Electronic Design

Flashback

FLASHBACK > 10 YEARS AGO

NOVEMBER 12, 1992
The State of California, concerned over its reputation for unhealthy air, has issued a mandate that requires 2% of road vehicles sold starting in 1998 and 10% of those sold in 2003 to be emission-free. To address that issue, a nonprofit California consortium involving 40 utility, industry, government, labor, and environmental organizations was formed to design a prototype battery-powered 2+2 coupe vehicle, which by nature is emission-free. The group, called Calstart... mainly consists of high-tech aerospace- and defense-related companies.

The vehicle designed by the group has a 100-mile range and 0 to 60 miles/hour acceleration in under 11 seconds. Its energy-management system (EMS) monitors the vehicle's performance with voltage, current, temperature, speed, and other sensors. This data is applied to mathematical models of the battery and vehicle to predict the vehicle's range under various driving conditions, as well as detect inefficient energy expenditures. The driver interacts through control buttons and a text display....

The most sophisticated on-board electronics is found in the navigation system. (Technology Advances, p. 29)

FLASHBACK > 25 YEARS AGO

NOVEMBER 8, 1977
An automobile radar braking system using a small antenna beam width and a limited radar range is virtually unhampered by the false alarms plaguing other automatic-radar braking systems being developed....

These false alarms have been reduced to almost zero by an unusual radar braking system developed for the Department of Transportation by Bendix.

Tests conducted by the company revealed that false alarms could be effectively suppressed by using a very narrow antenna beam and by limiting the radar detector range to restrict the distance at which brakes would be applied. Indeed, with a 2.5° beam width, false alarms were all but eliminated for a detection range between 100 and 300 ft....

To achieve a beam width of 2.5° to 4° with a 6-in. radar horn that wouldn't look too big on a compact car or require front-end modification to be installed, Bendix decided on a low-power, solid-state radar with a 25-mW Gunn oscillator operating at 36 GHz. A millimeter-wave band (above 40 GHz) had been considered, since the antenna would have been smaller. But back scatter from heavy rain would have been a problem. (News, p. 30)

FLASHBACK > 40 YEARS AGO

NOVEMBER 8, 1962
Not for a long time, if ever, will general-purpose computers, in which data is processed optically, be competitive with conventional stored-program digital systems.

This is the opinion of Dr. H. M. Teager, a professor at Massachusetts Institute of Technology, Cambridge....

Present all-electronic computers, he said, store from 104 to 107 bits of information accessible in 10-6 or 10-7 seconds; they have logic gates that switch in about 10-8 seconds, and operate according to programs fed in sequentially.

Optical systems would have to be organized for parallel processing at higher-than-foreseeable data rates to begin competing with such conventional systems, Dr. Teager declared.

He said that among possible memory designs, passive—or nondissipative—systems, such as those using phosphors, so far are too slow....

Optical systems appear better suited for special-purpose and non-numeric applications than for general-purpose computations, Dr. Teager contended. (News, p. 22)

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish