Re: Interesting thing about Tube Coil oscillators...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Trimmell by way of Terry Fritz <twftesla-at-uswest-dot-net>" <davidt-at-pond-dot-net>

Dave, Bert,

Thanks for the informative replies. This is something I may try, and see
where it goes. Looks like a good way to test the Q of a coil. Has anyone
actually expiremented with method? Coupling will be a bear, but I wonder
how it would work in a magnifier type arraignment, tight coupling for
power transfer, but low overall effective coupling?

Regards,

David Trimmell

On Thu, 8 Feb 2001, Tesla list wrote:

> Original poster: "David Sharpe by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <sccr4us-at-erols-dot-com>
> 
> Hi David! 
> 
> This type of oscillator is known as a Meisner Oscillator in that the 
> LOAD is resonant.  To increase your power into the resonator, the 
> coupling as Bert (Hi!) mentioned earlier should be maximized.  Since 
> you don't have two resonant circuits beating, you could couple up to 
> 0.6 or more and not have frequency splitting.  0.5-0.6 is about maximum 
> you'll get with air dielectric, I've pushed magnifier couplings (driver
primary
> 
> and secondaries) in excess of 0.62 using flux concentrators.  You're 
> big problem will be voltage standoff, not maximizing the coupling
coefficient. 
> 
> Regards 
> Dave Sharpe, TCBOR 
> Chesterfield, VA. USA 
> >
> >   
> > > 
> > > Original poster: "David Trimmell by way of Terry Fritz 
> > <twftesla-at-uswest-dot-net>" <davidt-at-pond-dot-net> 
> > > 
> > > Hello all, 
> > > 
> > > I was doing some testing of various VTTC configurations last night, and 
> > > thought I would try a "tankless" configuration. Running the output from 
> > > the Level Shifter (normally the B+, but in this case we are using the
tube 
> > > to self-rectify HV AC) into the base of my solenoid Primary (23 turns of 
> > > PVC insulted #12 on 6" form 79uH measured), the top of the primary was 
> > > connected to the plate of a single 833C. Grid coil with 22 turns of PVC 
> > > insulted #22 wire is 3/4 inch above secondary, with 4 to 25 K resistance 
> > > for bias, 0.001uF mica cap in parallel. Using this configuration the
coil 
> > > will oscillate, producing 3-4" discharge with 4800V on the plate. Power 
> > > consumtion was high ~25 Amps from wall at 40 volts into the PT
(60:1), but 
> > > grid current was low, even with only 4 K resistance, less then 30 mA. It 
> > > is quite intesting how I can get a coil that is self resonant at around 
> > > 380KHz to produce this discharge. I am asuming the parasitic capacitance 
> > > in the primary is working here? BUT that would put the Fr0 in the many 
> > > Megahertz range!? 
> > > 
> > > Anyone have agood explaination of what is really going on here? 
> > > 
> > > Regards, 
> > > 
> > > David Trimmell 
> >  
> 
> 
> 
> 
>