About C. J. Abate

C. J. Abate is Circuit Cellar's Editor in Chief. You can reach him at cabate@circuitcellar.com and @editor_cc.

APEI Builds First Multiphysics Simulation App with the Application Builder

Application Builder was released in October 2014 and is now available with COMSOL Multiphysics software version 5.0. The Application Builder allows COMSOL software users to build an intuitive interface to run any COMSOL model. COMSOL Multiphysics users are already building applications and exploring the benefits of sharing their models with colleagues and customers worldwide.

Image made using COMSOL Multiphysics and is provided courtesy of COMSOL

Image made using COMSOL Multiphysics and is provided courtesy of COMSOL

One such company is Arkansas Power Electronics Intl. (APEI), a manufacturer of high-power density and high performance power electronics products. APEI has found that the Application Builder can provide enormous benefits throughout the organization.

“I’m building applications to help us expedite our design processes,” says Brice McPherson, a Senior Staff Engineer at APEI. “Our engineers often spend time running analyses for the sales or manufacturing departments to find model results based on diverse conditions and requirements. The Application Builder will be hugely important for accelerating our work in this respect; any colleague outside of the engineering team will now be able to confidently run these studies by themselves, with no learning curve.”

The first application built by APEI looks at fusing current and ampacity of wire bonds—very small wires used to interconnect semiconductor devices with their packages.

The team at APEI envisions using the Application Builder for a variety of other projects, including applications to automate and streamline the calculation of wire bond inductance, package thermal performance, and more.

Source: COMSOL

Electrical Engineering Crossword (Issue 291)

The answers to Circuit Cellar’s October electronics engineering crossword puzzle are now available.291crossword (key)

Across

4.     PARAMETRON—Phase-locked oscillator

8.     UNBALANCED—Single-ended

9.     STRAY—Unwanted capacitance

10.   LEYDENJAR—Early capacitor [two words]

12.   ELECTROLYTE—Conducting fluid

14.   CROSSTALK—Caused when one circuit’s signal creates an unwanted effect on another

16.   ANECHOIC—Absorbs sound or electromagnetic wave reflections

17.   BIFILAR—Used in bipolar power-supply transformers to improve output voltage symmetry

18.   CRYSTALRECTIFIER—Semiconductor diode [two words]

19.   DOPPLEREFFECT—Frequency change that occurs when emitter and receiver move in unison [two words]

Down

1.     BLEEDER—A resistor that draws the critical amount of load current

2.     GAUSSMETER—Detects magnetic anomalies

3.     HETERODYNE—Two frequencies combine to produce new ones

5.     SURFACEMOUNT—Place components directly on PCBs [two words]

6.     HASH—Garbage or gibberish

7.     GALVANOMETER—Measures small voltages

11.   RECTIFIER—Passes current in only one direction

13.   CATWHISKER—Sharp, flexible wire that connects to a semiconductor crystal’s surface [two words]

15.   ANOTRON—Cold-cathode-glow discharge diode

 

Electrical Engineering Crossword (Issue 290)

The answers to Circuit Cellar’s September electronics engineering crossword puzzle are now available.CrosswordEmptyGrid (key)

Across 

2.     THREE—Trivalent valence

3.     PHYSICS—Kilby’s Noble Prize in 2000

5.     INVERTER—Converts DC to AC

8.     BATCH—BAT file

9.     MAXIM—Founded ARRL in 1914

10.   KEYBOARD—If you are AFK, what are you away from?

11.   UPENN—University that housed the ENIAC in a 30’ × 40’ room

12.   HERTZ—1 cycle per second

14.   NIBBLE—4 bits

17.   EXPLAINER—Asimov was the great what?

Down

1.     TRACK—PCB path

3.     PATCH—Quick fix

4.     SNIFFER—Used to monitor network traffic

6.     MAXWELL—A Gauss is one of these per square centimeter

7.     IBM—”Big Blue”

8.     BOOLE—“An Investigation of the Laws of Thought” (1854)

13.   TOGGLE—Move from setting A to B

15.   BLUE—Screen of death

16.   NINE—A nonet is a group of what?

17.   EW—Exawatt

Electrical Engineering Crossword (Issue 289)

The answers to Circuit Cellar’s August electronics engineering crossword puzzle are now available.289PuzzleGrid (key)

Across

1.     FAST—Ethernet at 100 Mbps

3.     FAB—IC factory

6.     XOR—Logic gate

7.     VERILOG—HDL created in the early 1980s by Goel and Moorby

9.     MIL—0.001 inches = 25.4 what?

10.   AMPHOUR—Current flow over time [two words]

13.   SANTOS—Greek national soccer team manager with a degree in electrical engineering

14.   NOLEAD—Quad, flat, … [two words]

16.   BUCK—Step-down

17.   FEMTO—0.000000000000001

18.   GND—Ground pin

19.   NULL—Zero

Down

2.     SLICE—Wafer or substrate

3.     FILO—Antonym for FIFO

4.     QUINARY—Base-5

5.     CODERDECODER—CODEC [two words]

7.     VERSORIUM—Gilbert’s static-detection device

8.     DISSIPATION—Release heat

11.   HAPTIC—Relates to touch

12.   JOULE—1 watt second

15.   DOPING—Process of purposely adding impurities

Electrical Engineering Crossword (Issue 288)

The answers to Circuit Cellar’s July electronics engineering crossword puzzle are now available.288Crossword (key)

Across

2.     QUIESCE—Inactive but still available

4.     GLUELOGIC—Used for circuitry interfacing [two words]

7.     AMAYA—Open-source web tool developed by members of the World Wide Web Consortium (W3C)

8.     ROUNDROBIN—A continuous sequence [two words]

9.     FATCLIENT—A tower PC, for example [two words]

11.   LOGICBOMB—Explosive code [two words]

15.   HEISENBUG—A software glitch that changes its conduct when analyzed

16.   STROBOSCOPE—Makes things appear to move slowly or not at all

17.   STATAMPERE—Approximately 0.333 nanoampere

18.   KORNSHELL—Unix command-line interpreter developed by and named after a Bell Labs employee [two words]

19.   VOXEL—Defines a point in 3-D

Down

1.     BEAMFORMING—Signal processing for sensor arrays

3.     SPIBUS—Works in double-duplex mode [two words]

4.     GREP—UNIX-based command-line utility

5.     SUPERHETERODYNE—Used to convert to intermediate frequencies

6.     ENDIAN—Creates data words

10.   PHOTOVOLTAICS—Uses solar power to create energy

12.   BITTORRENT—File sharing protocol

13.   BINARYPREFIX—E.g., gibi [two words]

14.   AUSTRUMI—Linux distribution based on Slackware

 

Linear LT3999 DC/DC Transformer Driver

Linear Technology recently launched the LT3999 monolithic push-pull isolated DC/DC transformer driver with two 1-A current limited power switches. It operates over an input voltage of 2.7 to 36 V and is targeted for power levels up to 15 W, making it a good option for a variety of industrial applications.

Source: Linear Technology

Source: Linear Technology

The LT3999’s features include:

  • Wide VIN range: 2.7 to 36 V
  • Dual 1-A switches
  • Programmable switching frequency: 50 kHz to 1 MHz
  • Synchronizable to an external clock up to 1 MHz
  • Duty cycle control for output voltage regulation
  • Low noise topology
  • Programmable input over- and under-voltage lockout
  • Cross-conduction prevention circuitry
  • Extended and industrial grades: –40° to 125°C operating junction temperature
  • Automotive temperature grade: –40° to 150°C operating junction temperature
  • Military temperature grade: –55° to 150°C operating junction temperature

The LT3999’s 1,000-piece price starts at $2.75 each for the E-grade.

Source: Linear Technology

 

New 8-Bit PICs for Sensor Applications

Microchip Technology recently expanded it’s PIC12/16LF155X 8-bit microcontroller family with the PIC16LF1554 and PIC16LF1559 (PIC16LF1554/9), which are targeted toward a variety of sensor applications. The PIC16LF1554/9 features two independent 10-bit, 100,000 samples per second ADCs with hardware Capacitive Voltage Divider (CVD) support for capacitive touch sensing.

Source: Microchip Techno

Source: Microchip Techno

Watch a short video:

The PIC16LF1554 MCUs are available now for sampling and production in 14-pin PDIP, TSSOP, SOIC, and 16-pin QFN (4 x 4 x .9 mm) packages. The PIC16LF1559 MCUs are available for sampling and production in 20-pin PDIP, SSOP, and QFN (4 x 4 x .9 mm) packages. Pricing starts at $0.63 each, in 10,000-unit quantities.

Source: Microchip Technology

EIM Bootcamp: Circuit Cellar Today & Tomorrow

BBC47

Elektor bootcamp discussion

Want a behind-the-scenes look at the Elektor and Circuit Cellar teams?  You can link to a short, free report on my recent visit to our company headquarters in Limbricht, Netherlands, where EIM staffers from around the globe met up for a corporate “bootcamp.” The purpose of the meeting was to assess the company’s current offerings (magazines, books, kits, etc.), discuss the needs of members, and plan for the future.

DOWNLOAD REPORT

Embedded Security (EE Tip #139)

Embedded security is one of the most important topics in our industry. You could build an amazing microcontroller-based design, but if it is vulnerable to attack, it could become useless or even a liability.  EmbeddSecurity

Virginia Tech professor Patrick Schaumont explains, “perfect embedded security cannot exist. Attackers have a wide variety of techniques at their disposal, ranging from analysis to reverse engineering. When attackers get their hands on your embedded system, it is only a matter of time and sufficient eyeballs before someone finds a flaw and exploits it.”

So, what can you do? In CC25, Patrick Schaumont provided some tips:

As design engineers, we should understand what can and what cannot be done. If we understand the risks, we can create designs that give the best possible protection at a given level of complexity. Think about the following four observations before you start designing an embedded security implementation.

First, you have to understand the threats that you are facing. If you don’t have a threat model, it makes no sense to design a protection—there’s no threat! A threat model for an embedded system will specify what can attacker can and cannot do. Can she probe components? Control the power supply? Control the inputs of the design? The more precisely you specify the threats, the more robust your defenses will be. Realize that perfect security does not exist, so it doesn’t make sense to try to achieve it. Instead, focus on the threats you are willing to deal with.

Second, make a distinction between what you trust and what you cannot trust. In terms of building protections, you only need to worry about what you don’t trust. The boundary between what you trust and what you don’t trust is suitably called the trust boundary. While trust boundaries were originally logical boundaries in software systems, they also have a physical meaning in embedded context. For example, let’s say that you define the trust boundary to be at the chip package level of a microcontroller.

This implies that you’re assuming an attacker will get as close to the chip as the package pins, but not closer. With such a trust boundary, your defenses should focus on off-chip communication. If there’s nothing or no one to trust, then you’re in trouble. It’s not possible to build a secure solution without trust.

Third, security has a cost. You cannot get it for free. Security has a cost in resources and energy. In a resource-limited embedded system, this means that security will always be in competition with other system features in terms of resources. And because security is typically designed to prevent bad things from happening rather than to enable good things, it may be a difficult trade-off. In feature-rich consumer devices, security may not be a feature for which a customer is willing to pay extra. The fourth observation, and maybe the most important one, is to realize is that you’re not alone. There are many things to learn from conferences, books, and magazines. Don’t invent your own security. Adapt standards and proven techniques. Learn about the experiences of other designers. The following examples are good starting points for learning about current concerns and issues in embedded security.

Security is a complex field with many different dimensions. I find it very helpful to have several reference works close by to help me navigate the steps of building any type of security service.

Schaumont suggested the following useful resources:

3400-F Ultracapacitor

Maxwell Technologies has announced the addition of a 2.85-V, 3400-F cell to its K2 family of ultracapacitors. It is the most powerful cell available in the industry-standard, 60-mm cylindrical form factor. Incorporating Maxwell’s DuraBlue Advanced Shock and Vibration technology, it is a rugged cell that’s suitable for high-energy storage in demanding environments (e.g., in public transit vehicles).maxwell

The electrostatic charge can be cycled over a million times without performance degradation. The cells can also provide extended power and energy for long periods of propulsion in automotive subsystems and give fast response in UPS/Backup Power and grid applications to ensure critical information is not lost during dips, sags, and outages in the main power source. In addition, they can relieve batteries of burst power functions, thereby reducing costs and maximizing space and energy efficiency.

The K2 family of cells work in tandem with batteries for applications that require both a constant power discharge for continual function and a pulse power for peak loads. In these applications, the ultracapacitor relieves batteries of peak power functions resulting in an extension of battery life and a reduction of overall battery size and cost. The cells are available with threaded terminals or with compact, weldable terminals.

[via Elektor]

Dutch Designer’s “Comfort Zone”

Check out this amusing workspace submission from Henk Stegeman who lives and works in The Netherlands (which is widely referred to as the land of Elektor). We especially like his Dutch-orange power strips, which stand out in relation to the muted grey, white, and black colors of his IT equipment and furniture. StegemanWorkspace

Some might call the space busy. Others might say it’s cramped. Stegeman referred to it his “comfort zone.” He must move and shift a lot of objects before he starts to design. But, hey, whatever works, right?

