UPS ( Uninterruptible Power System/Uninterruptible Power Supply), Uninterruptible power supply is a system equipment that connects a battery (mostly lead-acid maintenance free battery) to a host and converts DC power into mains power through shuttle circuits such as host inverters.

Mainly used to provide stable and uninterrupted power supply to single computers, computer network systems, or other power electronic devices such as solenoid valves, pressure transmitters, etc.

When the mains input is normal, the UPS stabilizes the mains voltage and supplies it to the load for use. At this time, the UPS is an AC mains voltage stabilizer, and it also charges the internal battery; When the mains power is interrupted (power outage due to unforeseen circumstances), UPS immediately supplies 220V AC power from the battery to the load through reverse zero switching conversion, ensuring normal operation of the load and protecting its software and hardware from damage. UPS equipment usually provides protection against high or low voltage.