초록 ▼

An explosive device comprises a charge of explosive material which can be fired by feeding power from a firing circuit to an igniter circuit which includes an electrically-energizable fuse. In order to check the integrity of the igniter circuit, a monitoring circuit feeds a continuous stream of elec

An explosive device comprises a charge of explosive material which can be fired by feeding power from a firing circuit to an igniter circuit which includes an electrically-energizable fuse. In order to check the integrity of the igniter circuit, a monitoring circuit feeds a continuous stream of electrical pulses to the fuse circuit at such a low energy level that the pulses cannot cause ignition of the explosive charge, but they are sufficient to cause a light-emitting diode to emit short bursts of light. The production of these bursts is monitored by a receiver circuit via an optical fibre, and provided that corresponding signals are received continuously by a timer, a lamp indicates that the igniter circuit is ready for operation. If there is a break in the received signals, for example due to open-circuiting of the fuse, an alarm is operated. The connections between the igniter circuit and the monitoring circuit may be made via a demountable transformer.

대표청구항 ▼

An explosive device, comprising an explosive charge; an igniter circuit including an electrically-energisable heating element for igniting the explosive charge; a firing circuit operable to feed electrical energy to the igniter circuit at a firing level sufficient to cause ignition of the explosive

An explosive device, comprising an explosive charge; an igniter circuit including an electrically-energisable heating element for igniting the explosive charge; a firing circuit operable to feed electrical energy to the igniter circuit at a firing level sufficient to cause ignition of the explosive charge; a light-emitting diode connected in series with the heating element; and a monitoring circuit operable to feed electrical energy to the igniter circuit at a level less than said firing level and to monitor radiant energy produced by said light-emitting diode in order to check the integrity of the igniter circuit.