Igniter for electric primer

Claim 1

An igniter for electric primer, applicable notably to the firing of mines, which comprises a two-wire flexible trapping line disposed across the trapped area and short-circuited at one end, a source of electric direct current, and controlled semiconductor element, comprising an anode, a cathode and a gate, which is connected in series with the electric primer and said electric current source, said two-wire trapping line being connected to said controlled semi-conductor element in order to release said element to its conductive state and therefore fire the primer when said two-wire line is broken; said igniter comprising further a capacitor, a first resistor connected to the positive terminal of said source of electric direct current, another resistor connected to the anode of said controlled semiconductor element, a double jumper comprising four contact studs, namely a first contact stud connected to the negative terminal of said source of electric current, a second contact stud connected to the cathode of said controlled semi-conductor element, to one end of said first resistor, to one end of said other resistor and to one plate of said capacitor, a third contact stud connected to the other plate of said capacitor and a fourth contact stud connected to the primer proper connected to the anode of said controlled semi-conductor element.