Hello,
I'm trying to copy the JBL LX 30 x-over from the Loudspeaker Component Series and what would i use in place of the 0.25mh center tapped inductor used in the HF portion of this x-over? Would using the center point of 2 - 0.125mh coils in series work the same way?
Thanks, Barry
I'm trying to copy the JBL LX 30 x-over from the Loudspeaker Component Series and what would i use in place of the 0.25mh center tapped inductor used in the HF portion of this x-over? Would using the center point of 2 - 0.125mh coils in series work the same way?
Thanks, Barry
Yes And No
The short answer is......Maybe.
As you can see in the two photos that each inductor measures about 1.00mH.
In series they measure 1.891mH.
Then the individual center tapped sections measure a little higher than the initial measurements.
This is because there is coupling between the two inductors.
With air core inductors rotated 90 degrees from each other you would probably have pretty good luck doing what you are describing.
Otherwise you will need some separation between the two inductors to eliminate cross-coupling.
The short answer is......Maybe.
As you can see in the two photos that each inductor measures about 1.00mH.
In series they measure 1.891mH.
Then the individual center tapped sections measure a little higher than the initial measurements.
This is because there is coupling between the two inductors.
With air core inductors rotated 90 degrees from each other you would probably have pretty good luck doing what you are describing.
Otherwise you will need some separation between the two inductors to eliminate cross-coupling.
Attachments
Bear in mind that the center tap (if the electrical center of the winding) of a 0.25mH inductor is going to be 1/4 the inductance of the entire winding. The inductance reflected at the tap is the square root of the turns ratio. (N=1/2?)
You could just purchase a 0.25mH inductor and unwind it, count the turns as you do so and then tap it at the mid point assuming that is what JBL really did. Might want to investigate a bit further.
You could just purchase a 0.25mH inductor and unwind it, count the turns as you do so and then tap it at the mid point assuming that is what JBL really did. Might want to investigate a bit further.
The mutual inductance is key as the unit is being used as an autoformer (single sided transformer) for step up or step down. I'd agree with Kevin about dewinding an inductor to add a center tap. That is the only way to get to what they had. 2 seperate inductors would not work.
David
David
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