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Old 07-01-2011, 12:45 PM
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Default Re: Another DIY DC controller mock

Right now the controller i have in the car is running a pair of Fuji 800amp single igbts. One as the switch the other with its g-e shorted as the freewheel diode. They are joined with a piece of 20x10mm copper bar. Thats a bad idea in theory as the link can ring like a bell and i go shooting down the road trailing flames like a dragster with a blown engine. In practice its worked fine. Remember that app notes are based on ideal conditions with unlimited resources and infinte development times. They are a guide at best.

I used a piece of standard copper clad pcb board , roughly routed on the drill press to cary the link caps. Kind of a poor man's laminated busbar. I used a 1uf RC snubber across the switch as i was seeing some alarming ringing on turn on if i remember rightly. My advice would be to use 2 resistors and a schottky diode to shape the turn on and turn off. You really need a hard turn on to punch through the miller knee.

What is the ton and toff of the devices your using? Are you using emitter resistors?
Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 1000 Amps, that's bad.
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