Contactor Driver Hardware Interlock Against Erroneous Closure
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Solution Overview
Problem
Existing contactor systems in aerospace electric power distribution are vulnerable to erroneous behavior due to software or firmware failures, necessitating costly and heavy additional components like Power Quality Monitors or AC relays to ensure safety, which can be improved with a hardware-based interlock solution.
Innovation Solution
A hardware-based interlock system using a comparator, latch, and logic gate to ensure that contactors only close when both software and hardware-based interlock signals agree, preventing erroneous closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional components like Power Quality Monitors or AC relays are added to protect against software failures, then system safety is improved, but device complexity and weight increase
Solution Approach 1:
The patent combines the software control function and hardware interlock protection function into a single integrated contactor control circuit. The hardware interlock circuitry is merged with the existing control logic, eliminating the need for separate Power Quality Monitors or AC relays while maintaining both software programmability and hardware-based safety protection.
Solution Approach 2:
The contactor control circuit is designed to perform multiple functions: software-based control logic execution, hardware interlock signal generation, voltage monitoring, and contactor actuation control. This multi-functional integration replaces what would traditionally require multiple separate components, reducing overall system complexity and weight.
2Reliability
If additional components like Power Quality Monitors or AC relays are added to protect against software failures, then system safety is improved, but weight increases
Solution Approach 1:
The patent combines the software control function and hardware interlock protection function into a single integrated contactor control circuit. The hardware interlock circuitry is merged with the existing control logic, eliminating the need for separate Power Quality Monitors or AC relays while maintaining both software programmability and hardware-based safety protection.
3Reliability
If hardware-based interlock circuitry is integrated into the control circuit, then independence from software errors is achieved, but device complexity increases
Solution Approach 1:
The hardware interlock circuitry acts as an intermediary layer between the software control logic and the contactor actuator. It receives control signals from the controller, validates them against hardware-based safety conditions (voltage thresholds, interlock signals), and only permits contactor actuation when both software and hardware conditions are satisfied. This intermediary function provides software-independent safety without requiring entirely separate protection systems.
4Reliability
If traditional separate protection components are used, then system safety is improved, but cost increases
Solution Approach 1:
The patent combines the software control function and hardware interlock protection function into a single integrated contactor control circuit. The hardware interlock circuitry is merged with the existing control logic, eliminating the need for separate Power Quality Monitors or AC relays while maintaining both software programmability and hardware-based safety protection.
Data Source
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AI summary
A closing mechanism controller includes contactor operating logic that generates a software or firmware based closing mechanism command signal. The controller also includes hardware interlock circuitry (154) that generates an interlock signal, the hardware interlock circuity (154) being configured to compare an interlock signal to the software based closing mechanism command signal and to provide an enable signal to the closing mechanism when the interlock signal matches the closing mechanism command signal.