by Connor Archard and Feiran Chen @ cornell.edu:
Our final project was to create a rapid prototyping machine for electrical circuits by repurposing an old pen plotter that we fitted with an electrically conductive pen. Our plotter utilized an atmega 1284P to control the x and y-axis motors, and to raise and lower the pen. We created a web app that allowed a user to draw out circuits quickly, and then send them to be printed out on our plotter over a wifi network as our host computer that maintained the serial connection with the atmega 1284P. The atmega 1284P would receive vectors of x and y coordinates from the host computer that would instruct it on how to move the plotter head. By measuring the position of the plotter head on each axis through the on-chip ADC and two servo potentiometers, we were able move the plotter head to an accuracy of approximately 1/10th of an inch on a typical piece of A4 paper.
Rapid Circuit Prototyping – Circuit Plotting - [Link]
by Ben Coxworth @ gizmag.com:
Someday soon, your milk carton may be able to tell you that the milk has spoiled, or your bandage may indicate that it needs changing. These and other things could be made possible by a new technique developed at Singapore’s Nanyang Technological University, which allows disposable electronics to be printed on a variety of surfaces, using an existing T-shirt printer.
Disposable electronic circuits produced with a T-shirt printer - [Link]
by Henrik’s Blog @ hforsten.com:
In my previous post I wrote about a circuit that would change it’s output depending on what was the spice simulations DC sweep range. Today I investigated the circuit a little and I was able to remove lots of components that didn’t affect the bug and this is the resulting circuit.
Metastable transistor circuit - [Link]
An application note from Texas Instruments, A single-supply Op-Amp circuit collection (PDF!):
There have been many excellent collections of op-amp circuits in the past, but all of them focus exclusively on split-supply circuits. Many times, the designer who has to operate a circuit from a single supply does not know how to do the conversion.
Single-supply operation requires a little more care than split-supply circuits. The designer should read and understand this introductory material.
A single-supply Op-Amp circuit collection - [Link]
w2aew @ youtube.com writes:
This video presents a simple automatic audio volume leveling circuit. The application that prompted this is a police/fire/emergency scanner. Often times, different services will have different volumes in the receiver – so adjusting for a comfortable listening level on one service/station will often lead to other services being too loud or too quiet. This circuit will automatically adjust the volume of each received signal based on the signal’s peak amplitude. Similar circuits have been widely published, so there’s really nothing new here – just a quick tutorial and demonstration of how this circuit works. An arrangement of capacitors and diodes are used to implement a peak detector to measure the input signal amplitude. The dynamic impedance of diodes is controlled/changed to adjust the signal level. The result is a leveling circuit that has a very wide input dynamic range with a near constant average output level.
Circuit fun: Automatic audio leveling circuit - [Link]
by INM – Leibniz-Institut für Neue Materialien:
When users operate their smartphones, tablets and so on, they do not give a second thought to the complicated electronics that make them work. All that concerns them is that they can happily swipe and tap away. To make the touchscreens work, they are provided on their surface with microscopically small electrical conductor tracks, which open and close circuits when touched with a finger. At the peripheries of the devices, these microscopic tracks merge into larger conductor tracks. Until now, several production stages have been needed to create them. The researchers at the INM – Leibniz-Institute for New Materials are now presenting a novel process that allows microscopic and macroscopic conductor tracks to be produced in one step.
Novel process allows production of the entire circuitry on touchscreens in one step - [Link]
EveryCircuit helps electronics enthusiasts to quickly prototype circuits and share their designs. Students find it useful because of real-time interactive simulation and visualization of circuit operation. EC was first released as an Android app (over 1M users). Thanks to Google’s new Portable Native Client technology that lets us run C++ code at full speed in Chrome browser, it is now available online.
EveryCircuit is a web and mobile app for EE students and circuit enthusiasts. Its interactive visual circuit simulation is great for understanding how circuits work and for quick prototyping of design ideas. And it has a huge online repository of educational and practical circuits designed by EveryCircuit community.
EveryCircuit – Interactive visual circuit simulation web app - [Link]
Wouldn’t it be ideal if you could just press ‘print’ to produce a printed circuit board? In a paper titled ‘Instant Inkjet Circuits: Lab-Based Inkjet Printing To Support Rapid Prototyping Of Ubicomp Devices’ researchers Yoshihiro Kawahara of the University of Tokyo, Steve Hodges of Microsoft Research and Benjamin Cook, Cheng Zhang and Gregory Abowd of the Georgia Institute of Technology have detailed exactly how it can be done using commercially available products. To start off with take a standard inkjet printer, fill its cartridge with silver nanoparticle ink and using a normal PCB layout program, print the PCB layout onto resin coated paper, PET film, photo paper or just plain paper. Once deposited the traces undergo a chemical sintering process as the pattern dries and they become conductive.
Instant Inkjet Circuits - [Link]
FidoCadJ is an easy to use graphical editor, with a library of electrical symbols and footprints (traditional and SMD). It aims to be an agile and effective small EDA tool for hobbyists. FidoCadJ stores its drawings in a compact text format, practical for the copy and paste in newsgroups and forums: this has determined its success on the Usenet and in numerous communities. FidoCadJ is multi-platform and runs on MacOSX, Linux and Windows
A multiplatform vector drawing program with a complete library of electronic symbols. Schematics and drawings are stored in a very compact text format. There is no netlist concept behind the drawings (so no simulation here, sorry!) but this allows a great graphical flexibility and ease of use, making FidoCadJ the perfect tool for exchange sketches in forum and newsgroup discussions with a few clicks. Drawings can be exported in several graphic formats, such as pdf.
FidoCadJ – Simple and intuitive 2D vector drawing for electronics and not only - [Link]