Intact Audio

hey-Hey!!!,
Has anybody tried a making a slanted gap choke? Spacer under one thin leg of the E, and none at the other? what does the L v. standing current look like? Enough variation in L to make a gentle saturation swinger for input service?
cheers,
Douglas

I have done some measurements and only got as far as to verify my conceptual view of what is going on. This i probably best for a mill discussion but my take on it depends on what the ultimate goal is.

Swinging choke are nonlinear devices and that nonlinearity is based on the manipulation of the gap to alter the saturation characteristics.

The place i would look to use the tapered gap would be where you are willing to give up greater overall linearity for a more controlled linearity over a wider range.

Since i am a visual guy, a few pictures may better show the relationships at hand. The things to remember are saturated "domains" behave as air, perm (inductance) is a function of flux density and the net result according to any single measurement parameter is simply the average of all of the parts.

A good analogy of a swinging choke to me is a triode structure with the grid/cathode structure at an angle wrt the plate structure.

dave

hey-Hey!!!,
The bottom picture looks good to me; it is about what I hoped for. Can you extract expected L values v. DC current in order to compare it to a straight gap choke?

It is indeed the non-linear behaviour I'd be looking for with such a design. It looks like it might serve well without requiring any special lamination stamping design or modification. The behaviour I'd expect to see from the lower snapshot( on L v. DC current and AC voltage ) is more desireable than the more complete saturation/uniform procession towards saturation I see in the upper one.
cheers,
Douglas

I haven't played enough with the program with inductors to see how the results work out in this situation. Femm is freeware and is pretty simple to get running (they have a few great tutorials) and you could simply run the sim at barious currents and plot the L vs. I characteristics. There is even the ability to see the resultant BH loop but i haven't attempted that yet.

dave

dave slagle wrote: Femm is freeware

I am drawing all sorts of giggles as I consider what I am going to turn up Googling ISO the download site... thanks.
Douglas