Abstract: A fiber-optically-and-pneumatically-controlled firing set for explosive-bridgewire detonators. The firing set consists of a detonation-controlling module and a battery-operated firing module that are interconnected by fiber-optic signal conductors and a pneumatic conduit. The firing set provides high voltage isolation between the control module and the firing module while employing redundant safety features including fail-safe pneumatic crowbar shunting of the firing module output, frequency-selective fiber-optic signal communication, controlled battery life and explosive material detonation enablement and multiple, fail-safe serial switching to control the energy transfer sequence in the firing module. Both high voltage and low potential uses of the invention are included.

Abstract: An electrical winding fault detection system wherein turn-to-turn and other winding faults in a polyphase alternating current machine are identified through processing of measured machine winding current flow changes, i.e., through identification of changes in electrical balance conditions in the machine. This disclosed processing includes scaling or normalization of measured operating currents using current measurements made while the machine is known to be in fault-free normal operating condition and altering the normalization by a relationship between average current flow in the fault-free condition and average current flow in the monitored changing load condition. Machine operation from a balanced energization source is preferred for successful use of the system; it is therefore especially suited to multiple phased machines operated from electronically derived alternating current energy. The invention is disclosed primarily in terms of a motor-operated machine; however, application to generator (i.e.