RE: why TC Different from others?

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>


 >> A TC primary and secondary form a transformer. The TC transformer produces
 >> RF when it operates. 1. Why don't other transformers with similar winding
 >> ratios produce RF?

 >The TC is air cored and rather loosely coupled.  Alot of the energy from the
 >primary does not go into the seconday but is radiated.

This is a common misconception.  That coils are loosely coupled does not at 
all imply that the transfer is lossy or that energy is radiated.  The 
degree of coupling only determines how rapidly the transfer between the two 
tuned circuits occurs.  If the coupling is low, the transfer takes longer 
and the gap fires for a longer interval per bang, so losses in the gap are 
greater.  Losses due to EM radiation are small compared to gap losses and 
are not a function of coupling.

Back to the original question, the transformer is not creating RF.  The 
thing that creates the RF is just the primary inductor, primary cap, and 
spark gap.  These components alone, without a secondary, will create 
fearsome RF; it just won't have anyplace to go, so it will be burned off as 
heat in the gap and capacitor (bad!).  Adding a tuned secondary provides a 
means to raise the voltage and to get the energy out of the primary tank.

Regards, Gary Lau
MA, USA