Re: just wondering

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

Original poster: "Antonio Carlos M. de Queiroz" <acmdq-at-uol-dot-com.br> 

Tesla list wrote:

 > Original poster: "john cooper" <tesla-at-tesla-coil-dot-com>
 >
 > Richard Hull has some tapes on his magnifier research and has reported
 > coupling coefficients of over 0.50 and I believe he either hit or slightly
 > exceeded 0.60, I'll have to review those tapes, but those numbers are
 > probably contemporary records for a magnifier and really do point out the
 > power processing abilities of a well built magnifier.  Tesla migrated to
 > his magnifier design due to this greater efficiency.  Gotta go check out
 > your link now.

0.6 is the maximum for a regular Tesla coil. Magnifiers can easily
work with more, but this is not common. The tight coupling between
primary and secondary is fundamentally a compensation for the the
presence of the third coil, that lowers the effective coupling
coefficient of the system.

Some examples of fast magnifier modes:
Mode:      L1-L2 Coupling:
1:2:3      0.6741998625
2:3:4      0.4633831313
3:4:5      0.3504383220
1:2:9      0.7666721982
2:3:14     0.6111887907
3:4:21     0.4555734516

The "mode" is the ratio between the resonance frequencies of the
assembled
system, that are three in a magnifier, if the capacitance across the
secondary coil is considered.
The first three modes in the example require high capacitances across
the secondary coil. Are the most efficient for energy conversion, but
may
not be the best for spark generation. The three last modes require low
capacitances that can be distributed, and look more as the magnifiers
built empirically for spark generation.
A program that can design and plot waveforms for magnifiers is my mrn6
program, available at http://www.coe.ufrj.br/~acmq/programs
See also the programs optmag and the older magsim.

Antonio Carlos M. de Queiroz