Archivo Descargado desde las WEBS http://www.enigmaelectronica.tk Http://www.enigma.phpnet.us By enigmaelectronica > 01 $7.00 CANADA $5.50 74470 89295 03 U.S. Cover.qxd 12/11/2008 1:25 PM Page 1 Vol. 30 No. 1 NUTS & VOLTS PROTO BUDDY • SPICE SIMULATION • MOSFETS • How To - SMT SOLDERING January 2009 Jan 09.qxd 12/10/2008 6:02 PM Page 6 January 2009 www.nutsvolts.com C o n t e n t s Features 50 Power MOSFETs ■ By Gerard Fonte Part 1 will cover the theory behind these useful devices that have a lot of overlooked features. 54 A Touch of Spice ■ By Peter Stonard This month, make discoveries about IC circuits that are well-known and learn more about the concepts of sub-circuits and macromodels. 60 How To: Surface Mount Soldering ■ By Robert Doerr Get over your fear of working with these tiny components. Page 44 Page 40 Projects Columns 34 Instrumentation for Model Rocketry Incorporate additional instrumentation to a flight recorder 12 TechKnowledgey 2009 to measure a rocket’s rate of roll, relative altitude, and Events, Advances, and News booster-stage separation detection. ■ By Michael Bessant Topics covered include reconnecting brain ●●●● Advanced Level cells, a new unified storage appliance, don’t mix headphones and pacemakers, plus more. 40 16x16 Tri-Colored LED Matrix — 15 Personal Robotics Real Time Clock for the Parallax SX52 Understanding, Designing & Constructing This project allows the user to create their own scrolling Robots display to show the time (or other messages) in multiple Robo resolutions for 2009. colors. ■ By Timothy Gilmore ●●●● Advanced Level 18 Stamp Applications Putting the Spotlight on BASIC Stamp 44 The Proto Buddy Projects, Hints & Tips Control from the couch — redux. Take proto circuit building to the next level with this device that allows you to expand your existing board so you can create all kinds of circuits. ■ By Jim Stewart 26 Q & A ●●●● Reader Questions Answered Here Intermediate Level High impedance preamp, audio to LED display driver, FM shutdown problem, more. Departments 68 Getting Started With PICs 08 DEVELOPING 86 NV WEBSTORE The Latest in Programming Microcontrollers 2 PERSPECTIVES 90 CLASSIFIEDS I C communication. 31 NEW PRODUCTS 92 TECH FORUM 32 SHOWCASE 96 AD INDEX 72 The Design Cycle Advanced Techniques for Design Engineers 66 ELECTRO-NET Chatting up a thumbdrive. Nuts & Volts (ISSN 1528-9885/CDN Pub Agree #40702530) is published monthly for $24.95 per year by T & L Publications, Inc., 430 Princeland Court, Corona, CA 92879. PERIODICALS 80 Smiley’s Workshop POSTAGE PAID AT CORONA, CA AND AT ADDITIONAL MAILING OFFICES. POST- An AVR C Programming Series MASTER: Send address changes to Nuts & Volts, P.O. Box 15277, North Hollywood, CA 91615 or Station A, P.O. Box 54,Windsor ON N9A 6J5; [email protected]. A menu navigator. 6 January 2009 DevPerspectives.qxd 12/11/2008 2:13 PM Page 8 DEVELOPING by Bryan Bergeron, Editor PERSPECTIVES Building a Home Recording Studio consideration, as is available space. A popular, low-cost option ($350 and up) is a studio ant to test the extent of your knowledge of applied in a box. This is an all-in-one, stand-alone recording Welectronics? Then try designing a home recording appliance, such as the 64-track Boss BR-600 Digital studio. Thanks to the affordable music recording and Recorder, with built-in microphone, drum machine, and playback devices you can have fun creating your own signal processing effects. A laptop or desktop computer music. Moreover — from an electronics enthusiast’s with an analog-to-digital interface for capturing sound and perspective — a home recording studio is a place where associated software, as well as microphones and preamps, you can apply your creativity. However, designing and is a modest cost solution. A computer offers more then getting the most out of a home recording studio flexibility and room for growth than a studio in a box. requires a considerable understanding of electronics, from power supplies and digital signal processing to acoustics. Power I’ve learned — the hard way — that the first thing to Options be aware of is the seemingly odd standards of the music Various options available for creating a home industry. For example, the power supply polarity used by recording studio range from a pocket digital recorder effects pedals and other audio peripherals is often and built-in microphone in your bedroom to a dedicated, ‘reversed.’ That is, it’s common practice with audio gear acoustically treated room with the latest computer outfitted with coaxial power connectors to have the hardware and software tools, professional microphones, outside of the jacket positive and the inside negative — mixers, and signal processors. Budget is obviously a exactly the opposite of most consumer electronics. I’ve &2/.40!.%,3%.