IDX pro concentric coil with copper foil shield

[ifrenide]

hello

[ifrenide]

Do you think copper foil shield for a concentric coil is a good idea? I forget to this question

[Krzysztof]

From the photograph it looks like a good quality compact scroll - then it has no right to work.

[ifrenide]

Hello , Krzysztof. Can you explain why it will not work?

[kt315]

delete the foil. do not ask why.

[ifrenide]

Hello KT315, I'm asking why, to learn a rule . not to make a coil . I want to know whether it gonna work or not , to match thevresult with ENI theory

[waltr]

The foil is the 'Shorted Turn'.
Try it and you'll find out.

[ifrenide]

[ifrenide]

but the foil is isolated from the windings, and connected to ground . could you please explain it in more detail

[ArchibaldSTM]

A gap must be made in the foil shield, otherwise there will be a short-circuited turn. And the thermal stability of the sensor will be very low.

[ifrenide]

So no problem if I use copper foil instead of graphite spray? the only l problem only when I dont leave a gap, otherwise it is ok to use cooper foil which doesn't expose a problem? am I right?

[MartinB]

You need to cut a gap of 5 to 10 millimetres wide in the copper otherwise your coil will not work. Your shielding needs to form a "C" not an "O"

[moodz]

So no problem if I use copper foil instead of graphite spray? the only l problem only when I dont leave a gap, otherwise it is ok to use cooper foil which doesn't expose a problem? am I right?

Use graphite spray ...copper foil is too conductive. It's a metal detector right? Would you expect it to detect a piece of copper foil? .... So why are you wrapping the detector in foil? The foil surface would need to be gapped all over to stop currents flowing due to the magnetic field induced eddy currents ... If you must use copper look up EMI tape not foil.

[ifrenide]

Thank you all for your help, I will cut the foil into 4 segments and I will connect each one to ground directly, and see what wil happen, at least I know now that copper foil itself is not a problem, but it must just arranged in a specific configuration to act as a shield. one more thing , I think copper foil conductivity is an advantage compared to graphite spray, and companies prefer graphite spray because it is easy to apply in a big mass production, compared to copper foil which is more difficult to be applied

[kt315]

I think copper foil conductivity is an advantage compared to graphite spray

are you able to HEAR suggestion??? either you re the professor in Preston University on cathedra of Physics?