View Single Post
Old 03-23-2011, 05:37 PM   #4533 (permalink)
isaac_alaska
EcoModding Apprentice
 
Join Date: Mar 2011
Location: alaska
Posts: 141
Thanks: 10
Thanked 37 Times in 19 Posts
Quote:
Originally Posted by MPaulHolmes View Post
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?
You're probably right. Do you have the schematic to the power board so i can see how it all gets set up? I was just tryin to use my SCR's cause they're big and pretty...but if i can't use them i'll have to find somethin else.
  Reply With Quote