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Old 10-21-2010, 10:47 AM   #3887 (permalink)
wakinyantanka
Custom EV Builder...
 
Join Date: Jul 2009
Location: Ohio
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Quote:
Originally Posted by MPaulHolmes View Post
Hello waktidlenayaandanadingdong! The usual goal of SR is to replace the diode with an "ideal diode". One that has a near 0v drop instead of like 1.2v drop of a standard diode. However, I don't care about that at all. I just wanted a TO-247 or TO-263 package "diode" that has the same 230amp rating as the mosfets. Such a diode does not exist. When life hands you lemons, you make lemonade! So, you can get rid of the diodes, and use 230amp mosfets. Hurray! You just have to make sure you don't have the freewheel mosfet and regular mosfet on at the same time, which is pretty easy if you are using a microcontroller with complementary pwm outputs. Heck, an AC controller has 6 outputs. 3 pairs of complementary outputs, so it can definitely be done safely. I don't know how the spikes will be. I think it will be pretty similar I'm thinking for similar current. That's one reason it might only be safe to run 1000amp at 120v. Spike of 20v at "hundreds" of amps, might turn into spike of 40 or 50 at "near 1000" amps, 50 + 144v = REAL DANG CLOSE TO 200V. hahaha.
So the SR microcontroller will have pairs of pwm outputs for driving multiple gate drivers? How many gate drivers could it handle and still be able to carry out the SR function? The 200v mosfets your using for this build, could they be upgraded to handle higher voltages? Let's say in the 160v range?
Thanks Again.
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