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Re: [TCML] DRSSTC weird waveform behavior



What driver design are you using (specifically the current sensor aspect)?
This looks to me to just be a controller with quite a few propagation delays
so the switch action is substantially after the zero crossing, which can
lead to serious ringing. This is why the prediktor current sense circuit was
made.

Tyler


On Fri, Jul 1, 2011 at 6:01 PM, Justin B <boshjack@xxxxxxxxxxx> wrote:

>
> Hello, Recently been working on my DRSSTC seeing what my ZCS is.  Came to
> find I have large voltage spikes, and my switching is late.
>
> After getting tips and suggestions from Kizmo, I have moved the gate
> resistor from 5ohms to 10ohms, which killed my spike down a little.  Then
> also he told me Steve had a similar issue, and fixed it with a 20 ohm
> resistor. seen here (
> http://www.stevehv.4hv.org/DRSSTC2/waveforms/badoutput.JPG)  So im sure
> the simple fix to my overshoot is to do the same. Add resistors.  But what I
> want to know, What the heck is the deal with the high squiggles on the
> Output voltage? If i adjust the duty cycle to ONE more cycle, it mirrors
> over the horizontal.  1 more cycle, mirrors again.
>
> So, Here are my waveforms.
>
> With 5.1 ohm resistor on the gates
> http://i.imgur.com/pUJvR.jpg
> http://i.imgur.com/GlcAU.jpg
>
> with 10ohm resistor on the gates
> http://i.imgur.com/ZrfeX.jpg
> http://i.imgur.com/JMKIF.jpg
>
> But what the heck is this??
> http://i.imgur.com/nfcC7.jpg
>
> Any help is wonderful, Thanks =)
> --Justin B
>
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