Two articles in the May 2009 issue of Power Electronics Technology magazine got my attention.First, “The Secret Mixed-Signal Life of PWM Peripherals,” looks closely at how to better use pulse-width modulators in microcontrollers. Many designs use a “bare” PWM output to control an external device simply by changing the on-off period to a driver circuit under software control. Keith Curtis, a technical staff engineer at Microchip Technology, explains how to include a few analog components in a control loop to handle some external signal-manipulation functions. Sometimes, the upper pulse-frequency limit of an MCU’s PWM output limit some types of control. The analog components help overcome this barrier. (This article is not a pitch for Microchip products.)
Curtis provides several useful examples in which external analog components enhance the operation of power circuits. Although these examples do not specifically aim to solve motor-control problems, they provide food for thought. Here’s the link to the complete article: powerelectronics.com/power_management/secret_mixedsignal_life_pwm_peripherals_0509. You must click back and forth between the article and each of the six diagrams. The printer-compatible version of the online article also lacks diagrams within the text.
A second article, “P-Channel Power MOSFETs Approach N-Channel Performance,” in the same issue offers information about two families of P-channel power MOSFETs developed by Ixys, the author’s employer. This information looks interesting and possibly useful in motor-control circuits. But this article got my attention for a different reason: Power Electronics Technology published a slightly revised version of the October 2008 Ixys application note, “IXYS P-channel Power MOSFETs and Applications,” IXAN0064 without a reference to its original source. Odd.
Unfortunately, the article/application note doesn’t list any Ixys part numbers–the only thing you can use to search for information on the Ixys Web site. So, that makes it difficult to get more information about the “Polar” and “TrenchP” P-channel MOSFETs from Ixys. But wait… Ixys ran a full-page advertisement for its power MOSFETs one page after the article/application note referred to above, so you might yet find some product information. You’ll have to find a paper copy of the paper magazine to see the ad, though. –Jon Titus
Truchard will be presented the award at the 2014 Golden Mousetrap Awards ceremony during the co-located events Pacific Design & Manufacturing, MD&M West, WestPack, PLASTEC West, Electronics West, ATX West, and AeroCon.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
The IEEE Computer Society has named the top 10 trends for 2014. You can expect the convergence of cloud computing and mobile devices, advances in health care data and devices, as well as privacy issues in social media to make the headlines. And 3D printing came out of nowhere to make a big splash.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.