Working principle of APC backup UPS power supply

APC backup type, also known as non online uninterruptible power supplies (0ff Line UPs), is just a “backup” type of UPS. The mains power directly supplies power to the electrical equipment and charges the battery (Normal Mode). Once the quality of the mains power supply is unstable or there is a power outage, the circuit of the mains power will be automatically cut off, and the DC power of the battery will be converted into AC power to take over the power supply task (BatteryMode) until the mains power returns to normal. “UPS will only intervene in power supply when the mains power is cut off”. However, the AC power converted from DC power is a square wave, limited to supplying power to capacitive loads such as computers and monitors.