A Few Caps For A Faster Multimeter

November 24, 2017 by 19 Comments

We just love it when someone takes apart a bench instrument. There is something about voiding a warranty and then making modifications that hits the spot and in a series of simple modifications, [Jack Zimmermann] dives into the guts if an Aneng AN8008.

The multimeter in question, the AN8008, is a low-cost true-RMS instrument that takes a bit longer to settle on the correct voltage reading than [Jack] would have liked. While poking around, he found that the DC rail inside the meter was host to noise spikes. He theorized that these were being coupled back from an element and proceeded to verify the decoupling arrangement.

The first step was to replace a Rubycon 100 uF capacitor with a Panasonic FM 100 µF which has an ESR of 0.4 Ohms, an improvement on the 1.4 Ohms of stock capacitor. Next came the addition of 0.1 µF, 1 µF and a 10 µF 0805 capacitors and finally a huge 1000 uF 10 V capacity which helped cut down the noise from 30 mV p-p to 3.6 mV p-p. And finally he added decoupling capacitors to the voltage reference chip in accordance with the manufacturer’s datasheet.

These small modifications improved the settling time as well as the stability of the measurements. [Jack] verifies the accuracy against a voltage reference and a bench meter which is good news considering the calibration certificate went out the door anyway.

This is one of the many DMM hacks we have covered in the past such as the Fluke 12E+ hack that enables hidden features though there may be other models out there with possible upgrades.

Modder Puts Computer Inside A Power Supply

November 24, 2017 by 15 Comments

When building a custom computer rig, most people put the SMPS power supply inside the computer case. [James] a.k.a [Aibohphobia] a.k.a [fearofpalindromes] turned it inside out, and built the STX160.0 – a full-fledged gaming computer stuffed inside a ATX power supply enclosure. While Small Form Factor (SFF) computers are nothing new, his build packs a powerful punch in a small enclosure and is a great example of computer modding, hacker ingenuity and engineering. The finished computer uses a Mini-ITX form factor motherboard with Intel i5 6500T quad-core 2.2GHz processor, EVGA GTX 1060 SC graphics card, 16GB DDR4 RAM, 250GB SSD, WiFi card and two USB ports — all powered from a 160 W AC-DC converter. Its external dimensions are the same as an ATX-EPS power supply at 150 L x 86 H x 230 D mm. The STX160.0 is mains utility powered and not from an external brick, which [James] feels would have been cheating.

For those who would like a quick, TL;DR pictorial review, head over to his photo album on Imgur first, to feast on pictures of the completed computer and its innards. But the Devil is in the details, so check out the forum thread for a ton of interesting build information, component sources, tricks and trivia. For example, to connect the graphics card to the motherboard, he used a “M.2 to powered PCIe x4 adapter” coupled with a flexible cable extender from a quaint company called Adex Electronics who still prefer to do business the old-fashioned way and whose website might remind you of the days when Netscape Navigator was the dominant browser.

As a benchmark, [James] posts that “with the cover panel on, at full load (Prime95 Blend @ 2 threads and FurMark 1080p 4x AA) the CPU is around 65°C with the CPU fan going at 1700RPM, and the GPU is at 64°C at 48% fan speed.” Fairly impressive for what could be passed off at first glance as a power supply.

The two really interesting take away’s for us in this project are his meticulous research to find specific parts that met his requirements from among the vast number of available choices. The second is his extremely detailed notes on designing the custom enclosure for this project and make it DFM (design for manufacturing) friendly so it could be mass-produced – just take a look at his “Table of Contents” for a taste of the amount of ground he is covering. If you are interested in custom builds and computer modding, there is a huge amount of useful information embedded in there for you.

Thanks to [Arsenio Dev‏] who posted a link to this hilarious thread on Reddit discussing the STX160.0. Check out a full teardown and review of the STX160.0 by [Not for Concentrate] in the video after the break.

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Retrotechtacular: How To Repair A Steam Locomotive

November 24, 2017 by 41 Comments

Steam locomotives, as a technological product of the 19th century, are not what you would imagine as fragile machines. The engineering involved is not inconsequential, there is little about them that is in any way flimsy. They need to be made in this way, because the huge energy transfer required to move a typical train would destroy lesser construction. It would however be foolish to imagine a locomotive as indestructible, placing that kind of constant strain on even the heaviest of engineering is likely to cause wear, or component failure.

A typical railway company in the steam age would therefore maintain a repair facility in which locomotives would be overhauled on a regular basis, and we are lucky enough to have a 1930s film of one for you today courtesy of the British London Midland and Scottish railway. In it we follow one locomotive from first inspection through complete dismantling, lifting of the frame from the wheels, detaching of the boiler, inspection of parts, replacement, and repair, to final reassembly.

We see steps in detail such as the set-up of a steam engine’s valve gear, and it is impressed upon us how much the factory runs on a tight time schedule. Each activity fits within its own time window, and like a modern car factory all the parts are brought to the locomotive at their allotted times. When the completed locomotive is ready to leave the factory it is taken to the paint shop to emerge almost as a new machine, ready for what seems like a short service life for a locomotive, a mere 130 thousand miles.

The video, which we’ve placed below the break, is a fascinating glimpse into the world of a steam locomotive servicing facility. Most Hackaday readers will never strip down a locomotive, but that does not stop many of them from having some interest in the process. Indeed, keen viewers may wish to compare this film with “A Study in Steel“, another film from the LMS railway showing the construction of a locomotive.

LMS Jubilee class number 5605, “Cyprus”, the featured locomotive in this film, was built in 1935, and eventually scrapped in 1964 as part of the phasing out of steam traction on British railways.

