Power Circuit Feed-Through Protection for Aircraft FCC
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Solution Overview
Problem
The existing electrical power supply systems in aircraft, particularly those for Flight Control Computers, are vulnerable to over voltage conditions at the 'OR point' source, which can damage the modules and those external to the FCC module, due to unregulated voltage fluctuations.
Innovation Solution
A power circuit with a gate drive sever comparator circuit and a back-up gate drive comparator circuit that disconnects the pre-drive transistor circuit from ground and switches a reference directly into shunt MosFets to reverse over voltage conditions, maintaining a regulated voltage between controlled limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a blocking diode is used to connect redundant power inputs at an OR point, then power redundancy is achieved, but the system becomes vulnerable to over voltage damage
Solution Approach 1:
A voltage regulator circuit is introduced as an intermediary component between the OR point and the power inputs. This regulator actively monitors and controls the voltage level, preventing over voltage conditions from damaging the FCC module while maintaining the redundant power input configuration. The regulator acts as a mediator that allows the blocking diode connection to function while protecting against its vulnerability.
Solution Approach 2:
The voltage regulator implements feedback control by continuously monitoring the voltage at the OR point and adjusting its output accordingly. When over voltage conditions are detected, the regulator reduces the voltage to safe levels, preventing damage to the FCC module. This feedback mechanism maintains power redundancy while actively protecting against the harmful over voltage effect.
2Object-affected harmful factors
If voltage regulation is implemented to prevent over voltage damage, then module protection is improved, but system complexity increases
Solution Approach 1:
The voltage regulator circuit is designed to perform multiple functions: it regulates voltage to prevent over voltage damage, maintains power redundancy operation, and provides stable power to the OR point. By consolidating these functions into a single multi-functional component, the circuit complexity increase is minimized while achieving comprehensive protection.
Solution Approach 2:
The voltage regulator is configured to automatically monitor and adjust voltage levels without requiring external intervention or complex control systems. The regulator self-regulates based on its internal feedback mechanisms, providing over voltage protection while maintaining simple operation and reducing the need for additional complex control circuitry.
Data Source
AI summary
A power circuit includes a gate drive sever comparator circuit operable to disconnect a pre-drive transistor circuit from ground in response to an over voltage fault condition. A back-up gate drive comparator circuit operable to switch a reference directly into a multiple of shunt MosFets such that the multiple of shunt MosFets are turned on to reverse the over voltage fault condition until voltage drops and the gate drive sever comparator circuit and the back-up gate drive comparator circuit turn off to maintain a regulated voltage between comparator controlled limits.