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Hi Alex, Sorry for the delay in responding. I have been out of town on business for a week and a half and have also doing some engineering consulting work. These activities have dramatically (and hopefully only temporarily) reduced the time I can devote to Tesla-related things. I did intend to answer your posting (and two others) on the board. In the meantime, can you provide me (via the message board) with the proposed dimensions and relative geometry of your driver primary and secondary coils? As you already have surmised, the main challenge with trying to obtain high coefficients of coupling between the driver primary and secondary will be in preventing secondary to primary flashovers. E-field control, and spacing will be most critical. 3 mm spacing will definitely NOT be sufficient. To maintain sufficient clearance AND high coupling, you'll need to use a helical primary with large diameter coilforms. The larger the primary and secondary diameters, the larger the spacing can be between coils for the same coupling coefficient... distance that you'll need to help prevent flashovers. The primary winding should use large diameter tubing to increase corona inception voltage. You may need to taper the primary winding outwards at the top to provide more clearance from the secondary. You may also need to supplement this with a larger diameter anti-corona ring at the top of the primary winding. The primary and secondary directions should be the same to help reduce voltage stress. You will most likely need to augment the insulation between the coils with rolled polyethylene sheeting. Best regards, -- Bert --
: Hi Bert,
: after a long time of calculating for my planed magnifier,
: I hope,that I´ve found two designs.
: (I want to have one mile of wire and nearly the same frequency
: as Tesla in the CSN.The extra coil should be also used as a normal TC)
: The Magnifier system Design 1.) mode 2,3,6
: extra coil: 12,44"diam.x 58.17" 1025turn AWG16 (1.32mm +0.11mm
: heavy build)
: Le=64.97mH /Cs=24.74pF/Ct=47.58pF/Cs+t=72.32pF
: Fres=125kHz (unloaded) Fres=73.42kHz (loaded)1/4
: 4.64:1 ratio ~3354ft wire 12.9ohms
: sec.coil: L2=30,5mH same wire AWG16 nearly /~2000ft wire 3mm spaceing
: data from magsim /turns 120-170 from different diameters
: C2=86.78pF 8 ohms
: prim.coil: L1= 172,5µH by C1=40nF (later 80nF)
: From this data I get: K1/2=0.565
: W0=153.7krad/s
: F0=24.47kHz
: F1=48.95kHz mode 2
: F2=73.43kHz mode 3
: F3=146.86kHz mode 6
: voltage gain: 23.52 (by C1=80nf around 33)
: transfer time 23,52µs
:
: Design 2.) Mode 2,3,6 also.
: Extra coil: same form (61"len.)1075 turns !!! AWG 16 nearly
: 3518ft wire/Le=68.4mH CS+Ct=75pF/Fres unloaded=120kHz
: loaded=70kHz 4.87:1 13.5ohms
: sec.coil: L2=32mH calculatet with magsim.
: C2=90pF 8ohms
: prim. coil
: L1=188.6µH (with C1=40nF)
: W0=147krad/s
: fo=23.40kHz
: F1=46.8 kHz mode 2
: F2=70.2 kHz mode 3
: F3=140,4kHz mode 6
: voltage gain 23.08 (80nF around 32)little less
: transfer time 21,36µs
:
: The problems are: 1.)Design 2.) has nearly Teslas frequency with
: wavelength of 4 miles!!!
: 1/4 wavelength than one mile but more than one mile of wire.
: The voltage gain is a little less.
: 2.) The secondary/driver coil is only 8-15" higher than prim.coil.
: How could I prevent arc-over? 3mm spaceing o.k.?
: I know designing magnifiers isn´t a "normal" job, I design
: against
: some magnifier rules (few turns/high ratio/heavy stranded wire etc.)
: The driver should driving the extra coil,because the impedance is around
: 10k
: lower.
: What design do you prefer?
: best reagards
: Alex
:
:
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