Last week, Vishay announced that it’s acquiring MCB Industrie S.A, a manufacturer of specialty resistors. Acquisitions have been a key piece of Vishay’s strategy, so we took a look at its track record to see the effect on market pricing of the target company’s products. (We used Octopart’shistorical pricing data.)
Today would be the 115th birthday of Harold Stephen Black, who invented the negative-feedback amplifier in 1927. The story goes that Mr. Black was taking the ferry from New Jersey to New York City (where Bell Labs was then located), and while on the boat he was struck by the idea to use negative feedback to linearize an amplifier stage.
The idea of negative feedback is a powerful one, because it provides a means to construct amplifiers with precise gain characteristics from parts with less than ideal specs. This makes it easier to build circuits with interchangeable, off-the-shelf parts. Gain can be adjusted using passive components, which are cheaper and easier to adjust.
Distortion and intermodulation are reduced significantly, and bandwidth is greatly increased. It also enables the construction of higher order filters without the use of inductors, which are heavy and prone to other problems. Though initially developed for vacuum tubes, the idea is very useful in transistor circuits, which can have wildly varying beta characteristics, even among devices on the same chip.
There are a lot of things to like about the video above, but my favorite part is the way he talks so earnestly about his failures, before finally succeeding.
In the June 2012 issue of Nuts & Volts, they did a spread about making a soil moisture sensor with an iPhone interface:
And when I heard my girlfriend say that she has trouble remembering to water her plants, I put two and two together.
Most of the N&V article discussed the code required to interface with the iPhone, but the important part for me was that their soil moisture sensor was nothing more than a simple conductivity sensor. The more water in the soil, the lower its resistance.
Such a sensor doesn’t measure soil moisture in any kind of universal unit, but for a single sensor in a particular soil sample, the measured conductivity is repeatable and proportional to the moisture level. I call these conductivity units “AMU”s or “Arbitrary Moisture Units”.
Each month this year, we’re exploring a different electronic component, delving into what it is, how it works, and how you use it in projects. Last monthwe looked at batteries. This month, we’ll tackle the resistor, the job of which is to limit the flow of electricity and thereby control it, guiding it toward one component while protecting another. As always, we’ll start things off with an introduction to resistors via an edited excerpt from Charles Platt’s essential Encyclopedia of Electronic Components: Volume 1.
Nothing is as fast and fun as prototyping on a breadboard, but at some point you will find that the chips you want to work with are only available in non-breadboard-friendly SMT/SMD (Surface Mount Technology/Surface Mount Device). Unlike most DIP chips and resistors, SMT parts do not have the leads going through holes in the PCB. Instead, they ‘float’ on top, with often-rectangular solder pads.
Although you may one day decide to use CAD software for laying out a custom PCB for these parts, you can do yourself a favor and prototype with SMT breakout/adapter PCBs. In this mini tutorial we’ll go over how to use these. It’s not hard, once you have the experience!
My first computer was a Texas Instruments TI-99/4A. Longtime readers may remember a previous article where we implemented TI-99/4A BASIC as a Scripting Language for modern computers. Recently I got nostalgic for the actual hardware so I got my 99 out of the closet where it had been for a decade or more.
There have been many studies of the causes of tombstoning; some published, some not. They tend to focus on a single process parameter as the root cause of tombstoning. However, there is no single process change that is a sure cure for tombstoning! Those that claim otherwise are either uninformed or trying to sell you something. Rather than limiting your view to a single solution, EFD recommends you heed all of the studies. Like pieces of a puzzle, each study does not reveal the whole picture, but looked at all together, the picture is clear.
The issue of tombstoning has risen to prominence because, while components and assemblies have become much smaller over the last decade, overall assembly processes have remained much the same. As components become smaller, so should your process windows.
Last year, my friend Chris Novello closed the 2012 Open Hardware Summit with a demo similar to this performance — remixing SMB in ways nobody had ever thought of before — to wild and well-deserved applause, I might add. Here he is doing it again! He writes:
In this video, I directly manipulate the RAM state of Nintendo’s Super Mario Brothers to transform it from a game into a strange instrument.
First, I play the game as it is traditionally played.. but I have access to the game’s memory, so I change Mario’s Y position using the Madrona Labs Soundplane (a surface that sends data to the computer about where it is being touched). This is how I hover Mario during the playthrough.
Also, before I start playing, I flip a switch on illucia that I assigned to trigger recording — not video, but actually recording the entire memory state of the NES for each game frame.
Think about it – Mario’s universe is held in RAM, which the NES uses to draw his world for each frame of the game. By recording the entire state of the NES memory for every frame, I’m able to go back to any moment in Mario’s life.
So then I use the X-axis of the Soundplane to sweep through the timeline of Mario’s universe.
Not only that, but the Soundplane is multitouch, so I use a second finger to specify start and endpoints in a playback loop. Technically, this is similar to the way samplers and granular synths work in audio.. but with the entire memory state of the NES. Conceptually, it is like Super Mario meets Groundhog Day. Mario’s universe computer/time machine gets caught in hellish loops.
Then I start using illucia to send alien data into various other places in Mario’s universe, which makes for all sorts of audiovisual insanity amidst the spacetime loops. This is sort of like circuit bending, but in a protected sandbox – at any point I can revert back to the clean recording of RAM states (aka moments in Mario’s universe).
