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Old 08-13-2012, 04:53 PM   #755 (permalink)
e*clipse
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Join Date: Jul 2010
Location: norcal oosae
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Wow. This is surreal. I'm also working on a motor controller.

Same microcontroller, same safety philosophy, same current sensing.

My main goal is a controller for a high voltage BLDC motor I have. I also saw the same controller could be used for 4 quadrant DC control.

That's cute. I guess you could say it's my progress... We need some "fast" smilies.

Regarding power switches, has anyone looked into the SOT-227 package?

1) Both IGBT's and Mosfets are available
2) The Mosfets can handle >200A @ 200V. IGBTs are available at >1200V. The limiting detail is the connector.
2) you get "bolt together" bus bars.
3) they are very compact
4) They are electrically isolated from the heat sink, like larger modules

Prices are ok; It may be worth paying a bit extra for the easy assembly and capability of replacing blown switches. The compact form factor and easy Isolation are also big advantages.

I would like to use your control board circuit - I think it's nicely worked out and the safety details are proven with the Cougar controller.

I am considering making a surface mount version of the control board. I don't consider surface mount soldering an problem - you just need to learn a few tricks like the ones Nic showed us. I have had great success with many boards in my toaster oven. The advantages I see are better shielding/less EMI problems and the ability to make a very compact controller. It may not be an issue with a car, but this also has potential for a good motorcycle controller.

I like the idea of a separate power/driver board.

Would anyone else be interested in a "compact" version of this design?
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