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DIY Stompboxes => Building your own stompbox => Topic started by: petemoore on May 07, 2004, 05:22:13 PM

Title: Moving core...
Post by: petemoore on May 07, 2004, 05:22:13 PM
Me with my mechanical appraoch all the time... :lol:
 These Wah cores...I know they're all solid...no moving parts.
 What if you could move the core inside the windings?
 Removing the core would certainly have an effect, moving it in relation to the windings would certainly also.
 Existing cores obviously make this impossible, speaker coils have jumped the mechanical hurdle of allowing a moving coil in a magnet...
 For a moment, forgetting the mechanical issues...any theories about what effect this would have on the coil, and wah circuit it might be in?
 There has to be something that was missed, that I can find...I'll keep looking... 8)
Title: Moving core...
Post by: puretube on May 07, 2004, 07:18:12 PM
the very first Wah-circuits were mechanically moving cores inside a coil...
(or at least moving the air gap of a big coil)
Title: Moving core...
Post by: R.G. on May 07, 2004, 07:40:02 PM
Quote[What if you could move the core inside the windings? /quote]
little or no effect on inductance as long as the coils stayed inside the core. It might change the self capacitance, and therefore the self resonances. Not particularly useful.

QuoteFor a moment, forgetting the mechanical issues...any theories about what effect this would have on the coil, and wah circuit it might be in?
You have to change what matters to the inductor. That is either (a)number ofd turns, (b)magnetic core path length (c) air gap and distribution.

This last is what seems to be what got tinkered with most on variable inductors. moving the high permeability core partially outside the coil works, as does having a core that can have an air gap in the magnetic path be mechanically opened and closed.

EE's really don't like inductors.
Title: Moving core...
Post by: Jason Stout on May 07, 2004, 08:03:14 PM
except in rf land...
Title: Learn somethings everyday...
Post by: petemoore on May 07, 2004, 08:41:11 PM
Thanks for indulging...I think I'll work on the Wah case for a while, before I start anything with moving wah coils.
Title: Moving core...
Post by: Jered on May 08, 2004, 02:22:42 AM
Try some different magnets on your wah inductor.
Jered