Abstract: An initiator (100) assembled from a housing (112), an output charge (144) and an initiation means (110, 120, 58, 54) includes a pulverulent ignition charge (46a) disposed in direct initiation relation to the initiation means, and an output charge (144) that may contain a pulverulent deflagration-to-detonation transition (DDT) charge (144a) and an explosive base charge (144b). The ignition charge (46a) has an average particle size of less than 10 microns, or even less than 5 microns, e.g., 1 to 2 microns. The initiation means may include a semiconductor bridge (18) and the ignition charge (46a) may be compacted with a force of less than about 5880 psi, e.g., with a force of 1000 psi. In another embodiment, an initiator (210) includes a low-energy electrical initiator (234), a loosely packed BNCP ignition charge (218) and a pyrotechnical output charge (214).

Abstract: An electronic delay circuit (10) for use in a detonator (100) has a switching circuit (20) and a timer circuit (22). Switching circuit (20) controls the flow of a stored charge of electrical energy from a storage capacitor (12) to a bridge initiation element such as a semiconductor bridge (18) or a tungsten bridge. The timing of the release of this energy is controlled by timer circuit (22). Switching circuit (20) is an integrated, dielectrically isolated, bipolar CMOS (DI BiCMOS) circuit, whereas timer circuit (22) is a conventional CMOS circuit. The use of a DI BiCMOS switching circuit allows for greater efficiency of energy transfer from the storage capacitor (12) to the semiconductor bridge (18) than has previously been attained.

Abstract: A detonator (100) assembled from a housing (112), an output charge (144) and an initiation means (110, 120, 58, 54) includes a pulverulent ignition charge (46a) disposed in direct initiation relation to the initiation means, and an output charge (144) that may contain a pulverulent deflagration-to-detonation transition (DDT) charge (144a) and a base charge (144b). The ignition charge (46a) has an average particle size of less than 10 microns, or even less than 5 microns, e.g., 1 to 2 microns. The initiation means may include a semiconductor bridge (18) and the ignition charge (46a) may be compacted with a force of less than about 5880 psi, e.g., with a force of 1000 psi.

Abstract: A detonator (10) contains an SCB initiator assembly (35) in initiation relation to an ignition charge (18). The SCB initiator assembly (35) contains an initiator element (36) having a bridge (60) of semiconductor material between two conductive lands (62a, 62b). The bridge (60) provides a resistance of at least about 50 ohms and has a volume between 48,600 cubic microns and 600,000 cubic microns with a typical thickness of two microns. A firing current of more than 200 milliamp provided to the initiator assembly (35) via input leads (26a, 26b) causes the bridge (60) to initiate the ignition charge (18).

Abstract: A detonation system especially useful for initiating a plurality of substantially simultaneous seismic detonations includes an electric trunkline circuit disposed on the surface of a firing site containing boreholes, within which booster charges having respective top and base portions are disposed. The booster charges are connected without intervening detonators to the downhole ends of equal-sized lengths of low-energy detonating cord, the surface ends of which are connected to semiconductor bridge-initiated electric detonators connected in series in the firing circuit. The resulting system, because of the small deviation in function time of the semiconductor bridge detonators, has greatly reduced scatter time as compared to prior art systems utilizing conventional downhole electric detonators, and has a safety advantage in that the boreholes are free of detonators.