Using Industrial CT To Examine A $129 USB Cable

October 24, 2023 by 79 Comments

What in the world could possibly justify charging $129 for a USB cable? And is such a cable any better than a $10 Amazon Basics cable?

To answer that question, [Jon Bruner] fired up an industrial CT scanner to look inside various cables (Nitter), with interesting results. It perhaps comes as little surprise that the premium cable is an Apple Thunderbolt 4 Pro USB-C cable, which sports 40 Gb/s transfer rates and can deliver 100 Watts of power to a device. And it turns out there’s a lot going on with this cable from an engineering and industrial design perspective. The connector shell has a very compact and extremely complex PCB assembly inside it, with a ton of SMD components and at least one BGA chip. The PCB itself is a marvel, with nine layers, a maze of blind and buried vias, and wiggle traces to balance propagation delays. The cable itself contains 20 wires, ten of which are shielded coax, and everything is firmly anchored to a stainless steel shell inside the plastic connector body.

By way of comparison, [Jon] also looked under the hood at more affordable alternatives. None were close to the same level of engineering as the Apple cable, ranging as they did from a tenth to a mere 1/32nd of the price. While none of the cables contained such a complex PCB, the Amazon Basics cable seemed the best of the bunch, with twelve wires, decent shielding, and a sturdy crimped strain relief. The other cables — well, when you’re buying a $3 cable, you get what you pay for. But does that make the Apple cable worth the expense? That’s for the buyer to decide, but at least now we know there’s something in there aside from Apple’s marketing hype.

We’ve seen these industrial CT scanners used by none other than [Ken Shirriff] and [Curious Marc] to reverse engineer Apollo-era artifacts. If you want a closer look at the instrument itself, check out the video below

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Game Graphics: Racing The Beam

October 24, 2023 by 15 Comments

Have you ever wondered how the graphics in your favorite video games worked? This is the start of a series on game graphics, and what better place to start than how exactly the original Mario Bros. got those glorious pixely pixels onto the screen. Buckle in, because we’re “racing the beam” with systems like the NES, Commodore 64, and many other classics from the 1980s.

And to understand the 1980’s, it’s important to understand how the televisions of the time worked. Cathode Ray Tube (CRT) televisions work by precisely bombarding a phosphor layer with electrons, which excites the phosphor, which then releases visible light. The beam scans from left to right then top to bottom, giving each pixel a small fraction of a second of time. All of this effectively means that pixel data needs be sent at the same time as when the pixels are being lit up, which is why this type of graphics is often dubbed “racing the beam”.

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Making Magnetic Tape From Scratch

October 24, 2023 by 34 Comments

The use of magnetic tape and other removable magnetic media is now on the wane, leading to scarcity in some cases where manufacture has ceased. Is it possible to produce new magnetic tape if you don’t happen to own a tape factory? [Nina Kallnina] took the effort to find out.

It’s probably one of those pieces of common knowledge, that magnetic media use iron oxides on their surface, which is the same as rust. But the reality is somewhat more complex, as there is more than one iron oxide. We follow [Nina] through this voyage of discovery in a Mastodon thread, as she tries first iron filings, the rust, and finally pure samples of the two iron oxides Fe3O4 and Fe2O3. She eventually achieves a working tape with a mixture of Fe2O3 and iron powder, though its performance doesn’t match manufactured tape. It turns out that there are two allotropes of Fe2O3, and she leaves us as she’s trying to make the one with better magnetic properties.

These results look promising, and while there is evidently a very long way to go before a home-made magnetic coating could replicate the exacting demands of for example a hard drive platter it’s evident that there is something in pursuing this path.

This may be the first time we’ve seen tape manufacture, but we’ve certainly seen extreme measures taken to rejuvenate old tapes.

Learning About Capacitors By Rolling Your Own Electrolytics

October 24, 2023 by 17 Comments

Ever wonder what’s inside an electrolytic capacitor? Many of us don’t, having had at least a partial glimpse inside after failure of the cap due to old age or crossed polarity. The rest of us will have to rely on this behind-the-scenes demo to find out what’s inside those little aluminum cans.

Perhaps unsurprisingly, it’s more aluminum, at least for the electrolytics [Denki Otaku] rolled himself at the Nippon Chemi-Con R&D labs. Interestingly, both the anode and cathode start as identical strips of aluminum foil preprocessed with proprietary solutions to remove any oils and existing oxide layers. The strips then undergo electrolytic acid etching to create pits to greatly increase their surface area. The anode strips then get anodized in a solution of ammonium adipate, an organic acid that creates a thin aluminum oxide layer on the strip. It’s this oxide layer that actually acts as the dielectric in electrolytic capacitors, not the paper separator between the anode and cathode strips.