Hi,

Attached you picture of my workspace.
Where ? (you might ask.)
I just move the keyboard aside.
To where ?
Euuh… (good question)

Regards

Henk
The Netherlands

Visit Circuit Cellar‘s Workspace page for more write-ups and photos of engineering workbenches and tools from around the world!

Want to share your space? Email our editorial team pics and info about your spaces!

WIZnet Announces WIZ550io & W5500 Discounts at EELive

Today at EELive! in San Jose, CA, WIZnet announced a special promotion tied to the WIZnet Connect the Magic 2014 Design Challenge, which it is sponsoring. For a limited time, WIZnet is offering discounted WIZ550io Ethernet controller modules and W5500 chips via its webshopWiznet-Challenge-EELive

Disclosure: Elektor International Media and Circuit Cellar comprise the challenge administration team.

At this time, WIZnet’s WIZ550io is on sale for $9.95 (original price, $17.00) and the W550 cost $1.49 (original price, $2.87).

WIZnet’s WIZ550io is a module for rapidly developing ’Net-enabled systems. It is an auto-configurable Ethernet controller module that includes the W5500 (TCP/IP-hard-wired chip and PHY embedded), a transformer, and an RJ-45 connector. The module has a unique, embedded real MAC address and auto network configuration capability.

WIZnet's WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

WIZnet’s WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

The W5500 is a hardwired TCP/IP embedded Ethernet controller that enables Internet connection for embedded systems using Serial Peripheral Interface (SPI).

W5500

W5500

Visit the WIZnet Connect the Magic 2014 Design Challenge webpage for more information about participation and eligibility.

IR Remote Control Testing (EE Tip #119)

On the Internet you can find them in all shapes and sizes: circuits to test remote controls. Here I describe a simple and cheap method that is not that well-known.

This method is based on the principle that an LED does not only generate light when you apply a voltage to it, but also works in the opposite direction to generate a voltage when light falls on it. Within constraints it can therefore be used as an alternative for a proper phototransistor or photodiode. The major advantage is that you will usually have an LED around somewhere, which may not be true for a photodiode.

IR remote tester

IR remote tester

This is also true for infrared (IR) diodes and this makes them eminently suitable for testing a remote control. You only need to connect a voltmeter to the IR diode and the remote control tester is finished. Set the multimeter so it measures DC voltage and turn it on. Hold the remote control close to the IR diode and push any button. If the remote control is working then the voltage shown on the display will quickly rise. When you release the button the voltage will drop again.

However, don’t expect a very high voltage from the IR diode! The voltage generated by the diode will only be about 300 mV, but this is sufficient to show whether the remote control is working or not. There are quite a few other objects that emit IR radiation. So, first note the voltage indicated by the voltmeter before pushing any of the buttons on the remote control and use this as a reference value. Also, don’t do this test in a well lit room or a room with the sun shining in, because there is the chance that there is too much IR radiation present.

To quickly reduce the diode voltage to zero before doing the next measurement you can short-circuit the pins of the diode briefly. This will not damage the diode.—Tom van Steenkiste, Elektor, 11/2010

Want tips about testing power supplies? We’ve got you covered! EE Tip #112 will help you determine the stability of your lab or bench-top supply!

Arduino-Based DIY Voltage Booster (EE Tip #117)

If your project needs a higher voltage rail than is already available in the circuit, you can use an off-the-shelf step-up device. But when you want a variable output voltage, it’s less easy to find a ready-made IC. However, it’s not complicated to build such a circuit yourself, especially if you have a microcontroller board that’s as easy to program as an Arduino. And this also lets you experiment with the circuit so you can get a better understanding of how it works.

Source: Elektor, April 2010

Source: Elektor, April 2010

No surprises in the circuit—a largely conventional boost converter. The MOSFET is driven by a pulse width modulated (PWM) signal from the microcontroller, and the output voltage is measured by one of the microcontroller’s analog inputs. The driver adjusts the PWM signal according to the difference between the output voltage measured and the voltage wanted.

We don’t have enough space here to go into details about how this circuit works, but it’s worth mentioning a few points of special interest.

