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Old 07-01-2011, 01:32 AM
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Default Re: Another DIY DC controller mock

Nice work val. From what I can see you are getting stuck on the miller plateau on turn on. That HCPL3120 driver does not have near enough kick for the application. Consider a 9amp driver sucj as the mic4421 or better still a VLA501 module.

If you drive the switch too fast the freewheel diode will not recover properly before the next cycle. I had this problem when I first ran my igbt controler at 16khz. Dropping to 8khz cured this problem. Consider snubber caps. At least 2 or 3 on the dc link and one across the switch. Next be aware of the ton and toff of the device and the freewheel. A lot of older modules have terrible values.


I have a few threads on here from late '09 dealing with these exact issues. Also got some videos on the subject. Hope that helps.
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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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