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Old 06-30-2009, 08:43 PM   #1867 (permalink)
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Originally Posted by sawickm View Post
What needs to be done to increase the current rating on the ReVolt unit ? Is it just adding more mosfet/diode/capacitor pairs and increasing the current limit range ? Would that require a software change too ?
If we used 2 mosfet drivers instead of just 1, things would be much more scalable. I think your idea would work really well. On the next version, we should really try to use 2 drivers. Ian of Zeva is using 4 right now, for 12 mosfets. It's working really well, and helps to keep things cooler, since he can then afford to use really really small gate resistors. It would require VERY minor software changes.

Originally Posted by sawickm View Post
What is the power rating for a mosfet/diode pair on the present power module ? The irfp4668 mosfet is rated at 130A @ 200V, and the stth6002 diode pair at 60A @ 200V. You said in one of the threads that they were rated around 50 amps per mosfet/diode pair, is this still true ?
50 amps per pair seems to be pretty safe. I would really like to change it to synchronous rectification, so we can use a mosfet/mosfet pair instead. The diode is really the weak link.

Originally Posted by sawickm View Post
I am interested in the design of a modular chassis for the ReVolt that would allow you to increase the current rating by adding power module PCBs (1-mosfet, 1-diode, 2-power capacitors ,1-gate resistor). They would just bolt to the buss bars, and the heatsink. You could repair or upgrade a bad power mosfet by swapping out a power module PCB, not the whole power PCB like you are using now. Using a standard buss bar chassis, the ReVolt could be assembled as a 500A, 750A, 1000A, etc. controller by just adding additional individual power module PCBs.
This sounds like a very good idea. I'm sure it could be made to work. There would only need to be minor changes, like where to put the bolts. If we had 1 bolt per mosfet/diode pair, instead of only like 4 or 5 (or whatever) altogether.
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