Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Advanced Micro Devices - Moderated (AMD) -- Ignore unavailable to you. Want to Upgrade?

To: wanna_bmw who wrote (80120)	5/15/2002 11:09:17 PM
From: Bill Jackson	Read Replies (1) \| Respond to of 275872

wbmw, Underhood can be very high. "As any electrical engineer can attest, extreme temperatures are also a swift killer of electronic components. Many system modules are installed under the hood, where they are subjected to heat radiating from the engine. The problem is, engines are running hotter than they did fifteen years ago in an effort to burn fuel more completely to comply with pollution standards. Typical measures to protect systems are found in Delco's products, according to Hach. To cope with a standard of 125°C underhood temperature, the IC's used are designed for a tolerance of up to 150°C. Modules are also equipped with thermal protection and thermal shutdown circuits. Thermistors used for thermal protection in Jacobs ignition products perform extra duty--they aid in adjusting the spark. Since the energy required to fire a cylinder's air-fuel mixture is less when the engine is hot, the thermistors act to inform the module to modify the output, extending the life of ignition components. The modules also benefit from a unique heat protection device. The internal components are coated after assembly with a wax-like material that melts at a specific temperature, drawing heat away from the components as it changes phase. That thermal energy is drawn away by the encapsulation material used to pot the module, and finally through the module's casing that is also designed for maximum heat radiation. Placement of modules under the hood plays a very large part in extending the life of electronic components. Engineers for years have taken advantage of airstreams along fender walls, even tapping into the ducting to the air cleaner. FEA software today permits designers to test thermal energies in underhood designs directly on their workstations. The cars presently on the drawing boards will be even more dependent on sophisticated electronic systems, as proposals for navigation systems and more exotic engine controls are made. All-electric cars will also require unique buffers against electrical assault and heat transients, as they gradually replace internal combustion vehicles. Electrical designers, it would seem, have their work cut out for them. and a dash temp of 120C is commonplace, esp in sunny south. ott.doe.gov Bill