Now we read that it is possible that we may get another huge solar flare in this current sunspot cycle, for some unknown reason. And the assertion is that it could take out the power grid. That could be interesting.
For adequate shielding we need both a magnetic shunt, to lead the magnetic flux past our protected device, and a conductive shield, to assure that there is no voltage gradient developed across our protected devices. My guess is that all of those low voltage plastic cased devices will not be adequately protected. A serious disconnect function, such as unplugging ones electric meter, could offer the best cheap and fast protection we would have. But I wonder, would it also destroy all of the electronic engine controls and leave us with no engine driven transportation? What would it do to the avionics in a plane? Do we even have a clue about this whole thing, or is it all speculation?
I was involved with emergency communications at the state level. We have a full enclosed room with a massive door that houses all of the HF and VHF communications equipment used to communicate with FEMA. The antenna and power circuits are filtered at the entrance with EMP devices. The military provides the technical support and maintenance.
I'm more concerned with on-board computers in cars, trains and aircraft that would fail. The power grid would loose regulation of voltage and frequency. Cell phones would be lost. The only communication that would work would be the old crossbar switches and the Model 500 telephone, if any still exist. The technically advanced nations are one EMP pulse away from the caves.
Was not too uncommon a requirement 20 years ago for US military aircraft. My company used to design/build product for varous military fighters and bombers and had to demonstrate EMP hardness of design. Usually it was done by analysis: only one facility that I could recall that could do the test. We haven't seen an EMP requirement now in over 10 years
A friend of mine worked as a technician in the army some time back. They were servicing some old Russian radar equipment where there was a lot of microwave diodes. They were all socket types (so you could change them) and spare ones were all packed tightly in lead (they looked like bullets on the belt). He was saying that it was because they were to survive nuclear EMP.
The zener won't help, since large currents will be induced in every conductor that is within the field of the EMP.
To protect an electronic device, you need to enclose it in an insulator, then in a Faraday cage or even multiple layers of Faraday cages with insulators in between them.
In the event of a nuclear explosion or massive solar flare, if protecting electronic devices is foremost on your mind, put each in a plastic bag, then wrap it completely in aluminum foil with no gaps. For extra protection, put all that in another plastic bag and wrap that one completely in aluminum foil.
And if that's not enough, then you probably won't be around afterward to worry about it!
I am curious as to whether normal Zener-type suppressor diaodes can protect agains EMP events such as would be caused by a nuclear explosion? someone I have argued this with says no, the energy levels are too high, but a lot of the suppressors can absorb a lot of energy. Anyone have any solid info on this?