[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Iron transformer positioning under the primary experiment

Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>

It's not only the metal proximity that should be considered. Any closed turns in a transformer coil that are under or near the primary coil will pick up spurious spikes and may damage the transformer or induce these nasty very low microsecond spikes into the 60 Hertz power line. Also, directly under the primary, a Terry filter really is of no value.

It is easy and cheap to simply enclose the power transformer and Terry filter in a suitable enclosure 5-6 feet away from the coil. No need to take chances. It is simply poor engineering practice.

Dr. Resonance

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Bart.

At 06:55 PM 7/6/2006, you wrote:
Cool Terry!

Referencing the white "reference", the loss when the MOT is center to the flat coil is negligible. Interesting how the loss was 5 to 10% when the MOT was 2" below and near the outer section of the coil. It would be sweet to see a magnetic field map of a flat primary. It would certainly help us visualize the situation.

This is what Ansoft's Maxwell 2D thing does:


It is not my coil but just a test I did to see how the program works. It is one of those "odd" mid 80's engineering programs that has been updated over the years. Seems to work fine but has long awkward data inputs and a lot of "personality". But it is powerful and is "free" :-)))) One could probably study it for years trying to figure out all its little tricks...


Here is a basic manual someone wrote that one can read through fast to get an idea of how to make it "go".


Funny that it was probably made to really rip on a 486-33DX :o))) It has no problem on a 3GHz with a gig of RAM :D

Did you also perform the test with a secondary in place? I wouldn't expect a change in MOT placement affect, but thought I'd ask anyway.

No but I did try a copper plate about 1.125 inches above the primary:



It actually has less loss than the transformer in a bad place (white)! The copper has "high Q" so it's eddy currents tend not to loose a bunch of power. Cool isn't it ;-)) Steve and Dan mentioned this and they are right!!

In the first Ansoft plot above you can see how close the energy stays to the primary coils. This free version is just 2D but it tells us pretty much what we want to know. I'll have to fiddle with it more to do something more real.



Take care,

Tesla list wrote:

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>


For my new little coil, I have to position the big iron MOT "somewhere". So I did some testing that I wrote up here real fast:


Looks like "directly under the primary" is the sweet spot!!