3 ms·
Microwaves aren't Faraday cages as it's too difficult to manufacture a perfect seal, instead the size of the holes in the door act as a tuned RF choke.
by anotherhue 13y ago
Microwaves aren't Faraday cages as it's too difficult to manufacture a perfect seal, instead the size of the holes in the door act as a tuned RF choke.
- sliverstorm 13y agoWhy on earth would you need a "perfect" seal?
- anotherhue 13y agoPeople sometimes like to watch the food being cooked, for one. At KW levels of power a few dB is still enough to do harm. Lots of nasty reports in the medical literature of this type of exposure, typically unlucky repairmen. The eye has very poor heat dissipation mechanisms, and they showed in the 70's the RF exposure could cause cataracts in rabbits. (I think dogs were exposed too -- it was a new field, so they didn't know what would happen) https://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4502597 https://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=45025...
- sliverstorm 13y agoNot an RF engineer here, though I know a few- is a nearly-but-not-quite-perfect Faraday cage really only going to attenuate a few dB?
- anotherhue 13y agoI meant to say that if a small portion of the energy leaked through, it would still be enough to be concerned about. Most cages will provide very good, though imperfect shielding, but cages of that quality are economically unviable for home purposes. I recall reading that they were subject to failure from every day wear and tear too, which would be hard to spot until it was dangerous. The chokes are just a more practical design.
- marshray 13y agoIt all depends^TM, mostly on the wavelength and the size and shape of the gap and the phase of the moon. dB is a logarithmic scale, so this kind of back-of-the-envelope reasoning is sometimes made easier and sometimes counterintuitive.
- anotherhue 13y agoI meant to say that if a small portion of the energy leaked through, it would still be enough to be concerned about. Most cages will provide very good, though imperfect shielding, but cages of that quality are economically unviable for home purposes. I recall reading that they were subject to failure from every day wear and tear too, which would be hard to spot until it was dangerous. The chokes are just a more practical design.
- deleted 13y ago[deleted]