Control Engineering's Ask Charlie blog covers all aspects of automation, especially discrete control, motors, drives, sensors, motion control, machine control and embedded systems. C.G. Masi answers questions from readers of Control Engineering's print and online magazines, newsletters and other publications. To comment on any blog posting, click on the post's highlighted question and scroll to the "Post a Comment" box at the bottom. Submit questions as comments to any existing post. When you submit a question, be sure to include your name, company name, job title and mailing address, and we'll send you your very own "Engineer and Proud of It!" pocket protector. en-us http://www.controleng.com/blog/820000282.html?nid=4165 Copyright 2008 Reed Business Information. Subject to its Terms of Use July 18, 2008 http://www.controleng.com/blog/820000282/post/20029602.html?nid=4165 Machine vision is not a discipline in itself, such as mechanical engineering. It is a skill involving specialized equipment. How you should go about gaining that skill depends on your goals. If you simply want to gain proficiency with specific equipment in your shop (as is the case with the pers… http://www.controleng.com/blog/820000282/post/410029041.html?nid=4165 Mathematically, a pole is any geometric singularity. For example, the Earth’s north and south poles are places where lines of longitude meet in singularities. In other words, the longitudes of these poles are undefined. Actual, physical poles don't seem to exist. Black holes are theoretical si… http://www.controleng.com/blog/820000282/post/1530028953.html?nid=4165 Digital filters capitalize on the fact that digital electronics looks at waveforms as a timed sequence of values, rather than instantaneous voltages. Digital filters start with an analog waveform, convert it to a digital waveform, perform operations on the digital values, then convert the waveform b… http://www.controleng.com/blog/820000282/post/970028697.html?nid=4165 I mentioned chemistry as being important to a mechatronics engineer working on environmental projects in my June 9, 2008 blog entry, and for most such projects that would be true. The thing to keep in mind is that mechatronics engineering integrates development projects at a very high level. Traditi… http://www.controleng.com/blog/820000282/post/1490028149.html?nid=4165 The other day, Control Engineering process industries editor Pete Welander and I were talking about the evolution of various standards on the way out to the parking lot, when this week’s question came up. We couldn’t remember quite when RCA connectors, one of several competing standards … http://www.controleng.com/blog/820000282/post/1600027760.html?nid=4165 Mechatronics is a cross-disciplinary system-level discipline. So, a mechatronics engineer needs a very broad technical background as well as communication and interpersonal skills. The term system-level gets bandied about a lot, but I’m not too sure how many engineers have a good working d… http://www.controleng.com/blog/820000282/post/150027415.html?nid=4165 Anyone who has actually put an operating laptop computer on top of their lap knows why cooling is important for any computer. Microprocessors dissipate a lot of electric power, which turns into heat, which must be removed somehow. They do this despite the fact that the metal-oxide-semiconductor (MOS… http://www.controleng.com/blog/820000282/post/790027079.html?nid=4165 The full text of the question is: Could you recommend some handheld instruments that can easily measure and indicate room air pressure (positive or negative, and how much)? The short answer is “No.” As a journalist I can’t recommend products. Also, I would need more information… http://www.controleng.com/blog/820000282/post/1270026727.html?nid=4165 The reader who sent in this question said he normally sizes motors to run at between 75% and 100% of rated speed, but asks about overdriving by 150% by setting the variable frequency drive (VFD) at 90 Hz, rather than 60 Hz. My knee-jerk reaction was that most AC motors can take it for short burs… http://www.controleng.com/blog/820000282/post/1080026308.html?nid=4165 As I was walking down the corridor at the last Embedded Systems Conference, a man stopped me. “I saw your media badge,” he said, “so I wanted to speak to you about my company GruntWare Inc.” Zen training has given me infinite patience, so I told him I’d listen to wh… http://www.controleng.com/blog/820000282/post/1720025972.html?nid=4165 Don't feel bad about being confused by "medium voltage drives" terminology. It’s a confusing because it sounds like a technical term, but really it’s marketing driven. Actually, there are two terms that can be confusing to anyone new to the field of automated control of electri… http://www.controleng.com/blog/820000282/post/990025499.html?nid=4165 This question relates to comments I made