The small capacitor across the diode improves the efficiency of the circuit. The load is represented by R3. The components used make it possible to supply over 1 A (current limited by the MSS1260T 683MLB inductor from Coilcraft), but maximum efficiency (89%) is at around 95 mA (at an output voltage of 10 V). To avoid damaging the controller’s analog input (≤5 V), the output voltage may not exceed 24 V. For higher voltages, the values of resistors R1 and R2 would need to be changed.

The MOSFET is driven by the microcontroller, which is nothing but a little Arduino board. The Arduino’s default PWM signal frequency is around 500 Hz—too low for this application, which needs a frequency at least 100 times higher. So we can’t use the PWM functions offered by Arduino. But that’s no problem, as the Arduino can also be programmed in assembler, allowing a maximum frequency of 62.5 kHz (the microcontroller runs at 16 MHz). To sample the output voltage, a frequency of 100 Hz is acceptable, which means we can use Arduino’s standard timers and analog functions. The Arduino serial port is very handy: we can use it for sending the output voltage set point (5–24 V) and for collecting certain information about the operation. Thanks to the Arduino environment, it only took about half an hour to program. Software is available. — Clemens Valens (Elektor, April 2010)

PCB Design Guidelines (EE Tips #113)

Designing a matching printed circuit board (PCB) can be a challenge for many electronics enthusiasts. To help ease the process, Circuit Cellar and Elektor editors compiled a list of tips for laying out components, routing, and more.PCB1

  • When compactness is not a major consideration and the boards will be assembled by hand, through-hole components are the better choice. In this case you can use the pins of these components as “vias.”
  • On the other hand, surface-mount components can save a whole load of drilling on self-made PCBs. They make it simpler to achieve objectives such as minimum length for traces , minimal area inside trace loops, etc.
  • The orientation of components should consider not only simplicity of assembly but also the need to test the circuitry afterward. This is the time to remember the need for test points!
  • The place for switches, press buttons, plug-in connectors, LEDs and other user-interface components is outside the enclosure. Anything requiring subsequent access should be on the front panel of the case.
  • Components that require assembling with the right polarity should all have the same orientation.
  • Manual routing is preferable to using the autorouter. The latter has its uses nevertheless for discovering bottlenecks and other critical points.
  • When routing, never even think about giving up! Many PCBs appear “unroutable” at the outset, yet after a while it turns out you have plenty of space to spare.
  • If you’re not satisfied with your efforts, it’s better to go back a step or two rather than just muddle onwards.
  • Complete the routing for each of the functional groups of the circuit first. Link the groups together only after you have finished this stage.
  • Short traces are better than long ones. High impedance connections are more sensitive to interference and for this reason require to be kept as short as possible.
  • Where traces form a loop, their surface area should be kept to an absolute minimum.
  • Decoupling capacitors must be located as close as possible to the switching element that needs to be decoupled.
  • Traces carrying signals should be routed early on (first the short ones, then the long ones). Except, that is, when the power supply traces are particularly critical.
  • Bus lines should be routed alongside one another.
  • Separate analog circuitry from digital whenever possible.PCB2
  • On multilayer boards arrange traces carrying signals so that one of the layers hosts the vertical traces and another one accommodates the horizontal ones.
  • If possible, reserve one layer or side exclusively for a continuous ground plane. Only in exceptional situations, e.g. with high speed op-amps, is this undesirable.
  • Keep traces carrying heavy currents well away from sensitive pickups, sensors and so on.
  • Beginners should take special care with mains and high voltages!
  • Ground and earth traces require exactly the same consideration as the power supply traces. Electromagnetic interference can be minimized by keeping the power and ground traces parallel (or better still arranged over each other on either side of a double-sided board).
  • Bends should be no more than 45°. Sharp angles between the traces and the pads are also to be avoided.
  • Observe PCB manufacturers’ requirements without exception in order to avoid unpleasant surprises later.
  • If you are using software for checking conformity to specifications, carry out these checks regularly at each design phase.
  • A border of 0.12″ (approximately 3 mm) around the edge of the PCB should be kept entirely clear of components.
  • If components are to be inserted by machine you must provide at least three location marks.
  • Don’t forget the holes for fixing screws or pillars!
  • Don’t skimp on text markings on the PCB: indicate polarity, voltages, on-board functions, part designation, design date, version number…
  • Check not just twice but three times that all components will actually fit the PCB!
  • Leave time at the end of the process for tidying up and optimizing.

Good luck!