A study of packaging and shipping procedures for small electroexplosive devices Final report, May 1, 1966 - Aug. 1, 1967
Packaging, shipping, and shielding procedures for electroexplosive devices
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Packaging, shipping, and shielding procedures for electroexplosive devices
A self-balancing bridge for ascertaining the electrothermal and nonlinear behavior of an electroexplosive device is described. A sinusiodal current is passed through the device which provides a signal in the form of a unique Lissajous display. The display can be qualitatively evaluated and abnormal units can be readily detected.
Discussion of NDT techniques and instrumentation developed to demonstrate the quality and normal behavior of 1-W/1-A no-fire electroexplosive devices (EEDs) without firing or degrading the units. Application of these techniques is limited to the bridgewire/explosive/header interface which is considered to be the most critical link in the electroexplosive chain. A certain amount of destructive testing required to determine the sensitivity and output of the EEDs can be accomplished by additional instrumentation that initiates and delivers energy in an impulsive manner with control of pulse width and amplitude.
A system for nondestructively testing electroexplosive devices by the thermal transient test technique is described. The signal, which is generated by pulsing the electroexplosive device bridgewire is reduced to digital form. The data is then interpreted by an appropriate program and the essential electrothermal parameters are resolved. The system is fast, eliminates arbitrary interpretation of the analog, and lends itself to production testing.
Control of RF hazard to electroexplosive devices
An electroexplosive device accepts electrical energy and converts it into heat which is used to initiate a primary explosion. Disadvantages of the current electroexplosive testing method have led to the development of a new testing procedure which is based on a principle of programmed pulsing to initiation. A series of stepwise increasing energy pulses is applied to the device which is tested until the initiation of the explosion occurs. The test principle is discussed along with the design of the apparatus.
Test set for measuring resistance, output, and functioning time of electroexplosive devices
Design procedure for low voltage capacitor discharge circuits to trigger electroexplosive devices in aerospace vehicles
Premature actuation protection against RF interference for electroexplosive devices in spacecraft pyrotechnic systems
Several nondestructive test techniques have been developed for electroexplosive devices. The bridgewire will respond, when pulsed with a safe level current, by generating a characteristic heating curve. The response is indicative of the electrothermal behavior of the bridgewire-explosive interface. Bridgewires which deviate from the characteristic heating curve have been dissected and examined to determine the cause for the abnormality. Deliberate faults have been fabricated into squibs. The relationship of the specific abnormality and the fault associated with it is discussed.
Many of the fundamental factors affecting the initiation of electroexplosive devices have not been satisfactorily explained. A description of a narrow, high current pulse generator capable of pulses 4 microseconds wide and 94 amperes is given which will be useful in the study of the initiation mechanism.
Explosives and pyrotechnic propellant materials which will withstand heat sterilization cycling at 125 C and ten year deep space aging under 10 to the minus 6th power torr and 66 C have been selected. The selection was accomplished through a detailed literature survey and an analytical evaluation of the physicochemical properties of the materials. The chemical components of the electroexplosive devices used in U.S. missiles and spacecraft were categorized into primary explosives, secondary explosives, and propellant ingredients. Kinetic data on such parameters as thermal decomposition and sublimation were obtained for these materials and used as a basis for the ten year life prediction. From these experimental data and some analytical calculations, a listing of candidate materials for deep space missions was made.
The Applications Technology Satellite F (ATS-F) is the latest of a series of satellites for communications, scientific experiments, and data collection. The physical configuration of the spacecraft is examined along with operational characteristics and EMC management and control. Predicted and encountered problems are discussed, giving attention to wiring pick-up and reradiation, input rectification and bias off-set, intermodulation products, harmonics, component degradation, electroexplosive devices, spacecraft test complex vulnerability, and launch environment testing. Approaches used for locating the problems are considered and a description is given of the key factors and constraints in achieving EMC.
Low-temperature sinter of semiconductor and polymer resin is useful in manufacture of circuit boards, cables, and electroexplosive devices. Material can absorb large amounts of heat and can withstand repeated exposures to electrostatic discharges with little deteriorating effects. These characteristics offer significant advantages over high-temperature-sintered, metal-oxide semiconducting materials.
The approach taken to test a completed DSCS communications satellite on a system level is described. Areas to be described are measuring RF isolation of separate communications subsystems and a test method which insures that one RF subsystem does not interfere with another. In addition, the method of complying with MIL-STD-1541 in the area of demonstrating safety of electroexplosive devices in an RF field is discussed.
Simulator evaluates performance of firing circuits for electroexplosive devices (EED's) safely and inexpensively. Tests circuits realistically when pyrotechnic squibs not connected and eliminates risks of explosions. Used to test such devices as batteries where test conditions might otherwise degrade them.