RE: [TCML] IGBT High Current Low Voltage TC Primaries

["Lau, Gary" <Gary.Lau@xxxxxx>]

This was one of many of Terry's posts that I saved myself.  In a post dated 11/1/2006, http://www.pupman.com/listarchives/2006/Nov/msg00006.html Terry points out that a fundamental problem with using low voltage primaries is that the resulting Q, when Lpri is so tiny, is too low to support any semblance of an oscillation.  Excellent reading!

Regards, Gary Lau
MA, USA


> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of bartb
> Sent: Tuesday, March 03, 2009 9:10 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] IGBT High Current Low Voltage TC Primaries
> 
> Hi Jim,
> 
> I think the closest you will find is the OLTC which Terry Fritz
> developed. Here is a concept schematic:
> http://www.classictesla.com/hot-streamer/temp/OL-DRSSTC.gif
> 
> It might be worth looking at Terry's OLTC info and maybe his SISG work
> as well in the Hot Streamer Temp directory.
> http://www.classictesla.com/hot-streamer/index.php?dir=temp/
> 
> I'm not studied on the OLTC concept, but I suspect this is close to what
> your contemplating.
> 
> Take care,
> Bart
> 
> 
> 
> Jim Harvey (UDN) wrote:
> > Please forgive this newbee!
> >
> > Is there any literature describing work done to use IGBTs to directly drive
> > the primary of a TC?
> >
> > I am looking to use IGBTs powered directly from 110 VAC or 220 VAC to switch
> > high currents into the primary.
> >
> > In summary:
> > 1. Power source is the AC line 110 or 220 VAC rectified.
> > 2. The IGBT switches this source directly into the TC primary.
> > 3. The IGBT is switched at the resonant frequency of the TC secondary.
> > 4. The primary is resonated with a capacitor to achieve resonance.
> >
> > It seems to me that, if we can get enough current into the primary, this low
> > voltage approach would work.
> >
> > Again, I am new to the list and don't have the knowledge of the history of
> > TCs over the last 20 years or so.
> >
> > Thoughts?
> > 73 & Stay Vertical,
> >
> > Jim Harvey (W7YV) - The Great Curmudgeon
> > P.O. Box 18009
> > Salt Lake City, UT 84118
> >  <http://www.harveyclan.net/> http://www.harveyclan.net
> >  <http://www.harveyclan.net/w7yv.htm> http://www.harveyclan.net/w7yv.htm
> >
> > FIST # 13337
> > SKCC # 3194
> >
> > "Calling CQ was like a box of chocolates. You never know what you're gonna
> > get."
> >
> >
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