US Patent 7100511 Dual redundancy system for electronic detonators

A detonator assembly (10) comprising a housing (12) disclosed and claimed. The assembly comprises an main circuit (11) comprising an electrically operable fuse (16) located in the housing. The assembly further comprises at least a first redundancy circuit (13) wherein at least one element of the main circuit is duplicated (18 for 16) also located in the housing. The invention also includes within its scope an initiation system (42) comprising at least one level of redundancy which may be in one or more or all of a blast controller (24), a harness (40) and detonator assemblies 10.1 to 10.n forming part of the system.