magnetic spray protection: myth or reality?

[barret77]

Hi

I have a question that regards the real benefits of applying  a coat of krylon magnetic spray in an enclosure: is there any? Are the magnetic spray particles enough to build magnetic protection to the effect?

My question regards the magnetic field; it's for my headphone amp that will be placed under a crt monitor and beside another crt monitor: it will have to survive a magnetic war field. For the electric field, I'm counting that the aluminium will be enough. Am I wrong?

[Paul Perry (Frostwave)]

It usually takes a lot to stop a magnetic field. I've had no luck with 1/4 inch steel. But often orientation can help.
I wouldn't personally expect any spray on stuff to do much for a magnetic field. At least in quantities one could afford.

[The Tone God]

I think the biggest issue would be the density of the particles in the mix. Are the particles dense enough to block out EM waves ? Are the particles conductive ? If so is there enough contact between particles to fully conduct (if necessary) ?

Typically chemicals that come from a spray container are dilluted down greatly to make them thin enough to be sprayed. With this in mind I would not trust it.

Andrew

[barret77]

yeah, that's what I think as well. I'm asking because I read some recomendations on the spray but never read any scientific approach to it...

what would do the trick to protect circuits in highly magnetical-field environments? anything at all?

anyway, I don't even know if I'll really have this problem... but ALL signal amplification in my bedroom seems to suffer due to the location (antennas nearby, poor old electric installation) and all the electronic equipment around... guess I'll paint the house with conductive paint!

[Paul Perry (Frostwave)]

About the only up-side of the move toward switchmode power supplies & flat screen monitors, is that (although there is plenty of scope for radio frequency noise) there is less scope for leaking magnetic fields (from CRT scan coils and power transformers).
Plus as 'stuff' becomes tinier & has less power overall, ther eis less scope for pushing magnetic pulses out in an efficient way.
Any magnetic material will sheild magnetic fields to some extent, but they only work by concentrating the field in the metal, and some materials are much better than others.
Shielding from electrostatic fields is a breeze in comparison.

[Joe Davisson]

FWIW, my DIY headphone amp sits right by the monitor, in a plastic box, and it seems pretty quiet. There's no insulator for magnetic flux, and trying to conduct it away is usually impractical. There shouldn't be any problem, the fields are very weak. I think an iron or steel box could actually be harmful to the monitor, so I would use plastic.