in an article that appeared in the March issue of Control Engineering entitled, “The culinary art of mechatronics.” In that article, I described the (so far) four generations of programming language, which are roughly: 1GL — machine code (… http://www.controleng.com/blog/820000282/post/480025248.html?nid=4165 We are indebted to Bill McGovern, national sales manager for Dataforth Corporation for this detailed history. The birth of battery technology is credited to the Italian physicist Luigi Galvani who, in 1780, discovered that a frog’s leg would “twitch” when brass hooks attached t… http://www.controleng.com/blog/820000282/post/1790024779.html?nid=4165 Off the top of my head, I can think of 3 non-volatile random access memory (NVRAM) technologies in current use. I’m here defining NVRAM as a bitwise readable, writeable, and erasable memory technology for typical general purpose computers. In NVRAM devices, each bit has its own memory address,… http://www.controleng.com/blog/820000282/post/620024462.html?nid=4165 Flash memory cells individually resemble metal-oxide-semiconductor field effect transistors (MOSFETs) with an extra electrode. N-channel MOSFETs consist of two highly doped N-type silicon spots (source and drain) in a lightly doped P-type substrate connected to ground. Electrical connections are mad… http://www.controleng.com/blog/820000282/post/1540023954.html?nid=4165 A buck regulator, more properly called a buck convertor, is a dc-dc step-down power supply utilizing the fact that inductors react to electric-circuit fluctuations in such a way to keep the current flowing through them constant. This inductor property follows directly from Faraday’s Law: … http://www.controleng.com/blog/820000282/post/1790023979.html?nid=4165 I’m revisiting this question because at least one reader was confused by my answer of March 24. If there’s one who commented, there must be many others who were also confused, but didn’t. So, I’ll try to clarify. The full text of the question I was trying to answer i… http://www.controleng.com/blog/820000282/post/1020023702.html?nid=4165 I’m not sure you’re asking the right question. What you really need for control applications is a controller, which is a complete computer system, not just the microprocessor. As a control engineer, that is what you want to concentrate on. The figure below shows a simple single-axis … http://www.controleng.com/blog/820000282/post/750023475.html?nid=4165 The full text of this question reads: What do we mean by say, 45 nanometer (45 nm) process in semiconductor fabrication? Does it refer to smallest component size or the wafer thickness? What are the difficulties and the limits in reducing the size? It is neither. Semiconductor fabrication proces… http://www.controleng.com/blog/820000282/post/600023060.html?nid=4165 The full text of this question is: I need to transmit voltage from fusebox to a receiver 5 m away. What kind of transmitter and receiver do I need? Good news is that 5 m is actually not a very long way to carry a voltage signal, so you may not need any transmitter at all, and you probably al… http://www.controleng.com/blog/820000282/post/300022630.html?nid=4165 Let me start by admitting that simulating a whole robot is a lot more complex than the simple mechatronic systems I’ve done in the past. That’s a quantitative difference, however, rather than a qualitative one. The approach is the same. In this entry, I’ll only have room to outline… http://www.controleng.com/blog/820000282/post/860022286.html?nid=4165 After an exhaustive Internet search (meaning that I searched until exhausted), I’m forced to conclude that “Power is nothing without control” originated as a marketing slogan for the Pirelli Tyre company. Despite its origin as a marketing slogan, there is good reason to recognize i… http://www.controleng.com/blog/820000282/post/1690021969.html?nid=4165 The acronym MRAM stands for magnetoresistive random access memory, or, alternatively, magnetic random access memory. MRAMs are a class of non-volatile random access memory (NVRAM) devices in which information bits are coded in the magnetic polarization direction of individual magnetic memory cells. … http://www.controleng.com/blog/820000282/post/1490021549.html?nid=4165 This question comes from Lynn Wheat, senior project engineer at AOC, a global supplier of resins, gel coats, colorants, and additives for composites and cast polymers, who earns an “Engineer, and Proud of It” pocket protector for sending it in. Lynn, who was responding to a sidebar i… http://www.controleng.com/blog/820000282/post/960021096.html?nid=4165 I first ran into the terms “top-down design” and “bottom up design” in the mid-1980s when working as a business systems analyst at radiopharmaceutical manufacturer New England Nuclear in Billerica, MA. At that time and in that department, there seemed to be some debate over w…