System of protection against short circuits and fulminations

Electronically fed apparatus protected against electric current short circuits, comprising a case defining openings therein and containing an electrical operating unit, a multiconductor feeding cable for a main feeding line connected to said operating unit, a two-conductor auxiliary elecrical line, connecting means for connecting said operating unit to a socket through said feeding cable, a pair of reciprocally spaced and electrically insulated wire nets screening each opening of the case, said auxiliary electrical line having each conductor connected to one of said wire nets, a switch connected to said main feeding line to disconnect each of the conductors of at least the main feeding line, a relay for holding said switch in a switched on position, a low tension auxiliary source consisting of a transformer means fed by said main feeding line downstream of said switch from a current supplied by said switch and an electronic cooperating circuit, said auxiliary source feeding said auxiliary electrical line and said relay through said electronic cooperating circuit, said electronic cooperating circuit being controlled by a short-circuit signal coming from said auxiliary electrical line for interrupting an electric current through said relay whereby said switch opens disconnecting the operating unit and auxiliary source from a source of voltage.