Initiating device for an electronic detonator

Abstract

This invention provides an initiating device 10 for an electronic detonator, which includes two spaced electrical conductors 12 located on an insulating substrate 14; and two separate resistive means in the form of thick film resistive bridges 16 extending between the electrical conductors 12, for releasing energy upon application of an electrical current to the resistive bridges 16. An explosives or pyrotechnic composition, generally designated by reference numeral 18, covers the resistive bridges 16. It will be appreciated that should one of the bridges 16 fail, the other bridge 16 would still initiate the device 10. The size of the contact interface between the bridge 16 and the explosives composition 18 is also doubled, making the initiating device 10 even more reliable. As a result the initiating device 10 is suitable for a wide range of different applications.

1 . An initiating device for an electronic detonator including at least two spaced electrical conductors; and a plurality of separate resistive means extending between the electrical conductors, for releasing energy upon application of an electrical current to the resistive means.  
     
     
         2 . An initiating device according to  claim 1  wherein the resistive means is in the form of bridge elements of a resistive substance.  
     
     
         3 . An initiating device according to  claim 2  wherein the bridge elements constitute thick film bridges.  
     
     
         4 . An initiating device according to  claim 2  wherein the bridge elements constitute thin film bridges.  
     
     
         5 . An initiating device according to  claim 1  wherein the resistive means comprises dope substances such as those used in the manufacture of integrated circuits, for creating plasma upon the application of the electrical current.  
     
     
         6 . An initiating device according to  claim 1  wherein the resistive means is in the form of a wire.  
     
     
         7 . An initiating device according to  claim 1  wherein the resistive means constitutes a conductive explosive or pyrotechnic composition.  
     
     
         8 . An initiating device according to any one of the preceding claims wherein resistive means is imbedded in an explosive or pyrotechnic composition.  
     
     
         9 . An initiating device substantially as herein described and exemplified.  
     
     
         10 . An electronic detonator provided with an initiating device according to any one of  claims 1  to  9 .