| ??? 02/22/12 14:19 Read: times |
#186137 - A watchdog isn't a fuse... Responding to: ???'s previous message |
Kalpak said:
A lightning strike or even near strike can arc over blown fuses, destroy arrestors and consequently destroy the load ahead.
So do you stop putting fuses or arrestors? No, I use even more or better fuses and arrestors if the application is critical! Kalpak said:
People die in accidents even in cars with all sorts of protection. So are air bags useless? If they make you driving faster? Then, yes! In Germany we had a car called "Audi Quattro". It was said, that is it nearly impossible to fail in a curve with this car. The consequence was that this car was involved in the most terrible and shocking accidents we had that time. Kalpak, a watchdog is not a fuse or an air bag. It's an additional feature that shall give you a good feeling. But it gives you only the illusion of safety. Why do you think, that after a lightning strike which upsets the µC, the watchdog is still working properly?? The watchdog isn't more immune to such kind of interference at all. If you want the watchdog to recover your µC in such events then you are realy lost! No, the only way to handle these problems is proper filtering, shielding and grounding. A proper Faraday cage gives you more saftey than dozens of watchdogs. Kai Klaas |