#,/352%3 #USTOMIZEDFRONTPANELSCANBEEASILY DESIGNEDWITHOURFREESOFTWARE &RONT0ANEL$ESIGNER s #OST EFFECTIVEPROTOTYPES ANDPRODUCTIONRUNS s 7IDERANGEOFMATERIALSOR CUSTOMIZATIONOFPROVIDED MATERIAL s !UTOMATICPRICECALCULATION s &ABRICATIONIN ORDAYS 3AMPLEPRICE PLUS3( WWWFRONTPANELEXPRESSCOM 8 January 2009 DevPerspectives.qxd 12/10/2008 3:48 PM Page 9 mistakenly plugged in a standard power brick to a preamp, the signal chain. This can be accomplished by using a which resulted in a fried one. You can avoid this mistake 3-to-2 pronged adapter. Some gear has a built-in ground by clearly marking your music power supply bricks to lift switch. There are obvious safety issues associated with distinguish them from your standard polarity bricks. lifting the ground in an AC powered device. In short, don’t allow your body to complete a ground fault circuit. Computer Tools Continued on page 10 Another industry standard that you’ll discover is Digidesign’s Pro Tools. This software and hardware combi- nation enables you to record and then manipulate sound on your PC. There are numerous software options for both PCs and Macs. For example, I use Logic Studio on a Mac. However, Pro Tools is the entrenched standard. Regardless of your computer hardware and software, you’ll need lots of disk storage and, more importantly, high throughput. Think fast terabyte drives. Expect to use 0.5 GB or more for an eight-track recoding of a 10 minute song. Cables Cables and connectors for recording are specialized. When selecting cable, think thick copper to minimize resistance losses. Conversely, when you select high-imped- ance microphone and instrument cables, think shielding for noise reduction and minimum capacitance per foot to minimize high frequency loss. Bulky XLR and old-fash- ioned 1/4 inch still handle most of the audio signals in a home or professional recording studio. While on the topic of impedance matching, consider that microphones, guitars, and other instruments typically present a high-impedance output (15K–1M ohm) which is much higher than the typical low-impedance line input to an analog-to-digital converter. You'll need a preamp or a direct box to compensate for the impedance mismatch and assure the signal level is appropriate for your input device. A direct box can be as simple as a transformer with input and output connectors. Signal Processors Stand-alone, floor, and rack- mounted signal processing options — filters, amplifiers, and various effects — can help you achieve the tone you demand. At a minimum, you should consider an eight channel virtual or hardware mixing board. A mixer allows you to adjust levels of various inputs and combine them into a single mono or stereo track. I prefer the feel of a real hardware mixer over a virtual mixer defined in software. Ground One of the headaches of connecting a half-dozen amplifiers, effect boxes, and computers together is that you have to pay attention to ground loops. Often, the only practical way to remove 60 Hz hum from the audio signal is to lift the ground on one or more devices in January 2009 9 DevPerspectives.qxd 12/10/2008 8:21 PM Page 10 Continued from page 10 Information You can be the best circuit designer in the world and find yourself lost Published Monthly By in the vocabulary and sheer volume of choices in the home recording world. T & L Publications, Inc. Prepare to spend some time in your local music store or, better yet, with 430 Princeland Ct. someone who has a system up and running. And avoid the common misstep Corona, CA 92879-1300 of designing your home recording studio one component at a time. You could (951) 371-8497 FAX (951) 371-3052 run out of money before you're through and end up with a mismatched, Webstore orders only 1-800-783-4624 expensive system. Better to configure the entire system and then look for the www.nutsvolts.com best price. Subscriptions Of course, you can save money — and have fun — by making your own Toll Free 1-877-525-2539 cables, effects boxes, and signal monitoring devices. NV Outside US 1-818-487-4545 P.O. Box 15277 North Hollywood, CA 91615 FOUNDER/ASSOCIATE PUBLISHER Jack Lemieux PUBLISHER Larry Lemieux [email protected] ASSOCIATE PUBLISHER/ VP OF SALES/MARKETING Robin Lemieux [email protected] EDITOR Bryan Bergeron [email protected] TECHNICAL EDITOR Dan Danknick [email protected] CONTRIBUTING EDITORS Jeff Eckert Russ Kincaid Vern Graner Fred Eady Joe Pardue Peter Stonard Gerard Fonte Mike Bessant Timothy Gilmore Robert Doerr Chuck Hellebuyck Jon Williams Jim Stewart CIRCULATION DIRECTOR Tracy Kerley [email protected] SHOW COORDINATOR Audrey Lemieux MARKETING COORDINATOR WEBSTORE Brian Kirkpatrick [email protected] WEB CONTENT Michael Kaudze [email protected] PRODUCTION/GRAPHICS Shannon Lemieux AJ Cohen ADMINISTRATIVE ASSISTANT Debbie Stauffacher Copyright © 2009 by T & L Publications, Inc. All Rights Reserved All advertising is subject to publisher’s approval. We are not responsible for mistakes, misprints, or typographical errors.