Once again, we present our picks for technical tutorials, calculation aids, and useful, interesting reading online.

WEIRD PATENTS
www.patscan.ca//bizarre_patents.html
Need a wall calendar for '05? Go to this site and print out a copy of Patscan's Bizarre Patent Calendar which features an oddball patent for each month of the year. Some of its real winners include a dog umbrella, a hat that doubles as a bird feeder, and a device that prevents thumb sucking. Patscan is a patent and trademark research firm that covers numerous subjects ranging from software business methods to fuel cells.

CHECK OUT URBAN LEGENDS
www.snopes.com/
You've probably heard the one about how cars equipped with remote keyless-entry systems can be unlocked via a cell phone, or that Edison promoted the electric chair in an attempt to discredit rival Westinghouse's plans for alternating current. You can check out these yarns and many others at the Urban Legends reference page. Science and autos are both focus areas, as well as more general subjects.

BONE UP ON MEASUREMENTS
www.NI.com
What we like best about the National Instruments site is the Web events section. You can watch archived tutorials covering various aspects of measurement and simulation technology. They are, of course, free. There are also a variety of text tutorials and application details available on the site as well.

HOLOGRAPHY CENTRAL
www.holography.ru/holoflash.htm
Russian holographic studios have developed a special technology for producing high-quality holograms. This site includes a gallery of Russian high-quality pictorial holograms as well as a series of lessons in holography and holographic technology.

BOB PEASE ONLINE
www.national.com/rap
This is the home page for the popular analog-circuit design guru Bob Pease, who graces the pages of our sister publication Electronic Design. Bob's new site features an archive of his published columns as well as a streaming video talk show he hosts.

PLAIN BEARING RESOURCE
www.ggbearings.com/
This site put up by the world's largest manufacturer of metal-polymer plain bearings features technical information on applying bearings that incorporate metal polymer, solid polymer, fiber-reinforced plastic composite, monometallic, and other materials.

AN EDUCATION IN VISION, LIGHT SENSING
www.bannerengineering.com
You can learn the mechanics and theory behind sensor technology through the short lessons found on this site. Topics include photoelectrics, vision sensors, machine safety, and measurement/inspection.

CHEAP TRAVEL
www.sidestep.com
Trying to stretch that departmental travel budget, or convince your boss that getting to that technical conference you're interested in won't be too expensive? Try this site, which searches airline Web sites and other outlets you wouldn't immediately think of. Makes a good companion to the wellknown travel sites. The site also provides a downloadable browser toolbar.

ELECTRONICS A THROUGH Z
www.alliedelec.com
The venerable Allied Electronics catalog is now online. Well known for stocking everything from test instruments to connectors, the electronic version features online ordering and even an e-newsletter.

ACTUATOR FACTS
www.exlarcorp.com
Go to the engineering reference page on this site to find several engineering resources that aid in learning and applying actuator technology. This area contains a host of engineering guidelines, formulas, manuals, tips and trouble-shooting ideas. Among the topics: Roller-screw basics, sizing and selecting actuators, conversion tables, and more.

LATCHES, HINGES GALORE
www.southco.com/
Fastening and hinging hardware for a wide variety of applications can befound here along with 3D CAD models in IGES or DXF formats, created using a 1:1 mm scale. Files include the views needed to define the products, the appropriate panel preparation, and part numbers.

ECLECTIC ELECTRICS
www.electricstuff.co.uk/
There is enough information on this site to get yourself into a whole lot of trouble: Tesla coils that generate enough energy to light up your neighbor's fluorescent tube lights, lasers that dim the building lights when they power up, and so on. There is also useful stuff such as how to make homebrew PCBs, building a cheap capacitance box, and a DIY PCMCIA serial interface.

HOW TO HANDLE HEATERS
www.watlow.com
Those designing with heating elements will appreciate the Reference section on Watlow's site. Included there are guides and tutorials on corrosion, temperature-sensor comparisons, general methods for determining heater requirements, how to decide where to place temperature sensors, and other useful topics.

FAQs ON LUBRICANTS
www.nyelubricants.com
Go to the Product Literature link on this site from Nye Lubricants and you will find a number of articles on how to use grease and other lubricants as well as what to watch out for in specific kinds of applications. Also there are some handy engineering charts. A separate FAQ page hosts an Ask the Expert form along with questions/answers.

VIEW VISION SYSTEM TUTORIALS
www.cognex.com
Cognex Corp. makes industrial-vision systems and pattern-recognition software. The education center on its site provides access to a variety of tutorial courses and videos. Some cover the operation of Cognex systems but others are basic explanations of lighting techniques and introductions to topics in industrial vision.

MANAGING THERMAL PROBLEMS
www.bergquistcompany.com
The technical library link on this site for a thermal materials company takes you to articles treating various problems in the management of thermal issues in electronics. Also available there are selection guides and application notes.

GUIDE TO RAILS AND GUIDES
www.kerkmotion.com
Kerk Motion makes actuators, slides, leadscrews, and related products. The technology section of its site goes into basics of axial take up, TFE coatings, and other useful specs and data.

RON KHOL BLOG AND FORUM
forums.machinedesign.com
If you like to read MACHINE DESIGN Editor Ronald Khol's editorials you might be interested in his blog postings. Our forum pages also carry the Development Nightmares that run in our electronic newsletters and previously published Vantage Point opinion columns.

IN-DEPTH MOTOR TUTORIALS
www.baldorprospec.com
Baldor Electric makes motors and generators of all shapes and sizes. Its ProSpec site holds a variety of tutorial and application articles that are helpful in designing or applying ac and dc motors. Users can also post questions there that motor experts will respond to within a day. The site requires registration for access, but registration is free.

MOTION EQUIPMENT
www.DanaherMotion.com
This new site features every product manufactured by the well-known Danaher Motion Co. Included is an online attribute-based search function that lets users review the firm's database of motor and drive products. The site offers 3D CAD templates with direct insertion capabilities into several versions of major CAD software platforms. 3D CAD models are available for products that include servomotors, linear bearings, and gearheads, as well as ball and leadscrews.

NEWS FOR NERDS
slashdot.org
First started in 1997 as an informal posting site for techies, Slashdot has evolved into a widely followed science and engineering destination with lively forums. Many of the topics tend to be oriented toward programming or IT but there is something for every kind of technologist here.

PROX, LEVEL, AND THERMAL SWITCHES
www.madisonco.com
This site includes a reference section that covers basics of float switches, multilevel switches, noncontact level switches, proximity and temperature switches, as well as thermocouple data.

FILTERING WITH POROUS METAL
www.appliedporous.com
Applied Porous Technologies develops and makes sintered-porous-metal media, sintered metal, and sintered-metal assemblies for applications in flow control, aeration, sensor protection, venting, and so forth. Under the News section you will find white papers and application information on topics in filtration, sintered-porous metal, etc.