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