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MPaulHolmes · 03-23-2011, 04:18 PM

they need to go from nonconducting to conducting in a very short time. LIke 50-100 nSec or something. So, usually you want to look for "ultrafast diode" or something. If it takes a "long time" to go to conducting, there would be a large voltage spike that would hit the igbt, since the current needs to keep flowing somewhere.

It says the turn on time is 7us for the hockey puck ones. Am I understanding that right? That would be catastrophically too long I think. The igbt would be off in maybe 1uS, so that leaves 6us of the current that is still going to flow somewhere to pile-drive through the igbt or the scr. Maybe creating thousands of volts. Am I understanding that right?

03-23-2011, 04:18 PM	#4532 (permalink)
MPaulHolmes PaulH Join Date: Feb 2008 Location: Maricopa, AZ (sort of. Actually outside of town) Posts: 3,832 Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000 Thanks: 1,368 Thanked 1,202 Times in 765 Posts	they need to go from nonconducting to conducting in a very short time. LIke 50-100 nSec or something. So, usually you want to look for "ultrafast diode" or something. If it takes a "long time" to go to conducting, there would be a large voltage spike that would hit the igbt, since the current needs to keep flowing somewhere. It says the turn on time is 7us for the hockey puck ones. Am I understanding that right? That would be catastrophically too long I think. The igbt would be off in maybe 1uS, so that leaves 6us of the current that is still going to flow somewhere to pile-drive through the igbt or the scr. Maybe creating thousands of volts. Am I understanding that right? __________________ kits and boards Last edited by MPaulHolmes; 03-23-2011 at 04:24 PM..