Field Coil Drivers having Least VC inductance?

[rhythmsandy]

http://shinshu.fm/MHz/06.94/images/th2BPR04.jpg

massive copper around the pole piece does it even do the job of reducing the Voice coil inductance substantially? as much as Fostex drivers? like 0.03mH?

 

[Greebster]

Don't believe so because this copper is powered by DC current acting as the magnet, thus same as a magnet I would think. If it wasn't energized believe would, but then you wouldn't have a field to buck against.

 

[rhythmsandy]

yeah i believe thats the way it works...! I dont even see copper caps on them how come they work at low distortion levels?

 

[Greebster]

Perhaps the underhung VC and a well designed Tpole.

 

[rhythmsandy]

VC inductance is a considerable problem even just a copper cap on the pole piece is not sufficient we need to use even for the Top plate ID and Under short rings as well The top place ID ring will substantially reduce the VC ind but the flux drops very much.

 

[Greebster]

Well there is more to distortion than a poor view of some unknown motor system, meaning we need more info than Feastrex is willing to provide. We could speculate all night pondering this and that but without knowing a few more facts the point is moot.

Have one in hand we could analyze, heck dissect that puppy with a band saw and acid test just to be sure they didn't hide another metal somewhere. I'm game

 

[454Casull]

Possibly the field coil motor is extremely resistant to flux modulation. Not sure how it would reduce inductance though.

 

[whgeiger]

VC Model

http://shinshu.fm/MHz/06.94/images/th2BPR04.jpg

massive copper around the pole piece does it even do the job of reducing the Voice coil inductance substantially? as much as Fostex drivers? like 0.03mH?

I am not sure why your focus is on VC Inductance alone. You may find your answer by reading the attached article that has been published on the Internet.

Regards,

WHG

 

[rhythmsandy]

I should agree the fact that the vc inductance has direct connection towards the THD of the driver but altogether It seems working as the field coil driver is resistant to the flux modulation.. Is that so?

 

[rhythmsandy]

even the copper seems to the contributing as demodulating rings. I think copper will do the purpose of both the things as magnetising the pole piece and also as demodulating rings.

the reason why is that? If the emf from the coil hits the copper I dont think it will reflect or be transparent to the magnetic force generated by the coil.