Which component maintains an alarm system after a power failure?

The component that maintains an alarm system after a power failure is the storage battery. When the main power supply is interrupted, the storage battery acts as a backup power source, ensuring that the alarm system remains operational. This capability is crucial for security systems, as they need to function continuously to alert users in case of intrusions or other emergencies, regardless of the status of the main electrical supply.

A capacitor, while useful in various electronic applications, typically stores small amounts of energy for short periods and is not designed for prolonged power support like a storage battery. A generator, on the other hand, provides power in the absence of main supply; however, it typically requires external fuel and does not offer the instant response that a storage battery provides when switching from main power. A power inverter converts direct current (DC) from batteries or other sources into alternating current (AC) for use by AC devices, but it does not store energy itself, making it unsuitable as the primary backup for maintaining an alarm system in the event of a power failure.