Winding the foils together with the paper separator is pretty straightforward, but there are some neat tricks even at the non-production level demonstrated here. Attachment of lead wires to the foil is through a punch and crimp operation, and winding the paper-foil sandwich is actually quite fussy, at least when done manually. No details are given on the composition of the electrolyte other than it contains a solvent and an organic acid. [Denki] took this as an invitation to bring along his own electrolyte: a bottle of Coke. The little jelly rolls get impregnated with electrolyte under vacuum, put into aluminum cans, crimped closed, and covered with a heat-shrink sleeve. Under test, [Denki]’s hand-rolled caps performed very well. Even the Coke-filled caps more or less hit the spec on capacitance; sadly, their ESR was way out of whack compared to the conventional electrolyte.

There are plenty more details in the video below, although you’ll have to pardon the AI voiceover as it tries to decide how to say words like “anode” and “dielectric”; it’s a small price to pay for such an interesting video. It’s a much-appreciated look at an area of the industry that few of us get to see in detail.

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Light Guns Aren’t Just For CRTs Anymore

October 23, 2023 by 17 Comments

For how much of a cultural phenomenon light gun games like Duck Hunt were, they didn’t survive the transition from CRT televisions to LCDs particularly well because of all of the technological quirks the light guns exploited in older technology that simply disappeared with modern TVs. But it’s not impossible to get a similar gameplay from modern technology as evidenced by the success of the Wii and its revolutionary Wiimote, and there are plenty of modern games that use similar devices. There are a few paths to getting older light guns working again, though.

The first system to note, called SAMCO, uses a system of LEDs and a camera to synchronize the game’s flashes to the new technology and translate the input back into the game. Gun4ir uses a similar technique, and boasts extremely high accuracy and low latency largely due to being programmed in assembly. Both systems can use either an infrared tracking sensor or a Wiimote sensor as the LEDs and while the SAMCO system can run on a Raspberry Pi Pico, Gun4ir exclusively uses ATmega32U4 boards with the optimized assembly programming.

Both SAMCO and Gun4ir offer PCBs for anyone looking to try them out without designing their own circuit boards, and once the electronics are assembled they can either be put in an original NES-era light gun, put in a custom printed enclosure, or even stuffed into a Nerf gun. For others looking for a more turnkey solution, there are also offerings from companies like Sinden which make complete system. You can always build your own system to restore the functionality of original light guns from scratch if that’s more your style.

Thanks to [LookAtDaShinyShiny] for tipping us off to the latest happenings in the light gun community!

Photo courtesy of Wikimedia Commons

The IMac GPU Becomes Upgradeable, With PCIe

October 23, 2023 by 11 Comments

Over its long lifetime, the Apple iMac all-in-one computer has morphed from the early CRT models through those odd table-lamp machines into today’s beautiful sleek affairs. They look pretty, but is there anything that can be done to upgrade them? Maybe not today’s ones, but the models from the mid-2000s can be given some surprising new life. [LowEndMac] have featured a 2006 24″ model that’s received a much more powerful GPU, something we’d have thought to be impossible.

The iMacs from that era resemble a monitor with a slightly chunkier back, in which resides the guts of the computer. By then the company was producing machines with an x86 processor, and their internals share a lot of similarities with a laptop of the period. The card is a Mac Radeon model newer than the machine would ever be used with, and it sits in a chain of mini PCIe to PCIe adapters. Even then it can’t drive the original screen, so a replacement panel and power supply are taken from another monitor and grafted into the iMac case. This along with a RAM and SSD upgrade makes this about the most upgraded a 2006 iMac could be.

Of course, another approach is to simply replace the whole lot with an Intel NUC.

DIY Shredder Creates Insulation

October 23, 2023 by 28 Comments

Plenty of us have experience with paper shredders, but there are all kinds of machines designed to completely destroy other materials as well, from metal and plastic, to entire cars. [Action BOX] built their own heavy-duty shredder capable of dismantling things like cell phones and other robust handheld objects, but after seeing what it would physically shred they decided to give it an actual job creating insulation for the attic space in their garage.

The shredder itself uses opposing metal plates arranged on sets of two cylinders, with each cylinder powered by it’s own large motor. In total, the entire system uses around 1.5 kW, so to make their green insulation project as green as possible they decided to power it with an equivalent amount of solar panels. For the insulation they’re using a year’s worth of boxes from various deliveries, and after a time-consuming process preparing the boxes for the shredder, shredding the strips of cardboard, and packaging it in garbage bags their efforts netted them enough to partially fill the space between four ceiling joists. Continue reading “DIY Shredder Creates Insulation” →