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How Does An Uninterruptible Power Supply (UPS) Work?

May 18, 2019

An uninterruptible power supply (UPS), also known as a battery backup power supply, provides backup power when a normal power supply fails or the voltage drops to an unacceptable level. The UPS allows the computer and connected devices to be shut down in a safe and orderly manner. The size and design of the UPS determines how long it can provide power.

The backup UPS uses battery backup power in the event of a power failure such as a power outage, voltage dip, or voltage surge. When the input utility voltage drops below the safe voltage or exceeds the safe voltage level, the UPS will switch to DC battery power and convert it to AC power to run the connected device. These models are designed for consumer electronics, entry-level computers, POS systems, security systems, and other basic electronic devices.


The uninterruptible power supply is a system device that connects a battery (mostly a lead-acid maintenance-free battery) to a host computer and converts the direct current into a commercial power through a module circuit such as a host inverter. It is mainly used to provide stable and uninterrupted power supply to a single computer, computer network system or other power electronic equipment such as solenoid valves, pressure transmitters, etc. When the mains input is normal, the UPS supplies the mains voltage to the load for use. The UPS is an AC voltage regulator at this time, and it also charges the battery inside the machine; when the mains is interrupted (accident blackout) When the UPS immediately converts the DC power of the battery through the inverter switching method, it supplies 220V AC to the load to keep the load working normally and protect the load from soft and hardware. UPS devices typically provide protection against excessive voltage or low voltage.