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

Re: 2nd light of the "Green Monster" - sec vs. pri height

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Jonathon,

Where the secondary resides in relation to the primary is not assigned to a predetermined standard. There are 2 limiting factors. Coupling between the two inductance's and of course the standoff voltage between coils. Both of these design factors have limitations in this application and affect one another. An example is if a coiler allowed a considerable perpendicular distance between coils. In this case, the secondary may very well drop below the primary to increase energy transfer time (adjusting the coupling). A tighter distance may require the secondary above the primary.

It is also possible to wind the primary too close to the secondary, thus, the standoff voltage may be too high and force the secondary above the primary. It's this particular case which will limit the maximum coupling possible. It isn't hard to make this blunder, which is why I prefer to have a little more perpendicular distance between coils (not a lot). Thus, most of my coils have been a little below the primary except one which was level with it. I think on average, coils are level or above the primary.

I prefer to design the primary so the coupling is about 0.15 when the coils are level for medium sized coils (4" to 8" range). Only slight adjustment is then required for maximum performance.

Take care,
Bart

Tesla list wrote:

Original poster: Kidd6488@xxxxxxx
Perhaps I've been away from coiling from too long, but aren't most coils either level, or the secondary is BELOW the primary? Mine is built to be adjustable but only from 0 to several inches above the primary.... What exactly does this change when changing the height?

Thanks!

Jonathon

In a message dated 8/7/2005 12:05:52 A.M. Eastern Standard Time, tesla@xxxxxxxxxx writes:
The bottom winding of
the secondary coil sits at 5/8" above the plane
of the primary coil.