Abstract A method and apparatus for controlling the fabrication of electroexplosive devices. An electroexplosive device is loaded with an explosive by pressure loading or ignition drop or other techniques, the explosive surrounding an electroexplosive bridgewire located within the device. A self-balancing bridge is connected to the bridgewire to monitor the bridgewire thermal conductance during loading. In one embodiment of the invention, an indicator is connected to the self-balancing bridge to display the variation in thermal conductance providing an indication of the thermal contact between the explosive and the bridgewire. In an alternative embodiment, the output of the self-balancing bridge is coupled to a comparator which compares the bridgewire thermal conductance to a desired value. The output of the comparator is an error signal which is amplified in an amplifier connected thereto, the amplified error signal being coupled to a control device to control the loading of the electroexplosive device and provide consistent and improved thermal contact between the explosive and the bridgewire.
A system for controlling the fabrication of electroexplosive devices comprising: explosive means; means for loading said explosive into an electroexplosive device; a bridgewire located within said electroexplosive device; means for sensing a thermal parameter of said bridgewire during loading of said device to provide an indication of the thermal contact between said bridgewire and said explosive.
Claim 2
Independent Claim
56 words
A system for controlling the fabrication of electroexplosive devices comprising: explosive means; means for loading said explosive into an electroexplosive device; a bridgewire located within said electroexplosive device; means for sensing a thermal parameter of said bridgewire during loading of said device to provide an indication of the thermal contact between said bridgewire and said explosive.
Claim 3
Dependent Claim
24 words
A system for controlling the fabrication of electroexplosive devices according to claim 1 wherein said thermal parameter is the thermal conductance of said bridgewire.
Claim 4
Dependent Claim
89 words
A system for controlling the fabrication of electroexplosive devices according to claim 2 wherein said means for sensing the thermal conductance of said bridgewire provides power to the bridgewire which satisfies the relationship P(t) ( gamma Delta R)/( Alpha Ro) wherein P(t) is the power supplied to said bridgewire, gamma is the thermal conductance of said bridgewire, Alpha is the temperature coefficient of resistivity of said bridgewire, Delta R is the resistance change in said bridgewire from the bridgewire cold resistance, Ro, due to temperature change in said bridgewire.
Claim 5
Dependent Claim
41 words
A system for controlling the fabrication of electroexplosive devices according to claim 3 wherein said means for sensing the thermal conductance of said bridgewire includes means for keeping said resistance change of said bridgewire constant during loading of said electroexplosive device.
Claim 6
Dependent Claim
24 words
A system for controlling the fabrication of electroexplosive devices according to claim 4 wherein said means for sensing thermal conductance is a self-balancing bridge.
Claim 7
Dependent Claim
67 words
A system for controlling the fabrication of electroexplosive devices according to claim 2 further comprising means for comparing a signal proportional to said sensed thermal parameter with a signal proportional to a predetermined value to obtain an error signal therebetween, and means to vary the loading of said electroexplosive device proportional to said error signal to control said thermal contact between said bridgewire and said primary explosive.