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Re: using XC to cancel XL



Hi Bryan,

> Original Poster: Bryan St <warp27-at-juno-dot-com> 
> 
> Reinhard
> Recently you stated that using (parallel?)capacitance to your NST's
> primary can "cheat" the magnetic shunts or increase power output. 
> Please clarify, because with a parallel capacitance that means it is
> simply across mains, meaning that every single other transformer or
> coil on your(in Germany it is about half a town per xformer, right?)
> will see that capacitor.  This will mean that there should be no
> significant benefits, unless I misunderstood you.  It will also try to
> put the mains out of phase, which annoys the power company, and will
> be reactively swishing power back and forth through mains, which can
> amount to losses with large caps in any wiring which could make a
> thermal fuse blow or a power cord(This is unlikely though, a 100 uf
> cap is only about a 27ohm reactor in us and 31 in 50hz so it isn't
> that significant). Bryan

The cap across the mains compensates for the transformer's 
inductance appearing across the mains.  That makes the supply 
company happy if the cap is the correct value for Fmains and Lp of 
the transformer (the conjugate of Xlp).  In the same way, fluoro 
lamps incorporate a cap to compensate for the ballast choke.  Such 
a cap has no ability to influence the transformer's throughput 
because the transformer primary is connected to a voltage source 
regardless.  

Regards,
Malcolm