I can't speak for low power FETs. The smallest thing I deal with is a 100 watt fan speed controller. I have a box under my lab bench that I call my "L'il box of larnin' " that contains all the FETs and IGBTs that have failed during development over the past 10 years or so. A thousand at least. There's not a single device in that box that failed open.
John On 09/28/2016 02:38 PM, Dan Hollis wrote: > I thought FETs always fail open, and it was SCRs which always fail shorted. > > -Dan > > On Wed, 28 Sep 2016, NeonJohn wrote: > >> >> >> On 09/28/2016 12:40 PM, Trumpeter wrote: >>> Thank you for this detailed explaination, even though some is over my >>> head. >>> >>> Should I check the resistance between the two joined pins and one of >>> the two pins on the other side? Could the over heating mosfet damage >>> other components or will it simply fail? >> >> The problem is that power FETS *ALWAYS* fail shorted. So you need to >> plan your circuit and any protection for that eventuality. I'd put a >> PolyFuse in the circuit supplying the circuit. That'll protect your >> transformer and power source when the FET lets its smoke out. >> >> John >> >> >> -- >> John DeArmond >> Tellico Plains, Occupied TN >> http://www.tnduction.com <-- THE source for induction heaters >> http://www.neon-john.com <-- email from here >> http://www.johndearmond.com <-- Best damned Blog on the net >> PGP key: wwwkeys.pgp.net: BCB68D77 >> >> -- >> You received this message because you are subscribed to the Google >> Groups "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send >> an email to [email protected]. >> To post to this group, send an email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/fbb5076d-89a9-df0a-ab3f-9646445982c4%40neon-john.com. >> >> For more options, visit https://groups.google.com/d/optout. >> > -- John DeArmond Tellico Plains, Occupied TN http://www.tnduction.com <-- THE source for induction heaters http://www.neon-john.com <-- email from here http://www.johndearmond.com <-- Best damned Blog on the net PGP key: wwwkeys.pgp.net: BCB68D77 -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/8f61d21d-adf9-c134-f559-0bc0170238db%40neon-john.com. For more options, visit https://groups.google.com/d/optout.
