Teardown: Alcatel Telic 1 Minitel Terminal

February 16, 2022 by Jenny List 35 Comments

For British teenagers in the 1980s, the delights of 8-bit computers such as the Sinclair Spectrum, Commodore 64, or BBC Micro were firmly restricted to the offline arena. We would read about the BBS scene on the other side of the Atlantic, but without cheap local calls and with a modem costing a small fortune, the chances of us ever experiencing one was zero. When we took the British school rite of passage of a trip to France though, we were astounded to see that every French person was not merely online, but that they were doing so with a neat little all-in-one terminal. We’d just been introduced to the French Minitel system, and in that minute shared a glimpse of the future.

Un Réseau Trés Français

The Minitel terminal is a small CRT monitor with a fold-down alphanumeric keyboard. — My Alcatel Minitel terminal

In the 1970s and 1980s, so-called videotext systems, terminal-based phoneline access to information services on central computers, were seen as an obvious next step for telephone network operators with an interest in profitable new products. In most countries this resulted in services such as the UK’s Prestel, a subscription service relying on costly hardware, but France Télécom instead pursued the bold path of making the terminals free to subscribers with free access to phone listings and yellow pages, but a business model based on pay-to-use premium services.

Thus, through the 1980s all French households had a Minitel terminal beside the phone, and the service became a runaway success. Ever since seeing Minitel terminals as a tourist I’d been fascinated by the service, so here in the 2020s when a friend was visiting their family in France I asked whether he could pick up an old Minitel terminal for me. Thus I found myself parting with around $25 and being rewarded with a slightly battered Minitel cardboard box containing one of the familiar brown Alcatel terminals. I certainly wasn’t expecting one in its original packaging. Continue reading “Teardown: Alcatel Telic 1 Minitel Terminal” →

First Days With A New Microscope

February 15, 2022 by Dan Maloney 35 Comments

For big-ticket purchases, I tend to do a lot of research before I open my wallet. I like to at least have the illusion that when I send my money off to a far-away stranger, I’m likely to get back something of equal value in a reasonable timeframe that does what I want it to do. So I tend more toward the “analysis paralysis” end of the spectrum, where I pore over so many specs and reviews that I end up buying nothing.

While that sounds like a bad thing, and sometimes is, I find that it tends to help me avoid rashly spending money on things that aren’t going to work for me. This is especially true in the area of tools, where while I’m trapped in my analysis loop, I often find a workaround or substitute that’s good enough to get the job done.

For some things, though, there is no substitute, and when you start working with SMD components that you’d have a hard time telling from a grain of salt, you’re probably going to need a microscope. I recently determined that this was where I was in my electronics journey, and now that I’ve worked my way through the analysis and procurement phase of the process, I thought I’d share my first impressions of my microscope, and what it’s like to get used to working with one.

Continue reading “First Days With A New Microscope” →

NASA Taps Lockheed To Bring Back A Piece Of Mars

February 14, 2022 by Tom Nardi 36 Comments

Since NASA’s Mariner spacecraft made the first up-close observations of Mars in 1964, humanity has lobbed a long line of orbiters, landers, and rovers towards the Red Planet. Of course, it hasn’t all been smooth sailing. History, to say nothing of the planet’s surface, is littered with Martian missions that didn’t quite make the grade. But we’ve steadily been getting better, and have even started to push the envelope of what’s possible with interplanetary robotics through ambitious craft like the Ingenuity helicopter.

Yet, after nearly 60 years of studying our frigid neighbor, all we have to show for our work boils down to so many 1s and 0s. That’s not to say the data we’ve collected, both from orbit and on the surface, hasn’t been extremely valuable. But scientists on Earth could do more with a single Martian rock than any robotic rover could ever hope to accomplish. Even still, not so much as a grain of sand has ever been returned from the planet’s dusty surface.

But if everything goes according to plan, that’s about to change. Within the next decade, NASA and the European Space Agency (ESA) hope to bring the first samples of Martian rocks, soil, and atmospheric gases back to Earth using a series of robotic vehicles. While it’s still unclear when terrestrial scientists should expect delivery of this interplanetary bounty, the first stage of the program is already well underway. The Perseverance rover has started collecting samples and storing them in special tubes for their eventual trip back to Earth. By 2028, another rover will be deployed to collect these samples and load them into a miniature rocket for their trip to space.

Launching the Mars Ascent Vehicle (MAV).

Just last week NASA decided to award the nearly $200 million contract to build that rocket, known officially as the Mars Ascent Vehicle (MAV), to aerospace giant Lockheed Martin. The MAV will not only make history as the first rocket to lift off from a celestial body other than the Earth, but it’s arguably the most critical component of the sample return mission; as any failure during launch will mean the irrevocable loss of all the samples painstakingly recovered by Perseverance over the previous seven years.

To say this mission constitutes a considerable technical challenge would be an understatement. Not only has humanity never flown a rocket on another planet, but we’ve never even attempted it. No matter what the outcome, once the MAV points its nose to the sky and lights its engines, history is going to be made. But while it will be the first vehicle to make the attempt, engineers and scientists have been floating plans for a potential Martian sample return mission for decades. Continue reading “NASA Taps Lockheed To Bring Back A Piece Of Mars” →

China Loves Battery Swapping EVs, But Will They Ever Make It Here?

February 9, 2022 by Zoe Skyforest 122 Comments

Electric vehicles promise efficiency gains over their gas-fuelled predecessors, but the issue of recharging remains a hurdle for many eager to jump on board with the technology. The problem is only magnified for those that regularly street park their vehicles or live in apartments, without provision to charge a vehicle overnight at home.

