Re: ALF: why not DRSSTC?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>


> I'm curious as to why not DRSSTC instead of OLTC?  It seems (at 
> least on our hobbyist level) that the DRSSTC can outperform an OLTC 
> for similar amount of silicon used.

Yes, me too. The OLTC II coil that I built is pretty much a 1/4 scale 
model of one of Greg's scale model ALF towers. It uses exactly the 
same drive system as Greg plans to use, although minus the energy 
recycling feature. I couldn't take advantage of this since I was 
using an old-fashioned resonant charging circuit rather than Greg's 
nice switched-mode CCPS. (there never seemed to be much energy left 
to recycle anyway...)

The other Steve's DRSSTC II used the same amount of silicon as my 
OLTC II: four 1200V 300A switches versus two 1200V 600A switches.

The DRSSTC II sparked about 11ft whereas the OLTC II struggled to 
reach 7ft (the biggest spark ever measured was 6' 9") with roughly 
the same input power of 4kW. Maybe energy recycling would shift the 
balance, but this vulgar display of plasma certainly convinced _me_ 
to can the OLTC and shift all my coiling activities to DRSSTCs.

Although I do keep the OLTCs around so I have something to play with 
when the DRSSTC blows up ;) Having said that, I haven't blown it yet.


Steve Conner
http://www.scopeboy.com/