Author: Al Williams

4296 Articles

They Don’t Make $37 Waveform Generators Like They Used To

October 14, 2025 by 21 Comments

[CreativeLab] bought a cheap arbitrary waveform generator and noted that it only had a two-pin power cord. That has its ups and downs. We feel certain the intent was to isolate the internal switching power supply to prevent ground loops through the scope probes or the USB connector. However, it is nice to have all your equipment referencing the same ground. [CreativeLab] agrees, so he decided to do something about it.

Opening the box revealed that there was hardly anything inside. The main board was behind the front panel. There was also the power supply and a USB board. Plus lots of empty space. Some argue the case is made too large to be deceptive, but we prefer to think it was to give you a generous front panel to use. Maybe.

It was a simple matter to ground everything to a new three-pin connector, but that left the problem of the USB port. Luckily, since it was already out on its own board, it was easy to wire in an isolator.

Honestly? We’d have hesitated to do this unless we had made absolutely sure it didn’t pose some safety hazard to “jump over” the switching power supply. They are often isolated for some reason. However, the likelihood is that it is just fine. What do you think? Let us know in the comments.

A similar unit had a reverse engineering project featured on Hackaday many years ago. While these used to be exotic gear, if you don’t mind some limitations, it is very easy to roll your own these days.

Continue reading “They Don’t Make $37 Waveform Generators Like They Used To” →

Building The LEM’s Legs

October 13, 2025 by 13 Comments

If you built a car in, say, Germany, for use in Canada, you could assume that the roads will be more or less the same. Gravity will work the same. While the weather might not be exactly the same, it won’t be totally different. But imagine designing the Lunar Excursion Module that would land two astronauts on the moon for the first time. No one had any experience landing a craft on any alien body before.

The LEM was amazing for many reasons, but as [Apollo11Space] points out, the legs were a particularly thorny engineering problem. They had to land on mostly unknown terrain, stay upright, allow for the ascent module to take off again, and, of course, not weigh down the tiny spaceship. They also had to survive the blast of the LEM’s engine.

Continue reading “Building The LEM’s Legs” →

SMD Soldering With Big Iron

October 13, 2025 by 32 Comments

You have some fine pitch soldering to do, but all you have on hand is a big soldering iron. What do you do? There are a few possible answers, but [Mr SolderFix] likes to pull a strand from a large wire, file the point down, and coil it around the soldering iron. This gives you a very tiny hot tip. Sure, the wire won’t last forever, but who cares? When it gives up, you can simply make another one.

Many people have done things like this before — we are guilty — but we really liked [Mr Solder Fix’s] presentation over two videos that you can see below. He coils his wire over a form. In his case, he’s using a screwdriver handle and some tape to get to the right size. We’ve been known to use the shanks of drill bits for that purpose, since it is easy to get different sizes.

Continue reading “SMD Soldering With Big Iron” →

DIY 35mm Film Scanning

October 12, 2025 by 24 Comments

If you are sitting on a horde of negatives, waiting for the digital photography fad to die off, it may be time to think about digitizing your old film. [Kinpro1024] can help with the PiDigitzier, an open-source film scanning solution. The build centers around a Pi Zero 2, a Pi HQ camera, and a diffusing  LED lighting fixture. Of course, there’s also some miscellaneous hardware and a camera lens; the example used a Pentax 50 mm f1.8 lens.

Half of the project is mechanical. An MDF tower provides a stable 250 mm workspace and decks that can slide up and down using threaded rods and curtain rods. Apparently, leveling the platforms is important not only for the optics but also to allow the MDF to move along the rods without binding.

Continue reading “DIY 35mm Film Scanning” →

Tubeless X-Ray Runs On Patience

October 12, 2025 by 9 Comments

Every time we check in on [Project326], he’s doing something different with X-rays. This week, he has a passive X-ray imager. On paper, it looks great. No special tube is required and no high voltage needed. Actually, no voltage is needed at all. Of course, there’s no free lunch. What it does take is a long time to produce an image.

While working on the “easy peasy X-ray machine,” dental X-ray film worked well for imaging with a weak X-ray source. He found that the film would also detect exposure to americium 241. So technically, not an X-ray in the strictest sense, but a radioactive image that uses gamma rays to expose the film. But to normal people, a picture of the inside of something is an X-ray even when it isn’t.

Continue reading “Tubeless X-Ray Runs On Patience” →

Toasty Subwoofer Limps Back To Life

October 11, 2025 by 6 Comments

[JohnAudioTech] noticed there was no bass on the TV at his parents’ house. That led to the discovery of a blown fuse and a corresponding repair. When he opened it up, he could smell that something had gone on in the amplifier. You can follow the repair in the video below.

His first theory was that some glue became conductive and shorted the power rails. We were skeptical, to be honest. When he fed power to it through a current limiter, he could hear a sizzling noise and even see a little glowing from the hot component.

Disassembly ensued. Removing the suspect components showed some seriously burned components and some charring under a switching transistor. The capacitors looked much worse for wear, and the PCB needed some wires to jumper burned conductors.

At the end, there was thumping, so it seems the surgery was a success. However, testing blew a fuse again, which made us nervous. Still, seems to work if you don’t drive it too hard.

We always enjoy watching a teardown, and if there’s a repair too, that’s even better.

Continue reading “Toasty Subwoofer Limps Back To Life” →

Possibly The Newest ISA Card

October 10, 2025 by 12 Comments

Back when the IBM PC was new, laying out an ISA board was a daunting task. You probably didn’t have a very fast ‘scope, if you had one at all. Board layout was almost certainly done on a drafting table with big pieces of tape. It was hard for small companies, much less hobbyists, to make a new card. You could buy a prototype board and wirewrap or otherwise put together something, but that was also not for the faint of heart. But with modern tools, something like that is a very doable project and [profdc9] has, in fact, done it. The card uses an ATMega328P and provides two SD cards for use as mass storage on an old computer.

The design tries to use parts that won’t be hard to get in the future. At least for a while, yet. There’s capacity for expansion, too, as there is an interface for a Wiznet 5500 Ethernet adapter.

Continue reading “Possibly The Newest ISA Card” →