Current Restriction Circuit for Power Source Backup
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Solution Overview
Problem
Existing power source backup systems face challenges in safely transitioning power to a load without causing damage from large current surges when a primary power source fails, due to significant voltage drops and resulting high currents, which can damage switches and require oversized components for safety.
Innovation Solution
A system incorporating a failure detection circuit and a current regulating circuit with series-connected diodes and switches, such as IGBTs or MOSFETs, to restrict current flow from a backup power source to the load, limiting current to safe levels (e.g., no more than 20, 50, 100, or 200 Amps) and allowing controlled switching without significant power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a backup power source is directly coupled to the load when the primary power source fails, then the load can be quickly powered, but large current surges will damage the switch and require oversized components
Solution Approach 1:
The patent introduces a current regulating circuit as an intermediary component between the backup power source and the load. This circuit includes series-connected diodes that act as a mediator to control and limit the current flow, preventing direct current surges from reaching the switch while still enabling power transfer when needed.
Solution Approach 2:
The current regulating circuit with series diodes is pre-configured in the circuit path before failure occurs. When the primary power source fails, the circuit is already prepared with current limiting protection in place, so the switch is immediately protected from current surges without needing to react or adjust during the transition.
2Reliability
If series diodes are added to restrict current, then switch protection is improved, but power loss increases due to voltage drop across diodes
Solution Approach 1:
The patent uses series diodes that provide sufficient current limiting protection (excessive action) to protect the switch from damage, even though this results in some power loss. The diodes are designed to handle the full current load while maintaining protection, accepting the energy trade-off as necessary for reliability.
3Strength
If oversized switches are used to handle current surges, then component durability is improved, but device complexity and cost increase
Solution Approach 1:
Instead of using an oversized switch to directly handle current surges, the patent introduces a current regulating circuit with series diodes as an intermediary. This mediator limits the current before it reaches the switch, allowing the use of a smaller, more economical switch while maintaining the same level of durability and protection.
4Reliability
If current is limited to safe levels, then component damage is prevented, but the ability to quickly restore full power is reduced
Solution Approach 1:
The current regulating circuit is pre-configured to allow full current flow when the primary power source is operational. When failure occurs and the backup source is activated, the circuit immediately begins limiting current to safe levels through the series diodes, balancing protection with as quick as possible power restoration.
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 system effectively prevents switch damage from large current surges while ensuring reliable power transfer during primary power source failures, reducing the need for oversized components and minimizing energy dissipation, thus being cost-effective and space-efficient.
Implementation Method 1
A current regulating circuit 112 may include a plurality of diodes 215, 216 electrically coupled in series with each other
Data Source
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AI summary
An example system includes a first power source. The system also includes a first load electrically coupled to the first power source. The system also includes a second power source. The system further includes a failure mitigation circuit. The failure mitigation circuit is to detect a failure of the first power source. The failure mitigation circuit is to electrically couple the second power source to the first load in response to detecting the failure. The failure mitigation circuit is to restrict a current flowing through the failure mitigation circuit from the second power source.