From
http://web.mit.edu/ssp/Publications/wor ... ic%20armor'
Electromagnetic armor of this type is being considered for use against APFSDS projectiles as well as
shaped charge jets. As in the case of jets, passing a very large electrical charge through the body of the
penetrator also causes fluctuating and distending instabilities that can lead to their disruption.58
A similar concept, called electrothermal armor, also employs two electrically charge plates,
except that, instead of a sizable air gap between the plate, there is a relatively thin layer of active
insulating material. When a jet or KE penetrator pierces the plates, a surge of electrical current causes
the insulating layer to expand explosively, throwing the plates apart with effects similar to that of ERA.59
EM armor relies on capacitor banks to provide the necessary electrical energy, which, like EM
guns, would be considerable. The energy required to launch plates against even contemporary KE
projectiles would be on the order of 1MJ of KE per plate, requiring a 5MJ capacitor bank that would
occupy 5m3 - roughly equal to one-third the internal volume of a modern tank.