Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx> Hi DC,They are trying to get high coupling with DRSSTCs to reduce the number of cycles and thus time it takes to bring the secondary voltage up. This helps to decrease the load on the IGBTs and gets a better LERT.
LERT is Load Energy Rise Time. The DRSSTC folks have found that there is an optimal time to energized the secondary to get the best sparks. This time is fairly fast and demands a higher coupling.
ScanTesla (the computer program) says that coupling otherwise does not matter too much and couplings like 0.13 might be just fine. But that is before this fast rise time effect is taken into account. ScanTesla can calculate LERT, but it does not really judge what is good or bad. LERT is a little to unknown right now to make "equations" but it seems to be a real important thing.
LERT might also be why coils with low surge impedance seem to do well. We really don't know right now what it all means...
Cheers,
Terry
At 02:47 PM 12/16/2005, you wrote:
Has anyone tried purposefully reducing the coupling to see the results? I'm not sure why you need the increase the coupling so much more than for classic TCs. Some experiments along these lines might produce interesting results........Dr. Resonance<snip<You don't really need to do heavy electrostatic analysis or differential equations to <get it right the first time!!<snip DC, Your approach to Tesla Coil Design is fine for conventional disruptive coils.I have been here 8 years now, and have gained enough experience to acnowledge that. However, the electrostatic analysis i am playing with, is aimed at the new breed of coils.The DRSSTC`s.Those of us that have built this type of coil can witness to the fact, that flashovers from secondary to primary still is a limiting factor with these coils.In an attempt to solve this problem, I have tried to add increasing amounts of dielectric in the space btwn. the 2 coils, only to observe that the problem got worse.