1st Quarter 2010
(C) 2010 Design/Analysis Consultants, Inc.
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This Issue: NEWS BITE: Small Alien Spacecraft Seen Landing In Australia! / NEWS BULLETS ALERT! Toyota Sudden Acceleration Update: It’s Not Just Floor Mats / TECH TIP: Preventing Output Dips In Linear Regulators / TECH TIP: Be Aware Of Aging Capacitors / DM 7.4 RELEASED: Tuned, Tanned, and Ready To Roll / HUG AN ENGINEER TODAY: Millisecond Response to Nerve Gas Threats / PECULIARITIES: The Mysterious Google Town That Doesn’t Exist
NEWS BITE: Small Alien Spacecraft Seen Landing In Australia!
(“The Tech Behind the Winning Solar Car” by John Boyd, Nov 2009 IEEE Spectrum)
The following excerpts are from “Toyota’s runaway-car worries may not stop at floor mats,” by Ralph Vartabedian and Ken Bensinger, 18 Oct 2009 L.A. Times:
“Toyota has blamed the incidents — apart from those caused by driver error — on its floor mats, asserting that if they are improperly installed they can jam open the accelerator pedal. A month after the Saylor crash, Toyota issued its biggest recall in company history, affecting 3.8 million vehicles in model years as far back as 2004. But auto safety experts believe there may be a bigger problem with Toyota vehicles than simply the floor mats.”
“…One remedy being considered by Toyota implicitly acknowledges what critics have been saying for almost 10 years: that the company’s highly computerized engine control system lacks a fail-safe mechanism that can quickly extinguish sudden acceleration events, whether they are caused by floor mats, driver errors or even unknown defects in the electronic control system, as alleged in some lawsuits.”
“…One obvious line of defense is to simply shut off the engine, a step that may not be intuitive on the ES 350. The car has a push-button start system, activated by the combination of a wireless electronic fob carried by the driver and a button on the dashboard.
But once the vehicle is moving, the engine will not shut off unless the button is held down for a full three seconds — a period of time in which Saylor’s car would have traveled 528 feet. A driver may push the button repeatedly, not knowing it requires a three-second hold.”
[DACI’s comment: Requiring three seconds to shut off a raging auto engine is wildly inconsistent with safety concerns, and indicates a case where a software feature (3 second turn-off) was not appropriately reviewed by the Toyota engineers responsible for safety.]
Functional Analysis: Regulators/Linear
MEETING DROPOUT REQUIREMENTS
The design of linear regulators must consider the valley of input ripple voltage, not just the average minimum DC value. Failure to consider input ripple can result in unacceptable output ripple. (Design MasterTM subscribers can download a sample analysis here: LM317T.)
Stress Analysis: Capacitors
Capacitors that are operated beyond their rated lifetimes will exhibit a significant reduction in capacitance, and suffer other parameter degradation as well. This can easily happen to electrolytic capacitors when they’re subjected to higher ambient temperatures, or to increased internal temperatures due to ripple current. To avoid trouble, be sure to check each capacitor’s lifetime rating against your application’s requirements. (The LM317T sample analysis mentioned above shows how DM’s Electronics Part Analysis Wizard was used to import part files for a full stress analysis, which includes a capacitor lifetime calculation.)
Design MasterTM V7.4 (Major Upgrade) has just been released.
Building on more than a decade of successful applications worldwide, the latest version of Design Master rolls into 2010 tuned, tanned, and more ready than ever to help you provide bulletproof designs.
We improved the text formatting and toned down the bright screen colors, added a handful of small but useful enhancements, and then went through and tidied up a few little quirks that are invisible to the average user, but may slow a power user down a bit.
Last but not least, for improved efficiency and flexibility we made one of our powerful under-the-hood algorithms accessible to the user via a new Calculate/Auto Scan option.
For more details, please click the link below. If you’re a subscriber, you can also download your update and the latest manual:
If you haven’t started using Design Master yet, you can learn about our free fully-functional 10-day trial version here:
Many thanks to all of you who have helped us improve Design Master over the years!
“A new molecule that detects and destroys lethal nerve gases has been developed by researchers in the US. It is hoped that the research will help develop new early-warning systems against chemical weapon attacks, and possibly give rise to an effective antidote.”
From “Nerve gas detection in a fraction of a second” by Lewis Brindley, Chemistry World, 24 Sep 2009
PECULIARITIES: The Mysterious Google Town That Doesn’t Exist
As initially reported in the London Telegraph, a town on Google Maps called Argleton, Lancashire, England, does not exist, even though details such as businesses and photos are provided. A traveler following Google’s instructions will be rewarded with a visit to an empty field.
According to the Telegraph, “Google and the company that supplies its mapping data are unable to explain the presence of the phantom town and are investigating.”
(As reported by Robert Charette in the IEEE Spectrum)