I had a client that built a transmitting device with filters that he had completely modeled in SPICE and it worked perfectly from anywhere in the building to any other building location. It overcame any shielding built into the walls. He was very happy with it until he took it outside because he wanted to see how far it would transmit line of sight.

Well he was originally getting some good range but then the range started to fall and after about 15 minutes it started to really act strange and the filters developed a mind of their own.

He dropped it off at my place and we talked about some other issues and then we fired it up. Again it worked perfectly.

From all my working experience I learned, the first place to look when you experience this type of flaky performance is temperature. It was 37 degrees F the time he took it outside, and he had tuned it indoors where it was 67-72 degrees. Taking a little can of “Freeze-it” I cooled various parts of his circuit. When I got to the power supply regulator, sure enough, it really started to act up.

Will Electric Vehicles Replace Gasoline Powered Vehicles, and if So When? Just the Facts and Figures

Regardless of how one feels about electric vehicles, the major questions to be addressed are whether they are a (a) “bump in the road,” with more technological and financial problems than we can never resolve satisfactorily, (b) viable and valuable [...]

Paper Accelerometer Could Mean Disposable Devices
Harvard lab’s paper MEMS could cost pennies and put motion sensors on mundane things
By Prachi Patel
.Paper Thin, Inexpensive, and Full Featured
Photo: Xinyu Liu/Harvard University
4 February 2011—Tiny microscale accelerometers revolutionized car air-bag deployment systems in the mid-1990s. Costing a few dollars apiece and just a few millimeters wide, these sensitive microelectromechanical [...]

by Brian Conley, PE

One thing that is both useful to know and fun is how to design with microcontrollers. You could spend hundreds of dollars on things like In Circuit Debuggers (ICDs) and compilers. Or you could try something from the open source environment called Arduino. For less than a hundred dollars, and maybe [...]

Speaker: Zhensheng Zhang
When: Thursday, November 4, 2010
Time: 6:00 PM – Social
7:00 PM – Speaker
Place: Tektronix Bldg 38, 14200S.SW. Zworykin Drive, Beaverton, Oregon 97077.
Cost: Free and open to the public. Registration is required
Registration: http://meetings.vtools.ieee.org/meeting_registration/register/3373
ABSTRACT
In this talk, we present a high level overview on the recent development of the cognitive radios/dynamical spectrum access (DSA) techniques, focusing on [...]