Battery swapping promises to solve that issue, letting drivers of EVs change out their empty battery for a freshly charged one in a matter of minutes. The technology has been widely panned and failed to gain traction in the US.

However, as it turns out, battery swapping for EVs is actually thing in China, and it’s catching on at a rapid rate.

Continue reading “China Loves Battery Swapping EVs, But Will They Ever Make It Here?” →

Hair Today Gone Tomorrow: Four Men Go To Fix A Wafer Prober

February 8, 2022 by Dave Rowntree 43 Comments

I’ve had a fairly varied early part of my career in the semiconductors business: a series of events caused me to jump disciplines a little bit, and after one such event, I landed in the test engineering department at Philips Semiconductors. I was tasked with a variety of oddball projects, supporting engineering work, fixing broken ATE equipment, and given a absolute ton of training: Good times! Here’s a story that comes straight off the oddball pile.

We needed to assemble a crack team of experts and high-tail it to deepest darkest Wales, and sort out an urgent production problem. The brief was that the wafer probe yield was disastrous and the correlation wafer was not giving the correct results. Getting to the punch line is going to require some IC fabrication background, but if you like stories about silicon, or red-bearded test engineers, it’s worth it. Continue reading “Hair Today Gone Tomorrow: Four Men Go To Fix A Wafer Prober” →

Remembering The MIT Radiation Laboratory

February 7, 2022 by Chris Lott 32 Comments

Back in the late 80s, our company managed to procure the complete 28 volume MIT Radiation Laboratory (Rad Lab) series, published in 1947, for the company library. To me, these books were interesting because I like history and old technology, but I didn’t understand why everyone was so excited about the acquisition. Only a cursory glimpse at the volumes would reveal that the “circuits” these books described used vacuum tubes and their “computers” were made from mechanical linkages. This was the 1980s, and we worked with modern radar and communications systems using semiconductors, integrated circuits, and digital computers. How could these old musty books possibly be of any practical use? To my surprise, it turned out that indeed they could, and eventually I came to appreciate the excitement. I even used several of them myself over the years.

Radiation Lab? Nuclear Radar?

In the years leading up to WW2, the idea of a civilian organization of scientists that would operate independently of the military and government bureaucracies was being championed by Dr. Vannevar Bush. The military and scientists had not worked well together during the first World War, and it looked like science and technology would be playing a much bigger role in the future.

It seemed certain that America would enter the conflict eventually, and Dr Bush and others believed that a new organizational framework was called for. To that end, the National Defense Research Committee (NDRC), which later became the Office of Scientific Research and Development (OSRD) was pitched to President Roosevelt and he approved it in June of 1940.

Almost immediately, a gift fell in the lap of the new organization — the Tizard Mission which arrived in the states from the UK in Sep 1940. They brought a literal treasure chest of technical innovations from the British, who hoped that US industry’s cooperation could help them survive what looked like certain and imminent invasion. One of those treasures was the cavity magnetron, which our own Dan Maloney wrote about a few years ago.

Within a few weeks, under the guidance of young Welshman “Taffy” Bowen, they had reviewed the design and gathered up the necessary equipment to fire it up. A 10 kV anode power supply and a 1,500 gauss electromagnet were procured, and the scientists gathered at the Bell Radio Laboratories in Whippany New Jersey on Sunday, Oct. 6, 1940. They powered up the cavity magnetron and were blown away by the results — over 10 kW of RF at 3 GHz (10 cm) from something the size of a bar of soap. Continue reading “Remembering The MIT Radiation Laboratory” →

3D Printed Radiation Shields Get Put To The Test

February 4, 2022 by Tom Nardi 19 Comments

Don’t get too excited, a 3D printed radiation shield won’t keep you from getting irradiated during WWIII. But until the Doomsday Clock starts clanging its midnight bell, you can use one to improve the accuracy of your homebrew weather monitoring station by keeping the sun from heating up your temperature sensor. But how much does it help, and what material should you load up in your extruder to make one? Those questions, and more, are the topic of a fascinating whitepaper included in the upcoming volume of HardwareX.

Design and Implementation of 3-D Printed Radiation Shields for Environmental Sensors not only tests how effective these low-cost shields are when compared to an uncovered sensor, but addresses specific concerns in regards to leaving 3D printed parts out in the elements. Readers who’ve squirted out a few rolls worth of the stuff will know that common polylactic acid (PLA) filament, while easy to work with and affordable, isn’t known for its resilience. In fact, one of the advertised properties of the renewable plastic is that it’s biodegradable (theoretically, at least), so leaving it outside for any length of time sounds like it’s bound to go poorly.

PLA’s mechanical strength dropped rapidly.

To make a long story short, it does. While the team demonstrated that the PLA printed radiation shield absolutely helped preserve the accuracy of the temperature and humidity sensors mounted inside of it, the structure itself began to deform rapidly from UV exposure. Further tests determined that the mechanical strength of the PLA showed a notable reduction in as little as 30 days, and a sharp decline after 90 days.

Luckily, there was more than one plastic horse in the race. In addition to the PLA printed shield, the team also tested a version printed in acrylonitrile styrene acrylate (ASA) which fared far better. There was no visible deformation of the shield, and after 90 days, the reduction in mechanical strength was negligible. It even performed a bit better when it came to shielding the temperature sensor, which the team believes may be due to the material’s optical transmission properties.

So there you have it: a 3D printed radiation shield will absolutely improve the accuracy of your weather sensors, but if you want it to last outside, PLA just isn’t going to cut it. On the other hand, you could also save yourself a whole lot of time by just using a stack of plant saucers. Whatever works.

Thanks to [tahnok] for the tip.