few seconds of audio.

Unfortunately, we won’t be hearing much actual music from the album – [Harbron] chose not to play the songs to avoid copyright issues on YouTube.

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Ramen Pen Lets You Doodle With Noodles

November 6, 2019 by Kristina Panos 25 Comments

Don’t write off your weird ideas — turn them into reality. For years, woodworkers have used pen bodies as a canvas for showing off beautiful wood. But what’s the fun in that? [JPayneWoodworking] made a pen out of Ramen noodles just to see if he could.

The process is pretty straightforward, as he explains in the build video after the break. He hammered the uncooked noodle mass into pieces small enough to fit a pen blank mold, but not so small that they’re unrecognizable. Then he poured in pigmented epoxy in orange, silver, and black. [JPayneWoodworking] chose those colors for Halloween, but rather than looking freaky, we think it makes the pen look like a bowl of beef broth-y goodness from a fancy Ramen place.

After adding the ~~flavor packet~~ pigments, he put it in a pressure tank to remove all air pockets. Once it sets up, the process is the same as any other pen blank — take it for a spin on the lathe, polish it up, ream it out, and fit it with the parts from a pen kit. We’d like to see the look on the face of the next person to ask [JPayneWoodworking] for a pen.

Want to get into woodworking just to make weird stuff like this? We don’t blame you. But how does a hardware hacker such as yourself get started? [Dan Maloney]’s got you covered.

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Downdraft Device Dismisses Dust

November 4, 2019 by Kristina Panos 9 Comments

Woodworking is messy business, especially the sanding part. But even if you don’t care what happens to your shop floor, you don’t want dead tree particulate matter in your lungs. Wearing a mask or even a respirator is a good start, but a dust collection system is better. Someday, [XYZ Create] might have a shop-wide sawdust-slurper installed. In the meantime, he made a downdraft table out of scrap plywood and a plastic storage box.

The only thing he didn’t already have on hand was a port that matched his shop vacuum. We like his workaround to avoid drilling a huge hole in plastic that would certainly crack — use a hose clamp to get the OD of the port, heat up the clamp on a hot plate, and let it melt a hole into the box. Hopefully, he at least opened a window. [XYZ Create] glued four pieces of scrap plywood together for the top, and drilled all 117 holes by hand. Who needs pegboard?

Not fancy or big enough for your needs? Here’s one with a built-in filtration system.

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Peep These Ultra-Real 3D-Printed Eyeballs

October 29, 2019 by Kristina Panos 10 Comments

For humans, life is in the eyes. Same deal with automatons. The more realistic the eyes, the more lifelike (and potentially disturbing) the automaton is. [lkkalebob] knows this. [lkkalebob] is so dedicated to ocular realism in his ultra-real eyeballs that he’s perfected a way to make the minuscule veins from a whisper of cotton thread.

First he prints an eyeball blank out of ABS. Why ABS, you ask? It has a semi-translucence that makes it look that much more real. Also, it’s easier to sand than PLA. After vigorous sanding, it’s time to paint the iris and the apply the veins. [lkkalebob] shaves strands of lint from red cotton thread and applies it with tweezers to smears of super glue.

Here comes our favorite part. To make the whole process easier, [lkkalebob] designed a jig system that takes the eyeballs all the way through the stages of fabrication and into the sockets of the automaton. The hollow eye cups pressure fit on to prongs that hold it in place. This also gives the eyeball a shaft that can be chucked into a drill for easy airbrushing. In the build video after the break, he uses the eye-jig to cast a silicone mold, which he then uses to seal the eyes in resin.