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I have been into looking into various options for IB coils. As usual, the more research I do into a subject of interest I tend to find more questions than answers.
A “bucking coil” creates a “null zone” for the Rx coil by using a reversed current flow to that of the primary Tx coil to create an opposing/cancelling magnetic field.
If the bucking coil was the same dimensions as the primary Tx and operated with the same current flow (amps and direction) we would have a Helmholtz coil with an enhanced and very uniform magnetic field. (see link). http://hyperphysics.phy-astr.gsu.edu...mholtz.html#c1
At the centre point between the coils is a null zone where a Rx coil could be sited and balanced.
This seems like a really “good idea”, so I’m sure there are plenty of negatives to this configuration.
Ground effects (permeability & capacitance) will affect the lower coil slightly more than the upper one, depending on how thick we want our coil assembly to be.
If they are wired in series then variations in current flow should balance within a few cycles and maintain the null. Responses from a “real” target should affect both Tx coils, ( I suspect coil separation distance will affect minimum detectable target size).
OR: Perhaps a real targets will not be detected as the null point will fully shield the Rx coil or perhaps a targets will only produce responses with the coils in “motion” ie. the fields constantly changing.
I’m sure that, with the wealth of experience available on this forum, the pros & cons can be examined.
A “bucking coil” creates a “null zone” for the Rx coil by using a reversed current flow to that of the primary Tx coil to create an opposing/cancelling magnetic field.
If the bucking coil was the same dimensions as the primary Tx and operated with the same current flow (amps and direction) we would have a Helmholtz coil with an enhanced and very uniform magnetic field. (see link). http://hyperphysics.phy-astr.gsu.edu...mholtz.html#c1
At the centre point between the coils is a null zone where a Rx coil could be sited and balanced.
This seems like a really “good idea”, so I’m sure there are plenty of negatives to this configuration.
Ground effects (permeability & capacitance) will affect the lower coil slightly more than the upper one, depending on how thick we want our coil assembly to be.
If they are wired in series then variations in current flow should balance within a few cycles and maintain the null. Responses from a “real” target should affect both Tx coils, ( I suspect coil separation distance will affect minimum detectable target size).
OR: Perhaps a real targets will not be detected as the null point will fully shield the Rx coil or perhaps a targets will only produce responses with the coils in “motion” ie. the fields constantly changing.
I’m sure that, with the wealth of experience available on this forum, the pros & cons can be examined.
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