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MOT Mutual inductance with DC PSU's



Original poster: tesla <tesla@xxxxxxxxxxxxxxx>

Hi Team

Looking for confirming comments on a problem I've been experiencing with a
larger DC resonant charging MOT system I'm trying to get going. (90nF CP and
30Hy Charging inductance from 6 gapped MOT's (2 in parallel of 3 in series
config)

I've configured an earlier 4 (or 6 if extra MOT's are added) MOT stack AC
system to run as DC with a FW bridge into DC Filter of 1.25 uF using 20 MWO
caps (across the plus to minus whole 12kv developed at the bridge O/P)

I've found the system will not draw much current into the Coil. I've
concluded that the Magnetic shunts in the MOT's is adding so much O/P L to
the system that large O/P inductive reactance of the MOT PSU iteself adds
too much current limiting impedance in a system that requires brief pulses
to charge the filter caps.

I've noticed in the past that MOT stacks pull much more mains current  into
a very capacitive load and I've always theorised that his was due to
cancellation of the very inductive O/P Z of the MOT's due to the magnetic
shunts.

I've removed the magnetic shunts from a MOT and the reduction of effective
O/P Z is dramatic and I believe that charging Caps via a rectifier system is
best done with magnetic shunts removed in the MOT's. Has anybody experience
with this situation ?. The primary current on a MOT with a SC secondary with
the shunts removed is at least 4 times the current with the magnetic shunts
in place.

Ta
Ted L in NZ