tag:blogger.com,1999:blog-8200098102909041178.post6649523520569029025..comments2024-03-24T09:12:10.872-04:00Comments on Shane Colton: Pan-Project Update 6/16/11Shane Coltonhttp://www.blogger.com/profile/10603406287033587039noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8200098102909041178.post-69936830693983825652011-06-18T10:08:27.931-04:002011-06-18T10:08:27.931-04:00Wow! I should have come visit. I bet you can hear ...Wow! I should have come visit. I bet you can hear the cars (at least the F1 cars) from there.<br /><br />I wish 904A. The problem is all FETs share one heat sink, so if the heat sink only has some certain area and heat dissipation ability, it will be less than the sum of all the FET individual ratings.<br /><br />Also the ratings don't account for switching losses, which are pretty high because of the large gate capacitance of four FETs in parallel. Then also noise spikes get worse as current goes up, even if the FETs would otherwise be fine. I think 200A is a reasonable goal, and will be happy if I get more.Shane Coltonhttps://www.blogger.com/profile/10603406287033587039noreply@blogger.comtag:blogger.com,1999:blog-8200098102909041178.post-30382822190803068292011-06-17T23:15:00.548-04:002011-06-17T23:15:00.548-04:00bye the way, I live 10 min away from the Grand Pri...bye the way, I live 10 min away from the Grand Prix. I am in Longueuil for my summer intern!<br /><br />So you have 8 mosfet per motor phase. 2 groups of 4 mosfet.<br /><br />Did you take the worst case of 26A x 4 = 104A then you have two set working so 208A total?<br /><br />right?<br /><br />(26A is Surface mounted on 1 in. square Cu board, steady state.) And on page diagram 3 they write "still air" That is having the heatsink made of cooper. You are going to have a big heat sink, so that will be 113A at 100C or 160A at 25C. So that is (113A*4)*2 = 904A? or 1280A...Jerome Demershttp://www.jeromedemers.comnoreply@blogger.com