As we’ve remarked in these pages before, oftentimes some of the best engineering around is invisible, hidden inside black boxes of one sort or the other. If the black box is sufficiently important in some way, professional forensic and reverse engineers can be employed to crack it open and reveal its secrets. But what about more humble items, such as the apparently unremarkable components that make up everyday electronics? Who cares enough to take the trouble to look inside them?
Eric Schlaepfer does. To the delight of a growing following, in March of this year, Schlaepfer started posting to his @TubeTimeUS twitter account magnified cross sections of capacitors, cables, LEDs, transistors, and more, usually with accompanying annotations.
His photography project began in a moment of idle curiosity, after fixing an old function generator that he used to test other circuits. He’d just finished replacing a number of capacitors. “I was kind of staring down at my desk, looking at these dead tantalum capacitors, and I picked one up,” he says. “I was just going to throw it in the waste can, but then I realized that I don’t really know what’s inside these things, and it might actually be interesting to take a look inside…so I just took out a sheet of sandpaper and started going at it.”
Schlaepfer took photos of the results and tweeted them, where they quickly drew a positive response. Encouraged, Schlaepfer dug around in his junk box, pulled out a standard quarter-watt carbon film resistor, and sanded away. He got another wave of positive responses. “It’s the sort of component that most hobbyists have experience with, right? People really like that,” says Schlaepfer, who began sanding down every component he could find.
Schlaepfer usually has plenty of candidates on hand. He is a hardware engineer at Google who’s also well known in the maker and vintage electronics communities and a frequent visitor to electronic flea markets, so he always has. He is the creator of the MOnSter 6502, a replica of the legendary 6502 processor made using thousands of surface mount transistors, and he also created the Three Fives kit, which lets you build a version of the venerable 555 timer chip using discrete transistors and resistors, and which IEEE Spectrumfeatured in our March 2014 issue.
The components take Schlaepfer anywhere from a few minutes to several hours to prepare, gradually moving to finer and finer grades of sandpaper. (He’s tried using electrical sanders and cutters to speed things up, but he says he has the best luck with sandpaper and elbow grease.) To take photographs of the exposed surfaces, Schlaepfer typically uses an old inspection microscope and simply holds his cellphone’s camera over the eyepiece. For items that are too large for the microscope, he uses a Nikon D40 DSLR with a 105-mm macro lens.
Mysteries Explained: Schlaepfer typically also posts annotated versions of his cross sections, such as this one of a VGA cable.Image: Eric Schlaepfer/Tube Time
“There’s a sort of a surprising beauty in a lot of these components,” says Schlaepfer. He notes that although engineers often have knowledge of how a component works in the abstract, the actual physical structure can be unexpected: “For example, I know that an electrolytic capacitor is made up of foil elements, wound with a paper material in between that holds the electrolyte.... But until I actually cut one in half in the axial direction, I didn’t know that it had this really interesting looking set of two interlocking spirals, which was the two plates of the capacitor.”
Schlaepfer also makes his cross sections publicly available on the Wikimedia Commons and is mulling a coffee-table book, although if he did that he’d “have to invest in a bit more complex photography rig!” he says, laughing.
This article appears in the August 2019 print issue as “The Hidden Beauty of Components?”