A UPS performs the following functions:

• Absorb relatively small power surges.
• Smooth out noisy power sources.
• Continuously provides power to equipment during line sags.
• Automatically shuts down equipment during long power outages.
• Monitoring and logging of the status of the power supply.
• Display the voltage/current draw of the equipment.
• Restart equipment after a long power outage.
• Display the voltage currently on the power line.
• Provide alarms on certain error conditions.
• Provide short-circuit protection.