Patent ID: 7755878
Filing Date: 2010-07-13
Classification: F42D

Abstract:
1. A blasting arrangement which includes (a) a plurality of detonators, (b) a blast control unit which is directly connected to the plurality of detonators and which contains a first energy source, the blast control unit being physically incapable of directly providing a voltage at a level which is suitable for arming the detonators, and (c) a blast key which is removably connected to the blast control unit and which includes a blast energy generator and optionally contains an on-board energy source, wherein, when the blast key is connected to the blast control unit, the blast energy generator is operable to produce a voltage at a level which is suitable for arming the detonators (i) by using energy selected from the first energy source in the blast control unit and (ii), when the on-board energy source is present, by using energy selected from one or both of the first energy source in the blast control unit and the on-board energy source in the blast key.