I then try to go back to “playing” the game, watching Mario navigate a melting world of glitched-out ephemera. I then push things into full on glitch insanity. I use a pair of rubberband mallets on the Soundplane to jump around in Mario’s universe while leaving illucia to send a heavy stream of alien data into Mario’s RAM state. I eventually (accidentally/luckily) land at a place that triggers the game over music, and end the take.
Will from FriedCircuits.us has been working on a new daisy-chainable LED Matrix Link prototype which makes use of a Maxim MAX7219 (which he will feature in his upcoming May wedding — fascinating!), so he has been investigating cheap sources for the IC suggested by friends and colleagues. His conclusion? Buyer beware when buying under market value on eBay. Learn more how to spot the fakes from his MobileWill blog:
I have been receiving feedback that I can use eBay suppliers to lower my price on the MAX7219. I had previously considered that option, but after some research I have found that a lot of people are receiving counterfeits on eBay. While some counterfeits may work, their reliability is questionable and that would make my product unreliable. I do not believe that it is “good business” to support businesses and companies which pirate technology and sell it as if it were legitimate. I sincerely hope everyone understands why I am skeptical about using an unknown supplier for parts. Here is a good forum post about coming across the fake variety: http://www.picaxeforum.co.uk/showthread.php?22481-Real-or-fake The more units I can sell initially will increase my per-part discount, which will allow me to lower my selling price.
For example if you look at the picture above, the line across the top is inline with pin 2. f you do a search on eBay or even Google image search you can see that they line up with pin 3. Also mine has a notch and the eBay ones all have a dimple. Not to mention there is no way someone can go to Maxim and get a price much lower then their lowest price they have.
Each week on the Adafruit blog we post up about amazing companies, people and articles about being a MAKER and a business. Over the years we’ve shared how we run Adafruit, published code from our shopping cart system and given presentations on running an open-source hardware company. Every Monday we’re going to try to collect some of these resources and tag them #makerbusinessmonday & #makerbusiness. They’re in our popular Maker Business category as well, enjoy!
If you are in the New York City area and have been looking to gain the skill to manufacture your own PCBs for the projects you are developing — perhaps on your way to launching a brand new kit or product — then check out the Zahn Center’s upcoming PCB making classes:
WHEN: April 6, 2013 @ 10:00 am – 6:00 pm
WHERE: Zahn Center, Room B20, Steinman Hall, 140th Street and Convent Avenue, New York, NY 10031
COST: $150 (plus fees)
Our first “Make your own PCB” class will be given by PCB designer extraordinaire, Jonathan Hirschman. In this class we’ll be helping you design and build your very own Arduino clone, similar to the one shown. The class is designed for everyone, of all skill levels, with no knowledge of electronics required – just a desire to learn and make.
The class will be given in two Saturday sessions (April 6th and April 20th, from 10am – 6pm). In the first session, you’ll learn about PCB design software, and then you’ll create your own Arduino clone design, and send your design out for fabrication. Two weeks later, you’ll be building and assembling your boards!
Even though this class is newbie friendly, we’ll be doing a pretty deep dive. You’ll learn how to read datasheets, how to design components in the layout software, power and ground planes, even how to make funky graphics. Want skulls and flames on your clone? No problem! We’ll also talk about the different manufacturing shops out there, pricing, location and what are some of their pros and cons. In the second session you’ll learn all about assembly and mounting, and how to correct when the tiny legs on your microntrollers don’t quite line up….
Back in the fall of 2008, the Large Hadron Collider experienced a setback when a section of the liquid helium coolant exploded. Aside from the damage caused by the explosion, there was damage to the electrical system. The lack of coolant resulted in a loss of superconductivity, which caused the temperature of the conductors to rise to damaging levels — the conductors were still carrying thousands of amps of current, but their resistance had increased by several orders of magnitude. Ohm, the humanity!
To help prevent such an occurrence in the future, the LHC team has begun installing special shunts, which will help lower the resistance of the conductors at non-cryo temperatures, in order to prevent similar damage from happening again.
On 19 September 2008, during powering tests on the Large Hadron Collider (LHC), a fault occurred in a superconducting interconnection between two magnets – a dipole and a quadrupole – resulting in mechanical damage and release of helium from the magnet cold mass into the tunnel. Proper safety procedures were in force, the safety systems performed as expected, and no-one was put at risk. But the fault did delay work on the LHC by six months.
After the incident, CERN engineers decided that such interconnections should be upgraded to avoid similar electrical faults in future. As a precaution, beams in the LHC were accelerated below the LHC’s design limit for the first three years of running. Upgrading the interconnections will be one of the main activities at the LHC during its two-year shutdown, allowing the LHC to run at 7 TeV per beam when it starts up again.
There are 10,000 “splices” – superconducting connections between magnets – on the LHC. Each splice carries 13,000 amps.
In the video above, Jean-Phillipe Tock of the Technology department explains how, over the next 18 months, technicians will add an additional piece – a “shunt” – to each splice. The shunt is a low-resistance connection that forms an alternative path for a portion of the current in the event that the splice loses its superconducting state. A total of 27,000 shunts will be installed in the 27-kilometre accelerator.