Detonator Wire Resistance Alteration via Electromagnetic Joule Heating
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Solution Overview
Problem
Existing explosive detonator systems pose challenges in controlled deactivation or reduction of performance characteristics, especially in environments where accidental or intentional detonation is a risk, due to their sensitive nature and potential for unstable mechanisms.
Innovation Solution
The method involves directing electromagnetic energy at the detonator's wire to cause Joule heating, reducing its electrical transmission capability by altering its resistance, effectively diminishing the detonator's performance without physical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electromagnetic energy is directed at the detonator wire to cause Joule heating, then the electrical transmission capability of the wire is reduced, but the risk of accidental detonation increases due to thermal effects
Solution Approach 1:
The patent applies parameter changes by precisely controlling electromagnetic pulse parameters (voltage, current, pulse width, frequency) to achieve controlled Joule heating that reduces wire electrical transmission capability without causing detonation. The system adjusts these parameters to stay within safe thermal margins while effectively diminishing detonator performance.
Solution Approach 2:
The patent implements feedback mechanisms by monitoring the electrical transmission capability of the detonator wire during the electromagnetic pulse application process. This feedback allows the system to adjust the electromagnetic energy delivery in real-time, ensuring the wire's transmission capability is reduced to the desired level without exceeding thermal thresholds that would cause accidental detonation.
2Ease of operation
If physical contact methods are used to deactivate detonators, then direct manipulation is possible, but safety risks increase due to handling sensitive explosive devices
Solution Approach 1:
The patent replaces mechanical contact-based deactivation methods with electromagnetic field-based methods. By using electromagnetic pulses to induce Joule heating in the detonator wire, the system achieves detonator deactivation without requiring physical contact or manual handling of the sensitive explosive device, thereby eliminating the safety risks associated with direct manipulation.
Solution Approach 2:
The patent introduces electromagnetic energy as an intermediary medium to transfer energy to the detonator wire. Instead of direct physical contact, the electromagnetic field serves as the mediator that delivers the necessary energy to alter the wire's electrical transmission capability, enabling safe remote deactivation of the detonator.
3Reliability
If high electromagnetic fluence is applied to ensure wire resistance change, then detonator effectiveness is reduced, but the complexity of controlling pulse parameters increases
Solution Approach 1:
The patent manages parameter control complexity by systematically varying electromagnetic pulse parameters (voltage, current, pulse width, frequency) within defined ranges to achieve the desired wire resistance change. The system employs parameter optimization techniques to identify effective parameter combinations that reliably alter wire resistance while maintaining controlled complexity in the pulse generation system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for controlled reduction of detonator performance, enhancing safety by minimizing the risk of accidental or intentional detonation, and enabling safer handling and management of explosive devices.
Implementation Method 1
Continuing direction of the electromagnetic energy at the detonator at a fluence or flow rate, frequency, and duration sufficient to cause Joule heating of a wire within the detonator
Data Source
AI summary
An inductively coupled transmission line with distributed electromotive force source and an alternative coupling model based on empirical data and theory were developed to initiate bridge wire melt for a detonator with an open and a short circuit detonator load. In the latter technique, the model was developed to exploit incomplete knowledge of the open circuited detonator using tendencies common to all of the open circuit loads examined. Military, commercial, and improvised detonators were examined and modeled. Nichrome, copper, platinum, and tungsten are the detonator specific bridge wire materials studied. The improvised detonators were made typically made with tungsten wire and copper (˜40 AWG wire strands) wire.