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A Giant Magellan Telescope Needs Giant Mirrors

November 24, 2017 by 47 Comments

The Giant Magellan Telescope doesn’t seem so giant in the renderings, until you see how the mirrors are made.

The telescope will require seven total mirrors each 27 feet (8.4 meters) in diameter for a total combined diameter of 24.5 meters. Half of an Olympic size pool’s length. A little over four times the diameter of the James Webb Space Telescope.

According to the website, the mirrors are cast at the University of Arizona mirror lab and take four years each to make. They’re made from blocks of Japanese glass laid out in a giant oven. The whole process of casting the glass takes a year, from laying it out to the months of cooling, it’s a painstaking process.

Once the cooling is done there’s another three years of polishing to get the mirror just right. If you’ve ever had to set up a metal block for precision machining on a mill, you might have an idea of why this takes so long. Especially if you make that block a few tons of glass and the surface has to be ground to micron tolerances. A lot of clever engineering went into this, including, no joke, a custom grinding tool full of silly putty. Though, at its core it’s not much different from smaller lens making processes.

The telescope is expected to be finished in 2024, for more information on the mirror process there’s a nice article here.

Racing Simulator Built From Scrapheap Finds

November 24, 2017 by 13 Comments

Paradise means something different for everyone, it could be a sitting by a fire on a rainy night or lying on a sun-kissed beach. But for us, and makers like [liltreat4you], it’s a well stocked scrap pile out behind the house. After buying a racing wheel and pedals for his Xbox, he took a trip out to his little slice of paradise and found nearly all the hardware he needed to build a professional looking race simulator. According to his breakdown, most of the money he spent on this build ended up going into that sweet red paint job and the speed-enhancing stickers.

Everything the light touches is our kingdom.

Not all of us are as lucky as [liltreat4you], and we probably won’t just happen upon a driver’s seat out of a Mazda, or a bunch of perfectly bent metal pipes from an old trampoline out on the back forty. But trolling Craigslist or cruising around for flea markets can still get you parts like these for cheap, so try not to be too discouraged if your backyard isn’t quite as well stocked.

Once he had the metal pipes and seat from the car, the rest of the build came together pretty quickly. After building an oval out of his salvaged pipes, he attached the seat and the arms that would eventually hold the steering wheel and display. A plate was also added at the bottom for the pedals to sit on. By using long bolts, [liltreat4you] was even able to add a degree of adjustment to the wheel position. Being that he got his seat out of a real car, there’s the usual adjustment you’d expect there as well.

Speaking of which, [liltreat4you] casually mentions that you should disconnect the battery of the donor vehicle before taking out the seat, as it’s possible that the removal of the seat or the disconnection of the seat harness can cause the airbags to deploy. We can neither confirm nor deny this, but it’s probably safe advice to follow.

The purists out there may claim that what [liltreat4you] has put together doesn’t quite meet the definition of simulator in its current form. But with the addition of some instrumentation and just a bit of physical feedback, he’ll be well on his way to the complete driving experience.

Precision Voltage Reference Source

November 23, 2017 by 10 Comments

[barbouri] found a few old (vintage?) parts from the early ’80’s while rummaging through his parts bin, and quickly spun out a small PCB to build a 10.000 V reference using these old ICs. Throwing together a small number of parts, he was able to build a source which might be good enough to use as a reference for another circuit or provide a quick calibration check for some of his bench instruments that have a resolution of 1 mV or maybe even 100 μV.

The AD584* pin programmable precision voltage references have been available since the ’80’s and offer four programmable output voltages of 10.000 V, 7.500 V, 5.000 V, and 2.500 V. The chip is laser-trimmed to ensure high accuracy and low temperature coefficient and requires just a few external components to function. It is available in TO-99 hermetically sealed metal can and 8-pin DIP variants. The “S” version of the device that [barbouri] used provides a temperature coefficient of 30 ppm/°C max over a -55 °C to +125 °C temperature range but other versions of the chip offer a better stability. Analog Devices seem to have discontinued the “L” version (pdf), since it is no longer listed in the current data sheet, but you can still get them from a few sources. The “L” version has a temperature coefficient of just 5 ppm/°C.

Using quality parts such as high stability resistors and TO-99 PTFE socket with gold-plated contacts, his observations confirm that the unit is stable within 30 μV, with a very slow voltage increase of a few microvolts every 6 hours. A 15 V linear regulator powers the device with input power coming from an external wall wart. A small aluminum enclosure houses the device, with two gold-plated 4 mm sockets for the output. If you would like to build your own, his board design is hosted on OSH park, or you can download the Eagle CAD design files. He’s posted all links on his blog post, and provides part numbers for all of the parts used. [barbouri] has been doing a good job of building handy devices for his work bench – check out his well-built milli Ohm Meter that we had featured earlier.

Bringing MATLAB To A Vacuum Near You

November 23, 2017 by 7 Comments

The essence of hacking is modifying something to do a different function. Many of us learned as kids, though, that turning the family TV into an oscilloscope often got you into trouble.

These days, TVs are flat and don’t have high voltage inside, but there’s always the family robot, often known as a Roomba. Besides providing feline transportation, these little pancake-shaped robots also clean floors.

If you don’t want to evict the cat and still get a robust domestic robot platform for experimentation, about $200 will get you a Roomba made to be hacked — the iRobot Create 2. [Gstatum] has a tutorial for using a Raspberry Pi and MATLAB to get one quickly running and even doing basic object recognition using the Pi’s camera.

The code even interfaces with Twitter. The impressive part is the code fits on about a page. This isn’t, however, completely autonomous. It uses a connected phone’s sensor’s so that the phone’s orientation controls the robot’s motion, but the robot does use sensors to prevent driving into walls or falling off a cliff. It also can detect being picked up and uses the Pi’s camera to detect a green flag.

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