Re: [TCML] DRSSTC CM600 Ringing

[Phillip Slawinski <pslawinski@xxxxxxxxx>]

Hi Tyler,

The scope shots you posted here don't look bad.  Any reason why you're
worried about the ringing?  What voltage are you running the bridge at in
those scope shots?

In the photo of your H-bridge it looks like you left quite a bit of extra
lead on the decoupling capacitor.  It may not matter much, but ideally you
want the lead length to be as short as possible.

I use a similar phase lead controller in my small coils, and I always get a
little bit of ringing on the first one or two cycles.

See here:
http://www.flickr.com/photos/pslawinski/4168411736/
http://www.flickr.com/photos/pslawinski/4482915060/

The ringing doesn't stop me from making sparks.
http://www.flickr.com/photos/pslawinski/4550187194/



On Wed, May 11, 2011 at 22:15, Tyler <tyler.c.c@xxxxxxxxx> wrote:

> I just recently finished rebuilding my coil with a new bridge built with
> CM600's, and a new controller that is fed by the hammertone prediktor phase
> lead.
>
> It is doing well, and can be adjusted for (almost) no ringing with the
> timing adjustments, definitely much less ringing than my previous designs.
> The problem is the first few cycles, no matter what I do I can't get rid of
> the ringing. No adjustment removes it, and I've never had a design that
> lacks this ringing.
>
> Can be seen in this scope shot (the horizontal line at the top of the
> waveform is the DC bus voltage):
> http://ctyler.scripts.mit.edu/IMG_0027.JPG
>
> Zoomed in here: http://ctyler.scripts.mit.edu/IMG_0030.JPG
>
>
> The only solution I've come up with that helped, but did not eliminate the
> problem, was putting in a big 25uF 1kv film capacitor directly across the
> rails at the IGBTs, which can be seen in my bridge photo:
> http://ctyler.scripts.mit.edu/IMG_0034.JPG
>
> Additionally, there seems to be a bit of extra ringing after the bridge
> turns off and the energy in the primary is going down, although it's
> possible this will go away when the secondary is in place?
>
>
> I've looked around quite a bit and haven't found a reliable solution to
> this
> problem, which is noted in a number of places. Has anyone found anything
> that helps out with this?
>
> Tyler
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla