Hi,On Feb 19, 2005, at 8:00 AM, velo1_4mb wrote:Put a 300-500 ohm resistor between the buffer and the MOSFET gate to limit current when the failure occurs.Not only that but it will provide a shunt which allows one to measure the current. Most any time I think the circuit can stand it I put 100 ohm resistors inline. Provides a bit of protection but also provides a location I can easily measure voltage across the resistor to "see" the current. Also because I often draw the schematic, lay out the PCB, and have a few boards built before powering the circuit the first time. -- David Kelly N4HHE, dkelly@HiWAAY.net ======================================================================== Whom computers would destroy, they must first drive mad. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/AVR-Chat/ <*> To unsubscribe from this group, send an email to: AVR-Chat-unsubscribe@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Have not followed the full thread but: MOSFets take alot of current to turn on and if this a N-CHANEL H_Bridge what kind of level shifting are you using to turn the high side gates on. the gate must be ~10v above the source which is the motor battery voltage.
I hope this helps
Mitch