thewizard-ga
The web has changed the way design engineers select electrical
components, though some of the old methods are hanging in there. The
four main factors that go into any component selection are:
Functionality, Quality, Price and Availability. In the old days, we
used to get on the phone and try to beg free eval (evaluation) parts
from vendors, on the theory that if the design was a success, the
components used in the prototype would have an enhanced chance of
making it into the mass-manufactured product. About the only part of
the begging process that's changed is you can now do it by e-mail!
The main resource for EE's involved in design back then was IC Master.
IC Master has moved to the web and continues to be a major source for
functionality information on ICs and components. You have to register
to use their online service, but it's free. They even have a feature
for checking manufacturer stock, which is critical if you're gearing
up for production.
http://www.ICMaster.com
EE's used to fill their shelves with databooks from the major
component manufacturers, like TI, Mototorla and Intel, which in
addition to component info, contained designs for subsystems. These
days, you can go directly to their websites and download PDFs, which
are easily located using the on-site search engines:
For TI, you can start off at:
http://www.ti.com/sc/docs/psheets/databook.htm
Or you can still call Texas Instruments Literature Response Center at
1-800-477-8924 for the books, but the web versions are more
up-to-date.
The best starting place for Motorola is:
http://e-www.motorola.com/
Motorola literature can still be purchased in book form:
http://merchant.hibbertco.com/mtrlext/help.html
Intel has a well designed site with online literature and books
available at:
http://developer.intel.com/
The big change has come in the area of finding out about components
which you don't know much about. In the old days, we might have turned
to Thomas Register and started contacting manufacturers who included
the part or something similar in their index. Thomas does have a free
version on the web, again you have to register:
http://www.thomasregister.com/
However, the sea change in searching for components is going straight
to Google! Google is also an excellent place to find out about the
potential quality issues with components, by searching on the part
number or brand-name accompanied by "trouble", "failure" or "problem",
to find posts about the component "features" the manufacturer might
not want you know about. By including the terms "datasheet" or "pdf"
in your request, you'll only get returns that include significant
manufacturer's information. After searching Google at their main page
://www.google.com
click on the Groups tab and try again, since design engineers share
information hundred of discussion groups. The more specific you can be
in your search, the better your result will be.
However, the best resource of all is always one's peers, and the
internet allows you to rub elbows with millions. For example, I just
dropped into the group
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&group=sci.electronics.design
And the latest post was "where can I buy components?"
http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&threadm=7c584d27.0208080253.c570cc7%40posting.google.com&prev=/groups%3Fhl%3Den%26lr%3D%26ie%3DUTF-8%26group%3Dsci.electronics.design
IEEE has an excellent site and membership is almost a must for EE
design engineers.
http://www.ieee.org/portal/index.jsp
A final comment on using the web for electronics component procurement
is you can tap into the surplus market. A nicely organized site
listing surplus dealers and along with new distributors and other
information is:
http://ee.cleversoul.com/distributors.html
Google Groups Search Terms Used
Power Supply Design
Surplus Electronic Components
Hope this answers your question, and happy designing! |
