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Old 10-06-2011, 10:06 AM   #587 (permalink)
CollinK
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Quote:
Originally Posted by sawickm View Post
Are you referring to Powerex BG2A reference design PCB, and dual VLA500 Gate Driver PCBs as open? Or are you going to design you own Gate Driver Interface? It would be nice to replace that Powerex stuff with a new low cost, open source Gate Driver Interface.
I think that either Paul or Mrbigh did some small modifications to the reference BG2A design but, yes, those boards. I know that the Powerex stuff is expensive ($43 per VLA500 board) but for my purposes that's OK. I suppose that's where the delineation between commercial and hobbyist becomes apparent. I'm dealing with a situation where it would seem to cost more time and effort to develop something custom and the VLA500 modules are cheap enough that it's not worth it. However, someone could, and maybe should, develop an open hardware driver. There's no reason that the control board could not still use the open drivers. The general layout of the VLA500 boards can be found in their documentation so an enterprising person could probably reverse engineer that and put discrete components on a board.


Quote:
Is this the base AC Controller Schematic you started with? https://www.onlinefilefolder.com/1sYLaUVLcWOoiL
Yes, that's the one. Obviously that schematic was based on a totally different drive strategy. I don't think it ended up being a cheaper strategy however... At least not by much.

Quote:
Will it still be a dsPIC base AC Controller?
Yes, in fact, since I already linked to the code, you could look at the code and see that it does indeed call for a dsPIC4011 chip. It will stay that way.

I accidentally ordered some dsPIC4012 chips and I'm thinking of using one of them on the board to do voltage readings of the 5V, 12V, 15V, and HV so that all the voltages can be monitored. I think that most people just use the cheapest PIC16 they can find to do this extra voltage monitoring but I'm also trying to build hybrid cars and might use the 4012 to do processing related to hybrid control. So, I'm likely to make my board have two dsPIC chips; a big 40 pin one, and a smaller 28 pin one. PIC chips aren't really a big expense anyway. Going with a second dsPIC instead of a PIC16 only is like a few bucks extra.

My goal is to put both processors on the canbus and have them both report what they know and listen for what they need.
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