Author: Al Williams

4389 Articles

Inside A “Budget” Current Probe

March 16, 2025 by 10 Comments

Current measurements are not as handy as voltage measurements. You typically need to either measure the voltage across something and do some math or break the circuit so a known resistor in your instrument develops a voltage your meter measures and converts for you. However, it is possible to get non-contact current probes. They are generally pricey, but [Kerry Wong] shows us one under $200 and, thus, budget compared to similar probes. Check out the review in the video below.

The OWON unit has three ranges: 4 A, 40 A, and 400 A. It claims a resolution of 10 mA and a bandwidth of 200 kHz. It requires a 9 V battery, which [Kerry] suspects won’t last very long given the rated power consumption number, although the measured draw was not as high as claimed. The specs aren’t great — this seems to be little more than a current probe meter with a connector for an oscilloscope, but if it meets your needs, that could be acceptable.

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A Look At The Panasonic FS-A1FM

March 16, 2025 by 12 Comments

MSX computers were not very common in the United States, and we didn’t know what we were missing when they were popular. [Re:Enthused] shows us what would have been a fine machine in its day: a Panasonic FS-A1FM. Have a look at the video below to see the like-new machine.

The machine isn’t just an ordinary MSX computer. The keyboard is certainly unique, and it has an integrated floppy drive and a 1200-baud modem. The case proudly proclaims that the floppy is both double-sided and double-density. Like most MSX computers, it had a plethora of ports and, of course, a cartridge slot. Unfortunately, the machine looks great but has some problems that have not been repaired yet, so we didn’t get to see it running properly.

He was able to get to the MSX-DOS prompt to show along with the BIOS menu. We hope he manages to get the keyboard working, and we were glad to see another computer from that era we had not seen before.

We don’t think anyone made one at the time, but we’ve seen a modern take on a luggable MSX. Of course, you can emulate the whole thing on a Pi and focus on the aesthetics.

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Repairing A Kodak Picture Maker Kiosk

March 15, 2025 by 9 Comments

Photo-printing kiosks are about as common as payphones these days. However, there was a time when they were everywhere. The idea was that if you didn’t have a good printer at home, you could take your digital files to a kiosk, pay your money, and run off some high-quality images. [Snappiness] snagged one, and if you’ve ever wondered what was inside of one, here’s your chance.

While later models used a Windows PC inside, this one is old enough to have a Sun computer. That also means that it had things like PCMCIA slots and a film scanner. Unfortunately, it wasn’t working because of a bad touch screen. The box was looking for a network on boot, which required some parameter changes. The onboard battery is dead, too, so you have to change the parameters on every boot. However, the real killer was the touchscreen, which the software insists on finding before it will start.

The monitor is an old device branded as a Kodak monitor and, of course, is unavailable. [Snappiness] found pictures of another kiosk online and noted that the monitor was from Elo, a common provider of point-of-sale screens. Could the “Kodak” monitor just be an Elo with a new badge? It turns out it probably was because a new Elo monitor did the trick.

Of course, what excited us was that if we found one of these in a scrap pile, it might have a Sun workstation inside. Of course, you can just boot Solaris on your virtual PC today. You might be surprised that Kodak invented the digital camera. But they failed to understand what it would mean to the future of photography.

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You Too Can Do The Franck-Hertz Experiment

March 15, 2025 by 5 Comments

We talk about quantum states — that is, something can be at one of several discrete values but not in between. For example, a binary digit can be a 1 or a 0, but not 0.3 or 0.5. Atoms have quantum states, but how do we know that? That’s what the Franck-Hertz experiment demonstrates, and [stoppi] shows you how to replicate that famous experiment yourself.

You might need to translate the web page if your German isn’t up to speed, but there’s also a video you can watch below. The basic idea is simple. A gas-filled tube sees a large voltage across the cathode and grid. A smaller voltage connects to the grid and anode. If you increase the grid voltage, you might expect the anode current to increase linearly. However, that doesn’t happen. Instead, you’ll observe dips in the anode current.

When electrons reach a certain energy they excite the gas in the tube. This robs them of the energy they need to overcome the grid/anode voltage, which explains the dips. As the energy increases, the current will again start to rise until it manages to excite the gas to the next quantum level, at which point another dip will occur.

Why not build a whole lab? Quantum stuff, at a certain level, is weird, but this experiment seems understandable enough.

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Make Your Cheap Thermal Camera Into A Microscope

March 14, 2025 by 17 Comments

[Project 326] has a cheap thermal camera that plugs into a smart phone. Sure they are handy, but what if you could hack one into a microscope with a resolution measured in microns? It is easier than you might think and you can see how in the video below.

Of course, microscopes need lenses, but glass doesn’t usually pass IR very well. This calls for lenses made of exotic material like germanium. One germanium lens gives some magnification. However, using a 3D printed holder, three lenses are in play, and the results are impressive.

The resolution is good enough to see the turns of wire in an incandescent light bulb. A decapsulated power transistor was interesting to view, too. Imaging heat at that much resolution gives you a lot of information. At the end, he teases that using first surface mirrors, he may show how to build an IR telescope as well.

Presumably, this will work with just about any IR camera if you adapt the lens holder. The unit in the video is a UNI-T UTi-260M. So when he says he spent about $35 on the build, that’s not including the $400 or so camera module.

IR imaging can pull off some amazing tricks, like looking inside an IC. If the thermal camera used in the video isn’t to your liking, there are plenty of others out there.

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Hackaday Podcast Episode 312: Heart Attacks, The Speed Of Light, And Self-balancing

March 14, 2025 by 7 Comments

Elliot does the podcast on the road to Supercon Europe, and Al is in the mood for math and nostalgia this week. Listen in and find out what they were reading on Hackaday this week.

The guys talked about the ESP-32 non-backdoor and battery fires. Then it was on to the hacks.

Self-balancing robots and satellite imaging were the appetizers, but soon they moved on to Kinect cameras in the modern day. Think you can’t travel at the speed of light? Turns out that maybe you already are.

Did you know there was a chatbot in 1957? Well, sort of. For the can’t miss stories: watches monitor your heart and what does the number e really mean?

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and stream it on the big speakers.

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You Know Pi, But Do You Really Know E?

March 14, 2025 by 29 Comments

Pi Day is here! We bet that you know that famous constant to a few decimal points, and you could probably explain what it really means: the ratio of a circle’s circumference to its diameter. But what about the constant e? Sure, you might know it is a transcendental number around 2.72 or so. You probably know it is the base used for natural logarithms. But what does it mean?

The poor number probably needed a better agent. After all, pi is a fun name, easy to remember, with a distinctive Greek letter and lots of pun potential. On the other hand, e is just a letter. Sometimes it is known as Euler’s number, but Leonhard Euler was so prolific that there is also Euler’s constant and a set of Euler numbers, none of which are the same thing. Sometimes, you hear it called Napier’s constant, and it is known that Jacob Bernoulli discovered the number, too. So, even the history of this number is confusing.

But back to math, the number e is the base rate of growth for any continually growing process. That didn’t help? Well, consider that many things grow or decay through growth. For example, a bacteria culture might double every 72 hours. Or a radioactive sample might decay a certain amount per century. Continue reading “You Know Pi, But Do You Really Know E?” →