Piezoelectric Impulse Switch with Dynamic Threshold Logic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inertial switches struggle to differentiate between high acceleration events of varying durations, often activating inadvertently during incidental low but long-duration accelerations, and fail to reliably trigger during intended events like munitions firing or vehicle impacts due to competing acceleration magnitude and duration requirements.
Innovation Solution
A self-powered piezoelectric-based impulse switch with false trigger protection logic, using a minimal number of components and fabricated on a single chip, capable of detecting acceleration or deceleration pulses of prescribed duration and amplitude, eliminating the need for accelerometers and processors, and allowing direct mounting on electronic circuit boards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the impulse switch is designed to activate at high acceleration levels, then reliability for intended events is improved, but false activation during incidental low but long-duration accelerations occurs
Solution Approach 1:
The patent implements dynamic threshold adjustment where the acceleration threshold is not fixed but varies based on the duration of the acceleration event. The system adapts the threshold in real-time to distinguish between short-duration high-g events (intended triggers) and long-duration low-g events (incidental movements), resolving the contradiction between reliability and false activation.
Solution Approach 2:
The patent changes the parameter of acceleration threshold dynamically based on event duration. By making the threshold a function of time rather than a constant value, the system can set higher thresholds for short events and lower thresholds for sustained events, eliminating false triggers while maintaining reliability for intended activation events.
2Measurement precision
If the impulse switch uses accelerometers and processors for precise detection, then measurement precision is improved, but device complexity and power requirements increase
Solution Approach 1:
The piezoelectric element serves dual functions: it both senses the acceleration event and generates the electrical energy needed to power the detection circuitry. This self-powered approach eliminates the need for external power sources and complex processing systems, achieving precise detection while minimizing device complexity.
Solution Approach 2:
The patent replaces complex electronic accelerometer systems with a piezoelectric-based mechanical sensing system. The piezoelectric element directly converts mechanical acceleration into electrical signals, eliminating the need for separate accelerometers, processors, and power management circuits, thus reducing complexity while maintaining detection precision.
3Ease of manufacture
If the impulse switch requires minimal components for low cost, then ease of manufacture is improved, but ability to differentiate acceleration events deteriorates
Solution Approach 1:
The patent uses parameter changes (duration-based threshold adjustment) rather than complex hardware to achieve event differentiation. This software-like logic implemented in the circuit allows minimal components to perform sophisticated discrimination between different acceleration event types, maintaining manufacturing simplicity while improving measurement precision.
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
The solution provides reliable detection of high-amplitude, long-duration acceleration pulses while preventing false triggers from incidental events, simplifying circuitry, reducing costs, and eliminating the need for physical wiring, thereby enhancing the safety and reliability of applications such as airbag deployment and munitions firing systems.
Implementation Method 1
A piezoelectric-based electrical energy generator is provided which generates an electrical charge in response to an applied acceleration pulse
Data Source
AI summary
A piezoelectric generator for generating power upon an acceleration and upon a deceleration of a body. The piezoelectric generator including: first and second masses; first and second springs, the first spring being connected to the body at one end and to the first mass at an other end, the second spring being connected to the body at one end and to the second spring at an other end; and a piezoelectric material connected to the first and second masses such that the piezoelectric material generates power when the body is accelerated or decelerated.