Re: Spark gap not firing

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 2/5/01 9:51:37 AM Eastern Standard Time, tesla-at-pupman-dot-com 
writes: 


>
> > 
> > > Hi Michael, 
> > > It sounds here as if you have the coil wired wrong. Connect the 
> capacitor in 
> > > parallel 
> > > with the NST. 
> > 
> > This is not right. The RSG should be in parallel with the NST. The cap 
> should 
> > be in series with the primary. It will work as you suggested, but you will 
> put 
> > the transformer at risk. Having the cap parallel with the transformer will 
> > cause the transformer to feel the full RF of each bang. By placing the RSG 
> > parallel with the transformer, the RF seen at the transformer is greatly 
> > reduced. I believe Greg L. stated the a reduction by a factor of 10:1. 
> >



Either configuration A or B should work: 

+-RFC-+---C1---+  +-RFC-+--o o--+     
    |     |        |          |     |  gap  | 
Xfmr   C1      L1   Xfmr   o gap    L1 
 |     |       |     |     o        | 
 +-RFC-+-------+     |     |        | 
                     +-RFC-+--------+        
                                      
        (A)                  (B) 

In configuration "A", since the capacitor is connected directly across the 
transformer, when the capacitor discharge starts, there is high voltage at 
high frequency across the capacitor and transformer = unhappy transformer 
despite RFCs. In configuration "B", however, when the gap fires it is a 
relatively low resistance in parallel with the transformer, so the 
transformer "sees" low voltage from cap. When the gap stops firing, the gap 
becomes a high resistance, but by this time most of the HF cap energy has 
been dissipated into the secondary's corona discharge = happy transformer. 

The setup shown below, which is an easy transposition mistake of "A", will 
never work: 

                  +-RFC---o o-+-+     
                  |       gap | | 
                 Xfmr        C1 L1 
                  |           | | 
                  |           | | 
                  +-RFC-------+-+ 

Matt D.