Which component prevents excessively high current flow in an aircraft’s electrical system?

A circuit breaker is designed specifically to protect electrical circuits from excessive current flow, which can lead to overheating and potential damage to the aircraft's electrical system. When the current exceeds a predetermined level, the circuit breaker interrupts the electrical circuit, effectively stopping the flow of current and preventing further damage.

In the context of an aircraft's electrical system, maintaining safe current levels is crucial to ensure the reliability and safety of avionics and other electrical components. Circuit breakers can be reset once the fault has been cleared, making them an effective protective measure in managing electrical issues.

While a voltage regulator helps maintain stable voltage levels within the system, it does not directly prevent high current flow. A battery isolator controls battery usage and isolation but does not manage current flow in the same protective manner a circuit breaker does. A transformer is primarily used to change voltage levels in the system and does not serve the purpose of curbing excessive current.